Midterm Outcomes in Patients After Central Acetabular Decompression for Central Acetabular Stenosis: A Comparison With a Matched Control Group

Abstract

Background:

Central acetabular stenosis (CAS), defined as an osteophyte within the acetabular fossa, is associated with higher rates of femoral head chondral damage and, when left untreated, inferior short-term outcomes after hip arthroscopic surgery. Central acetabular decompression (CAD) is an arthroscopic technique to resect the osteophyte and resurface the acetabular fossa to improve contact mechanics of the femoral head.

Purpose:

The primary aim was to provide the 5-year hip preservation rate and patient-reported outcomes in patients undergoing hip arthroscopic surgery for femoroacetabular impingement (FAI) concomitantly with CAD for CAS. A secondary aim was to compare outcomes in patients treated with CAD for CAS to a propensity score–matched control group of patients without CAS.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A surgical registry with prospectively collected data was reviewed for patients who underwent CAD for CAS identified during primary hip arthroscopic surgery for FAI. The primary outcome for the study was conversion to arthroplasty within 5 years postoperatively. Secondary outcomes included revision arthroscopic surgery and patient-reported outcome scores. Multivariate regression analysis was performed to evaluate the risk factors for progression to arthroplasty. A propensity score–matched control group based on preoperative age, sex, body mass index, and Tönnis grade was formed of patients undergoing hip arthroscopic surgery for FAI without CAS to evaluate the differences in outcomes between the 2 groups.

Results:

There were 155 of 189 eligible patients (82.0%) who had a minimum 5-year follow-up. Within this cohort, the mean age was 45.9 ± 10.8 years, with 90 female patients (58.1%). At the 5-year time point, the arthroplasty-free survivorship rate was 80.6% (125/155). For patients not requiring arthroplasty, significant postoperative improvements were durable (P < .001), with high satisfaction. On multivariate analysis, severe acetabular chondral defects were most predictive of conversion to arthroplasty. The control group of patients with FAI without CAS demonstrated lower rates of chondral damage and higher rates of arthroplasty-free survivorship (P < .01). For patients not requiring arthroplasty, postoperative outcome scores, rates of achieving clinically relevant outcome thresholds, and satisfaction with surgery were comparable between the CAD and control groups.

Conclusion:

Patients with CAS undergoing CAD during primary hip arthroscopic surgery for FAI had durable postoperative improvements and high satisfaction with surgery at a minimum 5-year follow-up. As expected, intraoperative chondral damage rates were significantly greater, and arthroplasty-free survivorship rates were lower, in the CAD group compared with the control group. Nonetheless, 81% of patients undergoing CAD who did not require arthroplasty had significant improvements that were comparable with the control group. We conclude that, with appropriate expectations, patients with FAI and CAS may be treated successfully with advanced arthroscopic techniques.