Summary

This systematic review and meta-analysis compares gender differences in the prevalence of FAIS morphology subtypes (cam, pincer, mixed), and evaluates for gender differences in PROs, pain scores, and post-operative complication rates after HA for the treatment of FAIS.

Abstract

Background

Trends between genders have been reported with respect to the prevalence, patient-reported outcomes (PROs), and complications of hip arthroscopy (HA) for Femoroacetabular Impingement Syndrome (FAIS), yet the results are mixed and lacking consensus.

Purpose

To (1) compare gender differences in the prevalence of cam and pincer morphology in FAIS, and (2) evaluate for gender differences in PROs, pain scores, and post-operative complication rates after HA for the treatment of FAIS.

Methods

Three databases (EMBASE, PubMed, Ovid [MEDLINE]) were searched from database establishment to November 2021. Studies were included that had gender-specific data related to the prevalence, outcomes, and complications of hip arthroscopy or FAIS. Reviews and commentaries were excluded. The data was combined and between-gender differences were analyzed. A meta-analysis using a random effects model was performed when possible. Pooled risk ratios and standardized mean differences were calculated for male and female data.

Study Design: Systematic Review
Level of Evidence: IV

Results

74 studies met the inclusion criteria, for a total of 213,059 patients. 62.4% were female hips (n=132,973) and 37.6% were male hips (n=80,086). The mean age of all patients was 30.7. Males more frequently experienced cam-type and mixed-type impingement, with the higher prevalence of mixed-type impingement being statistically significant (cam-type: RR 0.85 [0.69, 1.04], p=0.11; mixed-type: RR 0.69 [0.58, 0.81], p<0.001). Females experienced pincer-type impingement significantly more often than males (pincer-type: RR 2.35 [1.14, 4.86], p=0.02). Males also had a higher likelihood of undergoing femoroplasty (RR 0.90 [0.83, 0.97], p=0.006), acetabuloplasty (RR 0.87 [0.79, 0.97], p=0.01), or combined femoroplasty/acetabuloplasty (RR 0.63 [0.44, 0.90], p=0.01). While females showed greater improvements in HOS-SS scores (standard mean difference (SMD) 2.34, 95% CI [0.69, 3.98], p=0.005), mHHS (SMD 0.78, 95% CI [0.23, 1.34], p=0.006) and VAS pain scores (SMD 2.68, 95% CI [1.23, 4.14], p<0.001), both genders experienced far greater improvements than needed to achieve a minimal clinically important difference (MCID) at 1-, 2-, and 5-years post-operatively. Females had significantly higher post-operative complication rates after HA (RR 2.34 [1.33, 4.10], p=0.003), although no gender differences were found in THA conversion rates after HA (RR 0.87 [0.71, 1.08], p=0.21).

Conclusion

Males undergoing HA for FAIS had a higher prevalence of mixed-type FAIS. In contrast, females experienced pincer-type FAIS significantly more often than males. Females also gained greater improvements in PROs after undergoing HA for FAIS, though both genders exceeded the MCID. Despite higher post-operative complication rates for females after HA, the improvements in PROs among both genders suggest that males and females can each benefit from HA. Large high-quality directly comparative studies are needed to confirm any gender differences in the prevalence and outcomes of HA for FAIS.