Shoulder and elbow: Mcqs AND EMQS Answers

 

MCQs

1. e.  The posterior rotator cuff.

The primary cause of internal impingement is often anterior capsular laxity, which may result in posterior capsular tightness. This results in anterior shift of the axis of rotation of the humeral head in the sagittal plane, when the arm is in an abducted, externally rotated position, causing the posterior rotator cuff to impinge against the posterosuperior glenoid labrum. Examination may reveal a loss of >20 of internal rotation at 90º. Treatment is directed at posterior capsule stretching. Internal impingement is implicated in the development of articular sided rotator cuffs and posterosuperior labral tears.

2. b.  Centre of rotation more medial.

The advantage of a reverse shoulder arthroplasty is that the centre of rotation ( COR ) is medialized, which decreases the forces at the implant–bone interface and provides a mechanical advantage to the deltoid muscle to substitute for the deficient rotator cuff muscles to provide shoulder abduction.

3. e.  None of the above.

Whilst traumatic posterior shoulder dislocations are associated with epilepsy, they are not more common in this patient group than traumatic anterior dislocations.

4. c.  Zanca view.

Anteroposterior (AP), lateral and axial views are standard views taken for the shoulder; however, a Zanca view is the most accurate view to look at the ACJ. This view is performed by tilting the X-ray beam 10 to 15 toward the cephalic direction and using only 50% of the standard shoulder AP penetration strength. In a standard AP view of the shoulder, the ACJ will be over-penetrated (dark) and small or subtle lesions may be overlooked.

5. a.  Internal rotation (IR).

Glenohumeral internal rotation deficit (GIRD) is associated with throwing athletes. Repetitive throwing (cocking phase and deceleration phase) leads to a tight posterior capsule and loose anterior capsule. It is associated with internal impingement. On examination the full arc of rotation at 90 is maintained but excessive ER is present at the expense of decreased IR (loss of >20 of IR at 90 compared to contralateral side).

Treatment consists of posterior capsule stretching.

 

Postgraduate Orthopaedics, ed. Kesavan Sri-Ram. Published by Cambridge University Press.

# Cambridge University Press 2012.

6. d.  Brachioradialis.

Many muscle groups in the upper limb have dual innervation. Brachialis ( musculocutaneous and radial), flexor digitorum profundus (anterior interosseus and ulna), lumbricals ( recurrent median and ulna) and pectoralis major (lateral pectoral and medial pectoral) are examples.

7. d.  Inferior glenohumeral ligament complex.

The rotator cuff is a dynamic stabilizer and the capsulolabral tissues are considered static stabilizers. With the arm at 90 abduction, the anterior band of the inferior glenohumeral ligament complex is the primary static stabilizer to anterior translation.

8. c.  Young age (<25 years old) at time of dislocation.

The only consistent predictor of recurrence has been the age of the patient. In young patients (<25 years old), recurrence rates have ranged from 60% to 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 Hovelius et al. No difference in dominant and non-dominant extremities was noted.

9. c.  Diabetes mellitus.

Adhesive capsulitis affects an estimated 2–5% of the population. Several medical conditions have been associated with idiopathic adhesive capsulitis including diabetes and hypothyroidism. The reported incidence in diabetics is between 10% and 36%. Patients with insulin-dependent diabetes tend to have more severe limitation of movement and are more resistant to non-surgical treatment than non-insulin diabetics.

10. e.     Medial scapular winging.

The long thoracic nerve supplies serratus anterior, injury to which can result in medial translation of the scapular and the inferior angle rotated medially. Lateral scapular winging (lateral translation and the inferior angle rotated laterally) can occur as result of spinal accessory nerve palsy which supplies trapezius.

11. b.     Normal anatomic variant characterized by a cord-like MGHL and an absent anterosuperior labrum.

A Buford complex is a normal anatomical variant seen in 1.5% of individuals. A Buford complex consists of a cord-like MGHL and absent anterosuperior labrum complex. It should not be ‘repaired’. ‘Repair’ will result in decreased post-operative range of motion.

12. a.  Risk of dislocation.

As part of a deltopectoral approach, the subscapularis is taken down off the humerus.

This may be done trans-tendon, directly off bone, or with a lesser tuberosity osteotomy. In the initial post-operative period passive external rotation is limited to a maximum 30 to allow healing and protect the repair.

13. d.  Axillary.

The most common nerve to be injured in a traumatic anterior shoulder dislocation is the axillary nerve. This is because of its close association with the glenohumeral joint and its course around the surgical neck of the humerus. Based on clinical and electromyography (EMG) findings Visser et al. showed that the axillary nerve is injured in 42% of traumatic anterior dislocations.

14. d.  Extensor carpi radialis brevis.

The patient has lateral epicondylitis (tennis elbow), which usually involves a microtear of extensor carpi radialis brevis (ECRB). Histologically the lesion that was consistently identified at surgery was immature fibroblastic and vascular infiltration ( angiofibroblastic dysplasia) of the origin of ECRB.

15. d.  Anterior band of the medial ulnar collateral ligament.

The anterior band provides the major contribution to valgus stability. The olecranon is an important stabilizer of the elbow in extension; at 25 flexion the olecranon is unlocked from its fossa and the ulnar collateral ligament becomes the most important stabilizer. The radial head is an important secondary stabilizer in flexion and extension. The posterior band of the medial ulnar collateral ligament is a secondary stabilizer at 30 of flexion. The transverse band plays no role in joint stability because it originates and inserts on the same bone.

16. c.  Late cocking.

The late cocking and early acceleration phase of the overhead throw causes the greatest amount of valgus stress to the elbow. During this phase, the forearm lags behind the upper arm and generates valgus stress while the elbow is primarily dependent on the anterior band of the ulnar collateral ligament for stability. In deceleration, the elbow flexors are most active to prevent hyperextension.

17. c.  Activity modification.

Distal clavicular osteolysis is an uncommon cause of shoulder pain that can occur after acute injury or repetitive microtrauma. Initial treatment is non-surgical and includes activity modification and ACJ steroid injection. Arthroscopic resection of the distal clavicle should be considered in patients refractory to non-operative treatment.

18. a.  Inferior glenohumeral.

A humeral avulsion of the glenohumeral ligament (HAGL) lesion is a detachment of the inferior glenohumeral ligament (IGHL) off its humeral insertion. If missed, it can cause a failure of Bankart repair. The classic teaching is for repair via an open approach.

19. d.  External rotation deficit.

Healing of the tuberosities and their attached rotator cuff tendons is crucial in functional outcome after arthroplasty. Failure to properly position tuberosity fragments in the horizontal plane may result in insurmountable post-operative motion restriction.

20. a.  Weakness in external rotation.

Compression at the spinoglenoid notch will affect only the infraspinatus as the suprascapular nerve has already innervated the supraspinatus by this point. Compression at the suprascapular notch will affect both the supraspinatus and the infraspinatus. Prolonged impingement on the suprascapular nerve by a spinoglenoid cyst can result in atrophy of the infraspinatus muscles. This would show up as weakness in external rotation on examination. These cysts are associated with SLAP lesions and are formed

by a one-way valve effect, where synovial fluid can exit the joint into the cyst but not drain spontaneously.

21. b.  Superior placement of the glenoid component.

Superior positioning of the glenoid component as well as superior tilt of the component with respect to the scapula can lead to scapular notching, with a resultant poorer outcome. Inferior tilt and proper placement of the glenoid component protects against notching.

22. e.  Anteroinferior labral tear.

It has been shown in one study that 87% have an anterior glenoid labral tear ( Bankart lesion), 79% had anterior capsular insufficiency, 68% had a Hill–Sachs lesion, 55% had glenohumeral ligament insufficiency, 14% had complete rotator cuff tears, 12% had posterior glenoid labral tears and 7% had SLAP tears.

23. c.  Posterior interosseous nerve.

The posterior interosseous nerve is vulnerable as it winds around the neck of the radius within the supinator muscle. Fully supinating the forearm displaces the nerve laterally and posteriorly (away from the surgical site) at the same time more fully exposing the insertion of supinator.

24. b.  Decreased shoulder muscle strength and endurance.

McKee found that patients who had non-operative treatment of displaced (> 2 cm) midshaft clavicle fractures had significant decrease in both strength and endurance of about 80% compared to the contralateral side. Range of motion (ROM) of the affected shoulder was unaffected.

25. e.  Total elbow replacement.

The Larsen classification of the rheumatoid elbow is based on plain radiographs and is graded I–V:

Grade I – soft tissue swelling and osteoporosis.

Grade II – mild narrowing of the joint space and some marginal erosion.

Grade III – significant joint space narrowing.

Grade IV – integrity of subchondral plates is breached by deep erosions. Grade V – total joint destruction

26. b.  Rotator cuff repair.

A shoulder dislocation in a patient >40 years commonly results in a rotator cuff tear. In a shoulder with an intact rotator cuff, the dye will remain in the glenohumeral joint. A rotator cuff tear allows the dye to leak into the subacromial space. The most appropriate treatment is a rotator cuff repair.

27. e.  Radial head arthroplasty, coronoid open reduction internal fixation, and lateral collateral ligament repair.

A terrible triad of the elbow includes dislocation of the elbow with associated fractures of the radial head and the coronoid process. Ring et al. stressed that these injuries are prone to complications and advised against resection of the radial head due to instability, and instead recommended a radial head replacement if too comminuted for open reduction and internal rotation (ORIF). Coronoid fractures compromise elbow stability as well and require open reduction and internal fixation as with the lateral collateral ligament.

28. a.  Ligament avulsion off the humeral origin.

The LUCL is most commonly injured at the proximal origin. McKee et al. noted that in 62 consecutive operative elbow dislocations and fracture/dislocations, the LUCL was ruptured in all of the patients, proximally in 32, bony avulsion proximally in 5 , midsubstance rupture in 18, ulnar detachment in 3, ulnar bony avulsion in 1 and combined patterns in 3.

29. a.  Suprascapular-axillary.

Surgical fixation of a scapular neck fracture is performed via a posterior approach to the scapular/glenoid. The internervous plane is between the infraspinatus ( suprascapular nerve) and the teres minor (axillary nerve). The posterior branch of the axillary nerve has intimate association with the inferior aspects of the glenoid and shoulder joint capsule, and can be found in the interval between teres minor and teres major, which may place it at particular risk during a posterior approach to the shoulder.

30. c.  Internal rotation (IR) 30º, Flexion 30º, Abduction 30º.

Shoulder arthrodesis should be performed so that the arm rests comfortably at the side without scapular winging and so that the hand can be brought easily to the mouth and perineum.

 

EMQs

1. 1. b. Spinal accessory nerve. 2. c. Long thoracic nerve. 3. g. Radial nerve.

Injury to the spinal accessory nerve which supplies trapezius can result in shoulder depression with scapular lateral translation and the inferior angle rotating laterally because of the unopposed action of serratus anterior.

There are four supraclavicular branches of the brachial plexus: long thoracic nerve, dorsal scapular nerve, suprascapular nerve, nerve to subclavius.

In elbow arthroscopy the radial nerve is only 4 mm from the anterolateral portal, while the median nerve is 11 mm away from the anteromedial portal. The ulnar nerve is only at risk on the medial side of the elbow.

2. 1. c. Middle glenohumeral ligament (MGHL). 2. d. Anterior band of the inferior glenohumeral ligament (IGHL). 3. h. Subscapularis.

There are static and dynamic stabilizers of the shoulder. Static restraints: articular anatomy, glenoid labrum, capsule, ligaments, negative pressure. Dynamic restraints: rotator cuff, biceps. The MGHL (absent in up to 40%) is a primary restraint to anterior translation of the externally rotated arm in the midrange of abduction.

The anterior band of the IGHL is the primary restraint to anterior/inferior translation of the head with the shoulder abducted to 90º and in maximum external rotation ( ER ).

The posterior band of the IGHL is the most important restraint to posterior subluxation of the GHL with the shoulder in 90of flexion and internal rotation (IR). In ER, the subscapularis is an important dynamic stabilizer to posterior subluxation.

The superior glenohumeral ligament functions as a primary restraint to ER in the adducted arm.

3. 1. f. Serendipity view. 2. a. Supraspinatus outlet view. 3. g. Stryker notch view.

The different radiographic views are taken for – acromion morphology ( supraspinatus outlet view), Hill–Sachs lesion (anteroposterior (AP) in internal rotation (IR), Stryker notch view), acromioclavicular joint (ACJ) (Zanca), sternoclavicular joint (SCJ) ( serendipity), bony bankart (Garth), glenohumeral joint space (true anteroposterior (AP)), anterior/ posterior dislocation (axillary view).

4. 1. a. Lateral epicondylitis. 2. f. Posterior interosseous syndrome. 3. d. Posterolateral rotatory instability.

Posterior interosseous nerve (PIN) compression causes lateral elbow pain and ulnar drift with wrist extension as extensor carpi radialis longus (ECRL) is innervated proximal to PIN branch. Radial tunnel syndrome is a pain only problem without motor or sensory dysfunction.

Iatrogenic injury to the lateral ulnar collateral ligament, the main ligament implicated in posterolateral rotatory instability (PLRI) is a complication of a lateral release for tennis elbow. The anterior band of the medial collateral ligament is implicated in valgus instability.

5. 1. a. Lateral collateral ligament. 2. b. Lateral ulnar collateral ligament. 3. h. Ulnar collateral ligament.

Posterolateral rotatory instability (PLRI) of the elbow describes a rotational displacement as the ulna supinates past its normal limit and the radiocapitellar joint subluxes posterolaterally, permitting the coronoid process to slide beneath the trochlea. The lateral ulnar collateral ligament has been shown to be the essential lesion responsible for PLRI. The medial collateral ligament (of which the anterior bundle (ulnar collateral) is the most important) is the primary restraint to valgus instability. The posterolateral capsule and radial collateral ligament may be disrupted in a complete posterolateral dislocation but are not essential injuries for PLRI.

6. 1. i. Adhesive capsulitis. 2. g. Subcoracoid impingement. 3. d. Thoracic outlet syndrome.

Adhesive capsulitis is characterized by pain (particularly at night) and decreased active and passive range of motion (especially external rotation (ER)). Subcoracoid impingement (subscapularis impingement between the coracoid and lesser tuberosity) presents with anterior shoulder pain, the position of maximal discomfort 120–130 of forward flexion and internal rotation. On a CT scan a coracohumeral distance of <6 mm is considered abnormal. A local anaesthetic injection to the subcoracoid space should eliminate symptoms.

Thoracic outlet syndrome is associated with clavicle malunion (also scalene muscle abnormality, cervical rib). It most often affects subclavian artery, vein and the lower trunk (C8 and T1) of the brachial plexus. Abduction and ER with the neck rotated away leads to loss of pulse and reproduction of symptoms (Wright test).

7. 1. c. Subscapularis repair. 2. i. Reverse type total shoulder arthroplasty.
   3. g. Latissimus dorsi tendon transfer.

After a total shoulder arthroplasty external rotation, as well as active internal rotation, is limited to protect the subscapularis repair. This patient recruited his subscapularis rising from the chair. Initial treatment should be surgical repair.

A reverse type prosthesis is indicated for the second patient. The main complication associated with an unconstrained total shoulder arthroplasty in the presence of a cuff-tear arthropathy is loosening of the glenoid component.

The third patient is a candidate for a latissimus dorsi tendon transfer. The best outcome is achieved when the subscapularis is intact and there is full passive range of motion ( ROM ).

8. 1. f. Posterior approach to the shoulder. 2. f. Posterior approach to the shoulder.
   3. g. Lateral approach to the shoulder.

The posterior approach to the shoulder is the interval between infraspinatus ( suprascapular nerve) and teres minor (axillary nerve). It is the approach of choice for posterior glenoid, scapular fracture fixation. The lateral approach to the shoulder is a deltoid split through the anterior raphe. It is used for fixation of greater tuberosity fractures.

9. 1. j. Belly press. 2. h. Hornblower’s sign. 3. c. Hawkin’s sign.

The subscapularis has two portions, the upper portion innervated by the upper subscapular nerve (C5) and the lower portion from the lower subscapular nerve (C5–C6). The lift-off test is more accurate for the lower portion of the subscapularis and the belly press test more sensitive for the upper portion.

Hornblower’s sign (shoulder to 90 abduction, 90 external rotation and ask patient to hold position); if the arm falls into internal rotation it suggests a tear of teres minor.

10. 1. c. Pectoralis major rupture. 2. i. Glenohumeral osteoarthritis. 3. h. Subscapularis rupture.

Mechanism of injury is excessive tension on a maximally eccentrically contracted muscle. Bruising on the upper arm (rather than chest wall) suggests detachment at the humeral insertion rather than an intrasubstance tear.

Loss of external rotation can lead to degenerative joint disease following an anterior stabilization procedure. In time, this patient’s shoulder may show increased posterior glenohumeral wear.

Subscapularis tendon tears are a complication of open anterior stabilization surgery where subscapularis has been detached as part of the approach.The patient will have anterior shoulder pain and may report a sensation of instability. The lift-off test usually is positive.

11. 1. b. SLAP type II. 2. d. SLAP type IV. 3. i. Biceps tendon subluxation.

Snyder originally described four types of SLAP lesion. Type 1 biceps fraying, type II detachment of the biceps anchor, type III bucket handle tear, superior labral tear, intact biceps, in type IV it extends into the biceps tendon. The classification has since been expanded to include SLAP lesions associated with shoulder instability. Type II is the most common clinically significant type.

Biceps tendon subluxation is commonly associated with a subscapularis tear. A tear of the coracohumeral ligament or transverse humeral ligament may also result in subluxation.

12. 1. d. Open reduction and internal fixation (ORIF). 2. d. Open reductor and internal fixator (ORIF). 3. d. Open reduction and internal fixation (ORIF).

Displacement of the greater tuberosity >5 mm can result in symptoms of pain and limitation of movement. Osteonecrosis or loss of fixation is particularly likely after a headsplit fracture. However, in a young patient, ORIF should be attempted. A good result with ORIF is seen in valgus impacted fractures with low rates of avascular necrosis (AVN) if the posteromedial component is intact thus preserving the intraosseous blood supply.

13. 1. b. Triangular interval. 2. b. Triangular interval. 3. a. Triangular space.

The quadrangular space is bordered by teres minor (superiorly), teres major ( inferiorly), long head triceps (medially), and the humeral shaft (laterally). It contains the axillary nerve and posterior circumflex humeral vessels. The triangular space is bordered by teres minor (superiorly), teres major (inferiorly), and long head triceps (laterally). It contains the circumflex scapular vessels. The triangular interval is bordered by teres major ( superiorly), long head triceps (medially) and humerus (laterally). It contains the profunda brachii artery and radial nerve.

14. 1. d. Open reduction and internal fixation (ORIF). 2. e. Radial head replacement.
    3. j. Medial ligament reconstruction.

The examination and radiograph suggest that displacement of the fragment is great enough (>2 mm) to create a mechanical block. The prefered treatment is ORIF.

The second patient has an Essex-Lopresti fracture. Excision of the radial head without replacement will result in the radius migrating proximally causing wrist pain and loss of motion.

Repetitive valgus stress can result in rupture of the anterior band of the medial collateral ligament. Patients may complain of ulnar nerve symptoms. If initial non-operative management fails, especially in high level athletes, then medial collateral ligament reconstruction is favoured over direct repair.

15. 1. e. Lateral condyle. 2. a. Capitellum. 3. g. Trochlea.

Cubitis valgus deformity following a lateral condyle fracture can lead to tardy ulnar nerve palsy.

Osteochondritis dissecans is localized fragmentation of the bone and overlying cartilage of the capitellum; it frequently progresses to loose body formation, and sometimes progresses to post-traumatic arthritis. It tends to occur in patients 10–16 years of age.

‘CRITOL’ can be used to remember the chronological sequence of elbow ossification: capitellum – 2 years; radial head – 4 years; internal epicondyle – 6 years; trochlea – 8 years; olecranon – 10 years; lateral epicondyle –12 years.