Nonarthritic Hip Pathology Patterns According to Sex, Femoroacetabular Impingement Morphology, and Generalized Ligamentous Laxity

Lost in research translation: Female athletes are not male athletes, especially at the hip

Altered shape of the proximal femur (cam morphology) or acetabulum (pincer morphology) is indicative of femoroacetabular impingement, which can result in hip pain and osteoarthritis of the hip. As mechanical load during growth affects the resulting bone shape, there is strong evidence in males that cam morphology develops during skeletal growth while physes are open, rather than as an adaptation after growth plates are closed (skeletal maturity). This adaptation is particularly evident in athletes who participate at elite levels prior to skeletal maturity. The research providing this evidence, however, has primarily focused on male athletes. Despite the lack of inclusion in the research, females consistently comprise two thirds of the clinical and surgical populations with structural hip pain or pathology. Knowledge gained from male-dominated cohorts may not appropriately transfer to female athletes, especially at the hip. This perspectives article briefly reviews differences between females and males in femoral and acetabular structure, hormones, timing of puberty/maturation, hypermobility, activity level and movement control-factors which affect hip structure development and loading. Without female-focused research, the application of research findings from male athletes to female athletes may lead to ineffective or even inappropriate recommendations and treatments. Thus, there is a critical need for investment in research to promote life-long hip health for females.

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 Labral Morphological Changes in Patients with Femoroacetabular Impingement Speed Up the Onset of Early Osteoarthritis

Over the last decade, evidence has mounted for a prominent etiologic role of femoroacetabular impingement (FAI) in the development of early hip osteoarthritis (OA). The aim of this study was to compare the ultrastructure and tissue composition of the hip labrum in healthy and pathological conditions, as FAI and OA, to provide understanding of structural changes which might be helpful in the future to design targeted therapies and improve treatment indications. We analyzed labral tissue samples from five healthy multi-organ donors (MCDs) (median age, 38 years), five FAI patients (median age, 37 years) and five late-stage OA patients undergoing total hip replacement (median age, 56 years). We evaluated morpho-functional by histology and transmission electron microscopy. Extracellular matrix (ECM) structure changes were similar in specimens from FAI compared to those from patients with OA (more severe in the latter) showing disorganization of collagen fibers and increased proteoglycan content. In FAI and in OA nuclei the chromatin was condensed, organelle degenerated and cytoplasm vacuolized. Areas of calcification were mainly observed in FAI and OA labrum, as well as apoptotic-like features. We showed that labral tissue of patients with FAI had similar pathological alterations of tissue obtained from OA patients, suggesting that FAI patients might have high susceptibility to develop OA.

Hip microinstability diagnosis and management: a systematic review

PURPOSE

The purpose of this systematic review is to present the most common causes, diagnostic features, treatment options and outcomes of patients with hip micro-instability.

METHODS

Three online databases (MEDLINE, Embase, and PubMed) were searched from database inception March 2022, for literature addressing the diagnosis and management of patients with hip micro-instability. Given the lack of consistent reporting of patient outcomes across studies, the results are presented in a descriptive summary fashion.

RESULTS

Overall, there were a total of 9 studies including 189 patients (193 hips) included in this review of which 89% were female. All studies were level IV evidence with a mean MINORS score of 12 (range: 10-13). The most commonly used features for diagnosis of micro-instability on history were anterior pain in 146 (78%) patients and a subjective feeling of instability with gait in 143 (81%) patients, while the most common feature on physical examination was the presence of anterior apprehension with combined hip extension and external rotation in 123 (65%) patients. The most common causes of micro-instability were iatrogenic instability secondary to either capsular insufficiency or cam over-resection in 76 (62%) patients and soft tissue laxity in 38 (31%) patients.

CONCLUSION

The most common symptom of micro-instability on history was anterior hip pain and on physical exam was pain with hip extension and external rotation. There are many treatment options and when managed appropriately based on the precise cause of micro-instability, patients may demonstrate improved outcomes.

LEVEL OF EVIDENCE

IV.

Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome in Adolescents Improves Outcomes and Clinical Benefit Achievement Rates at Short-Term Follow-Up. A Multicenter Analysis

PURPOSE

To report minimum 2-year follow-up patient-reported outcome scores (PROs) and rates of achieving the minimal clinically important difference (MCID), the patient-acceptable symptomatic state (PASS), and the maximal outcome improvement (MOI) on adolescents following primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Second, to determine risk factors for revision surgery.

METHODS

Prospectively collected data from two high-volume hip arthroscopy centers were retrospectively reviewed on adolescents (≤19 years old) who underwent primary hip arthroscopy between November 2008 and February 2019. Adolescents with a minimum 2-year follow-up for the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sports Specific Subscale (HOS-SSS), International Hip Outcome Tool-12 (iHOT-12), and visual analog scale (VAS) for pain were included regardless of their growth plate status. Exclusion criteria were Tönnis grade >1, lateral center edge-angle <18°, and previous ipsilateral hip surgery or conditions. Preoperative and postoperative radiographic data, MCID, PASS, MOI, secondary surgeries, and complications were reported. A multivariable survival analysis for risk factors for secondary surgery was conducted.

RESULTS

A total of 287 hips (249 patients) were included (74.9% females). The mean values for age, body mass index, and follow-up were 16.3 ± 1.3 years, 22.3 ± 3.5, and 26.6 ± 9.4 months, respectively. Further, 88.9% underwent labral repair, 81.5% femoroplasty, and 85.4% capsular closure. Improvement for all PROs was reported (P < .001) with high patient satisfaction (8.8 ± 1.5). Achievement for the MCID was 71.7%, 83.0%, 68.1%, and 79.5% for the mHHS, NAHS, HOS-SSS, and iHOT-12, respectively. Achievement for the PASS was 68.3% for the mHHS and 73.2% for the NAHS. The MOI for mHHS, NAHS, and VAS was 58.3%, 77.0%, and 59.6%, respectively. Rates of revision hip arthroscopy, cam recurrence, and heterotopic ossification were 5.8%, 1.7%, and 5.5%, respectively. Acetabular retroversion was found to be a risk factor for revision surgery (P = .03).

CONCLUSION

The results of this multi-center study demonstrated that adolescents who underwent primary hip arthroscopy for FAIS reported significant improvement in all PROs, with satisfactory achievement rates for the MCID, PASS, MOI, and high patient satisfaction at a minimum 2-year follow-up.

LEVEL OF EVIDENCE

IV, retrospective multicenter study.

Effective Management Options for Treatment of Microinstability of the Hip: a Scoping Review

PURPOSE OF REVIEW

To review the recent literature identifying and summarizing the research involving management of microinstability of the hip and highlight new and evolving techniques in its treatment.

RECENT FINDINGS

Recent updates in the understanding of capsular management hip arthroscopy will likely lead to less revision surgery and a decreased incidence of persistent post-operative pain. Repair of residual capsular defects has shown good outcomes with high patient satisfaction. Capsular plication remains the gold standard for hips with increased pain that show signs of capsular laxity/deficiency on exam or imaging. Capsular reconstruction has shown equivalent results to other revision hip arthroscopy procedures with low rates of complications. Ligamentum teres pathology, although rare, should be considered a source of pain, particularly in patients with laxity on exam. In cases where CAM over-resection has occurred, remplissage using allograft is an effective option for restoring the capsular suction seal and stability. Microinstability is increasingly being recognized as a source of post-operative hip pain. Patients with collagen disorders remain a challenging clinical entity with increased rates of complications and post-operative pain. CAM resection should be performed carefully and not disrupt the suction seal but be sufficient to not cause further impingement. Improved evidence including well-designed prospective studies with large sample sizes will determine the future management of this complex problem.

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.