Ulnar Collateral Ligament Injuries of the Elbow

Ovid: 5-Minute Sports Medicine Consult, The

Ulnar Collateral Ligament Injuries of the Elbow
Marjorie Delo
  • Sprain or tearing of the ulnar collateral ligament (UCL) of the elbow secondary to acute or chronic valgus stress leading to pain, instability, and dysfunction
  • 2 main mechanisms: chronic deterioration of the UCL owing to repetitive valgus overload or, less commonly, an acute traumatic rupture
  • Most UCL injuries are seen in baseball players, but they also can be seen in wrestlers, javelin throwers, tennis players, football players, volleyball players, and in acute trauma victims.
  • UCL injuries typically are seen in skeletally mature athletes; skeletally immature athletes with open physes sustain medial apophyseal avulsion injuries but typically maintain an intact UCL.
  • Predominant gender: Male > Female.
  • Although the exact prevalence of UCL injury is unknown, there has been a definite increase in the number of surgical reconstructions performed in professional, collegiate, and high school athletes in recent years. This rapid increase has been attributed to overuse as well as improved diagnostics.
Risk Factors
  • Participation in sport that demands repetitive excessive valgus stress to the elbow, such as high-velocity throwing or overhead activity, is a risk factor for chronic injury.
  • Throwers who become front-on too early in the throwing motion are at increased risk.
  • Contact sports or sports with significant fall risk are a factor in acute injury.
General Prevention
  • Athletes who participate in throwing or overhead sports should be on a conditioning program that includes core stabilization, rotator cuff and forearm muscle strengthening, and posterior capsule stretching.
  • Athletic technique should be reviewed to minimize valgus stress to the elbow.
  • Single-sport athletes should have a 3-mo rest within a year.
  • The UCL is the primary restraint to valgus stress of the elbow in flexion.
  • The UCL is composed of 3 ligaments: The anterior bundle, posterior bundle, and transverse ligament.
  • The anterior bundle, which is composed of an anterior and posterior band with reciprocal functions, is the most important medial stabilizer of the elbow (1)[A]. Rupture of the anterior bundle is considered a complete tear of the UCL.
  • The posterior bundle provides secondary restraint beyond 90 degrees of flexion.
  • The transverse ligament is an extension of the joint capsule and does not contribute to valgus stability (2)[A].
  • Repetitive valgus load to the elbow is absorbed primarily by the UCL.
  • Over time, the UCL becomes overloaded, and microtraumatic tears occur, leading to altered elbow kinematics.
  • Cumulative microtrauma can lead to rupture of the UCL; altered mechanics lead to decreased throwing or hitting accuracy and velocity.
  • Acute rupture can occur in a previously attenuated ligament or in a normal ligament subjected to extreme valgus stress, such as an elbow dislocation.
Commonly Associated Conditions
  • Valgus-extension overload syndrome: Radiocapitellar and posteromedial olecranon impingement
  • Ulnar neuritis or subluxation
  • Loose osteochondral bodies
  • In acute rupture, the athlete may experience sudden pain, sometimes with an audible pop, and cannot resume play.
  • Chronic injuries present as persistent, insidious medial elbow pain, often accompanied by decreased command and velocity of throwing or hitting.
Physical Exam
  • Tenderness along the UCL
  • Joint effusion and ulnar nerve tenderness may be present.
  • Flexion contracture with pain at terminal extension is common.
  • Valgus stress test: The examiner stabilizes the arm and flexes the elbow to 30 degrees; valgus stress is applied. The test is positive if the athlete has pain, apprehension, or instability.
  • Milking maneuver: The forearm is supinated and the elbow flexed to 90 degrees; the examiner applies a valgus stress by pulling on the thumb while palpating along the UCL. Pain, apprehension, or instability indicate MCL injury, but this test can give a high number of false-positive results (3)[B].
  • Moving valgus stress test: This test is highly sensitive and specific for UCL injury (3)[A]. A constant valgus stress is placed on the elbow as the joint is moved through the arc of flexion and extension. The test is positive if the athlete's pain is reproduced between 70 and 120 degrees of flexion.
Diagnostic Tests & Interpretation
  • X-rays: 3-view series of the elbow should be performed to evaluate for osteophytes, calcifications within the ligament or soft tissues, osteochondral damage, and loose bodies.
  • Stress x-rays may show joint widening compared with the contralateral elbow; a difference in joint opening of 1–3 mm suggests UCL injury (1)[B].
  • Stress US is a relatively new method that can demonstrate joint space opening with application of valgus stress. US also can reveal disruption of the UCL in the hands of an experienced user (4)[B].
  • P.617

  • CT arthrography can visualize partial tears of the UCL but is used less frequently with the improving quality of MRI.
  • MRI can visualize attenuation, partial tearing, or complete tearing of the UCL, as well as evaluate the articular surface and surrounding soft tissue structures. Image enhancement is possible with saline or gadolinium.
  • Arthroscopy can evaluate and treat associated articular injuries but cannot visualize the UCL well. Stress testing under arthroscopy, however, can be diagnostic of UCL tear (5)[C].
Differential Diagnosis
  • Flexor/pronator tendonitis or rupture
  • Ulnar neuritis or subluxation
  • Medial triceps subluxation
  • Loose bodies
  • Olecranon osteophytosis
  • Medial epicondyle avulsion
  • Pronator syndrome
841.8 Sprain of other specified sites of elbow and forearm

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More