The purpose of this study was to identify cases of early failure following hip arthroscopy and compare to cases in which no additional surgery was required during a 2 year postoperative period. The 2 cohorts were evaluated to identify potential preoperative predictors of early failure following hip arthroscopy. Early failure was defined as conversion to total hip arthroplasty (THA) within 2 years of arthroscopic surgery.

Study variables included gender, age, preoperative diagnosis, minimum joint space, lateral center edge angle (LCEA), the presence or absence of subchondral acetabular cysts, and the size of cysts <1cm or >1cm).

The differences between the 2 cohorts in gender, age, and preoperative diagnosis were not statistically significant. Mean minimum joint space, LCEA, and presence of acetabular subchondral cysts were statistically different between the successful and failure cohorts. The difference in size of the cysts between cohorts was not statistically significant. Following multivariate analysis, the presence of acetabular subchondral cyst remained the only independent pre-operative predictor of failure following hip arthroscopy.

The presence of a subchondral acetabular cyst on MRI is associated with a high rate of THA following hip arthroscopy. While other predictors of early failure following hip arthroscopy may exist, we feel our study results should prove useful in counseling patients regarding appropriate treatment options for hip pain.