Conditions...

Extensor Tendinopathy "Tennis Elbow"

Introduction

Lateral pain in the elbow affects up to 3% of the population, and is considered an overload injury of the extensor tendons of the forearm 1-2 cm from where it attaches at the lateral epicondyle. It is usually an overload injury that often follows minor trauma to extensor forearm muscles.  Although usually self-limiting, symptoms may persist for over 1 year in up to 20% of people1.

Aetiology

The condition has traditionally been known as “tennis elbow”. In fact, the condition is more common in non-tennis players than in tennis players. Tennis is a direct cause in only 5% of people with lateral epicondylitis1.

The primary pathological process involved in this condition is tendinosis of the extensor carpi radialis brevis (ECRB) tendon, usually within 1-2 cm of its attachment to the common extensor  origin at the lateral epicondyle2. This condition will be referred to as extensor tendinopathy.

With wrist movements, especially wrist extension, a considerable shearing stress is placed on the ECRB tendon. The ECRB muscle crosses both the elbow and the wrist and, therefore, contracts eccentrically at both ends during certain manoeuvres. Additional stress is applied by the head of the radius which rotates anteriorly, compressing the ECRB tendon during pronation of the forearm2.

It is generally a work related or sport related pain disorder, usually caused by excessive quick, monotonous, repetitive eccentric contractions and gripping activities of the wrist3.

It is a degenerative or failed healing tendon response characterised by the increased presence of fibroblasts, vascular hyperplasia, and disorganised
collagen.

The abnormal tissue has a large number of nociceptive fibres, which may explain why the lesion is so painful. With continued use, tendinosis may extend into microscopic partial tears. Conversely, a tear may be the primary abnormality with degenerative change being secondary.

Signs and Symptoms

It has a well defined clinical presentation, the main complaints being pain and decreased grip strength, both of which may affect activities of daily living3. Some local swelling may be present with pain referring down the forearm and towards the shoulder. Occasionally anaesthesia may be present in the hand.

Differential Diagnosis

Other conditions that may cause lateral elbow pain include synovitis of the radiohumeral joint, radiohumeral bursitis and entrapment of the posterior interosseous branch of the radial nerve.

Prevalence

Lateral elbow pain is common (population prevalence 1–3%), with peak incidence occurring at 40–50 years of age. In women aged 42–46 years, incidence increases to 10%. In the UK, the Netherlands, and Scandinavia the incidence of lateral elbow pain in general practice is 4–7/1000 people a year2.

Physiotherapy treatment

An imposed period of relative rest in which tendon load is reduced to minimize progression of pathology is suggested. This period should not be complete cessation of the offending activity, but a decrease in the overall training volume of the activity. Complete rest through immobilization of a joint has a negative effect on tendon strength and should not be practiced3.

The aim of physiotherapy is to decrease pain and increase muscle strength and function.
Soft tissue therapy is performed at the site of the lesion and to adjacent tight or thickened tissues.  Deep Transverse friction at the site is performed as well2.

Active trigger points associated with muscle shortening are frequently found in the forearm extensor muscles, these trigger points are treated by means of digital ischemic pressure or dry needling.

Needle acupuncture may be more effective at increasing pain relief duration after one treatment, or at improving pain after 10 acupuncture sessions at 2 weeks, but may be no more effective at improving pain at 3 or 12 months1.

A home exercise program consisting of concentric and eccentric exercises  and stretching of the ECRB muscle and associated wrist extensors has proven to be successful.

Other treatment forms

Topical and oral NSAIDs have proven to provide short term pain relief.

Corticosteroid injections may be more effective at improving pain at 8 weeks and 6 months in patients who have had symptoms for less than 4 weeks1.

References

1.  Tennis Elbow. Willem Assendelft, Sally Green, Rachelle Buchbinder, Peter Struijs and Nynke Smidt BMJ 2003; 327; 329-330

2. Clinical Sports Medicine. Peter Brukner and Karim Khan with colleagues. Third edition (2006) pg. 289, 292-296

3. Tendinopathy in athletes. M. Reinking, Physical Therapy in Sport 13 (2012) pg. 3-10