Shoulder and Arm

When there is a fracture of the 'neck' of the humerous, what is usually being reffered to? What is the most common nerve affected?

It is extremely rare for fractures to occur across the anatomical neck of the humerus because the obliquity of such a fracture would have to traverse the thickest region of bone. Typically fractures occur around the surgical neck of the humerus. Although the axillary nerve and posterior circumflex humeral artery may be damaged with this type of fracture, this rarely happens. It is important that the axillary nerve is tested before relocation to be sure that the injury has not damaged the nerve and that the treatment itself does not cause a neurological deficit.

What causes 'winging' of the scapula?

Loss of function to the long thoracic nerve causes loss of function to serratus anterior. this causes the the medial border, and particularly the inferior angle, of the scapula to elevate away from the thoracic wall. This makes normal elevation of the arm impossible.

What are the types and grades of shoulder instability?

95% anterior. Types: Tubs, ambri, multidirectional, habitual. Grades: disclocation, subluxation, acute v. recurrent. May get secondary impingement in younger, hyerp-mobile patients.

What are the characteristics of Calcific Tendonitis?

Acutely painful and severe, insidious or rapid onset often brought about by minor trauma. This condition is caused by the deposition of hydroxyapatite crystals and fibrocartilage metaplasia. Causes intense inflammation and swelling. Patients present with acute pain or secondary impingement.

What vascular supply is injured by dislocation of the humeral head.

Anterior dislocation of the humeral head may compress the axillary artery, resulting in vessel occlusion. This is unlikely to render the upper limb completely ischemic, but it may be necessary to surgically reconstruct the axillary artery to obtain pain-free function. Importantly, the axillary artery is intimately related to the brachial plexus, which may be damaged at the time of anterior dislocation.

What is the mechanism of injury for an AC joint dislocation?

Medialisation of shoulder girdle on a fixed clavicle, driving the acromion down (i.e. downward sag of the shoulder). Most commonly a fall onto the shouder tip. Most common shoulder injury in contact sports.

Where does the clavical usually fracture?

Middle third. Medial and lateral thirds are rarely fractured.

What is the difference between primary OA and secondary OA?

Primary OA: often multi-joint involvement. Secondary OA: post instability, post trauma fracture, massive rotator cuff tear.

What are the characteristics of adhesive capsulitis?

Progressive pain and stiffness (pain initially, joint contractures may result). May run of about 18 months and can be severe. Caused by trivial trauma like poor sleep.

What are the three stages of rotator cuff degeneration?

Stage I - wear / degeneration Stage II - tear / tendon failure Stage III - repair / vascular response.

What injury tends to occur at the acromial end of the clavicle?

The acromial end of the clavicle tends to dislocate at the acromioclavicular joint with trauma ( Fig. 7.31 ). The outer third of the clavicle is joined to the scapula by the conoid and trapezoid ligaments of the coracoclavicular ligament. A minor injury tends to tear the fibrous joint capsule and ligaments of the acromioclavicular joint, resulting in acromioclavicular separation on a plain radiograph. More severe trauma will disrupt the conoid and trapezoid ligaments of the coracoclavicular ligament, which results in elevation and upward subluxation of the clavicle.

What boney feature does the profunda brachii artery run in?

The radial groove. Gives rise to the radial collateral artery which meets up distally with the radial artery.

What are common disorders of the rotator cuff? What is the most

The two main disorders of the rotator cuff are impingement and tendinopathy. The muscle most commonly involved is supraspinatus as it passes beneath the acromion and the acromioclavicular ligament. This space, beneath which the supraspinatus tendon passes, is of fixed dimensions. Swelling of the supraspinatus muscle, excessive fluid within the subacromial/subdeltoid bursa, or subacromial bony spurs may produce significant impingement when the arm is abducted.The blood supply to the supraspinatus tendon is relatively poor. Repeated trauma, in certain circumstances, makes the tendon susceptible to degenerative change, which may result in calcium deposition, producing extreme pain.When the supraspinatus tendon has undergone significant degenerative change, it is more susceptible to trauma, and partial- or full-thickness tears may develop ( Fig. 7.33 ). These tears are most common in older patients and may result in considerable difficulty in carrying out normal activities of daily living such as combing hair. However, complete tears may be entirely unsymptomatic.

What is a typical injury at the medial end of the clavicle? What is the major concern for an injury of this type?

The typical injury at the medial end of the clavicle is an anterior or posterior dislocation of the sternoclavicular joint. Importantly, a posterior dislocation of the clavicle may impinge on the great vessels in the root of the neck and compress or disrupt them.

What is the common injury at the glenohumeral joint and how does this occur? Which nerve may be affected? What is the likely cause of a posterior dislocation?

The glenohumeral joint is extremely mobile, providing a wide range of movement at the expense of stability. The relatively small bony glenoid cavity, supplemented by the less robust fibrocartilaginous glenoid labrum and the ligamentous support, make it susceptible to dislocation.Anterior dislocation from FOOSH occurs most frequently and is usually associated with an isolated traumatic incident (clinically, all anterior dislocations are anteroinferior). In some cases, the anteroinferior glenoid labrum is torn with or without a small bony fragment. Once the joint capsule and cartilage are disrupted, the joint is susceptible to further (recurrent) dislocations. When an anteroinferior dislocation occurs, the axillary nerve may be injured by direct compression of the humeral head on the nerve inferiorly as it passes through the quadrangular space. Furthermore, the "lengthening" effect of the humerus may stretch the radial nerve, which is tightly bound within the radial groove, and produce a radial nerve paralysis. Occasionally, an anteroinferior dislocation is associated with a fracture, which may require surgical reduction. Posterior dislocation is extremely rare; when seen, the clinician should focus on its cause, the most common being extremely vigorous muscle contractions, which may be associated with an epileptic seizure caused by electrocution.