Clinical Physical Exam Shows High Sensitivity for Detecting Labral Tears in Individuals With Femoroacetabular Impingement Syndrome.

PURPOSE: To determine the diagnostic performance of the combined use of radiographs and physical exam findings, compared with magnetic resonance arthrography (MRA) alone, for the primary diagnosis of labral tears in individuals with femoroacetabular impingement syndrome.

METHODS

A retrospective comparative case series was performed with data collected between 2012 and 2016. Patients were included if their chart indicated: (1) hip arthroscopy for femoroacetabular impingement syndrome was performed with intra-articular video recording; (2) diagnostic MRA was completed within 18 months prior to surgery and a detailed description of the acetabular labrum status was available in the radiological report; (3) diagnostic radiographs to detect the presence of femoroacetabular impingement syndrome; and (4) physical exam findings were documented for flexion, abduction, external rotation; flexion, adduction, internal rotation; and resisted straight leg raise tests. Exam findings were positive when all three clinical tests initiated a pain response. Intra-articular video recordings were used to confirm the presence of labral tears. The diagnostic performance for each tool (MRA, radiographs, physical exams) was determined by calculating the sensitivity, specificity, positive and negative predictive values, and accuracy. Diagnostic validity was evaluated using receiver operating characteristic curves.

RESULTS

A total of 224 records (108 males/116 females) were included. The sensitivity and specificity and diagnostic validity for MRA in detecting labral tears were 67%, 83%, and 0.751, respectively, while radiographs combined with physical exams and exam findings alone were 76%, 100%, and 0.879 and 94%, 100%, and 0.879, respectively.

CONCLUSIONS

Physical exams such as the flexion, abduction, external rotation; flexion, adduction, internal rotation; and resisted straight leg raise, when concurrently positive, may be relied upon for labral tear diagnosis due to their higher sensitivity and better diagnostic validity compared with MRA, in patients who are candidates for hip arthroscopy. MRA can be considered a secondary tool when further evaluation for intra- or extra-articular hip pathologies is needed, particularly when surgical intervention may be required.

LEVEL OF EVIDENCE: Level III, retrospective comparative case series.