Shoulder

Question 1

AC joint injury classification scheme

Answer 1

Type I injuries involve purely an AC joint sprain with intact CC ligaments. Type II injuries involve complete tearing of the AC joint and a sprain of the CC ligament with the CC measurement being < 25% greater than of the contralateral shoulder. Type III, IV, V, and VI injuries all involve complete tearing of both the AC and CC ligaments. Type III injuries have a CC distance measurement between 25 and 100% greater than that of the contralateral side (this patient) compared to Type V injuries which have a CC distance > 100% of the contralateral side. Type IV and VI injuries represent posterior and inferior dislocation of the clavicle, respectively. The coracoacromial ligament is generally spared in these injuries

Question 2

AC joint modified weaver-dunn reconstruction complications

distal clavicle resection, coracoacromial ligament transfer, and augmentation (modified Weaver-Dunn

Answer 2

does not restore native stability to AC joint. **Persistent horizontal (A to P) instability may cause persistent symptoms. **Anatomic repair and recon that preserve distal clavicle offer less risk of horizontal instability

Question 3

innervation to the AC joint

Answer 3

Supara scapular nerve posteriorly
Lateral pectoral nerve anteriorly

Question 4

Tx for AC joint injuries

Answer 4

Type: I-II nonop, good functional outcomes. full rehab 6-12 weeks
Type III: controversal, good results and return to sport for athletes
Type IV,V, VI surgery

Question 5

The importance of the ACLC to joint stability: The ACLC is critical for ? stability. and is compromised with ?

Answer 5

The importance of the ACLC to joint stability has been highlighted in multiple studies. The ACLC is critical for anteroposterior stability and is compromised with distal clavicle excision

Question 6

Which examination test is most specific for pain related to AC joint osteoarthritis?

Answer 6

Cross body adduction test: pain w/ shoulder in 90 FF and max adduction across body

cross-body adduction test is the most sensitive provocative test for AC joint osteoarthritis at 77%, the O’Brien active compression test has been shown to be most specific at 95%. CSI injection, only 44% accurately enter the joint.

Question 7

Most common complication following distal clavicle excision? Appropriate amount of distal clavicle excision?

Answer 7

Persistent pain is the most common complication following distal clavicle excision. Although the exact amount of distal clavicle that should be resected is a topic of debate, resection of 10 mm or more of the distal clavicle may lead to instability of the AC joint, especially if the AC capsule is sectioned.

Question 8

Which of the following is considered an advantage of arthroscopic distal clavicle excision compared with open distal clavicle excision?

Answer 8

Examination of the GH jt allows examination of SLAP tear which could mimic AC jt pain. Arthroscopic DCE sacrifices the inferior AC ligament and preserves the superior AC ligament.

Question 9

What ligaments provid the most restraint to the AC joint?

Answer 9

Posterior and superior acromioclavicular ligaments provide the most restraint to posterior translation of the acromioclavicular joint and must be preserved during a Mumford procedure. (Distal clavicle excision)

Question 10

The deltotrapezial fascia becomes confluent with which portion of the AC joint capsule, providing additional stability?

Answer 10

The musculotendinous aponeurosis of the deltotrapezial fascia interdigitates with the superior acromioclavicular joint capsule. The deltotrapezial fascia is believed to have synergistic stabilizing features with the capsule.

Question 11

Zanca views to evaluate AC joint injuries

Answer 11

Bilateral Zanca views are obtained with 10-15° of cephalad tilt in the AP orientation with 50% penetrance

Question 12

Risk factors that predispose an individual to rotator cuff tear and affect healing include

Answer 12

age, smoking, sex (female), family history, diabetes mellitus, and high cholesterol

Question 13

The risk of partial-thickness tears enlarging at 2 and 5 years is ??, respectively, whereas full-thickness tears have a ?? risk of enlarging of at 2 and 5 years, respectively. Fatty infiltration and degeneration?

Answer 13

The risk of partial-thickness tears enlarging at 2 and 5 years is 11% and 35%, respectively, whereas full-thickness tears have a 22% and 50% risk of enlarging of at 2 and 5 years, respectively.
Muscle degeneration is associated with full-thickness tears rather than partial-thickness tears. Fatty degen more common in older pts and larger baseline tears. RCT w/ fatty degen are more prone to enlarge over time.

Question 14

?% of rotator cuff tendon repairs do not heal; healing is affected by patient age, tendon retraction, and fatty muscle infiltration, with most failure occurring during ?

Answer 14

25% of rotator cuff tendon repairs do not heal; healing is affected by patient age, tendon retraction, and fatty muscle infiltration, with most failure occurring during active rehabilitation (2 to 3 months postoperatively)

Question 15

clinical findings is commonly associated with symptomatic partial-thickness rotator cuff tears?

Answer 15

a painful arc with active range of motion is common
impingement signs are usually positive,
lift-off test is normal.
Active and passive range of motion measurements are often equal, although active range of motion can be painful.
External rotation lag signs are often seen with larger full-thickness tears.

Question 16

The usual presentation of traumatic subscapularis tears is most often seen after forced

Answer 16

forced external rotation: The typical mechanism of injury is a fall and the patient grasps something to prevent the fall. This maneuver forces the arm into external rotation against resistance.

Question 17

What is the most important stabilizing mechanism in the midrange of motion of the glenohumeral joint?

Answer 17

Concavity compression is a stabilizing mechanism by which muscular compression of the humeral head into the glenoid fossa stabilizes the glenohumeral joint against shear forces. This is dependent on the depth of the concavity and the magnitude of the compressive force.

Question 18

What is the most consistent finding regarding glenohumeral kinematics in patients with symptomatic tears of the rotator cuff?

Answer 18

Superior translation of the humeral head with more than 30 degrees of abduction

Normal glenohumeral kinematics are represented by ball-and-socket modeling when the rotator cuff is intact. This is true for motion that involves more than 30 degrees of abduction. In patients with shoulder pain and symptomatic rotator cuff tears, superior translation occurs with abduction beyond 30 degrees. This is quite evident in massive tears but is seen consistently to a lesser degree with smaller tears.

Question 19

Patients over 40 with initial anterior dislocation

Answer 19

Patients older than age 40 years at the time of initial anterior dislocation have low rates of redislocation; however, 15% of these patients experience a rotator cuff tear. Moreover, there is a dramatic increase (up to 40%) in the incidence of rotator cuff tears in patients older than age 60 years. Axillary nerve injury may occur but is less common than rotator cuff tear.

A rotator cuff tear is the most common cause of recurrent instability following a first-time dislocation in patients older than age 40 years. Dislocations occur through a posterior mechanism rather than by an isolated labral avulsion or a Bankart lesion as seen in younger patients.

Question 20

Most common location for cuff tears

Answer 20

The most common location of rotator cuff tears is the junction of the supraspinatus and infraspinatus tendons, approximately 13 to 17 mm posterior to the biceps within the rotator crescent. This area is known to be a critical zone of hypovascularity, predisposing it to degenerative tears. The vascularity of this area also decreases with age, suggesting that the increasing incidence of rotator cuff tears with age is not related to chronic abrasive wear but to decreasing vascularity and degenerative changes.

Question 21

Impingement syndrome: tx outcomes surgery vs PT

Answer 21

Nonsurgical management also has been shown to be as effective and less expensive than surgical subacromial decompression with acromioplasty. If bony impingement caused by acromial spurring was the cause, physical therapy alone, with no modification of the bony architecture, would not be expected to lead to outcomes similar to those of acromioplasty

impingement syndrome caused by an acromial spur, as proposed by Neer, is not the primary process that explains the origin of most degenerative rotator cuff tears.

Question 22

Inflammatory markers elevated in subacromial bursitis

Answer 22

Several inflammatory markers have been shown to be elevated in subacromial bursitis. These include metalloproteases, tumor necrosis factors, and cyclooxygenase 1 and 2.

Question 23

Calcific tendonitis:
what are the 3 stages? What is deposited in the tendon? Symptomatic? How does it appear on imaging? Tx?

Answer 23

1. precalcific, calcific (3), and postcalcific
2. deposition of calcium phosphate crystals (hydroxyapatite) within the rotator cuff tendon.
3. 35% do not have symptoms, so evaluate pts for other symptoms
4. 1.5-2 cm from insertion, On MRI, calcium deposits appear hypointense on all sequences.
   On ultrasonography, calcium deposits appear hyperechoic.
   Tx: Nsaids, PT, CSI. 27 percent failure rate at 6 months associated w/ b disease, larger deposits adn extension of calcification medial to acromial. .
   USguided neddling to aspirate and then inject saline or steorid into lesion (UGNL) relief at 1 year, 5 year outcomes showed equal in comparison to CSI in SA alone. Arthroscopic debridment for recalcitrant disease

The precalcific stage generally is pain free; fibrocartilaginous metaplasia of tenocytes into chondrocytes occurs predominantly in less vascular areas of the tendon.

Calcific stage characterized by foci of calcium deposition; often separated by septae.

The resorptive phase typically is the most painful, directed by inflammatory response involving macrophages and multinucleated giant cells.

Question 24

Pt has right shoulder pain over GT and Neer Hawkins impingement, dx and initial mgmt

Answer 24

Subacromial impingement: Initial management should consist of stretching exercises directed at the posterior capsule and a program of rotator cuff and deltoid strengthening exercises performed below the horizontal in a ‘safe’ plane. The judicious use of subacromial cortisone injections (one or two) may be helpful. Anterior acromioplasty is reserved for patients who have failed to respond to nonsurgical management.

Question 25

Dislocation of the long head of biceps

Answer 25

Dislocation of the long head of the biceps tendon is the result of a defect in the region of the rotator cuff interval, coracohumeral ligament-superior glenohumeral ligament pulley, or an associated tear of the medial insertion of the subscapularis tendon. In the case of an intra-articular dislocation of the long head of the biceps tendon associated with a tear of the subscapularis tendon, stabilization of the biceps tendon is difficult in this situation; therefore, biceps release or tenodesis and repair of the subscapularis tendon is the treatment of choice.

Question 26

Initial postoperative management after repair of an acute rotator cuff tear includes

Answer 26

In the immediate postoperative period following repair of an acute rotator cuff tear, **passive forward elevation and external rotation should be performed within the safe zone determined at surgery.** Early active range of motion (prior to tendon healing), internal rotation behind the back, and resistive exercises increase the risk of rupture of the repair.

Question 27

Hx of extensive extensive arthroscopy debridement and synovectomy, Examination reveals a golf ball-sized swelling just lateral to the coracoid. The area is not warm and shows no other signs of infection. An MRI scan is shown in Figure 1. Management should now consist?

Answer 27

Deficiency of the rotator cuff interval may be acquired or congenital. In this patient, extensive debridement of the rotator cuff interval capsule at the time of arthroscopy most likely is the cause of the defect seen on the MRI scan. Surgical closure of the defect is the treatment of choice. During the repair, the shoulder should be placed in 30 degrees of external rotation to avoid overtightening. Care should be taken to include the leading edge of both the supraspinatus and subscapularis tendons in the repair because the rotator cuff interval capsular tissue is likely to be of poor quality.

Question 28

Functional Improvement after revision RCR is most likely to occur in

Answer 28

Functional improvement after revision rotator cuff surgery is most likely to occur in patients with an intact deltoid, good-quality rotator cuff tissue, preoperative active elevation alone to 90 degrees, and only one prior rotator cuff repair.

Question 29

what part of the labrum has the least vascularity

Answer 29

**Anterior/Superior** ## Footnote glenoid labrum receives its blood supply from the suprascapular, posterior humeral circumflex, and circumflex scapular arteries. The labral vessels arise from the capsular and periosteal vessels that penetrate the periphery of the labrum. The bone does not appear to be a source of vascularity. The posterior/superior and inferior labrum have a fairly robust vascular supply, whereas the anterior/superior labrum has relatively poor vascularity, which may influence the success of superior lateral repairs.

Question 30

Anatomic Variation of the glenoid labrum and MGHL in the anterosuperior quadrant of the shoulder, what's the most common?

Answer 30

1. Labrum attached to the glenoid rim and a flat/broad middle glenohumeral ligament is the most common "normal" variation. 86.6% ## Footnote Wide variations in the anatomy of the anterosuperior portion of the labrum and the middle glenohumeral ligament have been reported and are more common than previously thought. The labrum attached to the glenoid rim and a flat/broad middle glenohumeral ligament is the most common "normal" variation. A cord-like middle glenohumeral ligament is often associated with the presence of a sublabral hole. An anterosuperior labrum confluent with a cord-like middle glenohumeral ligament and no labral attachment to bone is the configuration of the Buford complex. The prevalence of each variation from one recent study is as follows: #1: 86.6%; #2: 3.3%; #3: 8.6%; and #4: 1.5%.

Question 31

Atraumatic neuropathy of the suprascapular nerve usually occurs at what anatomic location?

Answer 31

Suprascapular and spinoglenoid notches ## Footnote The suprascapular nerve passes through the suprascapular notch and the spinoglenoid notch before innervating the infraspinatus muscle. At both locations, the suprascapular nerve is prone to nerve compression, which often results from a ganglion cyst. The other anatomic locations are not associated with suprascapular nerve impingement

Question 32

With increasing abduction in the scapular plane, maintaining neutral rotation, contact area, and contact pressure per unit area between the humeral head and glenoid follows what pattern if the total load across the joint is held constant?

Answer 32

* glenohumeral joint becomes more congruent at higher levels of abduction. * contact area increases and contact pressure decreases * As the load is spread more evenly across the joint, contact pressure per unit area decreases as long as the total load across the joint is held constant.

Question 33

Which of the following ligaments are the primary static restraints to inferior translation of the arm when the shoulder is in 0 degrees of abduction and neutral rotation? Mid range of Abduction? 90 degrees of abduction?

Answer 33

**Superior glenohumeral and coracohumeral** midrange = MGHL 90 = infereior GHL ## Footnote Biomechanical ligament sectioning studies have implicated both the superior glenohumeral and coracohumeral ligaments as restraints to inferior translation when the shoulder is in 0 degrees of abduction and neutral rotation. Although there is controversy over the significance of each ligament, both are involved to some degree. The middle glenohumeral ligament is more important in the midranges of abduction, and the inferior ligament is more important at 90 degrees of abduction. The coracoacromial and coracoclavicular ligaments play no role in glenohumeral restraint.

Question 34

Long Thoracic Nerve injury? What nerve roots? What does it cause?

Answer 34

* Injury (from axillary dissection or aggressive retraction of the middle scalene muscle) results in **serratus anterior palsy** and **medial winging of the scapula **(superior elevation of the scapula with medial translation and medial rotation of the inferior pole of the scapula). * C5-7 ## Footnote The long thoracic nerve arises from the anterior rami of the C5 through C7 nerve roots to innervate the serratus anterior muscle. It is located on the superficial surface of the serratus anterior muscle, making it susceptible to injury, which may result in characteristic medial winging of the scapula.

Question 35

To avoid damage to the ascending branch of the anterior humeral circumflex artery during open reduction and internal fixation of a proximal humeral fracture, the blade plate should be placed in what position?

Answer 35

**Lateral to the bicipital groove and pectoralis major tendon** ## Footnote The pectoralis major tendon inserts lateral to the biceps tendon, which runs in the bicipital groove. The primary vascular supply of the articular surface of the humeral head is derived from the anterior circumflex humeral artery, which continues into the arcuate artery once it enters the bone. The entry point is on the anterolateral aspect of the humerus just medial to the greater tuberosity within the bicipital groove. To avoid compromising circulation, the blade plate should be placed lateral to the bicipital groove and pectoralis major tendon insertion.

Question 36

Most important structure preventing SC dislocation?

Answer 36

posterior sternoclavicular joint capsule is the most important structure for preventing both anterior and posterior translation of the sternoclavicular joint.

Question 37

arrow is pointing at what artery?

Answer 37

axillary artery commences at the first rib as a direct continuation of the subclavian artery and becomes the brachial artery at the lower border of the teres major. The arteriogram reveals a nonfilling defect in the third portion of the artery just distal to the subscapular artery. The complex arterial collateral circulation in this region often permits distal perfusion of the extremity despite injury.

Question 38

Axillary Nerve: Branch of? Nerve roots? Where does it exit? Branches? When is it at risk?

Answer 38

* Branch of posterior cord, C5-6 * closest to the glenoid labrum at the 6-o’clock position on the glenoid, at a mean of 12 mm. * exits quadralateral space (w/ posterior humeral circumeflex) * provides abduction of arm b/t 30-90 degrees 3 branches: * Posterior (teres minor and posterior and lateral deltoid area skin) superior lateral brachial cutaneous n, * anterior (deltoid), 5 to 6 cm distal to the midlateral acromial margin. * articular branch (innveration to GH jt) ## Footnote quadrilateral space (medial: long head of the triceps; lateral: humeral shaft; superior: teres minor; inferior: teres major) muscular branch supplying the teres minor lies closest to the glenoid labrum and is most susceptible to injury during arthroscopic capsular procedures. anterior branch to the deltoid is located 5 to 6 cm distal to the midlateral acromial margin; however, it can be as close as 3 cm. This distance is positively correlated with limb length; it is reduced by as much as 30% with abduction of the arm to 90°.

Question 39

MSC Nerve

Answer 39

* Lateral cord C5-7 * main trunk penetrates the coracobrachialis muscle 3 to 8 cm distal to the tip of the coracoid. * innervates the biceps brachii and the brachialis * terminates as the lateral antebrachial cutaneous nerve to the anterolateral forearm. ## Footnote It then travels deep to the biceps brachii but superficial to the brachialis before it emerges as the lateral antebrachial cutaneous nerve and provides sensation to the anterolateral aspect of the forearm. During its course, the musculocutaneous nerve provides motor innervation to the coracobrachialis, biceps brachii, and brachialis.

Question 40

Suprascapular nerve: root? sites of compression and what does that compression result in? Where is the nerve at risk of injury?

Answer 40

* Upper trunk C5-6 * Two possible sites of compression are the **suprascapular notch **and the **spinoglenoid notch.** * 1.5 cm medial to the posterior rim of the glenoid and can be endangered in this location with transglenoid fixation techniques. * innervates the supraspinatus and infraspinatus muscles. * Suprascapular nerve compression at the suprascapular notch causes denervation of the supraspinatus and the infraspinatus. Nerve compression at the spinoglenoid notch leads to selective denervation of the infraspinatus muscle.

Question 41

Spinal Accessory Nerve (Cranial Nerve XI)

Answer 41

* Injury from cervical lymph node biopsy or radical neck dissection results in trapezius palsy and lateral winging of the scapula (depression of the scapula with lateral translation and lateral rotation of the inferior pole of the scapula). ## Footnote The spinal accessory nerve (cranial nerve XI) innervates the trapezius, which attaches to the acromion, scapular spine, and clavicle. Subsequent injury to the spinal accessory nerve may result in lateral winging of the scapula.

Question 42

Scapula Dyskinesia: how to examine for it? lateral vs medial scapular winging?

Answer 42

Lateral scapular winging is defined by excessive lateral rotation or increased distance between the borders of each scapula. Medial scapular winging is defined by a prominent inferior scapular tip with asymmetric medial prominence during shoulder motion. To aid in the diagnosis, relief of symptoms via manual medial stabilization can be performed. Assessment of the gross muscle bulk of the serratus anterior and trapezius also should be noted because they may contribute to medial and lateral scapular winging, respectively

Question 43

Baseball pitchers who have internal impingement will most likely demonstrate what changes in range of motion?

Answer 43

* Pitchers tend to have a decrease in internal rotation and an increase in external rotation. **decrease IR increase ER** * increase in external rotation is felt to be multifactorial. * An increase in humeral retroversion occurs from repeated throwing. This results in increased soft-tissue stretching and results in a posterior capsular contracture.

Question 44

best imaging for SLAP tears

Answer 44

MRI-arthrography has been shown to be an accurate technique for assessing the glenoid labrum in patients with suspected labral tears. Often standard MRI technique will not identify labral lesions. The use of MRI-arthrography with an intra-articular injection of gadolinium provides improved visualization of labral lesions. Bencardino and associates demonstrated a sensitivity of 89%, a specificity of 91%, and an accuracy of 90% in detecting labral lesions. SLAP lesions can be visualized on coronal oblique sequences as a deep cleft between the superior labrum and the glenoid that extends well around and below the biceps anchor. Often, contrast will diffuse into the labral fragment, causing it to appear ragged or indistinct.

Question 45

posterior dislocation, what position to avoid after reduction?

Answer 45

Following brace immobilization in neutral to 5 to 10 degrees of external rotation and slight abduction, it is critical to **avoid internal rotation for 4 to 6 weeks.** ## Footnote Acute posterior dislocations occur rarely, accounting for less than 5% of acute dislocations. They are most often the result of falls on an outstretched hand. Reduction can be accomplished with flexion of the arm to 90 degrees and adduction to disimpact the humeral head from the glenoid rim. The arm is then externally rotated until the head has cleared the glenoid rim. Following brace immobilization in neutral to 5 to 10 degrees of external rotation and slight abduction, it is critical to avoid internal rotation for 4 to 6 weeks.

Question 46

A 56-year-old woman who underwent axillary node dissection 4 months ago now reports shoulder pain, weakness of forward elevation, and obvious winging of the scapula. What structure has been injured? Long thoracic? Spinal Accessory? Thoracodorsal?

Answer 46

The **long thoracic nerve C567**, which innervates the **serratus anterior**, is prone to injury because of its superficial location along the chest wall. The spinal accessory nerve innervates the trapezius, and the thoracodorsal nerve innervates the latissimus dorsi. The

Question 47

Normal acromiohumeral interval distance? What numbner is considered pathognomoinc for rotator cuff tear? What are findings consistent advanced cuff tear arthropathy?

Answer 47

Normal 7-14, less than 14 is radiographic marker for cuff disease * Acetabularization of the acromion, rounding of the greater tuberosity, and femoralization of the humeral head are signs of advanced rotator cuff arthropathy that can be appreciated on shoulder radiographs. * Chronic rotator cuff insufficiency may result in anterosuperior escape (migration of the humeral head through the rotator interval). This results from failure of the subscapularis and/or supraspinatus (rotator interval lesion).

Question 48

arrow demonstrates?

Answer 48

A, Normal infraspinatus muscle (arrow). B, Fatty infiltration of the infraspinatus muscle (arrow).

Question 49

LHB tendon best visualed on what view?

Answer 49

The LHB tendon is best visualized on axial MRIs. Medial dislocation of the LHB out of the bicipital groove may indicate a subscapularis tear ## Footnote Axial T2- weighted MRI of a shoulder shows medial dislocation of the biceps tendon (arrowhead), an empty bicipital groove (short arrow), and a subscapularis tear (long arrow).

Question 50

Humeral avulsion of the inferior glenohumeral ligament (HAGL), is best visual on what MRI view? What if they present delayed? Pathognomic sign for hagl?

Answer 50

Humeral avulsion of the inferior glenohumeral ligament (HAGL) Best visualized on **coronal oblique T2-weighted, fat-suppressed MRIs acutely postinjury** * Consider magnetic resonance arthrography in patients with a delayed presentation * J-sign on MRI is considered pathognomonic for HAGL

Question 51

MRI scan of a 20-year-old athlete who has a painful shoulder. This pathology is most commonly seen in

Answer 51

MRI scan reveals a posterior labral detachment. This injury is the result of a posteriorly directed force and is common to football players in blocking positions. Although this injury can occur with trauma in all types of athletes, it is seen with relative frequency in football. Treatment is aimed at labral repair with posterior capsulorrhaphy. Both open and arthroscopic techniques can be used.

Question 52

A 35-year-old woman dislocated her right shoulder in a fall from a step stool several months ago. She now reports several painful recurrences. Examination reveals anterior and inferior apprehension that reproduces her symptoms. An MRI scan is shown in Figure 1. What is this finding? What is the surgical tx?

Answer 52

**open repair of the lateral joint capsule disruption.** ## Footnote The MRI findings reveal a disruption of the humeral insertion of the glenohumeral ligaments and joint capsule (humeral avulsion of the glenohumeral ligament). This lesion has been reported to account for an 8% rate of recurrent dislocation in a subset of patients who are typically older than those with the more common lesions of the glenoid labrum (Bankart lesion). Open repairs have been reported to be successful in the prevention of recurrent instability. Since there is no Bankart lesion, open or arthroscopic labral repairs are not indicated. Nonsurgical management is possible if the patient does not want to undergo surgery; however, the recurrence rate is very high.

Question 53

Which of the following positions of immobilization has been shown to best approximate the anterior labrum against the glenoid rim following anterior dislocation of the shoulder?

Answer 53

**Adduction and external rotation** ## Footnote Following anterior dislocation of the shoulder, the affected arm is typically placed in a sling with the shoulder in adduction and internal rotation. A recent study has shown that placement in this position actually results in laxity of the anterior supporting structures of the shoulder, allowing the postinjury hemarthrosis to push the labrum and capsular ligaments away from the anterior glenoid rim. Thus, immobilization in this position may actually impede healing of these structures. Alternatively, resting the arm in a position of adduction and external rotation allows the anterior supporting structures to abut against the anterior glenoid rim by forcing the hemarthrosis posteriorly. Placing the arm in this position following anterior dislocation is believed to allow for better healing of the anterior labrum and ligaments.

Question 54

What radiographic view is used to assess humeral bone loss following glenohumeral joint dislocation?

Answer 54

Stryker Notch ## Footnote * Evaluate Hill-Sachs lesion after dislocation * With patient supine, the affected arm is placed on the top of the head with the fingers toward the back of the head; beam is centered over coracoid process with 10° cephalic tilt

Question 55

What radiographic view aids in the assessment of glenoid bone loss?

Answer 55

West Point view

Question 56

How is the radiographic beam directed and what is the patient position for the West Point view to evaluate glenoid bone loss?

Answer 56

Patient is prone with the involved shoulder raised above table level, centered on axilla with beam directed 25° downward and 25° medial

Question 57

Tendon transfer options for functionally irreparable RC tears, best for what pathology and outcomes? * Latissimus dorsi * Lower Trap * Pect minor * combine lat and teres major * Pect major * anterior lat dorsi?

Answer 57

Question 58

Lati Dorsi tendon transfer is best for?

Answer 58

Young patients with an intact subscapularis/teres minor and active elevation greater than 80° are ideal surgical candidates ## Footnote Latissimus dorsi tendon transfer is a surgical treatment option associated with favorable clinical and functional outcomes for irreparable posterosuperior rotator cuff tears.Latissimus dorsi tendon transfer can reduce humeral head migration and restore external rotation in patients with an irreparable posterosuperior rotator cuff tear. The tendon has a potential excursion of 33 mm.73 The transfer itself is associated with excellent strength and posterior force couple but exhibits poor synergism.

Question 59

Combined Latissimus Dorsi and Teres Major Tendon Transfer

Answer 59

* Latissimus dorsi tendon and teres major tendon transfer is associated with satisfactory outcomes, with **functional gains in external rotation in patients with a posterosuperior FIRCT and brachial plexus palsy** Poorer outcomes are associated with a nonfunctional subscapularis. * transfer combination also may be performed in the setting of reverse total shoulder arthroplasty with an external rotation lag sign.

Question 60

Pectoralis Major Tendon Transfer

Answer 60

* Pectoralis major tendon transfer provides an** internal rotation centering force for irreparable subscapularis tears**; however, reported outcomes reveal mixed results

Question 61

* Latissimus dorsi, teres major, and lower trapezius tendon transfers can be performed to manage irreparable * Pectoralis major, pectoralis minor, and anterior latissimus dorsi tendon transfers can be performed to manage irreparable

Answer 61

* posterosuperior rotator cuff tears. * anterosuperior rotator cuff tears.

Question 62

first step in mgmt for psuedoparalysis and RCT

Answer 62

**Physical therapy focusing on anterior deltoid strengthening** Collin and associates and Levy and associates have demonstrated significant functional improvement for treatment of CTA with pseudoparalysis with physical therapy. These studies found average improvement of active forward elevation from 40° to 160° when successful. Factors associated with physical therapy failure were rotator cuff tears involving 4 tendons or 3 tendon tears thatdo not allow for recentering of the humeral head.

Question 63

massive cuff tear, young patient/laborer, no OA, xamination of the right shoulder shows forward elevation to 115 degrees, external rotation at the side to 10 degrees and internal rotation to the lower thoracic spine. He has a negative belly press and lift off test and positive hornblower’s and external rotation lag signs.

Answer 63

His chronic posterosuperior cuff tear in the setting of young age and an intact subscapularis makes him a candidate for a latissimus dorsi tendon transfer to improve the patient’s function and pain. ## Footnote A pectoralis major transfer would be appropriate for a chronic subscapularis tear and in this case the patient’s is intact based on physical exam findings.

Question 64

Superior Capsular Reconstruction (SCR) indicated for? More successful outcome sin?

Answer 64

Indications for superior capsular reconstruction (SCR) include intractable pain and dysfunction who have failed conservative treatments with massive irreparable rotator cuff tears, typically of the supraspinatus and infraspinatus tendons. More successful outcomes have been associated in patients with minimal to no rotator cuff arthropathy (Hamada Stage 1 or 2), an intact or reparable subscapularis tendon and an intact deltoid muscle. Age has not been defined as a specific contraindication to performing SCR. Those with Grade 3 of Goutallier Classification have 50% rotator cuff muscle/fatty degeneration. This makes primary rotator cuff tear more difficult and prone to failure but is not a contraindication to SCR.

Question 65

* Normal insertional anatomy is not restored after RCR. The enthesis is replaced by?. * Torn rotator cuff tendon has ?

Answer 65

* Normal insertional anatomy is not restored after RCR. The enthesis is replaced by disorganized scar tissue with impaired mechanical properties after repair. * Torn rotator cuff tendon has low cellularity, poor blood supply of the enthesis, and degenerative changes

Question 66

Timing of RCR failure

Answer 66

* 3-6 months after repair * Re-tear rates ranged from 17% to 41%, all of which occurred within the first 6 months after RCR

Question 67

When comparing the addition of a trough at the greater tuberosity to direct repair of cortical bone, simulated rotator cuff repair in animal models has shown what type of change in the strength of the repair?

Answer 67

There was no difference observed in the healing of tendon to bone when comparing healing to cortical bone and to a cancellous trough.

Question 68

retear of a RCR

Answer 68

traumatic retear is different from a chronic tear and should be treated similar to an acute rotator cuff tear. Because the patient is younger than age 65 and has a small, single tendon tear, a revision rotation cuff repair is indicated with an expected tendon healing rate of greater than 95%. A physical therapy program is not indicated, and further delay in repair compromises his functional recovery. ## Footnote A cortisone injection is not indicated for this repairable tendon tear. Immobilization will not allow the tendon to heal once it has retorn. A debridement procedure is not indicated on this repairable tendon tear; this procedure is indicated in painful, chronic, irreparable tendon tears.

Question 69

Pt has chronic subscab tear, w/ MRI findings of retraction and atrophy. What's the best surgical treatment option?

Answer 69

Chronic subscapularis tendon ruptures preclude primary repair. In such instances, **subcoracoid pectoralis major tendon transfers** may improve function and diminish pain. The subcoracoid position of the transfer allows redirection of the pectoralis major in a direction recreating the vector of the subscapularis tendon

Question 70

Latissimus dorsi tendon transfer is considered a surgical option for treatment in patients with

Answer 70

* **chronic supraspinatus** and **infraspinatus tendon tears. ** * **Preoperative subscapularis function is necessary** for good clinical results. * Additionally, men with active elevation to shoulder level and active external rotation to 20 degrees have predictably good results. * Women with active shoulder elevation limited to below chest level have poor results from this procedure and should not be considered candidates. Postoperatively they lack pain control, active elevation, and active external rotation. * Muscular atrophy in the latissimus dorsi does not occur, and glenohumeral arthritic changes frequently develop postoperatively.

Question 71

Primary Stabilizers of the posterior shoulder?

Answer 71

posterior band of IGHL: primary restraint in internal rotation Subscap: primary dynamic restraint in ER, primary dynamic restraing against posterior subluxation. superior GHL and coracohumeral ligament: primary restraint to inferior translation of adducted arm and to ER. Primary static stabilizer to posterior subluxation w/ shoulder in flexion, adduction and internal rotation. ## Footnote posterior band of the IGHL is taught in abduction The SGHL and CHL are both taught in the position of flexion, adduction, and internal rotation,

Question 72

Kim Test

Answer 72

Posterior instability, posteroinferior labral lesion Kim test is more sensitive for posterior-inferior labral tears and is elicited by pain with forward flexion of the shoulder to 45 degrees while simultaneously applying axial load on the elbow, and posterior-inferior force on the upper humerus. When both the Jerk and Kim tests are combined, the sensitivity in diagnosis of a posterior labral tear increases to 97%.

Question 73

jerk test

Answer 73

applying a posterior force along the axis of the humerus with the arm in forward flexion and internal rotation, which in effect causes the humeral head to subluxate posteriorly and causes a clunk. Jerk test was more sensitive in detecting a primarily posterior labral lesion. ## Footnote Kim test is more sensitive for posterior-inferior labral tears and is elicited by pain with forward flexion of the shoulder to 45 degrees while simultaneously applying axial load on the elbow, and posterior-inferior force on the upper humerus. When both the Jerk and Kim tests are combined, the sensitivity in diagnosis of a posterior labral tear increases to 97%.

Question 74

Distal Clavicle Osteolysis: whats the cause? 1st line? surgery? complication of surgery? Theory to cause?

Answer 74

* repetitive stress and micro-fractures leading to bone resorption, common in weightlifters * A trial of rest, NSAIDs, physical therapy and modified weightlifting technique (avoiding manoeuvres with the elbows posterior to the torso) have shown to be successful in mitigating symptoms. * open or arthroscopic distal clavicle excision if non op fails * arthroscopic DCE (mumford): can address GH and other pathology, quicker recovery and return to activity * resect on .5-1 cm of DC, too large leads to AC jt instability * Complication: horizontal instability: avoid violating posterior superior capsule or it will lead to horizontal instability ## Footnote theory of overhead and weightbearing activities having an important role in the development of distal clavicle osteolysis.

Question 75

MDI (multidirectional shoulder instability) definition and diagnosis? exam findings? Treatment? Surgery?

Answer 75

* generalized instability of the shoulder in at **least 2 planes of motion** (anterior, posterior, or inferior) due to **capsular redundancy**.  * dx: presence of increased **anterior and posterior humeral translation, a sulcus sign, and overall increased external rotation** * Treatment is a trial of prolonged physical therapy focusing on** dynamic stabilization and periscapular muscle training**. * Arthroscopic stabilization with capsular shift is indicated for patients with persistent instability who fail an extensive course of physical therapy.  ## Footnote sulcus sign: assesses rotator interval, represents inferior laxity, laxity of rotator interval presents as increased ER w/ arm fully adducted and at 90degrees of abducted

Question 76

MDI: * 2 underlying mechanisms? * Pathoanatomy Hallmark findings? * referred to as AMBRI?

Answer 76

* Microtrauma from overuse: overhead throwing, volleyball, swimmers, gymnasts * generalized laxity, EDS and marfans * MRI: patulous inferior capsule on MRI (IGHL anterior and posterior bands) * Rotator interval deficiency * Atraumatic, Multidirectional, Bilateral (frequently), Rehab (often responds to), Inferior capsular shift (best alternative to non op) ## Footnote mage demonstrates a capacious and redundant posterior capsule.

Question 77

signs of generalized hypermobility - generalized ligamentous laxity = Beighton's criteria >4/9

Answer 77

* able to touch palms to floor while bending at waist (1 point) * genu recurvatum (2 points) * elbow hyperextension (2 points) * MCP hyperextension (2 points) * thumb abduction to the ipsilateral forearm (2 points)

Question 78

MDI athroscopic drive through sign?

Answer 78

a positive drive-through sign is considered the ability to pass an arthroscope easily between the humeral head and the glenoid at the level of the anterior band of the IGHL also associated with shoulder laxity

Question 79

PT regiment for MDI

Answer 79

3-6 months strengthening of dynamic stabilizers (rotator cuff and periscapular musculature) closed kinetic chain exercises ## Footnote closed kinetic chain exercises are used early in the rehabilitation process to safely stimulate co-contraction of the scapular and rotator cuff muscles

Question 80

MDI surgery? ## Footnote Arthroscopic image of a shoulder shows a patulous capsule with an expanded inferior pouch. The glenoid is below, and the humeral head is above.

Answer 80

must address capsule +/- rotator interval * inferior capsular shift (capsule shifted superiorly) * plication of redundant capsul * rotator inveral closure (open or closed) ## Footnote RI closure produces the most significant decrease in range of motion in external rotation with the arm at the side 0 degrees. Plicating anterior superior region of capsule by suturing superior and middle glenohumeral ligaments together

Question 81

what position in surgery moves axillary nerve away from glenoid?

Answer 81

abduction and ER moves axillary nerve away from glenoid

Question 82

thermal capsulorraphy

Answer 82

Thermal capsulorrhaphy utilizes heat generated by radiofrequency or laser ablation to cause capsular shrinkage in an effort to treat shoulder instability. However, high recurrence rates have been found, especially around two to three weeks after the index procedure, when the capsular tissue is the weakest. In the setting of recurrence following thermal capsulorrhaphy, open revision is recommended.

Question 83

Traumatic Anterior shoulder instability TUBS recurrence rate correlates w/? mechanism of injury? ## Footnote Traumatic Unilateral dislocations with a Bankart lesion requiring Surgery

Answer 83

* high recurrence rate that correlates with age at dislocation. up to 80-90% in teenagers (90% chance for recurrence in age less than 20) * anteriorly directed force on the arm when the shoulder is abducted and externally rotated ## Footnote In young patients (less than 25 years old), recurrence rates have ranged from 60-94%. Family history confers a 34% risk of recurrence, while dislocation in the contralateral shoulder is seen in 25% of recurrently unstable patients according to one study in JBJS (Hovelius et al, 2008).

Question 84

TUBS ontrack vs off track concept of Hillsachs lesion

Answer 84

* Hill-Sachs defect is "off-track" and will "engage" on the glenoid if the size of the Hill-Sachs defect > glenoid articular track (HSI > GT) * Hill-Sachs defect is "on track" and will NOT "engage" if the size of the Hill-Sachs defect < glenoid articular track (HSI < GT) ## Footnote Glenoid Track (GT) = 0.83D-d (D = diameter of inferior glenoid, d = width of anterior glenoid bone loss) Hill-Sachs Interval (HSI) = HS+BB (HS = width of the Hill-Sachs, BB = width of bony bridge)

Question 85

TUBS associated injuries?

Answer 85

**Brankart lesion:** is an avulsion of the anterior labrum and anterior band of the IGHL from the anterior inferior glenoid. present in 80-90% of patients with TUBS **Humeral avulsion of glenohumeral ligament:** **Glad: glenoid labral articular defect** sheared off articular cartilage with labrum, **high risk factor for failure after arthroscopy** **anterior labral periorsteal sleeve avulsion** Fractures and bone defects: **Bony bankart**: fx of anterior inferior glenoid **Hill-sachs: **chondral impaction of posterior superior humeral head secondary to contact w/ glenoid rim. Present in 80-100% of traumatic dislocations and 25% of subluxations ## Footnote 97% of patients with recurrent instability have either a Bankart or ALPSA lesion

Question 86

Bony Bankart Lesion: location of fx? if nor addressed arthrscopically? Whats a critical defect?

Answer 86

* fracture of the anterior inferior glenoid * higher risk of failure of arthroscopic treatment if not addressed * defect >20-25% is considered "critical bone loss" and is biomechanically highly unstable * studies suggest critical bone loss may be as low as 13.5% ## Footnote * present in up to 49% of patients with recurrent dislocations * critical bone loss: stability cannot be restored with soft tissue stabilization alone (unacceptable >2/3 failure rate), requires bony procedure to restore bone loss (Latarjet-Bristow, other sources of autograft or allograft). each dislocation event causes, on average, 6.8% bone loss. glenoid takes on an inverted-pear appearance as bone loss increases 89% failure rate following arthroscopic repair in patients with this glenoid morphology

Question 87

acute dislocation in young athlete vs older patients above 40

Answer 87

Acute traumatic shoulder dislocations in young athletes are associated with a high rate of anteroinferior labral tears. Acute traumatic shoulder dislocations in older patients (>40yrs) are associated with concomitant rotator cuff tears

Question 88

most frequently associated with heterotopic ossification about the shoulder?

Answer 88

* Multiple attempts at closed reduction of chronic unreduced fracture-dislocations * delayed surgery for proximal humeral fractures * associated closed head injury all have been associated with a higher incidence of heterotopic ossification.

Question 89

What is this finding? What is seen on radiographs? What should you suspect? Tx in recurrent instability?

Answer 89

Glenoid hypoplasia ## Footnote radiographs show glenoid hypoplasia. The common radiographic findings of glenoid hypoplasia include an inferior and posterior glenoid deficiency, enlargement of the distal end of the clavicle, and sometimes an indentation in the glenoid. It is usually bilateral and rarely associated with other syndromes; therefore, an echocardiogram, abdominal ultrasound, or a skeletal survey is unnecessary unless the patient has stigmata of a syndrome such as Holt-Oram or Apert's. Although posterior instability has been reported, the results of glenoid osteotomy have been variable and should not be considered initially. Physical therapy is the mainstay of initial management, but the patient should be counseled that this may be a recurrent problem with early osteoarthritis developing in many patients. Radiographs of the contralateral side should be obtained because this is usually bilateral.

Question 90

Athlete with subluxation event, symptoms of instability and this MRI. Tx?

Answer 90

Recent clinical studies have suggested that early stabilization of initial anterior dislocations may lead to better results than nonsurgical management in young, athletic patients. However, there are no data to support early surgery for anterior labral tears resulting from traumatic subluxation without dislocation. Initial treatment should consist of a short period of rest and immobilization, followed by a physical therapy rehabilitation program designed to restore motion, strength, and dynamic stability to the shoulder. If the athlete cannot return to play following nonsurgical management, surgical repair of the labrum, either through an open or arthroscopic approach, is indicated.

Question 91

35 y/o w dislocation, Examination reveals anterior and inferior apprehension that reproduces her symptoms. Tx?

Answer 91

open repair of the lateral joint capsule disruption. ## Footnote The MRI findings reveal a disruption of the humeral insertion of the glenohumeral ligaments and joint capsule (humeral avulsion of the glenohumeral ligament). This lesion has been reported to account for an 8% rate of recurrent dislocation in a subset of patients who are typically older than those with the more common lesions of the glenoid labrum (Bankart lesion). Open repairs have been reported to be successful in the prevention of recurrent instability.

Question 92

A football player sustains a traumatic anterior inferior dislocation of the shoulder in the last game of the season. It is reduced 20 minutes later in the locker room. The patient is neurologically intact and has regained motion. If the patient undergoes arthroscopic evaluation, what finding is seen most consistently?

Answer 92

**Avulsion of anterior inferior glenoid labrum** ## Footnote In an acute first-time dislocation, arthroscopy has been shown to reveal a Bankart lesion in most shoulders. The classic finding of labral detachment from the anterior inferior glenoid along with occasional hemorrhage within the inferior glenohumeral ligament is the most common sequelae of a traumatic anterior inferior dislocation. Acute treatment, if chosen, is repair of the labral tissue back to the glenoid plus or minus any capsular plication to address potential plastic deformation of the glenohumeral ligament. Acute treatment of a patient sustaining a first-time dislocation remains controversial. The potential indications may be patients whose dislocation occurs at the end of a season and when the desire to minimize risk of future instability outweighs the risks of surgical intervention.

Question 93

With the arm **abducted 90 degrees and fully externally rotated**, which of the following glenohumeral ligaments resists anterior translation of the humerus?

Answer 93

Anterior band of the inferior glenohumeral ligament complex *need to know, make cards for all* ## Footnote With the arm in the abducted, externally rotated position, the anterior band of the inferior glenohumeral ligament complex moves anteriorly, preventing anterior humeral head translation. Both the coracohumeral ligament and the superior glenohumeral ligament restrain the humeral head to inferior translation of the adducted arm, and to external rotation in the adducted position. The middle glenohumeral ligament is a primary stabilizer to anterior translation with the arm abducted to 45 degrees. The posterior band of the inferior glenohumeral ligament complex resists posterior translation of the humeral head when the arm is internally rotated.

Question 94

Acute redislocation of the glenohumeral joint is a complication that occurs following a first-time dislocation. This is most often seen with

Answer 94

fracture of the greater tuberosity and glenoid rim. ## Footnote Redislocation following acute dislocation occurs in approximately 3% of patients. This redislocation tends to occur in middle-aged and elderly patients. A higher incidence of redislocation occurs when there are accompanying fractures of the glenoid rim and the greater tuberosity.

Question 95

What is the most important stabilizing mechanism in the midrange of motion of the glenohumeral joint?

Answer 95

**Concavity compression** stabilizing mechanism by which muscular compression of the humeral head into the glenoid fossa stabilizes the glenohumeral joint against shear forces. This is dependent on the depth of the concavity and the magnitude of the compressive force.

Question 96

In which layer of the rotator cuff does the superior capsule lie?

Answer 96

Histologically the rotator cuff has been divided into 5 distinct layers. The superior capsule lies in layer 5, the deepest layer, lying between the supraspinatus and infraspinatus tendons. The capsule insertion spans approximately 50% of the greater tuberosity and is thickest anteriorly at the base of the coracoid and posteriorly at the scapular spine.

Question 97

Which of the following physical exam tests has demonstrated the highest sensitivity for a subscapularis tear?

Answer 97

The bear hug test has demonstrated the highest sensitivity for detecting a subscapularis tear on physical exam as explained in the study by Barth et al: Bear hug test: Sensitivity: 60%, Specificity: 92% Belly press test: Sensitivity: 40%, Specificity: 98% Lift off test: Sensitivity: 18%, Specificity: 100% The lift off test is not as sensitive for detecting subscapularis tears as at least 75% of the subscapularis tendon has to be disrupted before a positive sign is seen. The tests are dependent on positioning of the arm in space and contributions from other internal rotator muscles. The drop arm test has poor sensitivity for isolating the subscapularis muscle and is typically used to test the supraspinatus muscle. The internal rotation sign, not external, is typically used to identify subscapularis tendon tears.

Question 98

natural progression of massiver cuff tears

Answer 98

**Progression in tear size and shape leading to superior migration of the humeral head and glenohumeral degenerative changes** Patients with larger tears showed a higher progression of osteoarthritis compared to smaller tears at 4 year follow up. There was an overall increase in tear size, progression of fatty infiltration by a mean of one stage in three muscles, and a decrease in acromiohumeral distance at final follow up. In a review article by Tashjian symptomatic full-thickness tears progressed in tear size in approximately 50% of cases at an average of 2 years. Tear size progression was correlated with increasing symptoms. In a radiographic study by Chalmers et al full thickness tears had a greater progression in Hamada grades compared to controls, although the severity of the tear did not influence the magnitude of progression.

Question 99

internal impingement

Answer 99

throwing and overhead athetes diffuse pain in posterior shoulder along deltoid, worse w/ throwing Exam: decreased IR loss of more than 20 degrees at 90 compared to contralateral side, increased ER humeral head allows the rotator cuff to become impinged. impingement during max abduction, external rotation late cocking, and early acceleration phase. peel back phenomenon by posteriorsuperior labrum hypertrophy and scarring of posterior capsule glenoid (Bennett lesion) tightness of posterior band of IGHL Tx: PT cessation of throwing, posterior capsular stretching - athroscopic debridment of cuff and labrum for PASTA, Bennet lesions, and peel back labral lesions if non op fails ## Footnote xray of a bennet lesion. spectrum of injuries: fraying of the articular side of posterior cuff (supraspinatus-infraspinatus interval),posteriorsuperior labral lesions, bennett lesion, MRI may show partial articular-sided supraspinatus-infraspinatus tendon avulsion (PASTA), fraying, or tear

Question 100

GIRD

Answer 100

Glenohumeral internal rotation deficit (GIRD) 18° difference in internal rotation compared with the contralateral extremity. *decrease in IR, increase in ER, sulcus sing (stretching of anterior structure that resist er (CH ligament and rotator interval)* tx: rest from throwing and PT for 6 months, sleeper stretch (IR stretch at 90 abd w/ scapular stabilization) * tightening of posterior capsule or posteroinferior capsule leads to translation of humeral head (capsular constraint mechanism) * translation of humeral head is in the OPPOSITE direction from area of capsular tightening * posterior capsular tightness leads to anterosuperior translation of humeral head in flexion * posterorinferior capsular tightness leads to posterosuperior translation of humeral head in ABER * Associated conditions: GH instability, internal impingment, PASTA, slap slesions * throwers w/ GIRD are 25% more likely to have a slap lesion - peel back mechanism (biceps anchor and postero superior labrum peels back during late cocking because postero superior translation of humeral head and change in biceps force postriorly.

Question 101

GIRD: if loss of internal rotation is less than external rotation gain then? If if loss of internal rotation is more than external rotation gain then?

Answer 101

* if the GIRD (loss of internal rotation) is less than external rotation gain (ERG), the shoulder maintains normal kinematics * if the GIRD exceeds external rotation gain (ERG), this leads to deranged kinematics

Question 102

Slap Lesion risk factor: path: MRI shows: Tx options: Arthroscopic complications?

Answer 102

Superior Labrum from Anterior to Posterior Tear RF: GIRD defined as 18° difference in internal rotation compared with the contralateral extremity. Path: throwers may be due to tightness of the posterior-IGHL which shifts the glenohumeral contact point posterosuperiorly and increases the shear force on the superior labrum. SLAP lesion** increases the strain on the anterior band of the IGHL** and thus compromises stability of shoulder * anterior-superior labrum has poorest blood supply * anchors biceps tendon and is weak link that leads to SLAP lesion * MRI =/- arthrogram: T2 signal intensity b/t superior labrum, lateral to glnoid rim and posterior to biceps, may see paralabral cyst * Tx: rest PT NSAIDS * arthroscopic debridement with repair of the labrum/biceps versus debridement with biceps tenotomy/tenodesis * complication: overdrilling glenoid can injure suprascapular nerve; failed SLAP repair and persistent sympptes associated with age greater than 36, biceps tenodesis a better option.

Question 103

Throwing phases: Max forced is placed during ? Most injuries occur in what phase?

Answer 103

Force is transferred from the ground reaction forces through a stable base with mainly lower extremity movement during wind up. Maximal stress is placed on the shoulder in late cocking/early acceleration, during which the shoulder approaches maximal external rotation. The scapula is retracted, the elbow is flexed, and the humerus is in abduction and external rotation. The subscapularis, pectoralis major, and latissimus dorsi are eccentrically contracting to stabilize the joint. Most shoulder injuries occur in this stage. The acceleration phase is characterized by scapula protraction, humeral adduction, and internal rotation (force produced by the subscapularis, pectoralis major, and latissimus). Deceleration results in glenohumeral distraction and shear forces, with eccentric loading of the posterior rotator cuff and considerable biceps and brachialis activation to slow elbow extension.

Question 104

Peel back mechanism

Answer 104

When the arm is in the 90-90 position, the biceps tendon is shifted more posteriorly (because of external rotation), and the biceps anchor subsequently twists. This places a torsional force on the superior labrum. Although this is a normal adaptation for throwing athletes, it may become pathologic if the anchor becomes unstable

Question 105

Sick Scapula

Answer 105

A SICK scapula manifests with the involved shoulder appearing anterior and inferior (protracted), coracoid tenderness, and dyskinesis. **Scapular malpositioning**—The scapula protracts, rotating about a horizontal axis, with the upper scapula rotating anteroinferiorly; the shoulder appears lower than the contralateral side. **Inferior medial border prominence** **Coracoid pain and malpositioning**—Contraction of the pectoralis minor and the short head of the biceps contribute to the coracoid tilting inferiorly and laterally away from the midline. **Dyskinesis**—Decreased subacromial space leads to external impingement and rotator cuff weakness. **AAOS: In the static evaluation of the athlete's shoulder, a SICK scapula is characterized by which of the following scapula positions: Inferior, protraction, anterior tilt, inferior angle prominence ## Footnote Early in the condition, substantial deficits in range of motion and form (kinetic chain) may be noted before the onset of symptoms. Failure to address these factors early may lead to worsening dysfunction and increased risk for intraarticular damage.

Question 106

Risk factors for injury in the throwing shoulder?

Answer 106

* Deficiencies in the kinetic chain and athletic form * **Fatigue of the serratus anterior**, which leads to increased rotator cuff and periscapular muscle activation and increased scapular external rotation Deficits in range of motion: * Total range-of-motion deficit appears to be most correlated rather than glenohumeral internal rotation deficit alone (because of limited external rotation). * Increased risk of ulnar collateral ligament injury and medial elbow torque Limitation of external rotation leads to decreased arm slot or may allow the arm to lag while throwing (compensatory to maintain velocity)

Question 107

Baseball pitchers who have internal impingement will most likely demonstrate what changes in range of motion?

Answer 107

Pitchers tend to have a decrease in internal rotation and an increase in external rotation. The increase in external rotation is felt to be multifactorial. An increase in humeral retroversion occurs from repeated throwing. This results in increased soft-tissue stretching and results in a posterior capsular contracture.

Question 108

Benefit of MRI-arthrography for SLAP or Labral tears

Answer 108

MRI-arthrography has been shown to be an accurate technique for assessing the glenoid labrum in patients with suspected labral tears. Often standard MRI technique will not identify labral lesions. The use of MRI-arthrography with an intra-articular injection of gadolinium provides improved visualization of labral lesions. Bencardino and associates demonstrated a sensitivity of 89%, a specificity of 91%, and an accuracy of 90% in detecting labral lesions. SLAP lesions can be visualized on coronal oblique sequences as a deep cleft between the superior labrum and the glenoid that extends well around and below the biceps anchor. Often, contrast will diffuse into the labral fragment, causing it to appear ragged or indistinct.

Question 109

Baseball player, adolescent with this xray? What is it and next steps?

Answer 109

**Little Leaguer’s shoulder**, physeal widening. This condition is secondary to overuse (typically throwing) and responds well to rest from the inciting activity. The changes in the proximal humerus are classic for this condition and are not suggestive of a neoplastic process requiring biopsy for definitive diagnosis. **tx: rest from throwing activities.** cessation of throwing, then PT and progressive throwing program after sufficient rest. OB: repetitive torsional & distractive stresses at physis SHI. Hypertrophic zone (weakest portion of physis) Late cocking: 400% greater external rotatory force than physis can tolerate. Deacceleration: excessive eccentric stress Breaking pitches implicated # of pitches most important factor Complication: Premature growth arrest of proximal humeral epiphysis ## Footnote prevention: proper pitching mechanics, discourage breaking ball pitches, enforcement of pitch counts, avoid year round pitching.

Question 110

Leading cause of shoulder pain in throwing athlete?

Answer 110

*** Internal impingement of the shoulder** is a leading cause of shoulder pain in the throwing athlete. * The primary lesion in pathologic internal impingement is excessive tightening of the posterior band of the inferior glenohumeral ligament complex. * To obtain an accurate assessment of true glenohumeral rotation, the scapula is stabilized during examination. A loss of 20 degrees or more of internal rotation, as measured with the shoulder positioned in 90 degrees of abduction, indicates excessive tightness of the posterior band of the inferior glenohumeral ligament complex.

Question 111

Suprascapular nerve injuries are commonly seen in ? What are the symptoms? Initial management? Surgery?

Answer 111

* Suprascapular nerve injuries are more commonly seen in athletes who participate in overhead activities. * When a patient is evaluated for posterior shoulder pain and infraspinatus muscle weakness or atrophy, electrodiagnostic studies are an essential part of the evaluation. In addition, imaging studies are indicated to exclude other diagnoses that can mimic a suprascapular nerve injury. * Initial management should consist of cessation of the aggravating activity along with an organized shoulder rehabilitation program. If nonsurgical management fails to provide relief within 6 months to 1 year, surgical exploration of the suprascapular nerve should be considered. * Release of the spinoglenoid ligament with resultant suprascapular nerve decompression may result in pain relief and a return of normal shoulder function. In this patient, who has a chronic neuropathy and mild symptoms, surgery is indicated only if nonsurgical management fails to provide relief and he is unable to perform at his position.

Question 112

A 21-year-old pitcher reports shoulder pain with hard throwing. He notes that the pain occurs in the early acceleration phase of his throw. Given his history, what structures are at greatest risk for injury?

Answer 112

**Posterosuperior labrum, greater tuberosity, articular side of the rotator cuff** Internal impingement in the thrower's shoulder occurs in the abducted, externally rotated position as described by Walch and associates. The injury is thought to occur from repetitive contact between the posterosuperior portion of the labrum and glenoid against the articular side of the rotator cuff and greater tuberosity.

Question 113

A 22-year-old professional baseball pitcher has had pain in the axillary region of his dominant shoulder for the past several weeks. While throwing a pitch during a game, he notes a sharp pulling sensation with a "pop" in his shoulder. Examination the following day reveals tenderness along the posterior axillary fold and pain and weakness with resisted extension of the shoulder. What is the most likely cause of his symptoms?

Answer 113

**Tear of the latissimus dorsi tendon** Injury to the latissimus dorsi tendon recently has been reported as a cause of pain in the thrower's shoulder. The etiology of this injury is felt to be** eccentric overload during the follow-through of the throwing motion. **Recommended management for this unusual injury consists of a short period of rest, followed by physical therapy to restore shoulder motion and strength. Throwing is allowed when the athlete demonstrates full, pain-free motion and good strength and balance of the rotator cuff and scapular rotator muscles. Currently there are no defined indications for surgical repair.

Question 114

A 22-year-old college baseball pitcher reports the recent onset of anterior and posterosuperior shoulder pain in his throwing shoulder. Examination shows a 15-degree loss of internal rotation, tenderness over the coracoid, and a positive relocation test. Radiographs are normal, and an MRI scan without contrast shows no definitive lesions. A rehabilitation program is prescribed. Which of the following regimens should be initially employed?

Answer 114

**Stretching the posterior capsule and pectoralis minor tendon** Throwing athletes, particularly pitchers, have a high incidence of shoulder pain. Recent evidence suggests that posteroinferior capsular tightness and scapular dyskinesis may play a substantial role in the pathologic cascade, culminating in the development of articular surface rotator cuff tears and tearing of the posterosuperior labrum. These patients have posterosuperior shoulder pain primarily. Furthermore, these athletes are susceptible to a muscular fatigue syndrome, the SICK (Scapular malposition, Inferior medial border prominence, Coracoid pain and malposition, and dysKinesis of scapular movement) scapula syndrome. This patient has an internal rotation deficit and tenderness over the coracoid. The internal rotation deficit is addressed by stretching the posterior capsule. The tenderness over the coracoid has been attributed to a contracture of the pectoralis minor tendon secondary to scapular malposition. The initial phase of the rehabilitation regimen is directed at stretching the posterior capsule and pectoralis minor tendon.

Question 115

A 22-year-old professional baseball catcher has posterior shoulder pain and severe external rotation weakness with the arm in adduction. Radiographs are normal. MRI scans are shown in Figures 1 through 3. Management should consist of

Answer 115

arthroscopic repair and decompression. The MRI scans reveal a large posterior paralabral cyst associated with a posterior-superior labral tear. The cyst appears as a well-defined, smoothly marginated mass with low signal intensity on T1-weighted MRI scans and with high signal intensity on T2-weighted MRI scans. MRI also reveals changes in the supraspinatus and infraspinatus muscles secondary to denervation, including decreased muscle bulk and fatty infiltration. MRI has the added advantage, compared with other imaging modalities, of detecting intra-articular lesions, such as labral tears, which are frequently associated with ganglion cysts of the shoulder. In this case of a professional baseball player with a space-occupying lesion causing nerve compression with an associated labral tear, the treatment of choice is arthroscopic decompression of the cyst and repair of the tear.

Question 116

In overhead athletic activities, the kinetic chain generates what percentage of force from the leg and trunk segments of the chain?

Answer 116

50% to 60% The leg and trunk provide a stable base for arm motion, supply rotational momentum for force generation, and generate 50% to 55% of the total force and kinetic energy in the tennis serve.

Question 117

Sick Scapula Syndrome: what is it and how does it present?

Answer 117

* Scapular malpositioning * Inferior medial border prominence * Coracoid pain and malpositioning * Dyskinesis of scapular movement * Exam: - Scapular retraction test—Manually retract the scapula with the palm or forearm placed on the scapula and fingers over the coracoid; decreased pain and improved strength with supraspinatus testing - Scapular assist—Pain with shoulder elevation is reduced if the inferior scapula is manually assisted in abduction or elevation ## Footnote Related to scapular dyskinesis, which is the dynamic manifestation of this disorder Presents as anterior shoulder pain in the dominant arm of the throwing athlete, often with dead arm complaints The characteristic feature of this syndrome is the involved shoulder appearing to be lower than the contralateral shoulder (because of scapular protraction)

Question 118

A baseball player has had diffuse **scapular soreness for the past 8 weeks**. He reports that it began insidiously over several days and gradually has become worse. He denies any history of trauma. Examination reveals** drooping of the shoulder, with lateral winging of the scapula at rest**. He is otherwise neurologically intact. What is the best course of action?

Answer 118

**EMG/NCS** **Lateral scapular winging** is characteristic of trapezius palsy, During sports activity, injury to the spinal accessory nerve is rare but may occur with blunt or stretching trauma. Patients often report an asymmetric neckline, drooping shoulder, winging of the scapula, and weakness of forward elevation. Evaluation should include a complete electrodiagnostic examination. **Spinal accessory nerve CNXI** ## Footnote whereas medial scapular winging is characteristic of long thoracic nerve palsy.

Question 119

What type of exercise is used early in the rehabilitation process to safely** stimulate co-contraction of the scapular and rotator cuff muscles**? What are some other types of exercise later in the rehab process

Answer 119

**Closed kinetic chain** Closed kinetic chain exercises are used early in the rehabilitation process. The distal segment is fixed, and an axial load is applied which provides glenohumeral compression and reduces the demand on the rotator cuff. These exercises stimulate co-contractions of the scapular and rotator cuff muscles, load scapular stabilizers, and facilitate active motion. ## Footnote * Facilitated active motion exercises use proximal segment motion to stimulate and facilitate motion in the target tissue. These exercises are often performed in diagonal movements. * Resistive active motion exercises are used later in the rehabilitation process. These are typically open kinetic chain exercises that involve active glenohumeral motion with extrinsic loads such as weights or exercise tubing. * During the later stages of upper extremity rehabilitation, plyometrics are added. These exercises help to prepare the athlete for return to sport. When performed at slower speeds, these exercises emphasize stabilization and control. As the speeds increase, muscles begin to work in the stretch-shortening sequence associated with sports participation.

Question 120

Typical physical examination findings in someone with scapular dyskinesis include? Optimal rehabilitation for scapula dyskinesis should focus on?

Answer 120

* Tenderness at coracoid and subacromial space, weak core strength exam, (+) scapula assist test, (+) scapula retraction test * Improving core strength, improving glenohumeral internal rotation deficit, stretching the pectoralis minor, and strengthening the serratus and lower trapezius ## Footnote Altered kinematics of the scapula on dynamic use falls into three clinically recognizable patterns of scapular dyskinesis. Type 1: inferior medial scapular prominence; associated with labral pathology. Type 2: medial scapular prominence; associated with labral pathology. Type 3: superomedial border scapular prominence; associated with external (subacromial) impingement and rotator cuff pathology rather than labral pathology

Question 121

# entr Posterior Labral tear "Reverse bankart" demographics? pathology? anatomy of posterior labrum? clinic symptoms and exam manuevers? athroscopic treatment if non op fails requires? complications of athroscopic tx?

Answer 121

* Weightlifters, lineman (bench press, blocking) * repititive microtrauma to posterior capsulolabral complex, posterior directed force w/ arm flexed, IR, and adducted * Kim lesion: incomplete avulsion of posteroinferior labrum * posterior labrum anchors posterior inferior glenohumeral ligament (PIGHL) * vague, nonspecific posterior shoulder pain worsen with push/bench, clicking and popping * exam: posterior apprenhesion, posterior load-shift, **jerk test clunk highly sensitive **, **kim test shoulder abd 90 ff45 w/ posterior inferior force, highly sensitve/spef for posteroinferior labral tear** * non op: activity mod, nsais, PT * athroscopic labral repair capsullorrhaphy, suture anchor repair + capsullorrhaphy fewer recurrences and revisioncs than non anchored repairs, must probe posterior labrum to r/o subtle kim lesion. Complications of surgery: **axillary nerve palsy, posterior branch of axillary n**, travels 1mm off the inferior shoulder capsule and glenoid rim, at risk during suture passage **overtighting of posterior capsule**, leads to anterior subluxation or coracoid impingement

Question 122

**Quadrolateral space syndrome:** anatomy of the space? mechanism? greatest compression occurs with the arm in what position? clinical symptoms and exam? What will an MRI show? Diagnosis? Non op vs op?

Answer 122

* causes: iatrogenic (tight fibrous bands, muscular hypertrophy), p**aralabral cysts (most commonly inferior labral tears),** trauma, masses * Contents: axillary nerve (C5 nerve root, posterior cord), posterior circumflex humeral artery * arm is positioned in the late cocking phase of throwing (abduction and external rotation) * poorly localized pain to posterior lateral shoulder, worse at night, worse w/ OH activities, or late cocking/accel of throwing, paresthesias long lateral arm. * external rotation shoulder weakness w/ arm abducted. * MRI may show atropjy of teres minor (axillary innervation), compression of qualilateral space, inferior paralabral cyst w/ labral tear * **EMG to confirm diagnosis** * **diagnostic lidocaine to confirm dx**: block 2-3 cm inferior to standard posterior shoulder portal * Non-op: nsaids, activity restrictions, PT. most improve with 3-6 months of non-op *** nerve decompression** if failed non op, weakness and functional disability, space occuppying lesion. open release of quadrilateral space +/- arthroscopic repair of labral tear ## Footnote Prognosis: Long-standing cases often causes atrophy/weakness of teres minor and deltoid

Question 123

**Quadrolateral space syndrome:** What will an MRI show?

Answer 123

*** MRI may show atropjy of teres minor (axillary innervation), compression of qualilateral space, inferior paralabral cyst w/ labral tear** * **EMG to confirm diagnosis** * **diagnostic lidocaine to confirm dx**: block 2-3 cm inferior to standard posterior shoulder portal * Non-op: nsaids, activity restrictions, PT. most improve with 3-6 months of non-op *** nerve decompression** if failed non op, weakness and functional disability, space occuppying lesion. open release of quadrilateral space +/- arthroscopic repair of labral tear

Question 124

Medial vs lateral scapular winging

Answer 124

medial scapular winging: serratus anterior (long thoracic nerve), weak protraction, excessive medializing scapular retraction (rhomboid major and minor) and elevation (trapezius). young athlete more vomon lateral scapular winging: dysfunction of the trapezius (cranial nerve XI - spinal accessory nerve), weak superior and medializing force on the scapula excessive lateralizing scapular protraction (serratus anterior, pectoralis major and minor). usually iatrogenic

Question 125

suprascapular notch entrapment causes? Spinogelnoid notch entrapment casues? what's the pathoanatomy? Exam findings:

Answer 125

Suprascapular nerve (C5-6), emerges off superior trunk Suprascapular notch: weakness in both supra and infra Spinoglenoid: weakness in infra. Slap tears associated more w/ spinoglenoid cyst Supraspinatus: weakness seen with shoulder abduction to 90 degree, 30 degrees forward flexion, and with internal rotation (Jobe test positive) Infra: weakness to external rotation with elbow at side exam: may have Infraspinatus Atrophy along posterior scapula MRI: posterior labral lesions w/ associated cyst EMG/NCS: diagnostic Tx: Nonop w/ PT if no structural lesion on MRI Labral repair w/ cyst decompression if labral lesion w/ associated cyst on MRI. Spinoglenoid ligament release w/ nerve decompression if no structural lesion and failed extended non op management (1 yr) ## Footnote suprascapular ligament (artery runs above, nerve runs below) spinoglenoid ligament (overlies distal suprascapular nerve)

Question 126

Brachial Neuritis (Personage Turner Syndrome)

Answer 126

* severe shoulder pain followed by patchy muscle paralysis and sensory loss involving the shoulder girdle and upper extremity * Diagnosis is made clinically with a through neurological exam that may vary from moderate motorsensory changes to flaccid paralysis of the upper extremity and can be confirmed by EMG/NCS. * reatment is observation and pain control with recovery taking up to 3 years. Operative nerve exploration, neurolysis, nerve transfer or tendon transfer be be indicated if there is no evidence of EMG recovery by 9-12 months. * 2 clinical types: idiopathic neuralgic amyotrophy (INA) (this topic) hereditary neuralgic amyotrophy (HNA) poor prognosis: femail, lower trunk (upper has best prognosis), persistent pain and no motro function recovery by 3 months, hereditary causes age has no effect on prognosis Timing of recovery: 66% have recovery of motor function w/in 1 month - exellent in 36% at 1 year, 75% at 2 years, 89% at 3 years

Question 127

Pect Major Rupture

Answer 127

Lateral pectoral nerve: Clavicular head/upper portion of SC head Medial pectoral nerve: supplies lower portion of the head Tendinous avulsion, insertion of tendon lateral to bicipital groove Sternocostal head insertionis most common site of rupture RF: anabolic steroid use Mechanism: exessive tension on max eccentrially contracted muscle. occurs during the downward portion of a bench press, with the arm in the final 30 degrees of humeral extension while pushing against heavy resistance ## Footnote weakness most pronounced in adduction and internal rotation

Question 128

Adhesive capsulitis: Whats the path? What part of the shoulder is affected? Associated conditions? Exam findings? MRI findings Tx? PT vs Arthrsocopy. What needs to be arthroscopically release

Answer 128

* fibroblastic proliferation of joint capsule leading to thickening, fibrosis, and adherence of the capsule to itself and humerus * fibroblasts/myofibroblasts with abundant Type III collagen present * essential lesion involves the **coracohumeral ligament and rotator interval capsule** * DM (I &II) and Thyroid disorders * Exam: symmetric loss of A and PROM. ER deficit most common, tethered endpoint to motion. Painful throughout arc * MRI will show loss of axillary recess indicating contracture of joint capsule * PT: * Arthroscopic release: rotator interval released from anterior biceps tendon to superior edge of subscapularis, Coracohumeral ligament release, Posterior capsule release willl increase IR and cross body adduction ## Footnote Axillary nerve injury with capsular release perform inferior release near to glenoid rim

Question 129

What defines the rotator interval

Answer 129

a triangular region between the anterior border of supraspinatus and the superior border of subscapularis contains the SGHL and coracohumeral ligament

Question 130

main bloodsupply to humeral head

Answer 130

posterior humeral circumflex artery, which is the primary blood supply to the humeral head, and most likely to lead to AVN when injured. provides 65% of the blood supply

Question 131

What is the best imaging modality to evaluate for a concealed avulsion of the deep posteroinferior labrum?

Answer 131

A** Kim lesion** is a superficial capsulolabral lesion that results in a **concealed deep posterior labral avulsion with an intact superficial labrum.** Kim lesions typically occur as a result of posterior inferior direct forces, most commonly in young adults during overhead activities. Current guidelines indicate that **MRI is the best imaging modality for such lesions**.

Question 132

A 34-year-old male presents due to concerns that his right shoulder is unstable. To assess for p**osterior shoulder instability, the physician flexes and internally rotates the affected arm and flexes the elbow to 90 degrees. The physician then pushes on the flexed elbow, which causes posterior glenohumeral subluxation. **When the physician extends the patient's arm, the joint reduces. What is the name of the provocative test being performed?

Answer 132

The **Jerk test **is one of the several tests to evaluate for posterior shoulder instability. The Kim, posterior load and shift, and posterior stress tests are different provocative techniques to evaluate for posterior shoulder instability. In contrast, the Hawkings test assesses for shoulder impingement.

Question 133

Kim test

Answer 133

performed by having the patient seated, arm at 90° abduction, followed by flexing the shoulder to 45 forward flexion while simultaneously applying axial load on the elbow & posterior-inferior force on the upper humerus.

Question 134

performed by having the patient seated, arm at 90° abduction, followed by flexing the shoulder to 45 forward flexion while simultaneously applying axial load on the elbow & posterior-inferior force on the upper humerus.

Answer 134

Traumatic posterior bony Bankart lesions typically occur due to a posterior force on the humeral head when the shoulder is held in flexion and adduction. Current guidelines suggest that, in these patients, arthroscopic posterior stabilization maximally restores posteroinferior joint laxity.

Question 135

External rotation deficit after stabilizing procedure. what procedure will offer the best chance of restoring motion, decreasing pain, and preserving the native joint?

Answer 135

Loss of external rotation following stabilization procedures can result in progressive degenerative joint disease. A tight anterior capsule results in posterior humeral translation and progressive posterior glenoid wear. Patients with early degenerative joint disease and pain can be treated with anterior release to restore more normal glenohumeral biomechanics. This procedure not only improves function but also decreases pain in most patients. Closed manipulation at 15 years after surgery is unlikely to be successful and carries the risk of complications. Acromioplasty, posterior release, and removal of osteophytes do not address the pathology. Arthroscopic releases are favored for intra-articular procedures that have addressed the pathology of instability. Open releases are recommended for nonanatomic extra-articular repairs that include subscapularis tightening procedures.

Question 136

What is the most common complication following arthroscopic capsular release in a patient with adhesive capsulitis of the shoulder?

Answer 136

Failure to maintain range of motion

Question 137

primary static restraints to inferior translation of the arm when the shoulder is in 0 degrees of abduction and neutral rotation?

Answer 137

Biomechanical ligament sectioning studies have implicated both the superior glenohumeral and coracohumeral ligaments as restraints to inferior translation when the shoulder is in 0 degrees of abduction and neutral rotation. Although there is controversy over the significance of each ligament, both are involved to some degree. The middle glenohumeral ligament is more important in the midranges of abduction, and the inferior ligament is more important at 90 degrees of abduction. The coracoacromial and coracoclavicular ligaments play no role in glenohumeral restraint.

Question 138

In patients who have undergone nonsurgical management for idiopathic adhesive capsulitis, long-term follow-up studies have shown which of the following results?

Answer 138

**Decreased range of motion compared with the contralateral shoulder** ## Footnote Results have been satisfactory in many patients; however, at long-term follow-up, examination of the affected shoulder often shows some decrease in range of motion compared with the contralateral side. Although range of motion often improves over time, it does not return to normal in 60% of patients. Pain improves but is often increased compared with the contralateral side.

Question 139

With the arm abducted 90 degrees and fully externally rotated, which of the following glenohumeral ligaments resists anterior translation of the humerus?

Answer 139

Anterior band of the inferior glenohumeral ligament complex.. With the arm in the abducted, externally rotated position, the anterior band of the inferior glenohumeral ligament complex moves anteriorly, preventing anterior humeral head translation. Both the coracohumeral ligament and the superior glenohumeral ligament restrain the humeral head to inferior translation of the adducted arm, and to external rotation in the adducted position. The middle glenohumeral ligament is a primary stabilizer to anterior translation with the arm abducted to 45 degrees. The posterior band of the inferior glenohumeral ligament complex resists posterior translation of the humeral head when the arm is internally rotated.

Question 140

There is an increase in ? collagen found in patients with idiopathic adhesive capsulitis. There is also ? of the joint capsule which leads to thickening of the joint capsule and loss of active and passive range of motion.

Answer 140

There is an increase in Type III collagen found in patients with idiopathic adhesive capsulitis. There is also fibroblastic proliferation of the joint capsule which leads to thickening of the joint capsule and loss of active and passive range of motion.

Question 141

Risk factors for postoperative shoulder stiffness

Answer 141

Numerous risk factors have been identified in the development of postoperative shoulder stiffness, including female sex, age older 40 years, history of trauma, human leukocyte antigen-B27 positivity, and prolonged shoulder immobilization.25 A recent meta-analysis suggested a genetic predisposition to adhesive capsulitis , noting a higher incidence of this condition in White patients, patients with a positive family history, and patients with human leukocyte antigen-B27 positivity.27 Endocrine abnormalities, particularly diabetes mellitus), have been implicated in primary and secondary adhesive capsulitis and may be the strongest associated risk factor. Interestingly, patients with type 1 or type 2 diabetes have an increased risk for adhesive capsulitis , with a prevalence of 10.3% and 22.4% respectively (Resource 1).28 Thyroid disorders, clinical and subclinical hypothyroidism and hyperthyroidism, also appear to be another substantial risk factor for idiopathic and postoperative shoulder stiffness.29 These risk factors and comorbidities are important to note because they confer a poorer overall long-term functional prognosis.

Question 142

What is the best treatment option to decrease pain and improve function?

Answer 142

**Stemmed hemiarthroplasty** The radiograph and intraoperative photograph show osteonecrosis with near complete head loss/collapse. **A stemmed implant is more appropriate in this patient because there is very little bone to support a resurfacing implant. ** In a younger patient, a glenoid implant should be delayed as long as possible because of the eventual need for revision secondary to glenoid loosening and wear, especially in a young active male. The hemiarthroplasty may be converted to a total shoulder arthroplasty in the future.

Question 143

A cord-like middle glenohumeral ligament and absent anterosuperior labrum complex can be a normal anatomic capsulolabral variant. If this normal variation is repaired during arthroscopy, it will cause

Answer 143

If the Buford complex is mistakenly reattached to the neck of the glenoid, severe painful restriction of external rotation will occur.

Question 144

functional results after hemiarthroplasty for 3-4part proximal humerus fx are directly related to?

Answer 144

The radiograph shows **tuberosity malposition. **The effect of improper prosthetic placement has also been associated with poor outcomes. However, the malposition of the tuberosity seen on the radiograph clearly explains loss of motion in this patient. It has been demonstrated that the functional results after hemiarthroplasty for three- and four-part proximal humeral fractures appear to be directly associated with tuberosity osteosynthesis. The most significant factor associated with poor and unsatisfactory postoperative functional results was malposition and/or migration of the tuberosities. Factors associated with a failure of tuberosity osteosynthesis in a recent study were poor initial position of the prosthesis, poor position of the greater tuberosity, and women older than age 75 years (most likely with osteopenic bone). Greater tuberosity displacement has been identified by Tanner and Cofield as being the most common complication after prosthetic arthroplasty for proximal humeral fractures. Furthermore, Bigliani and associates examined the causes of failure after prosthetic replacement for proximal humeral fractures and found that although almost all failed cases had multiple causes, the most common single identifiable reason was greater tuberosity displacement.

Question 145

Walsch Classification: wear do type B glenoids have the most wear?

Answer 145

Type A glenoids exhibit concentric wear, with no subluxation of the humeral head. Type B glenoids exhibit biconcave, asymmetric wear, with posterior humeral head subluxation. Studies have demonstrated that the greatest degree of glenoid wear in B2 glenoids occurs in the posteroinferior glenoid. Type C glenoids exhibit excessive glenoid retroversion greater than 25°. Type D glenoids exhibit glenoid anteversion or anterior humeral head subluxation. ## Footnote Overall, the authors found that a majority of the erosion occurred in the posteroinferior glenoid near the 7- to 8-o'clock position. The authors conclude that knowledge of the typical orientation of glenoid wear in this subset of glenoid morphology is helpful in formulating a surgical plan. preoperative B2 glenoid is a risk factor for early glenoid component loosening

Question 146

TSA post op complication, subscap rupture

Answer 146

Subscap rupture, patient will feel anterior instability noticeable with external rotation of the shoulder. and loss of active IR ## Footnote The surgical approach involves detaching the subscapularis and capsule from the anterior humerus and dislocating the humeral head anteriorly. Post operatively, external rotation is limited to protect the subscapularis repair

Question 147

American Academy of Orthopaedic Surgeons Clinical Practice Guidelines for end-stage glenohumeral osteoarthritis (GH OA).

Answer 147

end-stage glenohumeral osteoarthritis (GH OA). According to the AAOS CPG, total shoulder arthroplasty (TSA) is recommended using an all-polyethylene cemented glenoid component. ## Footnote TSA is indicated for cases of end-stage GH OA. It is preferred to hemiarthroplasty. It is contraindicated in cases with insufficient glenoid bone stock (glenoid wear to the level of the coracoid), rotator cuff arthropathy or irreparable cuff tears and deltoid dysfunction. It provides good pain relief and has good survival at 10 years (>90%).

Question 148

inferior scapula notching rTSA

Answer 148

inferior scapular notching which preoperative superior glenoid erosion has been associated in the development and is correlated with decreased ROM, strength, and Constant scores. ## Footnote inferior scapular notching is the most common form and is usually the result of the superior placement of the glenoid component and with inadequate inferior tilt. Rarely does scapular notching necessitate revision surgery, but has been implicated with decreased abduction and flexion ROM, post-operative strength, and patient-reported outcomes compared to patients without notching.

Question 149

RevTSA mechanics

Answer 149

center of rotation (COR) becomes fixed medially and inferiorly, thus lengthening the deltoid and placing all deltoid muscle fibers lateral to the COR. This optimizes its function and it becomes the primary mover of the shoulder. Any technique/design that moves the COR medial and/or inferior, or lengthens the deltoid will increase the deltoid moment and muscle efficiency.

Question 150

Compared to a primary RSA, revision RSA significantly increases the risk of

Answer 150

glenoid component loosening and fracture with rates approaching ~25% at 5-year follow-up.

Question 151

greatest risk factors for infection after shoulder arthroplasty?

Answer 151

The greatest risk factors for infection have been found to be male, younger age, RTSA, and arthroplasty for traumatic reasons. Obesity, smoking, rheumatoid arthritis, and ASA class were not associated with an increased risk of infection. most common organisms being Staph and C. Acnes

Question 152

4 part proximal humerus fx, rTSA, What happens if the lesser tuberosity is placed too lateral (too closed to greater)

Answer 152

Placing the lesser tuberosity in a more lateral position will increase tension on the subscapularis and likely lead to a deficit in external rotation. Variable outcomes in the prosthetic reconstruction of 4-part humerus fractures often can be attributed to inconsistent and nonanatomic tuberosity placement. Frankle et al (2001) examined the effects of tuberosity malposition in proximal humeral reconstruction after 4 part fractures and found out that there was significant alteration in external rotation kinematics and torque requirements. Failure to properly position tuberosity fragments in the horizontal plane may result in insurmountable postoperative motion restriction.

Question 153

What are the proposed biomechanical advantages of the Grammont reverse total shoulder arthroplasty when compared to a standard shoulder arthroplasty? ## Footnote AAOS

Answer 153

The Grammont reverse total shoulder arthroplasty is designed to medialize the center of rotation, thereby increasing the deltoid moment arm and lengthening the deltoid.

Question 154

proper positioning of arm for shoulder arthodesis

Answer 154

40 abduction, 35 FF, 20 IR “In relation to the thorax, the following arm positions were selected for arthrodesis (range): abduction, 20° to 60°; anteversion, 20° to 40°; internal rotation 0° to 50°; and no external rotation.” The shoulder needs to be fused in a position of function, with mid-abduction and enough forward flexion and internal rotation so that his hand can reach his mouth.

Question 155

What prosthetic factor has the most impact on decreasing the rate of scapular notching in a Grammont-style reverse total shoulder arthroplasty?

Answer 155

**Inferior positioning of glenoid component** A low position of the glenoid base plate has been shown to have the greatest effect on decreasing scapular notching with a Grammont-style prosthesis. Scapular notching is the phenomena seen after reverse total shoulder arthroplasty when bone along the inferior scapular neck is lost. It is thought to be the result of repeated contact between the humeral component and the bone. The Grammont-style reverse total shoulder arthroplasty has a medialized center of rotation that decreases strain at the glenoid component but has less space for the humerus to clear the scapula. Scapular notching was seen least in components that are placed low on the glenoid. Posterior and inferior tilt has minimal effect on scapular notching and may even increase notching by bringing the humerus closer to the scapula. The use of locking screws and a cemented humeral stem had no influence on notching.

Question 156

Contraindications for rev TSA

Question 157

While performing a total shoulder arthroplasty, excessive retraction is placed on the "strap muscles" (short head of biceps and coracobrachialis). Neurovascular examination would reveal weakness of which of the following?

Answer 157

**Forearm Supination, elbow flexion** The musculocutaneous nerve can be as close as 3 cm to the coracoid process; therefore, this relationship is important to keep in mind when performing surgery in this area. Excessive traction on the musculocutaneous nerve could lead to a neurapraxia with resultant weakness of elbow flexion and forearm supinaton because of the loss of biceps function.

Question 158

Reverse total shoulder arthroplasty improves kinematics in the rotator cuff deficient joint by what directional change to the center of rotation?

Answer 158

Medial ## Footnote Surgical indications for reverse total shoulder arthroplasty are expanding. In the setting of rotator cuff tear arthropathy in which the native humeral head migrates superiorly, these implants impart several kinematic advantages. Implant center of rotation medial to the former joint surface improves glenoid component stability as the resultant force vector passes through the component throughout the arc of motion. A stable and fixed fulcrum for elevation is provided by matched radius of curvature between the glenoid and humeral components. A more distal center of rotation increases resting length and tone of the deltoid muscle, improving its effectiveness as a shoulder elevator. Medialized joint center of rotation increases the moment arm of the deltoid, requiring less muscle force to produce a given torque. This results in decreased articular shear stress.

Question 159

During TSA, If the fracture occurs at the greater tuberosity...

Answer 159

If the fracture occurs at the greater tuberosity, cerclage suture fixation of the tuberosity fracture with autogenous cancellous bone graft from the resected humeral head is the treatment of choice. The risk of intraoperative fracture in osteoporotic bone in patients with rheumatoid arthritis is significant. Fractures most often occur during humeral head dislocation and positioning for canal reaming.

Question 160

A 74-year-old woman with rheumatoid arthritis reports shoulder pain that has failed to respond to nonsurgical management. AP and axillary radiographs are shown in Figures 1 and 2. Examination reveals active forward elevation to 120 degrees and external rotation to 30 degrees. What treatment option results in the most predictable pain relief and function?

Answer 160

**Total shoulder arthroplasty with a cemented all-polyethelene glenoid component** Most studies have shown that total shoulder arthroplasties yield better pain relief and improved forward elevation when compared to hemiarthroplasty in patients with rheumatoid arthritis. Although rotator cuff tears are more common in this patient population, this patient has good forward elevation and no significant superior migration of the humeral head; therefore, a reverse arthroplasty is not indicated. The arthritis is too advanced in this patient to consider arthroscopy, but in less advanced cases it can improve range of motion and decrease pain. Metal-backed glenoid components have shown higher rates of loosening.

Question 161

A healthy 64-year-old man just underwent an uncomplicated shoulder arthroplasty for severe glenohumeral osteoarthritis. Intraoperatively, 60 degrees of external rotation was obtained. Postoperatively, he starts on a range-of-motion program. What limitations are recommended?

Answer 161

**Limit external rotation to the side to 60 degrees for the first 6 weeks.** The patient needs restrictions on his external rotation to allow healing of the subscapularis tendon repair. Limitation to 60 degrees is common if the tendon repair is robust and shows no evidence of tension on range-of-motion testing during the surgery. Restriction from external rotation stretching for even 3 weeks would compromise his ultimate functional recovery.

Question 163

What is the most important stabilizing mechanism in the midrange of motion of the glenohumeral joint?

Answer 163

Concavity compression is a stabilizing mechanism by which muscular compression of the humeral head into the glenoid fossa stabilizes the glenohumeral joint against shear forces. This is dependent on the depth of the concavity and the magnitude of the compressive force.

Question 164

An extended head hemiarthroplasty (rotator cuff tear arthropathy head) has what theoretic advantage when compared to a standard hemiarthroplasty?

Answer 164

Creates a metal-to-bone articulation with the acromion The theoretic advantage of a metal-to-bone articulation with the acromion is that there is a greater arc in which a smooth metal surface contacts the glenoid and acromion. This may improve pain and function, but no studies have evaluated this to date. One study showed results comparable to that of a standard hemiarthroplasty. There are no other biomechanic advantages.

Question 165

complications after rTSA

Answer 165

* Notching * instability, 4.7% cummulative incidence of dislocation * Acromial spine fractures, 4%, attributed to osteoporosis, increased glenoid offset, smaller humeral lateral offset, increased arm lengthening, thinner acromion. avg occurence post op 8 months * infection, 3.8% c.acnes * Higher risk of nerve injury compared to TSA, female patients and previous surgery had higher rates. * Glenoid component loosening is a rare complication after RSA and can be minimized via adequate baseplate support and fixation.

Question 166

Figures 1 and 2 are the radiographs of a 73-year-old man who was diagnosed with cuff tear arthropathy and underwent reverse shoulder arthroplasty. Two weeks after surgery with the shoulder still in the sling the patient turned suddenly and noted increasing pain and abnormal contour of the shoulder. He went to the emergency department and his radiograph is shown in Figure 3. What is the best definitive treatment option?

Answer 166

Glenoid revision ## Footnote The patient has the preoperative diagnosis of cuff tear arthroplasty and underwent reverse shoulder arthroplasty. The immediate postoperative radiographs reveal the inferior glenoid is not covered by the glenosphere and the humerus is not centered on the glenosphere. These finding indicate bony impingement between the inferior glenoid and inferior humeral polyethylene. He dislocated easily in the immediate postoperative period indicating impingement rather than tension as the cause of instability. The only effective treatment for would be revision of the glenosphere to completely cover the glenoid and eliminate the bony impingement.