Overuse injuries of the elbow are common and can result in pain and reduced tolerance for activity. Lateral epicondylitis, or tennis elbow, is the most common cause of pain on the lateral aspect of the elbow. The prevalence in the general population is approximately 1-3%, with the most common age group between 35 to 55 years of age. This area of the elbow is frequently injured by both athletes and workers who engage in repetitive wrist extension and pronation/supination of the forearm.
The most commonly affected tendon is the extensor carpi radialis brevis (ECRB). During repetitive wrist extension, the extensor muscle mass on the forearm is activated and its proximal attachment at the lateral epicondyle is repeatedly tugged. Repetitive overloading creates histological changes of the tendon characteristic of tendinosis, resulting in pain.
On examination, pinpoint tenderness over the lateral epicondyle is often present. Pain is reproduced with resisted wrist extension, particularly when the elbow is extended. Testing of the ECRB occurs with the elbow fully extended and resistance applied to the third metacarpal.
X-rays assess for calcifications that may be seen adjacent to the lateral epicondyle. MRI may demonstrate extensor tendon thickening or small tears, but it is often not necessary to make a diagnosis of lateral epicondylitis.
Initial management of lateral epicondylitis includes icing, activity modification, physical therapy, a home exercise/stretching program and a trial with a tennis elbow strap.
Multiple injection therapies have been studied in the medical literature, including steroid and platelet rich plasma (PRP) injections. Steroids are common in clinical practice and may provide relief when combined with physical therapy. In a multi-centered randomized controlled trial of 230 patients, a leukocyte rich PRP injection reported 84% successful outcome compared to 68% successful outcome in the control group (dry needling alone). In severe cases after physical therapy and injections have not provided sufficient relief, surgery may be considered.