Central Femoral Head Chondromalacia Is Associated with a Diagnosis of Hip Instability.

PURPOSE: To compare the locations and patterns of femoral head chondral damage in patients with instability in contrast to those with femoroacetabular impingement (FAI) without instability.

METHODS

All consecutive hip arthroscopies were reviewed from 2013 to 2020 from a single surgeon. Intraoperative records were reviewed on all patients identified to have femoral head chondromalacia. Data were collected to include laterality, location of femoral head chondromalacia, intraoperative diagnosis (instability and/or FAI subtype), and ease of distractibility. The location of the femoral head chondromalacia was defined on the basis of intraoperative description. Chi-squared and Fisher's exact tests were used for categorical variables, and a two-sample t test was used for continuous variables. Statistical significance was set at P < .05.

RESULTS

A total of 64 patients were in the study cohort, with 32 patients identified as having non-central head chondromalacia and 32 patients identified as having central head chondromalacia. Of the patients with central head chondromalacia, 81% were diagnosed with instability. Central head chondromalacia was associated with a sensitivity of 84% (71%-97%), specificity of 82% (69%-95%), and positive predictive value of 81% (67%-95%).

CONCLUSIONS

A high percentage of patients with central femoral head chondromalacia were found to have hip microinstability. These results suggest that there is a pattern of femoral head chondral damage in patients with hip microinstability.

LEVEL OF EVIDENCE: Level III, case-control study.