Summary

At a minimum of 10 years postoperatively, patients with global acetabular overcoverage had worse functional outcomes compared to those with lateral or no overcoverage, though no significant differences were found in reoperation or conversion to total hip arthroplasty (THA) between the groups.

Abstract

Objective

Previous studies assessing the outcomes of hip arthroscopy in patients with global acetabular overcoverage and focal superolateral acetabular overcoverage have been limited by short and intermediate-term follow-up periods and inconsistent radiographic criteria in defining these specific subpopulations of femoroacetabular impingement syndrome (FAIS) patients. The objective of this study is to evaluate the long-term postoperative outcomes for patients with FAIS in the setting of global acetabular overcoverage, lateral acetabular overcoverage, and normal acetabular coverage over a 10-year period.

Methods

Patients undergoing hip arthroscopy for FAIS were enrolled in a prospective cohort study, and those with a minimum follow-up of 10 years were included in this analysis. The patients were categorized based on the type of acetabular coverage: global overcoverage (lateral center-edge angle [LCEA] >40° with coxa profunda), lateral overcoverage (LCEA >40° without coxa profunda), and no overcoverage (LCEA <40°). Functional outcomes, measured by the modified Harris Hip Score (MHHS) and Nonarthritic Hip Score (NAHS), as well as survivorship rates, including revision arthroscopy and conversion to total hip arthroplasty (THA), were compared across these groups. All statistical analyses were considered significant at P < 0.05.

Results

A total of 162 patients were included in this analysis. The cohort had a mean age of 38.90 ± 12.61 years and a mean BMI of 24.86 ± 4.03, with an average follow-up duration of 11.63 ± 1.07 years. Among these patients, 73.5% (119/162) had no acetabular overcoverage, 17.3% (28/162) had lateral overcoverage, and 9.3% (15/162) had global overcoverage. Revision rates were 0% for the global overcoverage group, 7.7% for the lateral overcoverage group, and 5.3% for the no overcoverage group (P = 0.6786). THA rates were 0% for the global overcoverage group, 12% for the lateral overcoverage group, and 8.1% for the no overcoverage group (P = 0.5854). Functional outcome scores revealed significant differences among the groups, with the global overcoverage group exhibiting lower MHHS and NAHS scores compared to the other groups (MHHS: P = 0.0061, NAHS: P = 0.0057) (Table 1). Additionally, female sex (P = 0.04) and higher BMI (P < 0.0001) were associated with worse long-term hip function.

Conclusion

At a minimum of 10 years postoperatively, there was no significant difference in the rate of reoperation or conversion to THA between patients with global acetabular overcoverage, lateral overcoverage, and no overcoverage. However, patients with global overcoverage demonstrated worse functional outcomes compared to those with lateral or no overcoverage. Appropriate acetabuloplasty remains critical in managing these patients, and global acetabular overcoverage may portend worse long term functional outcomes compared to other FAIS subtypes.