Medial epicondylitis

Medial epicondylitis (plural: medial epicondylitides) (also known as golfer's elbow) is an angiofibroblastic tendinosis of the common flexor-pronator tendon group of the elbow.

Epidemiology

It is less common than lateral epicondylitis. As with lateral epicondylitis, it typically occurs in the 4^th to 5^th decades of life. There is no recognised gender predilection.

Clinical presentation

Patients typically present with insidiously medial elbow pain, swelling and tenderness, particularly over the medial epicondyle. The pain can worsen with wrist flexion and forearm pronation activities. Patients may offer a history of sports activities, including golf, overhead throwing sports, and racket sports. The patient's history may include the occurrence of an acute sports injury or acute trauma.

Pathology

It is thought to occur from valgus forces transmitted to the medial elbow during forearm pronation and wrist flexion may exceed the strength of the muscles, tendons, and supporting ligaments. Cumulative stress or overuse can lead to tendinosis involving the musculotendinous junction of the flexor-pronator muscle group at the medial epicondyle, with microtrauma and partial tearing that may progress to a full-thickness tendon tear.

Histology demonstrates tendinosis, enthesopathy, disorganisation of collagen architecture, mucoid change, fibrosis and variable vascular proliferation.

Radiographic features

MR imaging is the most widely used modality for assessment, although ultrasound also may be performed.

Plain radiographs

Adjacent to the medial epicondyle there may be calcific tendinopathy or enthesopathy.

Ultrasound

May be identified as outward bowing, heterogeneous echogenicity, or thickening of the common tendon, with subjacent fluid collection and intratendinous calcification. Discrete tears appear as hypoechoic regions with adjacent tendon discontinuity. Colour Doppler may show tendon hyperaemia. Dynamic assessment can also be performed to delineate instability.

MRI  

Described features on MRI include ²:

• thickening and increased signal intensity on both T1 and T2 weighted sequences of the common flexor tendon
• soft tissue oedema around the common flexor tendon - peritendonitis
• marrow edemaoedema in the medial epicondyle
• muscle atrophy may occur in longstanding cases

Treatment and prognosis

Treatment starts with the application of cold packs to the elbow and oral NSAID therapy. Other clinical approaches include the use of a splint, one or more local corticosteroid injections, application of ultrasound waves and guided rehabilitation program. Surgery is often performed if there is no clinical response after 3 to 6 months of conservative treatment.

Differential diagnosis

For a clinical differential diagnosis of medial elbow pain, consider:

• occult fracture
• medial osteoarthrosis
• medial collateral ligament injury