Shoulder & Elbow Flashcards
Most common nerve injury from elbow arthroscopy?
Transient ulnar nerve palsy.
Lateral elbow arthroscopy portals?
For elbow arthroscopy what is the location of proximal anterolateral portal and nerve at risk?
1-2 cm proximal and 1 cm anterior to lateral epicondyle
Radial nerve. Risk decreases as portal moved more proximally.
For elbow arthroscopy what is the distal anterolateral portal location and nerve at risk?
1 cm anterior and 1-3cm distal to lateral epicondyle
Radial nerve and lateral antebrachial cutaneous nerve.
For elbow arthroscopy what is the location of direct lateral (mid-lateral) portal and nerve at risk?
“soft spot” portal (in triangle formed by olecranon, radial head, epicondyle)
relatively safe, lateral antebrachial cutaneous nerve
Visualize medial elbow arthroscopy portals.
In elbow arthroscopy what is the location of the anteromedial portal? What nerve is at risk?
2 cm anterior and 2cm distal to medial epicondyle.
Medial antrebrachial cutaneous nerve and median nerve.
In elbow arthroscopy what is the location of the superiormedial portal? What sturcture is at risk?
2cm proximal to medial epicondyle, anterior to intermuscular septum.
Medial antrebrachial cutaneous nerve. Ulnar nerve 3-4mm away. Median nerve.
In elbow arthroscopy location of the straight posterior portal?
Structures at risk?
3cm proximal to olecranon, triceps midline (musculotend. junction).
Posterior antebrachial cutanous nerve and ulnar nerve.
In elbow arthroscpy what is an alternative that provides better posterior compartment visualization than the straight posterior portal?
Posterolateral -2-3 cm proximal to olecranon and just lateral to triceps. Center of anconeus triangle.
Structures at risk are posterior antebrachial cutaneous nerve, ulnar nerve, and medial brachail cutaneous nerve.
Contraindication to elbow arthroscopy?
Prior ulnar nevrve transposition.
What portal should generally be avoided in elbow arthroscopy?
Posteromedial.
Which total elbow design has the best results?
semi-constrained or “linked”. Sloppy hinge to reduce stress on the bone cement interface. Conrad-Moorey design is an example of this.
How long should you immbolizie a limb after TEA?
4 weeks. Early mobilization is associated with wound complications and early component loosening.
What is the most common mode of failure for a semi-constrained elbow?
Constrained?
Instability.
Aseptic loosening.
Apporaches for TEA?
Tri-ceps splitting, tri-ceps reflection, or tri-ceps sparing (difficult but ok for very distal humerus fractures)
Relative contraindication to unconstrained TEA?
Lates stage rheumatoid arthritis. Distended capsule, bone erosions, and ligamentous compromise make this option likely to be unstable.
15 yr survival of TEA in rheumatoid patients?
90%
Risk factors for little leaguers elbow?
Greater than recommended pitch count for age:
50 pitches for 8-10 year olds. Goes up by 10-15 pitches every 2 years.
More than 8 months of pitching per year.
Fastball speed > 85 mph.
More than 2 games per week.
Pitching when having pain or fatigued.
Participating in showcases
What elbow motion is necessary for a patient to perform ADLs?
Need 100 degree arc of motion.
Up to 30 degree loss of extension is well tolerated in most patients.
50-50 prono-supination.
Flexion loss casues more dysfunction than extension loss.
Which ligament contracture is involved in elbow stiffness?
Posterior oblique portion of the medial ulnar collateral ligament.
Seen when flexion is less than 90-100 degrees.
Primary ligaments of the elbow?
Medial ulnar collateral ligament.
Radial collateral ligament.
Annular ligament.
Two categories for pathoanatomy of elbow stiffness and contracture?
Intrinsic causes: within the joint such as loose bodies, intra-articular fractures, arthritis, and joint incongruity.
Extrinsic causes: without the joint such as eschar, HO, capsular contraction and ligament conracture.
First line of treatment for elbow contractures?
How long?
Supervised exercise therapy with static elbow splinting over a 6 month period.
Injury to what elbow structure lead to a positive pivot shift of the elbow.?
Lateral ulnar collateral ligament. Insufficiency of this ligament leads to posterolateral rotatory instability.
Most common type of elbow arthritis?
Rheumatoid arthritis.
20-50% of rheumatoid patients have elbow involvement.
Primary stabilizers of the elbow.
Anterior band of MCL. Anterior oblique fibers are most important.
LCL
Articular congruity between trochlea, coronoid, and olecranon.
Contraindication to TEA?
Prior ulnar nerve transposition.
Charcot joint.
Age <65 in active patients.
Individuals most likely to have primary OA of the elbow?
Middle Aged laborers.
Men 4:1
Option for young and active patient with end stage elbow arthritis?
Ulnar humeral distraction interposition arthroplasty
Outerbridge-Kashiwagie Procedure (olecranon fossa debridement).
What procedure is best for relieving pain in a young patient with symptomatic elbow arthrits that has failed non-operative treatment?
What procedure is best for improving elbow ROM in a young patient with symptomatic elbow arthritis that has failed non-operative treatment?
Arthroscopic debridement
Open debridement
Who usually gets osteochondritis dessicans of the elbow?
Children over 10.
Boys > Girls
Gymnasts and throwing athletes
Where is osteochondritis dessicans of the elbow most commonly found?
Capitellum
What is Panner’s Disease?
Osteochondrosis of the capitellum in children < 10 years old.
Involves the entire ossific nucleus of the capitellum not just an area.
Surgery not recommended. Benign and self-limiting.
Presentation of OCD of the elbow?
Insidious activity related onset.
Lateral elbow pain.
Early mild loss of extension.
Small effussion.
Catching, crepitus, and locking is a late finding.
Three types of OCD lesions in elbow.
Type I: Intact cartilage, bony stability may or may not be present.
Type 2: cartilage fracture, with bony collapse or displacement.
Type 3: Loose bodies in joint
Non-operative treatment of OCD lesion of the elbow.
Cessation of activities for 3-6 weeks. +/- immobilization.
Gradual return to activities over 6-12 weeks.
This is for stable type I lesions
Return to activity after microfracture or cartilage fixation of elbow OCD?
Early protected ROM
Strengthening at 2 months
No throwing or weight bearing until 4-6 months.
Another potential cause for lateral elbow pain in a child other than OCD that does not typically cause an effussion?
Plica
Eccentric overload at the origin of which tendon causes lateral epicondylitis?
ECRB
May also involve ECRL and ECU
What does microscopic evaluation of tissue involved in lateral epicondylitis show?
Angiofibroblastic hyperplasia
disorganzied collagen
What condition can be associated 5% of the time with lateral epicondyltis?
radial tunnel syndrome
PIN enters the supinator just distal to the radial head.
What tendons are involved in the common extensor wad?
ECRB, ECRL, ED, ECU, and Aconeus.
Anconeus shares the same attachment site as ECRB at the lateral epicondyle.
Success rate of non-operative treatment of lateral epicondylitis?
How long before considering operative treatment?
95%
At least 6 months.
Where is the ECRB located in relation to the ECRL
Whend debriding ECRB what is the risk of extending beyone the equator of the radial head?
Deep and Posterior
LUCL injury.
What is the treatment of choice for lateral epicondylitis?
Physical therapy.
Should perfrom Eccentric exercises.
What muscles are included in the flexor pronator mass?
What is their innervation?
Pronator teres ( median)
FCR (median)
FDS (median)
Palmaris Longus (median)
FCU (ulnar)
What is a commonly associated condition of medial epicondylitis?
What condition needs to be ruled out?
Ulnar neuritis
UCL injury or incompetency
What are complications of corticosteroid injections in peritendinous tissues
Skin depigmentation
Subcutaneous atrophy
Tendon weakening
Ulnar nerve injury
What is valgus extension overload?
Posteriormedial elbow pain common in throwing athletes.
Can lead to MCL becoming attenuated, loose bodies, capitellum
What condition is most associated with Pitchers Elbow?
Cubital tunnel syndrome 25% of the time.
When does pain typically occure with pitchers elbow?
Deceleration phase.
Will find loss of terminal elbow extension.
What is the most common finding on plain films for a patient with valgus extension overload?
Osteophyte formation in the posteromedial olecranon fossa.
What is the operative treatment for valgus extension overload?
What is a potential complication?
Resection of posteromedial osteophytes, removal of loose bodies, and debridement of chondromalacia?
Resection of olecranon leading to loss of bony restraint, increased tension in the MCL and possible valgus instability .Care should be taken to only resect osteophytes and not normal olecranon.
How do you test for valgus instability of the elbow?
Milking Maneuver.
Bend elbow to 90 degrees and pull the thumb laterally.
How do you perform a lateral pivot-shift test of the elbow?
Patient supine with affected arm overhead.
Supinate forearm and apply valgus stress to the elbow while bringing it from full extension to 40 degrees of flexion.
What are the bundles of the MCL of th elbow?
What are their stability roles?
Anterior and posterior bundles. (Also known as anterior and posterior oblique ligament). Anterior bundle is subdivided into anterior and posterior bands.
Anterior band is the primary restraint to valgus stress at 30-120 degrees. isometric during elbow ROM.
The posterior band is the primary restraint at 120 or more degrees.
Transverse ligament is the third portion and has no contribution to stability.
Where does a partial distal biceps avulsion occur?
Radial side of the tuberosity footprint.
What are the two distinct origins, insertions, and primary fuctions of the bicep?
Short Head: O- coracoid process I- distally on radial tuberosity, better flexor.
Long Head: O-superior glenoid and glenoid labrum I-Proximally on radial tuberosity (oval footprint), better supinator.
How much strength is lost with a distal biceps avulsion?
50% supination sustainted
40% supination
30% flexion
15% grip strength
When considering surgical repair for a distal biceps rupture:
Can you hyperflex to acheive fixation?
Do subacute and chronic repairs require direct repair or allograft augementation?
Ok to hyperflex. No loss of motion, nor does it lead to flexion contracture.
Still can perfrom direct repair without allograft.
What nerve injury is most common in distal biceps reconstruction?
Lateral antebrachial cuntaneous nerve.
Caused by too much retraction.
Typically resolves in 3-6 months.
More common with the single incision technique
What internal is used for a single anterior incision distal biceps repair technique?
If using a two incision technique what posterior interval is used?
Brachioradialis and pronator teres
ECU and EDU. Do not use interval between ECU/Anconeus and Anconeus and Ulna. Exposing the ulna can lead to HO.
How to you avoid PIN injury in distal biceps repair?
Avoid forceful lateral retracion.
Maintain supination, especially when drilling beath pin.
In wich phases of throwing is the most valgus stress placed on the elbow?
- Acceleration phase (early)
- late cocking
How do elbow MCL injuries typically present if they aren’t traumatic.
loss of velocity and accuracy.
Medial or posterior pain with late cocking and early acceleration.
Should be distinguished from posteromedial pain that is felt during deceleration phase that is seen with valgus extension overload.
Differentiate VPMRI and VPLRI of the elbow?
What is the first line of treatment for MCL injury in throwers.
6 weeks of no activity withthrowing for flexor-pronator strengthening.
Which method of anterior band MCL reconstruction is best?
Humeral docking is stronger, has higher rate of return to sports, and lower complication rates.
Still only 95% strenght of native ligament.
Autograft favored. palmaris longus, gracilis if they don’t have one.
Early motion. Strengthening at 6 weeks. No valgus stess until 4 months. Takes 9-12 months to return to throwing.
What is the biomechanical mechanism that leads to LCL injury and PLRI of th elbow?
forearm supination, axial loading, valgus(posterolateral stress), and elbow extension.
This leads to progressive failure of lateral collateral ligament complex and the anterior capsule.
What makes up the LCL Complex?
- Accessory lateral collateral ligament.
- Annular ligament.
- Lateral radial collateral ligament.
- Lateral ulnar collateral ligament. Primary stabilizer to varus and ER stress. O-lateral epicondyle I-tubercle of supinator crest of ulna.
Causes other than traumatic for PLRI of the elbow?
Iatrogenic injury: Any procedures that go posterior to the equator of the radial head.
Chronic attenuation: seen from cubitus varus malunion.
Non-operative treatment for acute elbow dislocations?
Immobilize for 5-7 days.
Depending on stability may use extension block. Progress by 30 degrees of extension weekly with forearm in full pronation.
Graft Configuration for LUCL Complex Reconstruction.
tunnel through supinator crest and Y tunnel thorugh humerus.
Graft needs to cover more than 25% of the radial head to create a sling.
Graft secured with arm in neutral rotation and 45 degrees of flexion.
Can tie sutures over bone or use interference screws.
What happens to the center of rotation in a reverse shoulder arthroplasty?
It is moved inferior and medialized.
This allows the deltoid muscle to act on a longer fulcrum.
What is a absolute contraindication to reverse shoulder arthroplasty?
Axillary nerve palsy or deltoid deficiency.
Where should the baseplate be positioned in a reverse shoulder arthroplasy?
Inferiorly with inferior tilt.
Shown to decrease implant loosening and scapular notching.
What intraoperative event increases the risk of post-op dislocation in reverse shoulder arthroplasty?
Failing to repair the subscaularis.
What is the most common cause of revision surgery in reverse shoulder arthroplasty?
Prosthetic loosening.
What is the position for shoulder arthrodesis?
30-30-30
30 Abduction
30 forward flexion
30 internal rotation
Indications for shoulder arthrodesis?
stabilization of paralytic disorders.
brachial plexus palsy.
salvage of failed shoulder arthroplasty.
Recurrent shoulder instability.
Painful ankyloses after chronic infection.
Irreparable deltoid and rotator cuff deficiency with arthropathy.
Contrainidications to shoulder arthroplasty?
ipsilateral elbow or contralateral shoulder arthrodesis.
Lack of functional scapulothoracic motion.
trapezius, levator scapulae, or serratus anterior paralysis.
Charcot arthropathy during acute stages.
Progressive neurologic disease.
Elderly patients.
When do you consider doing a hemiarthroplasty over a reverse total shoulder?
If the patient can acheive forward flexion > 90 degrees and the rotator cuff is deficient.
indications for hemiarthroplasty?
Osteonecrosis of humeral head only.
proximal humerus fracture.
Primary arthritis if glenoid bone stock is inadequate or risk of glenoid loosening is high (young active laborers).
Contraindication specific to hemiarthroplasty?
Coracoacromial ligament deficiency.
This is a barier to proximal migration in cases where the rotator cuff is deficient.
Superior escape will occur if both coracoacromial ligament and rotator cuff are deficient.
What is ideal retroversion in hemiarthroplasty and total shoulder arthroplasty?
30 degrees.
What happens if the tuberosity is not properly reduced in shoulder arthroplasty?
What movement will be compromised if the lesser tuberosity is placed to laterally?
deficit in rotation.
Subscapularis will be on more tension, this will lead to less external rotation.
What kind of organism is prpionibacterium acnes?
How long can it take for cultures to become positive?
anaerobic organism.
7-21 days.
What is Wright’s Test?
Test for thoracic outlet syndrome.
Palpate radial pulse.
Patient rotates neck away from side being tested.
Examiner rotates and maximally abducts the shoulder. Holding the arm above the level of the head for 1 minute.
Positive test is reduction in amplitude or loss of radial pulse. Reproduction of pain or paresthesias.
What is the hornblower’s test?
Abducting shoulder to 90 and external rotation 90 degrees.
If the shoulder falls into internal rotation it may represent teres minor pathology.
What nerve is most at risk with a Latarjet procedure?
Musculocutaneous nerve.
The Axillary nerve can also be injured especially during graft fixation but its less common.
Most common location of ulnar nerve compression?
Between the two heads of the FCU.
What provides the majority of stability to the elbow from 0-25 degrees?
Olecranon (bony restraint)
What injuries do the Snyder and Maffet classifications describe?
SLAP tears.
Which rotator cuff tendon is most commonly torn in older patients with anterior shoulder dislocations?
Supraspinatus.
Subscapularis tears are more common in posterior dislocations.
What is associated with inferior scapular notching?
Superior placement of the glenosphere.
Inadequate inferior tilt.
Superior glenoid errosion presdisposes to both of the above.
Superolateral approach.
What classifies glenohumeral internal rotation deficit (GIRD)
Decrease in internal rotation of 25 degrees or more of the affected shoulder compared to the contralateral side.
What injury will you see axillary webbing with?
Pectoralis major rupture.
What is a common physical exam fidning in patients with multidirectional instability?
Increaed external rotation in adduction.
What is SICK scapula syndrome?
Scapular malposition, Inferior medial border prominence, Coracoid pain and malposition with dysKinesis of scapular movement.
The pectoralis minor tendon can contract secondary to scapular malpositioning leading to significant tendonitis and pain.
What portion of the labrum is most susceptible to vascular insufficiency?
Anterior superior portion.
An inverted pear shaped glenoid is indicative of what?
Severe Glenoid bone loss.
Greatly increases the risk of instability even after labral repair.
What is the orientation of the humeral head relative to the transepicondylar axis of the distal humerus?
What is the neck shaft angle?
Retroverted 30 degrees
130-140 degrees
Where should the greater tuberosity be postioned relative to the humeral canal axis?
Upper edge of the humeral head?
medial edge of greater tuberosity should be 10mm lateral to humeral canal.
Superior edge of tuberosity is 6mm inferior to upper edge of humeral head.
What is the importance of a MRI prior to surgery for a proximal humerus fracture malunion?
Status of rotator cuff and labrum
Look for any delotid atropy secondary to axillary nerve injury
Long head biceps injury
Any osteonecrosis
What are some surgical techniues for minor proximal humerus head deformities when an osteotomy is not indicated?
Arthroscopic tuberoplasty
acromioplasty
capsular release
bursectomy
What amount of greater tuberosity displacement/malunion in a proximal huemrus malunion warrants an osteotomy?
> 1.5cm should do osteotomy with subacromial decompression.
What degree of greater tuberosity displacement will lead to altered rotator cuff biomechanics?
>5 mm
What is the most common complications following posterior labral repair?
Stiffness due to immobilization and scar tissue formation.
2nd most common complications is recurrent posterior instability.
What is considered normal vertebral height acheived on internal rotation of the shoulder?
T4-T8
What is a t Sign test?
Used to test for impingement of rotator cuff tendon/bursa against the coracoacromial arch. However, stiffness, OA, instability, and bone lesions can also produce a positive test.
TECHNIQUE: Use one hand to prevent motion of the scapula. Raise the arm of the patient. Pain is elicited as greater tuberosity impines agianst the acromion (often between 70-11 degrees). Patients must have full range of motion for a postive finding.
Neer Impingement Test- Perform the same test above following a subacromial lidocaine injection. Considered positive if there is redcuiton in pain.
How do you perform a Hawkin’s Test and what is it used for?
Positive with impingement.
Peformed by flexing shoulder to 90 degrees, flex elbow to 90 degrees, and forcibly internally rotate driving the greater tuberosity farther under the CA ligament.
How do you perform a Jobe’s Test and what can it test for?
Abduct arm to 90 degrees, angle forward 30 degrees (bringing it into the scapular plane), and internally rotate (thumb pointing to floor).
Then press down on arm while patient attempts to maintain position. Positive test is weakness and pain.
Tests for supraspinatus weakness and IMPINGEMENT.
How do you perform an internal impingement test?
Regarding testing of subscapularis:
Which test is most sensitive and specific?
Which test is more accurate for inferior portion of subscapularis?
Which test is more accurate for superior portion of subscapularis?
Internal Rotation Lag Sign- Where patients hand is brought begind their back and lifted 20 degrees from the lumbar spine and then asked to hold it there.
Lift off test
Belly Press test
How do you perform a bear hug test?
Patient places ipsilateral palm on opposite deltoid and tries to resist the examiner pulling it away anteriorly.
Positive if at least 20% weaker than contralateral side.
Tests subscapularis.
How do you test the infraspinatus?
Strength is tested by testing external rotation strength while the arm is in at the side and neutral internal and external rotation.
External rotation lag sign- passively flex the elbow to 90 degrees. Holding wrist to rotate the shoulder to maximla external rotation. Tell the patient to hold the arm in that externally rotated position. If the arm starts to drift into internal rotation it is positive.
How do you test the teres minor?
Test external rotation strength with the arm held in 90 degrees of abduction.
Hornblower’s sign- Bring the shoulder to 90 dgrees of abduction, 90 degrees of external rotation and ask the patient to hold this position.
Positive if the arm falls into internal rotation. It may represent teres minor pathology.
What is a crank test?
Tests for labral injuries or SLAP lesions.
Hold the patient;s arm in an abducted position and apply passive rotation and axial rotation.
Positive when there is clicking or pain in the glenohumeral joint. .
What is an O’Brien’s Test?
What does it test for?
Also known as an active compression test.
Tests for labral injuries and slap lesions. Also test for AC joint pathology.
Positive when ther is pain over the AC joint when pronated or deep in the glenohumeral joint, but no when the forearm is supinated.
Pateint forward flexes the affected arm to 90 degrees while keeping the elbow fully extended. The arm is then adducted 10-15 degrees across the body. The patient then pronates the forearm so the thumb is pointing down. The examiner applies downward force to the wrist while the arm is in this position while the patients resists. Then down with the patient supinating the forearm.
How do you test for anterior shoulder instability?
How do you test for posterior shoulder instability?
What is a sulcus sign?
How is it graded?
Used to diagnose multidirectional instability (MDI)
Have the patient stand relaxed with their arms at their side. Grab the affected arm and pull it inferiorly. If there is a sulcus that forms at the superior aspect of the humerla heat, the test is positive.
Sulcus is considered positive if it stays increased (2+ or 3+) with ER at side (pathologic rotator interval.
SULCUS GRADING: 1+ acromiohumeral interval <1cm
2+ acromiohumeral interval 1-2cm
3+ acromiohumeral interval > 2cm
What provides horizontal stability to the AC joint?
What provides vertical stability?
horizontal- acromioclavicular ligament. Superior, inferior, anterior, and posterior components. Superior ligament is strongest, followed by posterior.
vertical- Coracoclavicular ligament. Conoid (inserts 4.5 cm from end of clavicle) and Trapezoid (inserts 3cm from end of clavicle).
Conoid is the more important of the two.
What is a normal coracoclavicular distance?
superior coracoid to inferior clavicle is 11-13mm
When fully abducting your shoulder what two joints allow that motion and how much does each contribute?
2:1 ratio of glenohumeral joint and scapulothoracic joint.
120 degrees from the former and 60 degrees from the latter.
What are the three attachements to the coracoid?
coracobrachialis, pectoralis minor, and short head of the biceps attach to the coracoid.
What is the normal version of the humeral head and the glenoid?
HUMERAL HEAD- approximate retroversion of 20 degrees from the transepicondylar axis of the distal humerus.
Articular surface inclined upward 130 degrees from the shaft.
GLENOID- pear shaped surface with average upward tilt of 5 degrees
Average 5 degrees of retroversion in relation to the axis of the scapular body. However, it varies from 7 degrees of retroversion to 10 degrees of anteversion.
What structures pass through the rotator interval?
Long head of the biceps tendon, coracohumeral and superior glenohumeral ligament.s
What are the boundaries of the rotator internval?
Medially by lateral coracoid base
Superiorly by anterior edge of supraspinatus
Inferiorly by superior border of subscapularis
Lateral apex formed by transverse humeral ligament
Describe the glenohumeral ligaments and their restraints in different arm positions.
What does the anterior labrum anchor within the shoulder?
anchors IGHL
This is the weak link that leads to bankart lesions
What are the various anatomic variatns of the glenoid labrum?
Normal Variant 86%
Sublabral foramen 12%
Sublabral foramen + cordlike MGHL
Buford Complex (absent anterosuperios labrum + cordlike MGHL 1.5%. Cordlike middle glenohumeral ligament with attachement ot base of biceps anchor and complete absence of the anterosuperior labrum.
Attaching a Buford complex will lead to painful and restricted external rotation and elevation?
What are common findings on radiographs in subacromial impingement?
Proximal migration of the humerus
Traction osteophytes
Calcification of the coracoacromial ligament
Cystic changes within the greater tuberosity
Type III-hooked acromion
Os acromiale- seen well on scapular Y. See image.
What are the three ossification centers of the acromion?
Meta-acromion (base): origin of posterior portion of deltoid
Meso-acromion (mid): Origin of middle deltoid
Pre-acromion (tip): Origin of anterior deltoid fibers and coracoacromial ligament
Blood supply is acromiale branch of thoracoacromial artery.
What treatment is recomended for os acromiale?
At what phase of the throwing cycle are athletes at risk for rotator cuff tears?
Deceleration phase.
Must susceptible to tensile failure due to eccentric loading during this phase.
partial thickness rotator cuff tears seen from internal impingement.
What is the rotator cable and crescent?
Rotator crescent: is a thin, crescent-shaped sheet of rotator cuff comprising the distal portions of the supraspinatus insertions. The cresecent is bounded at its proximal margin by a thick bundle of fibers called the rotator cable.
What is the tangent sign with regards to rotator cuff pathology?
Failure of the supraspinatus to cross a line drawn between the superior borders of the scapular spine and coracoid process on a sagittal MRI slice.
What is a PASTA lesion?
Articular sided rotator cuff tear where tendon is avulsed from the bone.
>7mm of exposed bony footprint wetween articular surface and intact tendon represents significant (>50%) cuff tear.
What two tendons attatch to the superolateral margin of the subscapularis tendon?
Coracohumeral and superior glenohumeral ligaments
Marked by the asterisk in the image.
Useful because the subscap becomes scarred to deltoid fascia making it hard to identify.
The coracohumeral and superior glenohumeral ligaments form a complex otherwise known as a comma sign that can be used to identify the scarred and rectracted subscap tendon.
What is another cause of biceps subluxation other than subscap tears?
Disruption of the biceps sling.
Comprised of: fibers of the subscapularis, supraspinatus, coracohumeral ligament, and superior glenohumeral ligaments.
What view is needed besieds AP and Axillary lateral to evaluate the AC joint?
Zanca View- performed by tilting the x-ray beam 10-15 degrees cephalad and using only 50% of the standard shoulder AP penetrance.
This view is not needed but useful to know about. Basmania- scapular Y with cross-body adduction stress to look for instability.
What is the Rockwood Classification of AC joint injuries?
What causes distal clavicle osteolysis?
Repetitive stress and micro-fracture that leads to osteopenia.
Most patients are males in their 20s. Common in weight lifters.
Differentiated from AC joint arthritis by lack of acromial involvement on radiographs. Will see cysts, osteopenia, resorption/erosion and tapering of the distal clavicle.
What injury does this image dipict?
HAGL- Humeral avulsion of the glenohumeral ligament.
Describe the instability severity score for the shoulder?
What are the physical exam findings found or helpfult signs in a patinet with shoulder instability?
What lesions are associated with posterior shoulder instability?
What provocative tests can be performed in the setting of chronic posterior instability?
What may a lightbulb sign on AP radiograph of the shoulder be indicative of.
Posterior shoulder dislocation.
What is Beighton’s criteria?
9 point scoring system for hypermobility.
Score greater than 4 is associated with multidirectional instability of the shoulder.
Score greater than 6 is associated with connective tissue disorders such as Marfan’s and Ehlers-Danlos Syndrome.
What is the classification system for SLAP tears?
What is the most common type?
Snyder Classification: original classification which includes Types I-IV in the image.
Maffet sub-classification: Includes the original I-IV and added Types V-VII.
Most common is Type II. Labral fraying with detached biceps tendon anchor. 41% of the time.
For SLAP lesions that have failed non-operative treatment which undergo arthroscopic debridement?
Which undergo debridement with repair of the labrum and biceps.
Which undergo debridement labral repair and biceps tenotomy/tenodesis?
Types I, III, and IV involving < 1.3rd of the cieps tendon -> Arthroscopic debridement
Type 2 tears -> Arthroscopic debridement with repair of the labrum/biceps. Highly controversial. General consensus is to perfrom tenotomy for those over 40 years of age. These are traditionally found in overhead athletes. Return to play rates after SLAP repairs are significantly lower for pitchers compared to non-pitchers.
Type I, II, and IV tears with >1/3rd of the biceps tendon -> Arthroscopic debridement with repair of debridement of the labrum with biceps tenotomy/tenodesis.
What is the difference between internal impingement and external impingement (subacromial)?
Subacromial or “external” impingement occurs on bursal side of rotator cuff.
Internal impingement occurs on the articular side.
Caused by repetitive impingement of posterior under-surface of supraspinatus tendon and greater tuberosity.
Pathologic micromotion of the humeral head allows the rotator cuff to become impinged between the greater tuberosity and the glenoid.
Assuming this is an atraumatic injury that occured over time what does this image depict?
Bennett Lesion (exostosis of posteroinferior glenoid)
Seen in internal impingement.
What are some of the image findings consistent with internal impingement?
Radiographs may show a Bennett lesion.
MRI or MR arthrogram.
Can show pathology of the rotator cuff and/or labral pathology:
Partial articular-sided supraspinatus-infraspinatus tendon avulsion (PASTA), fraying, or tear.
Signal at greater tuberosity and/or posterosuperior labrum.
Treatment for internal shoulder impingement?
What are the various eponyms for Brachial Neuritis?
Parsonage-Turner Syndrome
Scapular winging whn long thoracic nerve involved.
Neuraligc amyotrophy (HNA) or idiopathic neuralgic amyotrophy (INA)
Acute brachial neuropathy/ neuritis/ plexopathy /plexitis
Idiopathic brachial plexus neuropathy/ neuritis
What is more common medial or lateral scapular winging?
Describe each?
Medial scapular winging.
Type of scapular winging is defined by direction of the superomedial corner of the scapula.
Medial- dysfunction of serratus anterior (long thoracic nerve) leads to excessive medializing scapular retraction (rhomboid major and minor) and elevation (trapezius). usually in a young athletic patient.
Lateral- Dysfunction of the trapezius (cranial nerve XI- spinal accessory nerve) excessive lateralizing scapular protraction (serratus anterior, pectoralis major and minor). Usually iatrogenic (history of neck surgery)
Causes of Medial Scapular Winging?
What is most common?
While they can be mechanical such as traumatic avulsion of the serratus anterior or displaced fractures of the inferior pole of the scapula. The vast majority are neurologic and there are several different causes. Please see image.
Repetitive stretch injury is most common!
What are the two clinical types of brachial neurtis?
Idiopathic neuralgic amyotrophy- Unclear etiology, likely multifactorial with autoimmune, genetic, infectious, environmental, and biomechanical processes all playing a role.
Hereditary neuralgic amyotrophy- Very rare. 200 families worldwide. Autosomal dominant. Mutations in the gene Septin 9 on chromosome 17q24. Cytoskeleton protein highly expressed in glial cells in neuronal tissue.
DIFFERS FROM IDOPATHIC FORM: Dysmorphic features (short stature, hypotelorism, cleft palate, facial asymmetry, unusual skin folds).
Higher inicidence of recurrent episodes. Younger age of onset. Frequent involvement of nerve outside the brachial plexus. More severe paresis. Worse functional outcomes.
What are the three distinct spaces of thoracic outlet syndrome?
Interscalene triangle- contains brachial plexu trunks and subclavian artery.
costoclavicular space- contains brachial plexus divisions and subclavian artery and vein
retropectoralis minor space- contains brachial plexus cords and axillary artery and vein.
Provocative tests for thoracic outlet syndrome?
What are the borders of the Quadrilateral Space?
Triangular Space?
Triangular interval?
What may you see on imaging of a patient with quadrilateral space syndrome?
MRI- artrophy of teres minor (axillary innervation). Compression of quadrilateral space (see image). May show inferior paralabral cyst that is associated with a labral tear.
ARTERIOGRAM- may show lesions in posterior humeral circumflex artery.
EMG- used to confirm the diagnosis and will show axillary nerve involvement.
What is the treatment of avascular necrosis of the humeral head?
Normal x-rays and changes on MRI: Initially PT and conservative care. If no improvement then core decompression and arthroscopy ( confirm the integrity of cartilage)
If a crescent sign without collapse then humeral head resurfacing.
Collapse -> Hemiarthroplasty.
What is scapulothoracic dyskinesis?
What are the causes?
What is the pathoanatomy?
Also known as SICK scapula
Abnormal scapula motion leading to shoulder impingement and dysfunction.
Neurologic injury, pathologic thoracic spine kyphosis, periscapular muscle fatigue, poor throwing mechanics, secondary to pain (shoulder, neck)
Scapulothoracic power imbalance leads to protraction of scapula -> leads to alteration of mechanics at glenohumeral joint. Excessive stress placed on anterior capsule of shoulder and posterosuperior labrum.
Athletes have increased risk of injuring labrum, rotator cuff, and capsule.
Scapula may be lower and protracted as seen in image.
What radiograph is the best for visualizing hill sachs defects?
Stryker notch view.
obtained by positioning the patient supine with the arm flexed toward the celining, flexed at the elbow, and the patient’s hand placed on top of the head and the xray beam is directed anteroposterioly with 10 degrees of cephalic angulation.
