CHAPTER 5 The elbow

Anatomical features 76

General points 76

Important relations 76

Elbow function 77

Tennis elbow 77

Cubitus varus and cubius valgus/elbow instability 77

Tardy ulnar nerve palsy 78

Ulnar neuritis and the ulnar tunnel syndrome 78

Olecranon bursitis 78

Pulled elbow 78

Osteoarthritis and osteochondritis dissecans 78

Rheumatoid arthritis 79

Tuberculosis of the elbow 79

Myositis ossificans 79

Inspection 80

Movements 81–82

Palpation 82–83

Tennis elbow tests 83–84

Radiographs 84–86

Pathology 87–89

Aspiration of the elbow joint 89

Fig. 5.A.

Anatomical Features

General Points

The calliper-like close fit between the ulna and the trochlea (1) contributes to the impressive stability of the normal elbow; this is aided by the strong collateral ligaments (2). Instability may be seen following certain fractures of the coracoid or olecranon, owing to impairment of the stabilising bony features of the joint. It may follow ligamentous laxity from repeated stretching and tears in athletes; or it may occur when the ligaments become lax in the course of rheumatoid arthritis or an elbow joint infection.

At the end of flexion the coronoid process tucks into the coronoid fossa (3), and at full extension, the olecranon process fits into the olecranon fossa (4). The clearances are small, and only a little local disturbance, such as a small loose body in one of the fossae, may produce a significant restriction of movement.

The elbow joint is normally extended by gravity (G); forced extension is powered by triceps (T); and triceps acting with the elbow flexors (biceps (Bi) and brachialis (Br)) holds the elbow straight and rigid.

The axis (5) of pronation and supination passes through the radial head and the attachment of the triangular fibrocartilage.

Mechanically, pronation and supination may be restricted by problems involving the elbow, wrist or forearm bones. Pronation is controlled by pronator teres and pronator quadratus; supination is carried out by biceps and supinator.

Important Relations

• The median nerve (MN) and brachial artery (BA) lie medial to the biceps tendon and superficial to the brachialis muscle.

• The radial nerve (RN) and its important posterior interosseous nerve branch (P1) lie lateral to the biceps tendon.

• The ulnar nerve (UN) at the elbow lies behind the medial epicondyle.

• The main extensor muscle origin (E) is from the lateral epicondyle.

• The main flexor origin (F) is from the medial epicondyle.

Elbow Function

Note that disturbance of arm function secondary to elbow pathology is disproportionately greater when the shoulder is also impaired (see also p. 57).

Tennis Elbow

This is by far the commonest cause of elbow pain in patients attending orthopaedic clinics. It is generally believed to be due to a strain of the common extensor origin, but fibrosis in extensor carpi radialis brevis or a nerve entrapment syndrome have been suggested as alternative causes. The patient, usually in the 35–50-year age group, complains of pain on the lateral side of the elbow and difficulty in holding any heavy object at arm’s length. There may be a history of recent excessive activity involving the elbow, e.g. dusting, sweeping, painting, or even playing tennis.

In sportsmen, a period of rest or modification of a flawed game-playing technique may allow the condition to settle. In manual workers relief may follow avoidance of the suspected causal activity, although this may not always be possible. When these basic measures fail, an elbow clamp (employed to redirect the pull of the forearm extensors) can be effective. Symptoms are also usually relieved by one to three injections of local anaesthetic and hydrocortisone into the painful area, and local ultrasound may be tried. Excellent results have been claimed from extracorporeal shock-wave therapy. In resistant cases, when all conservative measures have failed, exploration of extensor carpi radialis brevis may be considered (with excision of any fibrous mass or lengthening of the tendon).

In golfer’s elbow there is a similar history, but here pain and tenderness involve the common flexor origin on the medial side of the elbow. This condition is much less common than tennis elbow.

Cubitus Varus and Cubitus Valgus/Elbow Instability

A decrease or increase in the carrying angle of the elbow generally follows a supracondylar or other elbow fracture in childhood. Although the normal child has great powers of spontaneous recovery following injury, there may nevertheless be some epiphyseal damage that fails to correct; where there is evidence of interference with the carrying angle the child should be observed for a number of years. If there is failure of spontaneous correction, or even deterioration, and the deformity is very unsightly, correction by osteotomy may be undertaken. In later life either of these deformities may be followed by a tardy ulnar nerve palsy.

Medial instability may occur in athletes who subject their elbows to severe valgus stresses by throwing, e.g. javelin throwers and baseball pitchers. There may be attenuation of the medial collateral ligaments, or even rupture. Mild cases may subside with rest, but in some a reconstruction may become necessary if there is the desire to continue with the activity. Instability is also seen in rheumatoid arthritis, the Ehlers–Danlos syndrome, and in Charcot’s disease.

Tardy Ulnar Nerve Palsy

This ulnar nerve palsy is slow in onset and progression. It appears usually between the ages of 30 and 50, and the preceding injury to the elbow, considered responsible for the ischaemic and fibrotic changes in the nerve, has usually been in childhood. It is seen most frequently where there is a cubitus valgus deformity. The progress of the palsy may be arrested by transposition of the nerve from its normal position behind the medial epicondyle to the front of the joint.

Ulnar Neuritis and the Ulnar Tunnel Syndrome

Ulnar neuritis, with its frequent accompaniment of small muscle wasting and sensory impairment in the hand, may occur as a complication of local trauma at the elbow or at the wrist. At the elbow, it is also seen where the nerve is abnormally mobile. In these circumstances it is exposed to frictional damage as it slips repeatedly in front of and behind the medial epicondyle. In such cases reanchorage or transposition may prevent further deterioration. Some advocate epicondylectomy.

The nerve is also subject to pressure as it passes between the two heads of flexor carpi ulnaris below the elbow (the cubital tunnel), or as it lies in the ulnar tunnel in the hand. Where the local findings are not clear enough to localise the site of involvement, nerve conduction rate studies are often most helpful.

In a number of cases no obvious cause for an ulnar neuritis may be found.

Olecranon Bursitis

Swelling of the olecranon bursa is common in carpet-layers and others who repeatedly traumatise the posterior aspect of the elbow joint. Swelling of the bursa is also common in rheumatoid arthritis, and there may be associated nodular masses in the proximal part of the forearm. The condition is usually painless unless there is an associated bacterial infection within the bursa. Excision is sometimes advised for cosmetic reasons.

Pulled Elbow

This condition occurs in young children under the age of 5, and is produced by traction on the arm, as for example when a mother snatches the hand of a child wandering towards the edge of a pavement. The radial head slides out from under cover of the orbicular ligament, and the child complains of pain and limitation of supination. The orbicular ligament and radial head may be reduced by forced supination while pushing the radius in a proximal direction (by forced radial deviation of the hand). On the other hand, spontaneous reduction, without manipulation, usually occurs within 48 hours of the incident if the arm is rested in a sling.

Osteoarthritis and Osteochondritis Dissecans

Primary osteoarthritis of the elbow joint is not uncommon in heavy manual workers. Osteoarthritis is also seen secondary to old fractures involving the articular surfaces of the elbow. It may also follow osteochondritis dissecans. Both osteoarthritis and osteochondritis dissecans may give rise to the formation of loose bodies, which restrict movements or cause locking of the joint. The joint may lock in any position, and the patient often develops the trick of unlocking the joint himself. If loose bodies are found, they should be removed to prevent further incidents of locking and to reduce the risk of their causing more damage to the articular surfaces. Joint replacement surgery in those suffering from osteoarthritis of the elbow is seldom indicated, as the physical demands are likely to exceed the capabilities of any current replacement.

Rheumatoid Arthritis

Rheumatoid arthritis may affect either one or both elbows. If both elbows are involved the functional disability may be particularly great.

Clinically there may be marked synovitis, painful restriction of movements, and a fixed flexion deformity. Pronation and supination may be restricted and painful, although in some cases the distal radioulnar joint may be responsible. When there is gross destruction of the elbow, the ulnar nerve may be affected and the joint may become flail.

Medical treatment and steroid injections may help in the early stages. Later, synovectomy with excision of the radial head may delay progress; and in advanced cases, with gross instability, joint replacement may be considered.

Tuberculosis of the Elbow

Tuberculosis of the elbow is now very uncommon; marked swelling of the elbow with profound local muscle wasting is usually so striking that there is unlikely to be a delay in further investigation by aspiration and synovial biopsy.

Myositis Ossificans

This condition occurs most commonly after supracondylar fractures and dislocations of the elbow. Calcification occurs in the haematoma that forms in the brachialis muscle covering the anterior aspect of the elbow joint. It is particularly common in association with head injuries, and may also follow over-vigorous physiotherapy. It leads to a mechanical block to flexion. If discovered at an early stage, complete rest of the joint is necessary to minimise the mass of material formed. In later cases it may be excised after the lesion has appeared quiescent for many months, and postoperatively a single dose of radiation therapy may help prevent recurrence.

5.1. Inspection (1):

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