Intraoperative cartilage degeneration predicts outcome 12 months after hip arthroscopy

Abstract

Background: When considering arthroscopic surgery for treatment of hip pain, it is important to understand the influence of joint degeneration on the likelihood of success. Previous research has shown poorer outcomes among patients with osteoarthritis but new arthroscopic techniques including femoroacetabular impingement correction and microfracture may lead to better arthroscopic outcomes.

Questions/purposes: We investigated the effect of intraarthroscopic articular and rim cartilage degeneration on the outcome after hip arthroscopy using contemporary techniques.

Methods: The modified Harris hip score (MHHS) and nonarthritic hip score (NAHS) were completed preoperatively and 12 months postoperatively by 560 patients undergoing hip arthroscopy after March 2007. Change in these scores was compared between patients with and without acetabular or femoral articular cartilage degeneration and between patients with and without rim cartilage degeneration. Correlation and regression analyses were used to predict the change in outcome scores based on the severity of cartilage degeneration.

Results: Hips without degeneration had greater improvement in the outcome scores. The presence of cartilage degeneration showed negative correlations with change in outcomes. The best model to explain change in MHHS included preoperative score, articular cartilage degeneration grade, and rim lesion grade (adjusted R(2) = 0.24).

Conclusions: Our data support previous findings regarding the negative influence of cartilage degeneration on improvement after hip arthroscopy. Nevertheless, many patients with cartilage degeneration still improved and the severity of degeneration accounts for little of the resulting variance in change. Future studies must determine the clinical importance of the improvements gained by patients with cartilage degeneration and identify other predictors of outcome.

Level of evidence: Level III, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

Fig. 1

A flowchart shows selection of study participants. Duplicate patients are those who had two or more hip arthroscopies during the inclusion period. Only outcomes from the latter surgery were included.

Fig. 2A–B

The mean (SD) change in the MHHS and the NAHS after 12 months for each grade of (A) articular cartilage degeneration and (B) rim cartilage degeneration are shown. MHHS = modified Harris hip score; NAHS = nonarthritic hip score.