Clinical Review

Valgus Extension Overload in Baseball Players

Am J Orthop. 2016 March;45(3):144-151

References

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In addition, VEO may lead to injury in the lateral compartment as well. After attenuation and insufficiency of the UCL due to repetitive stress, excessive force transmission to the lateral aspect of the elbow occurs. Compressive and rotatory forces escalate within the radiocapitellar joint, causing synovitis and osteochondral lesions.^3,23 These osteochondral lesions include osteochondritis dissecans and osteochondral fractures that may fragment and become loose bodies.

Evaluation of VEO

History

Patients will typically have a history of repetitive throwing or other repetitive overhead activity. VEO is most common in baseball pitchers but may also occur in other sports, such as tennis, football, lacrosse, gymnastics, and javelin throwing. In baseball pitchers, clinical presentation is often preceded by a decrease in pitch velocity, control, and early fatigability. It presents with elbow pain localized to the posteromedial aspect of olecranon after release of the ball, when the elbow reaches terminal extension. Patients also report limited extension, due to impinging posterior osteophytes. Also, locking and catching caused by loose bodies and chondromalacia may be present. VEO may also occur in combination with concomitant valgus instability, as well as in a patient with a prior history of valgus instability. Flexor pronator injury, ulnar neuritis, and subluxation may also be present in a patient with VEO.

Physical Examination

VEO may occur in an isolated fashion or with concomitant pathology. Therefore, a comprehensive physical examination includes evaluating the entire kinetic chain of throwing and a focused examination covering VEO and associated valgus instability. Patients may exhibit crepitus and tenderness over the posteromedial olecranon and a loss of extension with a firm end point. The extension impingement test should be performed where the elbow is snapped into terminal extension. This typically elicits pain in the posterior compartment in a patient with VEO. The arm bar test involves positioning the patient’s shoulder at 90° of forward flexion, full internal rotation, with the patient’s hand placed on the examiner’s shoulder.²⁴ The examiner pulls down on the olecranon, simulating forced extension; pain is indicative of a positive test. It is important to note if there are signs of ulnar neuritis or subluxing ulnar nerve, especially if planning to utilize medial portals during arthroscopic treatment.

Examination maneuvers for valgus instability should also be conducted during evaluation of VEO. The physical examination for valgus instability in the elbow is ideally performed with the patient seated. Secure the patient’s wrist between the examiner’s forearm and trunk, and flex the patient’s elbow between 20° and 30° to unlock the olecranon from its fossa. Proceed to apply valgus stress. This stresses the anterior band of the anterior bundle of the UCL.^6,25,26 Palpate the UCL from the medial epicondyle to the proximal ulna as valgus stress is applied. Occasionally, valgus laxity can be appreciated when compared to contralateral side. The milking maneuver is a helpful test to determine UCL injury. Pull on the patient’s thumb while the forearm is supinated, shoulder extended, and the elbow flexed beyond 90°.⁶ The milking maneuver exerts valgus stress on a flexed elbow. A patient with an injured UCL will experience the subjective feeling of apprehension and instability, with medial elbow pain.

The most sensitive test is the moving valgus stress test. This is performed with the patient in the upright position and the shoulder abducted 90°. Starting with the arm in full flexion, the examiner applies a constant valgus torque to the elbow and then rapidly extends the elbow. Reproduction of pain during range of motion from 120° to 70° represents UCL injury, while pain with extension beyond 70° represents chondral injury to the ulnohumeral joint. Be aware that the absence of increased pain with wrist flexion, along with pain localized slightly posterior to the common flexor origin, differentiates a UCL injury from flexor-pronator muscle injury.^6,26,27Examine range of motion in affected and unaffected elbows. Loss of terminal extension may be present, along with secondary to flexion contracture due to repeated attempts at healing and stabilization.²⁵

Imaging

Imaging is essential to the accurate diagnosis of VEO and related conditions. Anterior posterior (AP), lateral, and oblique radiographs of elbow (Figures 3A-3C) may show posteromedial olecranon osteophytes and/or loose bodies. Calcification of ligaments or other soft tissues may also be seen. An AP radiograph with 140° of external rotation may best visualize osteophytes on posteromedial olecranon.18 A computed tomography scan with 2-dimensional sagittal and coronal reconstruction and 3-dimensional surface rendering (Figures 4A, 4B) may best demonstrate morphological abnormalities, loose bodies, and osteophytes. Magnetic resonance imaging (MRI) is essential for assessment of soft tissues and chondral injuries. MRI may detect UCL compromise, synovial plicae, bone edema, olecranon, or stress fractures.