Shoulder Flashcards
What is the primary restraint to inferior translation of the shoulder at 0° degrees of abduction (neutral rotation)?
SGHL
What resists anterior and posterior translation in the midrange of abduction (~45°) in ER of the shoulder?
MGHL
In the shoulder, what is the primary restraint to anterior/inferior translation 90° abduction and maximum ER (late cocking phase of throwing)
anterior band IGHL
What is the most important static stabilizer of the shoulder joint?
superior band IGHL
What is the function of the superior band IGHL?
the most important static stabilizer about the shoulder joint
What is the composition of the glenoid labrum?
fibrocartilagineous tissue
What is a Buford complex?
A normal variant of the shoulder labrum; there is absence of the anterosuperior labrum with a cord-like MGHL that attaches to the long head of the biceps tendon
What happens if a Buford complex is attached?
Painful and limited ER and elevation
What is the approximate retroversion of the humeral head?
20 degrees
What is the average version of the glenoid?
average version is 5° of retroversion in relation to the axis of the scapular body and varies from 7° of retroversion to 10° of anteversion
What are the muscle attachments to the coracoid?
- coracobrachialis
- pectoralis minor
- short head of the biceps
What is the average acromiohumeral interval?
acromiohumeral interval is 7-8mm
What provides the blood supply to the humeral head?
The ascending branch of the anterior humeral circumflex artery and the posterior humeral circumflex artery (most current literature supports this as the main blood supply to the humeral head)
The rotator cuff experiences the greatest stress at which phase of throwing?
deceleration phase; eccentrically slowing the arm
Hornblower’s sign is indicative of what?
Teres minor injury
Anterior shoulder dislocations in patients older than 40 years may result in rotator cuff tears; what is the most commonly affected rotator cuff tendon?
Supraspinatus
What patient is the optimal candidate for a latissimus dorsi transfer?
young laborer with massive posterior/superior RCT, atrophy and fatty infiltration
What nerve is most at risk during pectoralis major tendon transfer?
Musculocutaneous
What nerve is most at risk during latissimus dorsi tendon transfer?
Radial nerve
What is the most common finding during arthroscopic surgery for traumatic anterior shoulder instability?
anteroinferior labral tear
What is the blood supply to the serratus anterior?
Long thoracic artery (superiorly); thoracodorsal artery (inferiorly)
What is the innervation of the trapezius?
Spinal accessory nerve (cranial nerve XI)
What is the innervation of the rhomboid muscles?
Dorsal scapular nerve
What are the contents of the quadrilateral space?
axillary nerve (C5) and posterior humeral circumflex artery
What is the innervation of teres minor?
axillary nerve
Suprascapular notch entrapment of the suprascapular nerve causes weakness in what muscle(s)?
supraspinatus and infraspinatus
Spinoglenoid notch entrapment of the suprascapular nerve causes weakness in what muscle(s)?
infraspinatus ONLY
What genetic mutation is associated with Parsonage-Turner syndrome?
gene septin 9 on chromosome 17q24
What are the soft tissue adaptations to glenohumeral internal rotation deficit (GIRD)?
increased sulcus sign, humeral head and glenoid retroversion, SLAP tears and articular sided partial RCTs; will see increased shoulder ER and a deficit in IR
What are the properties of C. acnes?
gram positive, facultative, aerotolerant, anaerobic rod that ferments lactose to propionic acid
What nerve roots supply the long thoracic nerve?
C5, C6, C7
The long thoracic nerve supplies which muscle?
Serratus anterior
Injury to the serratus anterior or long thoracic nerve causes what type of scapular winging?
Inferomedial scapular winging (the inferior and medial border to wing out as the serratus is not able to hold it lateral/anterior)
What is the innervation of the rhomboids?
Dorsal scapular nerve
The latissimus dorsi muscle is innervated by what nerve?
thoracodorsal nerve
What nerve innervates teres major?
lower subscapular nerve
Which nerve roots supply the dorsal scapular nerve?
C4 and C5 (mostly C5)
What nerve roots supply the thoracodorsal nerve?
C6-C8
Which nerve roots supply the suprascapular nerve?
C5 and C6
What are the anatomic boundaries of the rotator interval?
Superior: anterior border of the Supraspinatus tendon
Inferior: the superior border of the subscapularis
Medial: coracoid
Lateral: transverse humeral ligament
What are the contents within the rotator interval?
Long head of the biceps tendon; superior Glenohumeral ligament; coracohumeral ligaments
Which nerve could be injured during a latissimus dorsi transfer due to its proximity?
Radial nerve; it runs immediately deep (anterior) to LD tendon 3 cm medial to its insertion on the humerus
If someone has an internal rotation contracture of the shoulder, they can not abduct beyond […] degrees
120 degrees
What prevents anteroinferior translation of long head of biceps (biceps pulley)?
SGHL
In the shoulder, what is the most important restraint to posterior subluxation at 90° flexion and IR?
Posterior band of the IGHL
Tightness in the […] leads to internal impingement and increased shear forces on superior labrum in the shoulder
posterior band of the IGHL
Which band of the IGHL anchors into anterior labrum?
anterior
What is the origin and insertion of the coracohumeral ligament?
coracoid to rotator cable
The coracohumeral ligament limits […] translation with shoulder in flexion, adduction, and internal rotation
posterior
The glenoid labrum creates […] percent of the glenoid socket depth
50
Which region of the glenoid labrum has the poorest blood supply?
anterior-superior labrum
What is the medial boundary of the rotator interval?
coracoid
What is the superior boundary of the rotator interval?
Supraspinatus
What is the inferior boundary of the rotator interval?
Subscapularis
What is the lateral boundary to the rotator interval?
transverse humeral ligament
What is the average diameter of the humeral head?
43mm
The humeral head has an approximate retroversion of […] degrees from transepicondylar axis of the distal humerus
20
The humeral head articular surface inclined upward […] degrees from the shaft
130
The glenoid has an average upward tilt of […] degrees
5
What is the average version of the glenoid?
5° of retroversion
The ascending branch of anterior humeral circumflex artery runs along the […] aspect of the long head of the biceps in the bicipital groove
lateral
A sulcus sign of […] has a specificity of up to 97% for multidirectional instability
2 cm
What exam finding is most commonly associated with multidirectional instability?
Sulcus sign (great than 2 cm is very specific)
Acute SIT (supraspinatus, infraspinatus, teres minor) tears seen in patients greater than […] yrs with a shoulder dislocation
40
What pain symptom in rotator cuff tears is a poor indicator for non-operative management?
Pain at night
In asymptomatic patients 60 yrs and older, […] percent will have a RCT on MRI
55
Bursal-sided rotator cuff tears greater than […] mm depth is an indication for rotator cuff repair
3
Partial articular-side rotator cuff tears measuring greater than […] percent can be treated with tear completion and repair
50
Which tendon must be intact in order to perform a superior capsular reconstruction?
subscapularis
[…] transfer is best for irreparable posterosuperior cuff tears with intact subscapularis
Latissimus dorsi
Release of the coracoacromial ligament leads to […] translation of the glenohumeral joint.
anterior/inferior
What nerves are at risk during a latissimus dorsi transfer for cuff tears?
radial n and posterior branch of axillary nerve
Which nerve is at risk during the latissimus dorsi tenotomy for a latissimus d transfer?
radial nerve
Which nerve at risk during passage of latissimus dorsi tendon deep to deltoid to subacromial space in lat transfer?
posterior branch of axillary nerve
Most common cause of failed RCR is failure of cuff tissue to heal, resulting in […] from repaired tissue
suture pull out
What is the most common cause of rotator cuff repair failures?
Failure to heal, leading to suture pull out
Patient age greater than […] is a risk factor for rotator cuff repair failure
65
Rotator cuff tear size greater than […] cm is a risk factor for repair failure
5
What nerve can be injured in a pec major transfer?
Musculocutaneous
In a shoulder hemiarthroplasty, deficiency of the […] will lead to subcutaneous humeral escape
coracoacromial arch
The […] and […] AC ligaments are most important for AC joint stability
posterior; superior
Which coracoclavicular ligament is most important for vertical stability?
conoid
The trapezoid CC ligament attaches to the trapezoid tubercle, which is […] to the conoid tubercle
anterolateral
The conoid CC ligament attaches to the conoid tubercle, which is […] to the trapezoid tubercle
posteromedial
A Rockwood Type IV AC joint injury displaced posteriorly and becomes entrapped in the […] muscle
trapezius
What is a normal coracoclavicular (CC) distance?
11-13 mm
Which ligaments are affected by the so called “comma-sign” seen in shoulder arthroscopy?
SGHL and CHL; (demonstrates subscapularis tearing)
What is the gram stain of C acnes?
gram positive rod
The coracohumeral and superior glenohumeral ligaments form a complex that marks the superolateral margin of the […] tendon.
subscapularis
What is the innervation of teres major?
lower subscapular nerve
The lower subscapular nerve is a branch of what brachial plexus cord?
posterior
What is the innervation of teres minor?
Axillary nerve
Which ligaments compose the long head of the biceps sling?
SGHL and CHL
Bony bankart with greater than […] percent is considered “critical bone loss” and biomechanically unstable
> 20-25%
Greater tuberosity fractures are associated with anterior shoulder dislocation in patients greater than […] years of age
50
The abduction and external rotation (ABER) MRI sequences can be utilized to better visualize the […] glenoid labrum
antero-inferior
Arthroscopic Bankart repair requires how many suture anchors?
At least 4;
What is the primary restraint to shoulder internal rotation?
Posterior band of IGHL
What muscle is the primary dynamic restraint against posterior shoulder subluxation in external rotation?
Subscapularis
A Kim lesion of the shoulder is […] labral avulsion
posteroinferior
A […] month regimen of PT and dynamic stabilization trial is needed for multidirectional instability of the shoulder.
3-6
Closure of the […] produces the most significant decrease in shoulder range of motion in external rotation with the arm at the side
rotator interval
What is the most common finding during surgery for traumatic anterior shoulder instability?
Anterior inferior labral tear (Bankart lesion)
What ligament is affected by a HAGL lesion?
anterior band of IGHL
What is the best radiograph for identifying a Hill-Sachs lesion?
Stryker notch view
In multidirectional instability, the exam finding of an increase in shoulder external rotation in adduction corresponds with an incompetent […]
rotator interval
Patients with adhesive capsulitis that are younger than […] are at increased risk for bilateral disease
50
Adhesive capsulitis is commonly associated with what medical conditions?
Diabetes, thyroid disease
What type of collagen is abundantly present in adhesive capsulitis?
Type III
In a type B glenoid, the humeral head is subluxated […]
posteriorly
In a type B2 glenoid, the glenoid wear is most pronounced […]
posteroinferior
In a type B or C glenoid, what is the glenoid version?
retroverted
In a type D glenoid, what is the glenoid version?
anteverted
In a TSA with glenoid retroversion less than […] degrees, eccentrically ream anterior glenoid
15
In a TSA with glenoid retroversion greater than […] degrees, build up posterior glenoid with allograft
15
Which glenoid component design is more biomechanically superior, peg or keel?
Peg
Do cemented or uncemented glenoid components have a lower rate of loosening?
Cemented; (note: cemented all-polyethylene glenoid resurfacing is standard of care)
Are metal or polyethylene glenoid components more superior?
Polyethylene; (note: cemented all-polyethylene glenoid resurfacing is standard of care)
Do conforming or nonconforming glenoid components have a larger radius of curvature?
nonconforming
In TSA, the position of humeral stem should be in […] degrees of retroversion
25-45
In a TSA, the top of the humeral head should be […] mm superior to the top of the greater tuberosity
5 to 8
In a TSA, humeral […] stem components allow for modular conversion to reverse total shoulder arthroplasty
platform
What is the most common form of instability after TSA?
Anterior
In TSA, […] glenoid wear associated with glenoid component loosening.
posterior
In TSA, the […] artery, branch off the anterior humeral circumflex artery, can be damaged during biceps tendon elevation.
arcuate
Iatrogenic rotator cuff injury can occur in a TSA if the humeral neck osteotomy is […] to level of rotator cuff insertion
inferior
C acnes converts […] to propionic acid
lactose
Is C acnes aerobic or anaerobic?
Anaerobic
Which nerve is most commonly injured in TSA?
Axillary
In a rTSA, the center of rotation is moved […] and […]
inferiorly and medialized
What is the most common cause of early failure in a rTSA?
Dislocation
What is the position of dislocation in rTSA?
extension, internal rotation, adduction (note: getting up out a chair)
What is the strongest risk factor for dislocation following a rTSA?
irreparable subscapularis
Age less than […] years is a risk factor for infection following a rTSA
65
Are males or females a greater risk factor for infection following a rTSA?
males
What autoimmune disorder is a risk factor for acromion or scapular spine fracture following rTSA?
Rheumatoid arthritis
Release of […] increases both inferior translation and external rotation of the humeral head with the shoulder adducted
rotator interval (CHL and SGHL)
The upper and lower subscapular nerves come off the […] cord of the brachial plexus and innervate
posterior
The lateral border of the rotator interval is formed by the […]
transverse humeral ligament
The medial border of the rotator interval is formed by the […]
coracoid process
Glenoid retroversion of greater than […] degrees cannot be safely corrected with eccentric anterior reaming
15
What arthroscopic landmark is used for complete release of the rotator interval?
Coracoacromial ligament
SLAP lesion increases the strain on the […] band of the IGHL and thus compromises stability of shoulder
anterior
SLAP lesions may be due to a tight […] band of the IGHL
posterior
Most common pattern of biceps tendon attachment to the superior labrum is […] to the 12 o’clock position
posterior
The LH of the biceps contributes to […] and […] stability during late-cocking phase of throwing
torsional; horizontal
The LH of the biceps contributes to torsional and horizontal stability during […] phase of throwing
late-cocking
What portion of the shoulder labrum has the poorest blood supply?
anterior-superior labrum
A paralabral ganglion cyst of the shoulder is most commonly found in the […] notch
Spinoglenoid
What is the most common complication following SLAP repair?
Stiffness
In SLAP repairs, overdrilling the glenoid can injure the […] nerve
suprascapular
In shoulder internal impingement, what area of the glenoid is most affected?
posterior superior glenoid
Internal shoulder impingement occurs on which side of the rotator cuff?
articular/underside
Internal shoulder impingement is thought to be due to tightness in the […] band of the IGHL.
posterior
In internal shoulder impingement, there is greater than […] degrees loss of of IR at 90° compared to contralateral shoulder
20
Throwers with GIRD are […] percent more likely to have a SLAP lesion
25
What is the firstline treatment for GIRD?
rest from throwing and physical therapy for 6 months
The term internal impingement is used in throwers to describe a condition where the posterior-superior glenoid labrum impinges on which structure?
Posterior articular rotator cuff
SLAP repairs are generally not indicated for patients over the age of […] due to increased rate of post-operative stiffness.
40
SLAP repair failures have been associated with patient ages greater than […] years.
36
Suprascapular notch entrapment results in weakness of what muscle(s)?
Supraspinatus and Infraspinatus
Spinoglenoid notch entrapment results in weakness of what muscle(s)?
Infraspinatus only
What shoulder pathology is associated with suprascapular neuropathy?
SLAP tears
What nerve roots make up the suprascapular nerve?
C5, C6 (superior trunk)
The suprascapular nerve innervates which muscles?
Supra and Infraspinatus
The suprascapular nerve runs […] the suprascapular ligament.
below
The suprascapular artery runs […] the suprascapular ligament.
above
Transglenoid fixation resulting in a suprascapular neuropathy will result in […] weakness.
Infraspinatus
Medial scapular winging is seen in dysfunction of the […] muscle.
serratus anterior
What is the innervation of the serratus anterior?
Long thoracic nerve
What nerve roots innervate the serratus anterior?
C5, C6 and C7
What nerve roots make up the long thoracic nerve?
C5, C6 and C7
Lateral scapular winging is seen in dysfunction of the […] muscle
trapezius
What is the innervation of the trapezius?
Spinal accessory nerve (CN XI)
What is the origin of serratus anterior?
Ribs 1-8
What is the insertion of serratus anterior?
Anteromedial border of scapula
What is the blood supply of serratus anterior?
superiorly: long thoracic artery
inferiorly: thoracodorsal artery branches
The spinal accessory nerve exits the cranium through the […] foramen
jugular
What is the innervation of the rhomboids?
dorsal scapular nerve
The long thoracic nerve travels […] to the axillary vessels and brachial plexus
posterior
What is the innervation of the sternocleidomastoid?
Spinal accessory nerve
There are higher rates and degree of shoulder arthropathy inpatients greater than […] years old with a shoulder dislocation
25
[…] cultures are the gold standard for diagnosis periprosthetic shoulder joint infection.
synovial tissue (as opposed to aspirate)
