Medial Epicondylitis

Medial epicondylitis, also known as golfer's elbow, pitcher's elbow, or medial tennis elbow, is caused by degeneration of the common flexor tendon secondary to overload of the flexor-pronator muscle group that arises from the medial epicondyle.7-9 The spectrum of damage to the muscle-tendon unit that may be characterized with MRI includes muscle strain injury, tendon degeneration (tendinosis), and tendon disruption (Fig. 4.3).

MRI is useful for detecting and characterizing acute muscle injury and for following its resolution.10 The STIR sequence is the most sensitive for detecting muscle abnormalities. The common flexor tendon and MCL should be evaluated carefully for associated tearing when there is evidence of medial muscle strain injury on MRI. Alternatively, increased signal intensity on STIR and T2-weighted sequences may be seen after an intramuscular injection and may persist for as long as one month.11 Abnormal signal intensity within a muscle may simply be

Epizondylus Radial

FIGURE 4.3. A 42-year-old golfer with persistent symptoms of medial epicondylitis after a steroid injection. T1-weighted (A) and STIR (B) coronal images reveal detachment of the common flexor tendon from the medial epicondyle (curved arrows). The underlying anterior bundle of the MCL (straight arrows) appears normal.

FIGURE 4.3. A 42-year-old golfer with persistent symptoms of medial epicondylitis after a steroid injection. T1-weighted (A) and STIR (B) coronal images reveal detachment of the common flexor tendon from the medial epicondyle (curved arrows). The underlying anterior bundle of the MCL (straight arrows) appears normal.

due to the effect of a therapeutic injection for epicondylitis rather than an indication of muscle strain. Steroid injections ideally should be done after MRI to avoid the confounding appearance of the injection on the structures about the elbow.

A normal muscle-tendon unit tears at the myotendi-nous junction.12 A much more common clinical entity, however, is failure of a muscle-tendon unit through an area of tendinosis.13 Degenerative tendinosis is common about the elbow.9,14 MRI can determine if tendinosis is present, rather than partial tearing or complete rupture. This distinction is primarily made on the T2-weighted images by evaluating the morphology of the tendon adjacent to the epicondyle. The tendon fibers are normal or thickened in cases of degenerative tendinosis, thin in cases of partial tears, or absent in cases of complete tears. The coronal, sagittal, and axial sequences are all useful for assessing the degree of tendon injury.

The appearance of medial and lateral epicondylitis about the elbow is similar to the appearance of other common degenerative tendinopathies that involve the attachment of tendons to bone. Similar criteria can be used to evaluate the common flexor and common extensor tendons in the elbow, the supraspinatus tendon in the shoulder, the patellar tendon in the knee, and the plantar fascia in the foot on MRI. In each of these conditions, degenerative tendinosis and a failed healing response precede rupture.13,15-17

MRI facilitates surgical planning by delineating and grading tears of the common flexor tendon and by evaluating the underlying MCL and adjacent ulnar nerve. Ul-

nar neuritis commonly accompanies common flexor tendinosis and may be difficult to identify clinically. Patients who have a concomitant ulnar neuropathy have a significantly poorer prognosis after surgery compared with patients who have isolated medial epicondylitis.18,19 Patients who have coexisting ulnar neuritis and common flexor tendinosis (25% to 50% of patients who undergo surgery for medial epicondylitis) need transposition or decompression of the ulnar nerve in addition to debride-ment and repair of the abnormal flexor tendon.7,8,18,19

In skeletally immature individuals, the flexor muscle-tendon unit may fail at the unfused apophysis of the medial epicondyle. Stress fracture, avulsion, or delayed closure of the medial epicondylar apophysis may occur in young baseball players secondary to overuse (Little League elbow).20 MRI may detect these injuries before complete avulsion and displacement by revealing soft tissue or marrow edema about the medial epicondylar apophysis on the STIR images.21

Cure Tennis Elbow Without Surgery

Cure Tennis Elbow Without Surgery

Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.

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Responses

  • Tullio
    Do steroid injections affect the stir sequence on mri?
    7 years ago

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