Comparison of the posterolateral rotatory drawer test and MRI in diagnosing chronic lateral collateral ligament insufficiency of the elbow.

Abstract

Lateral collateral ligament (LCL) insufficiency of the elbow can be diagnosed using various clinical examinations. Among them, the posterolateral rotatory drawer (PLRD) test has been reported to have high sensitivity and specificity. MRI is also frequently used to assess the LCL complex but studies show variable efficacy raising doubt about its reliability as a gold standard diagnostic tool. Currently, no comparative studies exist between clinical testing and advanced imaging for LCL insufficiency. Hence, the aim of this study is to directly compare the PLRD test and MRI in terms of sensitivity and specificity for diagnosing LCL insufficiency. We conducted a retrospective study using data from a single surgeon's database, including patients who underwent elbow arthroscopy (gold standard), MRI and preoperative PLRD test between April 2017 and April 2025. All patients had MRI reviewed by consultant specialist musculoskeletal radiologists. Sensitivity and specificity of the PLRD test and MRI was calculated using arthroscopy as the reference standard for LCL insufficiency. Eighty-one patients were eligible for inclusion. Of these, 14 had a positive PLRD test, 9 had positive MRI findings, and 14 had positive arthroscopic findings. The PLRD test demonstrated a sensitivity of 85.7% (95% CI 57.2% to 98.2%) and specificity of 97.0% (95% CI 89.6% to 99.6%). In contrast, MRI had a sensitivity of 42.9% (95% CI 17.7% to 71.1%) and a specificity of 95.5% (95% CI 87.5% to 99.1%). In our cohort, the PLRD test outperformed MRI in diagnosing LCL insufficiency. It is important for clinicians to be aware that a negative MRI does not preclude the presence of LCL insufficiency, and we recommend the PLRD test is used as the primary preoperative clinical assessment tool. Level III; Diagnosis Study.