Lateral Epicondylitis [Tennis Elbow]

Lateral Epicondylitis is also known as Tennis Elbow, although this is a misnomer as histology shows tendinosis with degenerative angiofibroblastic hyperplasia rather than inflammation. [1]

It was first described in 1873 and then named “lawn tennis arm’ by Major in 1883. [2,3] It is the most commonly diagnosed cause of elbow pathology.

Epidemiology

It affects 1-3% of people each year. The dominant arm is most often affected with males and females presenting equally, usually between 35 and 50 years of age. The common presenting complaints are related to manual labour and strain when performing repetitive tasks. [4]

Pathoanatomy

Extensor Carpi Radialis Brevis (ECRB) and Extensor Digitorum Communis (EDC) arise on the anterior surface of the lateral epicondyle and make up the Common Extensor Origin (CEO). Anconeus arises posteriorly with Extensor Carpi Radialis Longus (ECRL) and Brachioradialis originating more proximally on the anterior aspect of the supracondylar ridge. Tennis elbow develops as a result of degeneration and micro-tears of the tendon that lead to Stage 2 Tendinosis (as classified by Nirschl and predominantly seen in the ECRB tendon). It is most commonly seen with overuse injuries. There is a non-inflammatory failure of tendon healing. A genetic component for development of tennis elbow has been postulated. [5]

Presentation

The patient presents with pain around the lateral aspect of the elbow, which may radiate distally over the extensor surface of the forearm. They complain of pain whilst griping, especially with a pronated forearm. There isn’t usually a history of an acute injury but often a history of a recent increase in activity levels such as repetitive/overuse tasks.

Diagnosis

Clinical examination is the mainstay of diagnosis. The main area of tenderness is the anterior aspect of the lateral epicondyle at the origin of ECRB or just distal to this. A weak and painful grip should be demonstrable.

Provocative clinical tests include:

1. Pain over the lateral epicondyle when the patient makes a fist in a pronated forearm with the elbow extended and wrist dorsiflexed with resistance applied.
2. Manoeuvre of passive stretch of the ECRB (in an extended elbow and a pronated forearm with the wrist is flexed and ulnar deviated) creates pain over lateral epicondyle.

Differential Diagnoses 

Intra-articular pathology

Radiocapitellar joint (RCJ) chondral lesions and a posterolateral plica may present with lateral elbow pain. RCJ stress testing (pronation-supination of the forearm with valgus load on the elbow) will elicit pain and occasional crepitus. With posterolateral plicas, subjective and objective findings may be vague but pain on palpation posterior to the epicondyle and a painful click when supinating the forearm in extension should be found. [6]

Radial Tunnel Syndrome

Pain should be more distal (3-5cm from the lateral epicondyle) and slightly ulnar as well as being exacerbated by resisted supination. Nerve conduction studies are often normal.

Posterolateral Rotatory Instability [PLRI]

There should be a history of injury and there may be complaints of giving way. Instability testing for PLRI will be positive.

Cervical spine / Radicular pathology

Limitation of neck movement associated with pain, along with other radicular signs should be found on history and examination.

Investigations

History and clinical examination are the most important steps in diagnosing tennis elbow and further investigations are not always needed. Radiographs may show lateral epicondylar calcification in 22-25% of patients and will also exclude significant degenerative changes of the RCJ [7]. Ultrasound scans may show tendinosis within the tendon. MRI scans will help to exclude other pathologies such as subtle osteoarthritis and ligament damage.

Non-operative Management

Watchful wait

83% of patients will be better at 1 year without intervention with 40% having minor discomfort at 5 years [8,9]. Poor prognostic indictors include compensation claims, manual work and high initial pain levels. [8] 

Physiotherapy / orthoses

Patients must remove the exacerbating factors that overload the tendon. If rest improves the pain then a programme of eccentric exercises and graduated loading can be effective. [10] Tennis Elbow clasps are known to work by offloading the degenerate tendon area and are more effective in reducing pain and improving pain free grip strength than watchful waiting, showing significant benefits by 12 weeks. [11]

Corticosteroid Injections

Steroid injections provide good initial relief, which peaks at 6 weeks. Recurrence of pain after the initial relief is common. Steroid injections are worse than physiotherapy or watchful waiting at 1 year. [12] They can also cause sub-cutaneous fatty atrophy at the injection site and patients need to be warned of this.

Platelet Rich Plasma Injections

More than 75% of patients improve their VAS at one year and this is significantly better than corticosteroid injections. [13] Currently it is not clear if this option is better than good quality conservative management or surgery.

Operative Management

This can consist of open or arthroscopic surgery and should not be considered before 6-12 months of good quality conservative management. There are many techniques described for open surgery including releasing and reattaching ECRB, ECRB denervation, ECRB debridement and decortication of the epicondyle.

During arthroscopic surgery, the ability to assess for other pathologies is the main benefit and is then followed by ECRB release. Lo and Safran (2007) found little difference in outcomes between either technique. Open surgery can show improvement in 97% of patients with 93% returning to sport in the long term. [14].

Summary

Lateral epicondylitis is a common and self-limiting disease process that causes tendinopathy at the CEO. It may resolve over time and settle with conservative management, if the exacerbating factors causing repetitive overloading are removed. Physiotherapy and PRP injections are better in the long-term than corticosteroids. If symptoms don’t settle after appropriate conservative management then a large number of operative techniques give a good outcome in the vast majority of patients.