Presentation

Pain over the lateral side of the elbow, exacerbated by activities involving active wrist extension or passive wrist flexion with the elbow extended, is the commonest form of presentation. The diagnosis is made by clinical signs and symptoms, which are usually both discrete and characteristic. There should be point tenderness over the origin of the extensor carpi radialis brevis muscle from the lateral epicondyle (ECRB origin). There should be pain on passive wrist flexion and also with resisted wrist extension (Cozen test), both tested with the elbow extended. Pain should be less with the elbow flexed. Finally Mill’s manoeuvre is used to confirm the diagnosis; with flexion of the wrist and fingers elbow extension provokes the pain. Most of the time there is no redness, swelling or oedema present.

In patients with lateral elbow pain differential diagnostic considerations include radial nerve entrapment, lateral sided intra-articular abnormalities, posterior lateral rotatory instability, lateral triceps dislocation, lateral anterior brachial cutaneous neuropathy and finally cervical osteoarthritis with nerve root compression.

If the degenerative involvement of the ECRB origin is sufficient to compromise the load-bearing capacity of the ECRB tendon, load transfer to the EDC portion of the conjoint tendon may occur. Rarely, even the posteriorly located ECU tendon may also be involved. In these cases involvement of the lateral ulnar collateral ligament (LUCL) may occur with resulting posterolateral instability as a sequel. Posterior interosseous nerve (PIN) involvement may reflect the anatomical proximity of the supinator tendon origin on the deep surface of the ECRB tendon and the secondary changes in the arcade of Frohse, which also originates on this tendon. In cases of radial nerve impingement (radial tunnel syndrome) under the arcade of Frohse, pain is usually concentrated more distally and resisted extension may not be painful, whereas resisted extension of the thumb and the index finger will. In addition, resisted forearm supination may be painful, something which is usually not the case in patients with lateral epicondylitis. However, in 5% of patients, it is said that both conditions can coexist.²² Verhaar and Spaans studied a number of patients with supposedly radial tunnel syndrome. They found that in 14 out of 16 cases there was no evidence of PIN compression on electromyography (EMG). As a consequence they concluded that these data did not support the hypothesis that the signs and symptoms of the majority of cases diagnosed as radial tunnel syndrome are caused by compression of the PIN.²³

Intra-articular abnormalities such as loose bodies and radiocapitellar osteoarthritis should be suggested by painful clicking on terminal elbow extension and forearm supination, but also maximal tenderness situated more posteriorly over the posterior radiocapitellar joint. Posterolateral rotatory instability may present similarly with additional symptoms and signs, but with symptoms of ‘giving way’ and signs of varus instability. Finally lateral triceps dislocation and lateral antebrachial cutaneous neuropathy should be considered as parts of the differential diagnosis.

Lateral tennis elbow is thus seen in patients with repetitive stress to the extensors of the wrist and fingers and possibly the supinator muscles. On the other hand, medial tennis elbow (or golfer’s elbow) characteristically occurs with wrist flexor activity and active pronation. Finally posterior ‘tennis elbow’ is the result of the development of tendinosis at the triceps attachment onto the olecranon in patients who undertake repetitive resisted elbow extension.

Investigations

Lateral and medial epicondylitis are essentially a clinical diagnosis. Although additional investigations can be useful to confirm the diagnosis or indeed exclude other conditions. Radiographic examination can reveal small areas of calcification over the lateral epicondyle of the humerus indicating a calcific tendinopathy. Nirschl and Pettrone reported 22–25% of these calcifications in patients with tennis elbow⁴ (Fig. 35.2). Usually however, radiographs are normal. Tendinopathy of the extensors of the wrist can be visualized by sonography or magnetic resonance imaging (MRI), the latter being more expensive, the former being more operator dependent. Ultrasound investigation visualizes focal hypoechoic areas and intrasubstance tears, as well as peritendinous fluid and thickening of the common extensor tendon.²⁴ Sensitivity is reported to be 64–88% for evaluation of the common extensor origin architecture, but specificity is quite variable (36–100%), depending on the study^25,26 (Fig. 35.3).

Figure 35.2 (A,B) Radiographs of the elbow showing the dynamic character of the calcifications in the common extensor tendon: left in 2004 and right in 2010.

Figure 35.3 (A,B) Magnetic resonance imaging (MRI) scan in a case with lateral epicondylitis: oedema is present within the common extensor tendon.

MRI can also be used for the investigation of suspected intra-articular abnormalities, the intactness of the radial collateral ligament complex as well as the extent of any tear or disease in the common extensor tendon. In 90% of patients, oedema is present within the tendon. It should, however, be noted that oedema has also been seen in 14–54% of asymptomatic patients. Finally the increased T2 signal may persist for weeks after the symptoms have resolved.^27–30

Treatment options

Treatment of lateral epicondylitis can be divided into conservative and operative. A further division would be treatments aimed at diminishing inflammation, treatments based on altering biomechanics and, finally, treatments aimed at regenerating tendinopathy.