Sex Differences in Clinical Outcomes Following Surgical Treatment of Femoroacetabular Impingement

Females and Males Achieve Similar Improvement, Outcomes, and Survivorship Following Hip Arthroscopy with Labral and Capsular Repair for Femoroacetabular Impingement Syndrome at Minimum 10-Year Follow-Up

PURPOSE

To evaluate the effect of patient sex on 10-year patient-reported outcomes (PROs) and survivorship after hip arthroscopy (HA) for femoroacetabular impingement syndrome (FAIS).

METHODS

Patients who underwent primary HA for FAIS with minimum 10-year follow-up from 1/2012-12/2013 were retrospectively reviewed. Female patients were propensity-matched to male patients in a 1:1 ratio by age and body mass index. PROs and rates of minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) achievement were compared between cohorts. Rate of reoperation-free survivorship was compared between sexes.

RESULTS

One-hundred and twenty-one- females (age: 36.2 ± 12.3 years) were matched to 121 males (age: 35.7 ± 11.3 years, p = 0.594) at average follow-up of 10.4 ± 0.4 years. There were no differences in any preoperative demographic characteristics between the groups (p ≥ 0.187). Both groups demonstrated significant improvement in every PRO measure between the preoperative and 10-year postoperative time points (p < 0.001). The magnitude of improvement was similar between the groups for all PRO measures (p ≥ 0.139). At 10-years, female patients trended towards higher MCID achievement for the Hip Outcome Score-Activities of Daily Living subscale (HOS-ADL) than male patients (72.7% vs. 57.3%, p = 0.061), with otherwise similar MCID achievement rates. Females trended towards significantly lower HOS-Sports Subscale PASS achievement (65.4% vs. 77.1%, p = 0.121) with otherwise similar PASS achievement rates between the groups (p ≥ 0.170).

CONCLUSION

Female and male patients experienced similar improvement in PROs at ten-year follow-up. MCID and PASS achievement rates were predominantly similar between sexes. Survivorship did not differ between groups. Long-term success can be expected for appropriately indicated patients undergoing HA for FAIS, regardless of sex.

LEVEL OF EVIDENCE

III, Retrospective Cohort Study.

Hip arthroscopy is an effective treatment for high-level female athletes

OBJECTIVES

This study aimed to assess the outcomes of hip arthroscopic surgery in high-level female athletes diagnosed with femoroacetabular impingement (FAI) compared to those with lower levels of sports activity. Additionally, we investigated the effectiveness of patient-reported outcomes (PROs) and the potential ceiling effect as a lack of sensitivity in detecting clinically statistically significant changes in high-level female athletes due to high baseline scores.

METHODS

We conducted a retrospective analysis of prospectively collected data from female patients who underwent hip arthroscopy for FAI between January 2016 and August 2022 with a minimum 1-year follow-up. Patients were categorised into two groups: high-level athletes (group A) and low sports activity level (group B). Various PROs, visual analogue scales for pain, and patient satisfaction were assessed preoperatively and postoperatively. Return to sports (RTS) rates were determined based on the patient's reported ability to return to their previous level of sports activity. The minimally clinically important differences (MCIDs) and the Patient-Acceptable Symptomatic State (PASS) analyses were used to evaluate the clinical impact of the Hip Outcome Score-Sport Subscale (HOS-SSS).

RESULTS

A total of 11 high-level female athletes were included in group A, and 22 were included in the low sports activity level group B. Both groups showed significant improvements in PROs, with no significant differences between them. RTS rates were lower in high-level athletes (63.6%) than in low sports activity patients (85.7%). Visual analogue scales for pain improved significantly in both groups. Patient satisfaction was high in both groups, with a median score of 9. The HOS-SSS showed no ceiling effect, and the MCID and PASS analyses indicated that a high proportion of patients in both groups achieved clinically relevant improvement in HOS-SSS.

CONCLUSION

Hip arthroscopic surgery is effective for FAI treatment in high-level female athletes, with outcomes similar to those in patients with lower sports activity levels. The absence of a ceiling effect in sports-related outcomes suggests that PROs can detect clinically significant changes in high-level female athletes. Although RTS rates were lower in high-level athletes, this difference was not significant. These findings underscore the value of using PROs to evaluate outcomes in female athletes with different sports-activity levels.

LEVEL OF EVIDENCE

IV.

Risk Factors for Suboptimal Outcome of FAI Surgery in the Adolescent Patient

BACKGROUND

Surgical treatment for adolescent patients with femoroacetabular impingement (FAI) is increasing. The purpose of this study was to determine the clinical outcomes of FAI surgery in a multicenter cohort of adolescent patients and to identify predictors of suboptimal outcomes.

METHODS

One hundred twenty-six adolescent hips (114 patients < 18 years of age) undergoing surgery for symptomatic FAI were studied from a larger multicenter cohort. The group included 74 (58.7%) female and 52 male hips (41.3%) with a mean age of 16.1 (range 11.3 to 17.8). Clinical outcomes included the modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score (5 domains), and University of California Los Angeles activity score. Failure was defined as revision surgery or clinical failure (inability to reach minimally clinical important differences or patient acceptable symptoms state for the mHHS). Statistical analysis was used to identify factors significantly associated with failure.

RESULTS

There was clinically important improvement in all patient-reported outcomes for the overall group, but an 18.3% failure rate. This included a revision rate of 8.7%. Females were significantly more likely than males to be classified as a failure (25.7 vs. 7.7%, P =0.01), in part because of lower preoperative mHHS (59.1 vs. 67.0, P < 0.001). Mild cam deformity (alpha angle <55 degrees) was present in 42.5% of female hips compared with 17.3% male hips. Higher alpha angles were inversely correlated with failure. Alpha angles >63 have a failure rate of 8.3%, between 55 and 63 degrees, 12.0% failure rate, and <55 degrees (mild cam) failure rate of 37.5%. Patients who participated in athletics had a 10.3% failure rate compared with nonathletes at 25.0% ( P =0.03, RR (relative risk) 2.4).

CONCLUSIONS

Adolescent patients undergoing surgical treatment for FAI generally demonstrate significant improvement. However, female sex, mild cam deformities, and lack of sports participation are independently associated with higher failure rates. These factors should be considered in surgical decision-making and during patient counseling.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Outcomes After Hip Arthroscopy Show No Differences Between Sexes: A Systematic Review

PURPOSE

To assess differences in postoperative outcomes between male and female patients following hip arthroscopy.

METHODS

A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Medline, Embase, Cochrane, and PubMed databases were searched. Key words included "hip," "arthroscopy," "outcome," "gender difference," "sex difference," "gender," and "patient-reported outcome." Studies were included that reported sex-specific analysis of outcomes following primary hip arthroscopy with minimum 2-year follow-up. Methodological Index for Non-Randomized Studies criteria were applied to each study. Data collected included patient-reported outcome measures (PROMs), complications, rates of revision arthroscopy (RA), and conversion to total hip arthroplasty (THA). Forest plots were generated for the most frequently reported PROMs, RA, and THA rates.

RESULTS

In total, 38 studies met the inclusion criteria, with 40,194 (57% female) hips included. The most common indications for hip arthroscopy were femoroacetabular impingement and labral tears. Eighteen studies reported PROMs, with no clear trend towards sex differences. Eleven studies reported on RA rates, with 4 showing a significantly greater rate of RA in female patients. Seventeen studies reported on conversion to THA, with an overall conversion rate of 9.64%. There were no clear sex differences in conversion to THA.

CONCLUSIONS

There was no difference between sexes for postoperative PROM scores. Male patients were less likely to reach the MCID for the HOS-SSS than female patients in the majority of studies, and there were no sex differences for PASS rates. There were no significant differences between sexes in revision arthroscopy rates and conversion to total hip arthroplasty.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II, III and IV studies.

The Impact of Age on Clinical Outcomes of Acetabular Microfracture During FAI Surgery

BACKGROUND

Full-thickness acetabular cartilage lesions are common findings during primary surgical treatment of femoroacetabular impingement (FAI).

PURPOSE

To evaluate clinical outcomes after acetabular microfracture performed during FAI surgery in a prospective, multicenter cohort.

STUDY DESIGN

Cohort Study; Level of evidence, 3.

METHODS

Patients with FAI who had failed nonoperative management were prospectively enrolled in a multicenter cohort. Preoperative and postoperative (mean follow-up, 4.3 years) patient-reported outcome measures were obtained with a follow-up rate of 81.6% (621/761 hips), including 54 patients who underwent acetabular microfracture. Patient characteristics, radiographic parameters, intraoperative disease severity, and operative procedures were analyzed. Propensity matching using linear regression was used to match 54 hips with microfracture to 162 control hips (1:3) to control for confounding variables. Subanalyses of hips ≤35 and >35 years of age with propensity matching were also performed.

RESULTS

Patients who underwent acetabular microfracture were more likely to be male (81.8% vs 40.9%; P < .001), be older in age (35.0 vs 29.9 years; P = .001), have a higher body mass index (27.2 vs 25.0; P = .001), and have a greater alpha angle (69.6° vs 62.3°; P < .001) compared with the nonmicrofracture cohort (n = 533). After propensity matching to control for covariates, patients treated with microfracture displayed no differences in the modified Harris Hip Score or Hip Disability and Osteoarthritis Outcome Score (P = .22-.95) but were more likely to undergo total hip arthroplasty (THA) (13% [7/54] compared with 4% [6/162] in the control group; P = .002), and age >35 years was associated with conversion to THA after microfracture. Microfracture performed at or before 35 years of age portended good outcomes with no significant risk of conversion to THA at the most recent follow-up.

CONCLUSION

Microfracture of acetabular cartilage defects appears to be safe and associated with reliably improved short- to mid-term results in younger patients; modified expectations should be realized when full-thickness chondral lesions are identified in patients >35 years of age.

Sex-Based Differences in Prevalence, Outcomes, and Complications of Hip Arthroscopy for Femoroacetabular Impingement: A Systematic Review and Meta-analysis

Background

Trends between the sexes have been reported regarding prevalence, patient-reported outcomes (PROs), and complications of hip arthroscopy (HA) for femoroacetabular impingement syndrome (FAIS), yet current results lack consensus.

Purpose

To evaluate sex-based differences after HA for FAIS in (1) prevalence of cam and pincer morphology in FAIS and (2) PROs, pain scores, and postoperative complication rates.

Study Design

Systematic review; Level of evidence, 4.

Methods

The EMBASE, PubMed, and Ovid (MEDLINE) databases were searched from establishment to February 28, 2022, according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Included studies had sex-based data on prevalence, outcomes, and complications of HA for FAIS. Reviews and commentaries were excluded. Data were combined, and between-sex differences were analyzed. Meta-analyses using random-effects models were performed when possible. Pooled risk ratios (RRs) and standardized mean differences were calculated.

Results

A total of 74 studies were included (213,059 patients; 132,973 female hips [62.4%] and 80,086 male hips [37.6%]). The mean age was 30.7 ± 7.7 years among male patients and 31.1 ± 7.8 years among female patients. Male patients experienced mixed-type impingement significantly more often (39.4% vs 27.2% for female patients; RR = 0.69 [95% confidence interval [CI], 0.58-0.81]; P < .001), whereas female patients experienced pincer-type impingement more often (50.6% vs 30.8% for male patients; RR = 2.35 [95% CI, 1.14-4.86]; P = .02). Male patients had higher likelihoods of undergoing femoroplasty (89.8% vs 77.4% for female patients; RR = 0.90 [95% CI, 0.83-0.97]; P = .006), acetabuloplasty (67.1% vs 59.3% for female patients; RR = 0.87 [95% CI, 0.79-0.97]; P = .01), or combined femoroplasty/acetabuloplasty (29.2% vs 14.5% for female patients; RR = 0.63 [95% CI, 0.44-0.90]; P = .01). Although female patients showed greater improvements in Hip Outcome Score-Sport-Specific subscale (P = .005), modified Harris Hip Score (P = .006), and visual analog scale pain (P < .001), both sexes surpassed the minimal clinically important difference at 1, 2, and 5 years postoperatively. Female patients had higher complication rates (P = .003), although no sex-based differences were found in total hip arthroplasty conversion rates (P = .21).

Conclusion

Male patients undergoing HA for FAIS had a higher prevalence of mixed-type FAIS while female patients had more pincer-type FAIS. Female patients gained greater improvements in PROs, although both sexes exceeded the minimal clinically important difference, suggesting that both male and female patients can benefit from HA.

Majority of competitive soccer players return to soccer following hip arthroscopy for femoroacetabular impingement: female and older aged players are less likely to return to soccer

PURPOSE

To determine return to soccer rates and soccer performance in a large cohort of competitive soccer players after hip arthroscopic surgery for the treatment of femoroacetabular impingement (FAI) and to identify possible risk factors associated with not returning to soccer.

METHODS

An institutional hip preservation registry was retrospectively reviewed for patients identified as competitive soccer players who underwent primary hip arthroscopy for FAI performed between 2010 and 2017. Patient demographics and injury characteristics as well as clinical and radiographic findings were recorded. All patients were contacted for return to soccer information using a soccer-specific return to play questionnaire. Multivariable logistic regression analysis was used to identify potential risk factors for not returning to soccer.

RESULTS

Eighty-seven competitive soccer players (119 hips) were included. 32 players (37%) underwent simultaneous or staged bilateral hip arthroscopy. The mean age at surgery was 21.6 ± 7.0 years. Overall, 65 players (74.7%) returned to soccer, of which 43 players (49% of all included players) returned to pre-injury level of play or better. Most common reasons for not returning to soccer were pain or discomfort (50%) followed by fear of re-injury (31.8%). The mean time to return to soccer was 33.1 ± 26.3 weeks. Among 22 players who did not return to soccer, 14 (63.6%) reported satisfaction from surgery. Multivariable logistic regression analysis revealed female players (odds ratio [OR] = 0.27; confidence interval [CI] = 0.083 to 0.872; p = 0.029) and older aged players (OR = 0.895; 95% CI = 0.832 to 0.963; p = 0.003) were less likely to return to soccer. Bilateral surgery was not found to be a risk factor.

CONCLUSION

Hip arthroscopic treatment for FAI in symptomatic competitive soccer players allowed three-quarters of them to return to soccer. Despite not returning to soccer, two-thirds of players who did not return to soccer were satisfied with their outcome. Female and older aged players were less likely to return to soccer. These data can better guide clinicians and soccer players with realistic expectations related to the arthroscopic management of symptomatic FAI.

LEVEL OF EVIDENCE

III.

Sex-Based Differences in Outcomes After Hip Arthroscopic Surgery for Femoroacetabular Impingement: A Systematic Review

BACKGROUND

While sex-based differences in outcomes after hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) are often recorded, no studies have been dedicated to analyzing the literature as a whole.

PURPOSE

To investigate whether sex is a predictor of outcomes in studies evaluating hip arthroscopic surgery for FAIS.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review was conducted following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We searched the PubMed, Embase, Cochrane, Ovid, and PubMed Central databases for English-language studies that evaluated sex-specific outcomes in human populations. The search terms used were as follows: ("Hip Arthroscopy") AND ("Femoroacetabular Impingement" OR "FAI") AND ("Sex" OR "Gender" OR "Male" OR "Female"). Studies with evidence levels 2 through 4 were included. The studies were then screened, followed by data extraction. Modified Harris Hip Score (mHHS) outcomes and return-to-sport (RTS) rates were recorded. These were analyzed using random-effects meta-analysis. Heterogeneity was calculated using the I ² statistic.

RESULTS

Of 256 full-text articles screened, 48 articles were included in this analysis; of these, 14 studies (29%) concluded that female sex was a negative predictor of postoperative outcomes, while 6 studies (13%) found female sex to be positive predictor. The remaining 28 studies (58%) found no sex-based differences in postoperative outcomes. Of 7 studies (416 male and 519 female) included in the mHHS analysis, 2 studies concluded that male patients had significantly higher postoperative mHHS scores. Of 6 studies (502 male and 396 female) included in the RTS analysis, 1 study concluded that male patients had a significantly higher RTS rate.

CONCLUSION

Almost one-third of the included studies determined that female sex was a negative predictor of postoperative outcomes, 13% found female sex to be a positive predictor, and 58% found no sex-based differences. Our study illustrates an insufficiency of high-level evidence supporting sex-specific differences in outcomes after hip arthroscopic surgery, but findings indicated that the postoperative mHHS score and RTS rate may be influenced by sex.

Elite Female Athletes Demonstrate a Comparable Improvement in Midterm Patient-Reported Outcome Scores and Rate of Return to Sport Compared With Elite Male Athletes After Hip Arthroscopic Surgery: A Sex-Based Comparison in Professional and Collegiate Athletes

BACKGROUND

Few studies have compared outcomes, return to sport (RTS), and continuation of sport (CTS) after primary hip arthroscopic surgery between matched groups of male and female athletes with a minimum 5-year follow-up.

PURPOSE

(1) To report minimum 5-year patient-reported outcome (PRO) scores as well as RTS and CTS rates for elite female athletes undergoing hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) and (2) to compare clinical results with those of a matched control group of elite male athletes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively reviewed for elite (collegiate or professional) female athletes who underwent primary hip arthroscopic surgery for FAIS between March 2009 and March 2016. Inclusion criteria were preoperative and minimum 5-year scores for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score-Sport Specific Subscale, and visual analog scale for pain. Exclusion criteria were Tönnis grade >1, hip dysplasia, previous ipsilateral hip surgery/conditions, and those unwilling to participate. Rates of achieving the minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and maximum outcome improvement satisfaction threshold (MOIST) were recorded in addition to RTS. CTS was also recorded and defined as athletes reporting continued sport activity at a minimum 5-year follow-up after initially reporting returning to sport. Elite female athletes were propensity matched in a 1:1 ratio to elite male athletes for comparison.

RESULTS

A total of 81 hips in elite female athletes that underwent primary hip arthroscopic surgery met the inclusion criteria, and follow-up was available for 65 hips (80.2%) at a mean of 67.6 ± 6.5 months, with a mean age of 24.3 ± 6.8 years. Female athletes demonstrated significant improvements in all recorded PRO scores; achieved the MCID, PASS, and MOIST at high rates; returned to sport at a rate of 80.4%; and continued sport at a rate of 97.1%. Female athletes demonstrated lower preoperative PRO scores compared with male athletes, but postoperative PRO scores; improvements in scores; rates of achieving the MCID, PASS, MOIST; and RTS and CTS rates were similar between female and male athletes.

CONCLUSION

Elite female athletes undergoing primary hip arthroscopic surgery for FAIS demonstrated favorable PRO scores and high RTS and CTS rates at a minimum 5-year follow-up. These results were comparable with those of a propensity-matched control group of elite male athletes.

Females and Males Achieved Comparable Outcomes and Clinical Benefits Following Primary Hip Arthroscopy with Labral Repair, but Age Affected Outcomes and Conversion to Total Hip Arthroplasty. A Short and Mid-Term Follow-Up Analysis with Dual Stratification

PURPOSE

To report and compare, according to sex and age, minimum 2-and minimum 5-year patient-reported outcome scores (PROs) and survivorship in a large cohort of patients who underwent primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

METHODS

Data from February 2008 to September 2018 were reviewed. Patients aged 60 and younger who underwent primary hip arthroscopy with minimum 2-year follow-up were included. Exclusion criteria were Tönnis grade >1, hip dysplasia, previous hip conditions, or any labral treatment different than repair. Minimum 5-year PROs were also collected. All patients included were divided into groups by sex. For further analysis, males and females were stratified according to age: < 21 years old, 21-30 years old, 31-40 years old, 41-50 years old, and 51-60 years old.

RESULTS

In total, 1,326 hips had minimum 2-year follow-up, including 860 (64.9%) females and 466 males (35.1%), with a mean age of 31.6 years (range, 12.8-60.9 years) and a mean follow-up of 58.7 ± 28.9 months. Of those, 772 had minimum 5-year follow-up, 515 females (66.7%), and 257 males (33.3%) with a mean age of 31.7 years (range, 13.1-60.7 years) and a mean follow-up of 78.5 ± 23.0 months. All patients showed significant improvements in PROs at minimum 2-and 5-year follow-up (P < .001). Between sex analysis revealed comparable PROs at latest follow-up between females and males across any age group. Within sexes, and when sexes were combined, patients <21 years old had significantly better outcomes compared to other age groups. There were more females <21 years old that required revision arthroscopy than males <21 years old (P = .015). Conversion to total hip arthroplasty (THA) showed no significant difference between sexes (P > .05). Rates of THA were <21 years (.8%), 21-30 years (2.1%), 31-40 years (4%), 41-50 years (8.9%), and 51-60 years (14.3%).

CONCLUSIONS

Following primary hip arthroscopy for FAIS, all patients reported significant improvements in all PROs at minimum 2-and minimum 5-year follow-up, with females and males achieving similar success. Age affected outcomes, with patients under 21 years old reporting better scores regardless of sex. Although the conversion rate to THA was similar between the sexes, it was lower in the younger ages groups in both sexes.

LEVEL OF EVIDENCE

III, retrospective comparative observation trial.

Sex-Based Differences in Athletes Undergoing Primary Hip Arthroscopy With Labral Reconstruction: A Propensity-Matched Analysis With Minimum 2-Year Follow-up

Background:

There is a paucity of literature comparing sex-based outcome differences in athletes after primary hip arthroscopy with labral reconstruction for femoroacetabular impingement syndrome (FAIS) and irreparable labral tears.

Purpose:

To report sex-based differences in clinical characteristics, patient-reported outcome (PRO) scores, and return-to-sports (RTS) rates in athlete who underwent primary hip arthroscopy with labral reconstruction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data were reviewed for recreational, organized amateur, high school, collegiate, and professional athletes who underwent primary hip arthroscopy with labral reconstruction for FAIS and irreparable labral tears between July 2014 and May 2019. Inclusion criteria included preoperative and minimum 2-year postoperative PRO scores (modified Harris Hip Score, Non-Arthritic Hip Score, Hip Outcome Score–Sports Specific Subscale, International Hip Outcome Tool [iHOT-12], and visual analog scale [VAS] for pain). Exclusion criteria were Tönnis grade >1, hip dysplasia (lateral center-edge angle, <18°), or prior ipsilateral hip surgery/conditions. Patients were divided into groups by sex and were propensity-matched in a 1:1 ratio by age, body mass index, graft type, labral tear size, and sports level.

Results:

A total of 101 hips were eligible, and 94 hips (93.1%) had a minimum 2-year follow-up. Twenty-nine female athlete hips were propensity-matched to 29 male athlete hips. Female athletes underwent higher rates of capsular repair (79.3% vs 24.1% for men; P < .001) and lower rates of acetabular microfracture (0.0% vs 20.7% for men; P = .024). Both female and male athletes experienced significant improvement on all PRO scores (P < .001 for all), high RTS rates (women, 84% vs men, 80.8%), and high rates of achieving the minimal clinically important difference for the iHOT-12 and VAS pain (women, 88.5% vs men, 71.4% for both) and achieving the patient acceptable symptom state for the iHOT-12 (women, 88.5% vs men, 71.4%), with no significant difference between the sexes.

Conclusion:

Despite different clinical characteristics and surgical procedures, both female and male athletes undergoing primary hip arthroscopy with labral reconstruction had significant improvements in all PROs at the minimum 2-year follow-up, high RTS rates, and similar rates of achieving the minimal clinically important difference and patient acceptable symptom state.

Outcome-Affecting Parameters of Hip Arthroscopy for Femoroacetabular Impingement with Concomitant Cartilage Damage-Data Analysis from the German Cartilage Registry

This study aims to report on a prospectively collected, multicenter database of patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAI) and concomitant cartilage damage (according to the International Cartilage Repair Society) and to assess the outcome-affecting parameters. In the study, 353 hips with up to 24 months’ follow-up were assessed by iHOT-33 scoring and achievement of the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) levels. Multiple and binary regression analyses were performed to identify factors related to (un-) favorable outcomes and to assess their clinical relevance with regard to achieving the MCID and PASS. Multiple regression yielded the parameters of male sex (p = 0.022) and lower body mass index (BMI) (p = 0.019) at 6 months, lower BMI (p = 0.022) and younger age (p = 0.022) at 12 months, and younger age at 24 months (p = 0.039) to be significantly associated with higher iHOT scoring. Male sex (p = 0.019) and lower BMI (p = 0.018) were significantly correlated with achievement of the PASS in binary regression at 6 months, whereas at 12 (p = 0.010) and at 24 (p = 0.003) only younger age was shown to be significantly correlated. None of the parameters was statistically associated with achievement of the MCID. As the parameters of younger age, male sex, and lower BMI were identified as temporarily correlated with a preferable outcome in general and with achievement of the PASS in particular, these findings help to preoperatively identify factors associated with (un-) favorable therapy results.

One Bony Morphology, Two Pathologic Entities: Sex-Based Differences in Patients With Borderline Hip Dysplasia Undergoing Hip Arthroscopy

BACKGROUND

Sex-based differences have been largely uncharacterized for patients with borderline hip dysplasia (BHD) undergoing hip arthroscopy.

PURPOSE

To evaluate for sex-based differences in clinical and pathologic characteristics as well as surgical outcomes in patients with BHD undergoing hip arthroscopy.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Between January 2011 and December 2018, data were prospectively collected on all patients with BHD undergoing primary hip arthroscopy. Patients were included if they had preoperative and minimum 2-year postoperative scores for the modified Harris Hip Score (mHHS), Non-arthritic Hip Score (NAHS), and visual analog scale for pain. Patients with previous ipsilateral hip conditions or surgery, Tönnis grade >1, lateral center-edge angle <18° or >25°, or workers' compensation status were excluded. Patients were then divided by sex and propensity score matched in a 1:1 ratio for body mass index, age, and Tönnis grade. The rates of patients who achieved the minimal clinically important difference were recorded for the mHHS and NAHS. The rates of achieving the patient acceptable symptomatic state for the mHHS were calculated.

RESULTS

A total of 344 hips met the inclusion criteria, and 317 hips (92%) had adequate follow-up. Propensity score matching created cohorts of 109 male and 109 female patients. Male patients had significantly higher preoperative average alpha angles (69.79° vs 58.17°, P < .001), more often requiring a femoroplasty (97.2% vs 83.5%, P < .001), and had higher rates of complex labral tearing (50.5% vs 33.0%, P < .001). Male patients also had higher rates of grade 3 and 4 acetabular labral articular disruption (62.4% vs 19.3%, P < .001) and higher rates of grade 3 and 4 acetabular cartilage injury (59.6% vs 20.2%, P < .001) requiring a microfracture more frequently (32.1% vs 7.3%, P < .001). Female patients more typically had painful internal snapping requiring iliopsoas fractional lengthening (60.6% vs 32.1%, P < .001). Female patients also underwent capsular plication more regularly to address hip instability (79.8% vs 45.9%, P < .001). Male and female patients showed significant improvements in all outcome scores after surgery (P < .001). Female patients achieved the minimal clinically important difference for the NAHS at higher rates (85.3% vs 71.6%, P = .020).

CONCLUSION

Female and male patients with BHD who underwent hip arthroscopy achieved favorable outcomes but had notably dissimilar pathology. Hence, although they share similar acetabular bony morphology, male and female patients with BHD may represent 2 very different pathologic entities.