Purpose: To study the usefulness of stress radiography for evaluation of injury to the medial collateral ligament (MCL).
Materials and methods: Forty-two injured athletes and four healthy athletes without symptoms underwent examination performed with a stress device. The increase in joint space width between the medial epicondyle and coronoid process, measured on anteroposterior radiographs obtained after 0 and 15 daN force was applied to the lateral elbow joint, was used to assess the extent of ligament tear. The validity of this technique was tested with study of selectively severed cadaveric MCLs.
Results: All complete and large partial tears were correctly diagnosed with stress radiography when the increase in joint space width was larger by 0.5 mm in the affected elbow compared with the opposite normal elbow. In subjects with values less than 0.5 mm, the MCLs were normal or showed a small tear that could be managed conservatively.
Conclusion: Stress radiography of the MCL enables accurate diagnosis of large and complete tears and distinction between such tears and small partial tears and normal ligaments.