Disclosures: Alicia Salamani, MD: No financial relationships or conflicts of interest

Objective: To determine correlations of a positive medial apprehension test with physical exam findings and to determine biomechanical indicators of a positive test.

Design: Retrospective Case-Series Setting : Sports Medicine Clinic Participants : 204 patients with a positive medial apprehension test during the manual physical examination of the knee.

Interventions: Not Applicable

Main Outcome Measures: All variables within the patient chart were examined to determine their correlations with positive medial apprehension. The variables examined included: OA, age, sex, initial diagnosis, risk factors, physical exam findings including: positive lateral apprehension test, lateral facet tenderness, medial facet tenderness, patellar tendon tenderness, patellar origin tenderness, medial reticular tenderness, lateral reticular tenderness, positive PF compression test, positive McMurray test, quad strength, hamstring strength, effusion, positive circumduction, global tenderness as well as prior injuries. 12 of the patients underwent an automated 3D knee examination inside a CT scanner which performed axial rotation of the tibia (external and internal).

Results: The variables with the strongest correlation with a positive medial apprehension test were medial facet tenderness and joint line tenderness. Previous meniscal surgery or arthroscopic surgery were also correlated to a positive test. The biomechanical factors that were most often seen in patients with a positive medial apprehension test were: 1) increased medial roll of the patella during external rotation of the tibia; and 2) increased medial translation during internal rotation testing. Conclusions: A positive medial apprehension test is not a clear indicator of medial subluxation or patellar dislocation. The factors that were most correlated to a positive test could be indicators of other conditions (medial facet tenderness could indicate OA or chondromalacia patella and joint line tenderness could indicate meniscal injury or previous surgery). Biomechanical indicators may prove to be a more reliable method for determining the 3D behavior of the patella to determine whether subluxation of the patella is actually happening.

Level of Evidence: Level III

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PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/the-significance-of-medial-apprehension-test/