History
Patients with posterolateral rotatory instability often remember a distinct traumatic event, most frequently a posterior dislocation. The athlete has a sense of instability and reports a snapping sensation that causes pain during throwing.
Patients with olecranon impingement syndrome often complain of posterior elbow pain with locking or snapping when throwing. The pain is worst when the elbow is extended. Throwers often complain of loss of velocity and control.
Patients with an anterior capsule strain present with anterior elbow pain, which often is aggravated by repetitive hyperextension and is not affected by elbow flexion.
Patients with a medial collateral ligament (MCL) sprain experience referred pain down the arm into the little finger and ring finger, which mimics the symptoms of cubital tunnel syndrome. A more common reason for this condition is ligament laxity in C6 and C7 or in the ulnar collateral ligament (UCL), not a pinched nerve.
MCL insufficiency manifests as medial elbow pain with laxity to valgus stress.
Medial epicondylar apophysitis is caused by repetitive valgus stress and generally manifests as progressive medial pain, decreased throwing effectiveness, and decreased throwing distance.
Medial epicondyle fracture manifests as point tenderness and swelling over the medial epicondyle, often with an elbow flexion contracture greater than 15°.
Neurologic injuries such as C8-T1 radiculopathy and ulnar neuritis, though uncommon in children, can manifest as medial elbow pain and should be included in the differential diagnosis.
Physical Examination
A number of clinical diagnostic procedures are helpful in establishing elbow instability and collateral ligament injury.
In the valgus stress test, the elbow is flexed to 20-30º, and abduction or valgus force is then applied at the distal forearm. [13]
The “milking maneuver” is performed with the arm at 70°, with the valgus force applied by supporting the elbow and tractioning the thumb.
With the moving valgus stress test (the most sensitive of these procedures), pronation, valgus of the forearm, and internal rotation of the shoulder cause pain at 70-120° flexion arc (see the image below).
Moving valgus stress test. Pronation, valgus of forearm, and internal rotation of shoulder lead to pain at 70-120° flexion arc.
In the lateral compression test, the examiner applies valgus stress while going from flexion to extension and back. This is repeated in the radioulnar joint in various degrees of pronation and supination. One hand is just above the elbow joint, and the other is placed on the wrist.
In the varus stress test, the elbow is flexed to 20-30º, and the patient's arm is then stabilized with one of the examiner's hands placed at the medial distal humerus (elbow) and the other above the patient's lateral distal radius (wrist). An adduction or varus force is applied at the distal forearm by the examiner to test the radial collateral ligament (RCL).
In the pivot shift test, the patient lies supine with the arm overhead. The elbow is supinated, and a valgus force and axial force are applied to the elbow. The patient may complain of pain or apprehension. Then, starting in extension, the elbow is flexed with a reduction “clunk” occurring, typically at 40-70° of flexion.
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Horii circle.
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Schematic diagram of medial collateral ligament of elbow shows 3 bundles. Anterior bundle is major stabilizer of elbow to valgus stress.
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Moving valgus stress test. Pronation, valgus of forearm, and internal rotation of shoulder lead to pain at 70-120° flexion arc.
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Docking (top) and figure-eight (bottom) techniques for medial collateral ligament (MCL) reconstruction. Single-strand reconstruction with ulnar Endobutton fixation technique and 2-strand docking technique appear to be viable options for reconstruction of MCL of elbow to resist valgus loading.
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Single-strand reconstructions with interference screw (top) and Endobutton (bottom).
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LUCL (lateral ulnar collateral ligament) isometric point.
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LUCL (lateral ulnar collateral ligament) isometric point.
