Abstract
Thrower’s elbow is the name given the constellation of symptoms, rather than a single pathologic process, that results from this repetitive microtrauma to the elbow. Contributing to this symptom complex are medial epicondylitis (golfer’s elbow), growth abnormalities of the medial epicondyle (medial epicondylar apophysitis), medial epicondylar fragmentation, stress fractures involving the medial epicondylar epiphysis, and avulsion fractures of the medial epicondyle. In addition, the findings of osteochondrosis of the humeral capitellum, osteochondritis dissecans of the humeral capitellum, osteochondritis of the radial head, hypertrophy of the ulna, traction apophysitis of the olecranon, triceps tendinitis, and mild instability of the ulnar collateral ligament complex may be observed alone or in combination with the foregoing pathologic processes. Less commonly, nerve entrapment syndromes and subluxation of the ulnar nerve can also occur.
Keywords
thrower’s elbow, valgus stress overload, elbow pain, medial epicondyle, athletic injury, ultrasound guided porcedure, diagnostic ultrasounography, sports injury ulnar collateral ligament
ICD-10 CODE M24.829
The Clinical Syndrome
Thrower’s elbow is a valgus stress overload syndrome caused by continual microtrauma to the medial and lateral elbow from a repetitive throwing motion. Also known as little leaguer’s elbow, the pathophysiology of thrower’s elbow initially involves damage secondary to significant valgus stress placed in the medial structures and compression of the lateral structures of the elbow during throwing activities. The medial epicondyle, medial collateral ligaments, and the medial epicondylar apophysis are especially susceptible to this repetitive stress, and ongoing tissue damage often exceeds the ability of the athlete’s body to repair the damage (see Fig. 39.1 ). When this occurs, the result is acute, localized, medial elbow pain combined with decreased throwing accuracy and throwing distance.
Thrower’s elbow is the name given the constellation of symptoms, rather than a single pathologic process, that results from this repetitive microtrauma to the elbow. Contributing to this symptom complex are medial epicondylitis (golfer’s elbow), growth abnormalities of the medial epicondyle (medial epicondylar apophysitis), medial epicondylar fragmentation, stress fractures involving the medial epicondylar epiphysis, and avulsion fractures of the medial epicondyle. In addition, the findings of osteochondrosis of the humeral capitellum, osteochondritis dissecans of the humeral capitellum, osteochondritis of the radial head, hypertrophy of the ulna, traction apophysitis of the olecranon, triceps tendinitis, and mild instability of the ulnar collateral ligament complex may be observed alone or in combination with the foregoing pathologic processes. Less commonly, nerve entrapment syndromes and subluxation of the ulnar nerve can also occur ( Box 41.1 ).
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Medial epicondylitis (golfer’s elbow)
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Medial epicondylar apophysitis
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Medial epicondylar fragmentation
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Stress fractures involving the medial epicondylar epiphysis
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Avulsion fractures of the medial epicondyle
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Osteochondrosis of the humeral capitellum
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Osteochondritis dissecans of the humeral capitellum
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Osteochondritis of the radial head
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Hypertrophy of the ulna
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Traction apophysitis of the olecranon
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Triceps tendinitis
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Mild instability of the ulnar collateral ligament complex
Signs and Symptoms
The pain of thrower’s elbow almost always includes pain localized to the region of the medial epicondyle in a manner analogous to golfer’s elbow ( Fig. 41.1 ). The patient may note the inability to hold a coffee cup or use a hammer, and the examiner may notice reduced grip strength. Sleep disturbance is common.
Other symptoms are the result of the other specific pathologic processes at play at the time of the examination. Patients suffering from thrower’s elbow may exhibit mild instability of the ulnar collateral ligament complex caused by repetitive stretch injuries, as well as a decreased ability to extend the elbow fully. Active compression across the radiocapitellar joint from muscular forces may reproduce the patient’s pain, as will an active radiocapitellar compression test, which is performed by having the patient pronate and supinate the forearm in full extension ( Fig. 41.2 ).
Physical examination may also reveal localized tenderness along the flexor tendons at or just below the medial epicondyle. If the patient has an acute injury to the elbow, swelling and ecchymosis may be present. Increased valgus angle greater than 11 degrees in male patients and 13 degrees in female patients may also be noted. Flexion contracture may be present and results in a loss of full elbow extension ( Fig. 41.3 ). In some high-performing athletes, these range-of-motion abnormalities represent adaptive changes and are not often the sole cause of the patient’s pain symptoms. Palpation of the ulnar collateral ligament may reveal tenderness to palpation or complete disruption ( Fig. 41.4A ). Valgus instability in the patient suspected of suffering from thrower’s elbow can best be assessed by performing the milking maneuver of Veltri, which is done by grasping the thrower’s thumb with the arm in the fully cocked position (90 degrees of shoulder abduction and 90 degrees of elbow flexion) and then applying valgus stress by pulling down on the thumb (see Fig. 41.4B ). The test result is considered positive if the patient’s pain is reproduced.
