Risk of failure of primary hip arthroscopy-a population-based study

Patients with a history of lumbar fusion have a higher risk of revision arthroscopy and conversion to total hip arthroplasty after primary hip arthroscopy

PURPOSE

To characterize the risk of revision hip arthroscopy or conversion to total hip arthroplasty (THA) among patients with a history of lumbar fusion undergoing primary hip arthroscopy.

METHODS

We used the Statewide Planning and Research Cooperative System, an administrative database including all ambulatory and inpatient surgery encounters in New York (NY), to identify all patients who underwent hip arthroscopy for FAI between 2010-2020. Patients with prior lumbar fusion were identified using CPT and ICD 9th/10th Revision coding definitions. Patients with and without prior fusion were matched in a 1:5 ratio according to age and comorbidity burden. The number of levels fused was defined in the following fashion: i) no fusion, ii) 1-2 levels, or iii) ≥3 levels. Patients were followed for two years to evaluate the rate of revision hip arthroscopy or conversion to THA. Multivariable logistic regression models were used to measure the association between number of levels fused and revision hip arthroscopy or conversion to THA.

RESULTS

Between 2010-2020, there were 23,277 patients that underwent primary hip arthroscopy in NY state. Of these, 348 (1.4%) had a prior lumbar fusion. After matching for age and comorbidities, the composite rate of revision hip arthroscopy or conversion to THA was higher in patients with prior lumbar fusion compared to patients without (16.5% vs. 8.5%; P < 0.001). This risk increased with the number of levels fused (1-2 levels: 15.1%; aOR, 1.8; 95% CI, 1.3-2.6; vs. ≥3 levels: 26.3%; aOR, 3.4; 95% CI, 1.7-7.0).

CONCLUSION

Patients with a history of lumbar fusion had significantly higher rates of revision hip arthroscopy and conversion to THA compared to patients without prior fusion. The risk of revision hip arthroscopy or conversion to THA was increased approximately 2-fold in patients with 1-2 levels fused and 3-fold in patients with 3 or more levels fused.

LEVEL OF EVIDENCE

Level III, prognostic retrospective matched comparative case series.

Unnecessary interventions for the management of hip osteoarthritis: a population-based cohort study

BACKGROUND

Patients aged 40-60 years who require total hip arthroplasty (THA) often first receive unindicated hip arthroscopy or magnetic resonance imaging (MRI). Our objective was to identify potentially inappropriate resource utilization before THA, specifically reporting on the proportion of patients aged 40-60 years who underwent hip arthroscopy or MRI in the year before THA.

METHODS

We conducted a retrospective, population-based study at the provincial level. We retrieved data from the Canadian Institute for Health Information (CIHI). We included all Ontario residents who underwent an elective, primary THA for osteoarthritis between Apr. 1, 2004, and Mar. 31, 2016. We identified the rates and timing of patients who underwent an MRI or hip arthroscopy before their index THA.

RESULTS

The percentage of patients who underwent an MRI before THA increased significantly over the study period, from 8.7% in 2004 to 23.8% in 2015. There was also a significant but variable trend in the percentage of patients who underwent a hip arthroscopy before THA.

CONCLUSION

Our results demonstrate a high, gradually increasing proportion of patients who received a hip MRI and a low but increasing proportion of patients who received hip arthroscopy in close proximity to THA. Multidisciplinary collaboration may improve knowledge translation and help reduce the rate of clinically unnecessary diagnostic and therapeutic interventions in this population of patients who require THA.

Increasing Hip Arthroscopy Case Volume Is Associated With Increased Risk for Revision Surgery but Not Conversion to Total Hip Arthroplasty or 90-Day Hospitalizations: A Cross-Sectional Analysis of 468 Surgeons

PURPOSE

To analyze the effects of surgeon-specific factors, including case volume, career duration, fellowship training, practice type, and region of practice, on rates of 2-year revision surgery, conversion to total hip arthroplasty (THA), and 90-day hospitalizations following hip arthroscopy.

METHODS

The PearlDiver Mariner Database was used to query patients undergoing hip arthroscopy between 2015 and 2018. Surgeons performing these procedures were identified, and surgeon-specific demographics and variables were collected from publicly available data. Patients were followed for 2 years to assess for reoperations, including revision hip arthroscopy and conversion to THA, as well as 90-day hospitalizations, including emergency department visits and hospital readmissions. International Classification of Diseases, Tenth Revision codes were used to track the laterality of revision hip procedures. Associations between surgeon-specific factors and postoperative outcomes were assessed through univariate and multivariate analyses.

RESULTS

In total, 20,834 patients underwent hip arthroscopy procedures by 468 surgeons. Multivariate analysis with logistic regression adjusted for patient-related factors (age, sex, obesity, Charlson Comorbidity Index, and smoking status) identified increasing surgeon case volume to be associated with increased risk for 2-year revision hip arthroscopy (P < .001), but not 2-year conversion to THA or 90-day hospitalizations. Nonsports medicine fellowship-trained surgeons were associated with greater risk for 2-year THA conversion (P < .001) and 90-day hospital readmissions (P < .01). Surgeons practicing in an academic setting demonstrated greater risk for 90-day hospital readmissions (P < .001). Surgeons practicing in the West region of the United States were more likely to incur 2-year revision hip arthroscopy procedures compared to surgeons in the South, Midwest or Northeast (P < .001).

CONCLUSIONS

Increasing surgeon hip arthroscopy case volume is associated with an increased risk for 2-year revision hip arthroscopy but not conversion to THA or 90-day hospitalizations. Further, non-sports medicine fellowship-trained surgeons were associated with higher risk for 2-year THA conversion after hip arthroscopy.

LEVEL OF EVIDENCE

Level III, retrospective cohort analysis.

Injections prior to hip arthroscopy are associated with increased risk of repeat hip arthroscopy at 1 and 5 years

INTRODUCTION

Previous studies have shown that intra-articular hip injections prior to hip arthroscopy (HA) can be a helpful diagnostic tool. However, local anesthetic and corticosteroid injections can be chondrotoxic and corticosteroid injections have been shown to increase the risk of infection during subsequent surgical intervention. The purpose of this study was to evaluate whether preoperative injections adversely affect outcomes of HA using a national database.

MATERIALS AND METHODS

The TriNetX database was retrospectively queried. Patients undergoing HA for femoroacetabular impingement with at least 1 year of claims runout were included in the analysis. Patients were grouped by whether they had a hip injection within 1 year prior to HA. The rates of repeat HA, total hip arthroplasty (THA), infection, osteonecrosis, and new onset hip OA at 1- and 5-years postoperatively were compared between groups. Statistical significance was assessed at α = 0.05.

RESULTS

6511 HA patients with previous injection and 1178 HA patients without previous injection were included. Patients with a previous injection were overall younger (32.3 vs. 34.7 years, p < 0.001), more likely to be female (69 vs. 48%, p < 0.001) and had a higher BMI (26.3 vs. 25.7 kg/m2, p = 0.043). At 1 and 5-years postoperatively, patients with any injection were 1.43 (p < 0.001) and 1.89 (p < 0.001) times more likely to undergo repeat HA, respectively. At 1 and 5-years postoperatively, patients who underwent a corticosteroid injection were 2.29 (p < 0.001) and 1.89 (p < 0.001) times more likely to undergo repeat HA than patients with local anesthetic injection only and 1.56 (p < 0.001) and 2.08 (p < 0.001) times more likely to undergo repeat HA than patients with no injection.

CONCLUSIONS

Intraarticular hip injections prior to hip arthroscopy, particularly corticosteroid injections, are associated with increased risk of repeat hip arthroscopy at 1 and 5 years. Additional studies are needed to elucidate this risk.

A High Incidence of Perineal Post-Related Complications After Hip Arthroscopy Is Self-Reported by Patients in Anonymous Online Forums

Purpose

To evaluate online, self-reported pudendal nerve or perineal injuries related to the use of a perineal post during hip arthroscopy.

Methods

Public posts on Reddit and the Health Organization for Pudendal Education were searched to identify anonymous individuals reporting symptoms of pudendal nerve or perineal injury following hip arthroscopy. Included posts were by any individual with a self-reported history of hip arthroscopy who developed symptoms of pudendal nerve injury or damage to the perineal soft tissues. Demographic information and details about a person's symptoms and concerns were collected from each post. Descriptive statistics were used to analyze the data.

Results

Twenty-three online posts reported on a perineal post-related complication following hip arthroscopy. Sex information was available in 16 (70%) posts (8 male, 8 female). Twenty-two posts reported a sensory injury, and 4 posts reported a motor injury with sexual consequences (sexual dysfunction, dyspareunia, impotence). Symptom duration was available in 15 (65%) posts (8 temporary, 7 permanent). Permanent symptoms included paresthesia of the perineum or genitals (7) and sexual complaints (5). Two posts stated they were counseled preoperatively about the possibility of this injury. Zero patients reported that a postless hip arthroscopy alternative was an option made available to them before surgery.

Conclusions

A high incidence of permanent pudendal nerve, perineal skin, and genitourinary/sexual complications are self-reported and discussed online by patients who have undergone post-assisted hip arthroscopy. These patients report being uninformed and undereducated about the possibility of sustaining a post-related complication. No patient reported being informed of postless hip arthroscopy preoperatively.

Clinical Relevance

Identifying and evaluating self-reported patient information in online medical forums can provide important information about patient experiences and outcomes.

Increased 90-Day Readmissions and Complications Following Hip Arthroscopy in Centers With Low Surgical Volume in New York State

PURPOSE

To (1) classify surgical centers in New York State by volume of hip arthroscopies performed, (2) calculate rates of readmissions and complications by center volume, and (3) identify socioeconomic predictive factors for readmissions and complications following hip arthroscopy.

METHODS

Patients who underwent hip arthroscopy at New York State health care facilities from 2010 to 2020 were retrospectively identified using the New York Statewide Planning and Research Cooperative System (SPARCS) database. Hip arthroscopic procedures were identified using the following Current Procedural Terminology codes. Surgical center volumes were classified into 3 categories: low (<85th percentile), medium (85th-95th percentile), and high (>95th percentile). Incidence of readmissions and complications within 90 days was abstracted from SPARCS. Neighborhood socioeconomic status was quantified using the U.S. Area Deprivation Index. Multivariable logistic regression was used to determine whether center volume and other socioeconomic variables were independent predictors of outcomes.

RESULTS

In total, 50,252 patients who underwent hip arthroscopy were identified in SPARCS from 2010 to 2020. Of these patients, 13,861 (27.6%) underwent surgery at low-volume centers, 11,757 (23.4%) at medium-volume centers, and 24,634 (49.0%) at high-volume centers. Minorities, publicly insured patients, and patients from lower socioeconomic status neighborhoods made up a larger proportion of cases seen by low-volume centers versus high-volume centers (P < .001). Patients in the low-volume group experienced significantly greater 90-day rates of readmissions (P < .001) and all-cause complications (P < .001) than the other groups. Furthermore, high-volume centers were independently associated with lower odds of readmission (odds ratio 0.57, P < .001) and all-cause complications (odds ratio 0.73, P < .001) versus low-volume centers.

CONCLUSIONS

Low-volume surgical centers are associated with increased readmission and complication rates following hip arthroscopy, independent of other socioeconomic factors such as age, sex, race, insurance status, and neighborhood socioeconomic status.

LEVEL OF EVIDENCE

Level III, retrospective comparative prognostic trial.

Revealing a Natural Model of Pre-Osteoarthritis of the Hip Through Study of Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is considered the mechanical cause of hip osteoarthritis (OA). Surgical intervention involves labrum repair and osteochondroplasty to remove the impingement, alleviating symptoms. Nevertheless, some patients progress to hip OA after surgery, indicating that factors other than mechanical abnormality are contributing to hip OA progression. This review article discusses our laboratory's studies on hip FAI and OA, undertaken to identify key molecular players in the progression of hip OA. Transcriptome analysis identified peroxisome proliferator activated receptor gamma (PPARγ) as a crucial molecule in early hip OA. PPARγ, widely expressed in chondrocytes, has a protective role in preventing OA, but its true mechanism remains unknown. We observed a dysregulation of DNA methyltransferase (DNMT) in the progression of hip OA, with high expression of DNMT1 and 3A and downregulation of DNMT3B. Moreover, we established that DNMT3A is the main molecule that is binding to PPARγ promoter CpG area, and hypermethylation of this area occurs during disease progression. This suggests that epigenetic changes are a main mechanism that regulates PPARγ expression. Finally, we developed a novel rabbit model of hip FAI and OA and are currently performing studies to validate our small-animal model to human FAI.

Editorial Commentary: The Hip Arthroscopy Volume-to-Competency Learning Curve Debate Is Complicated: Learning When "Enough Is Enough" Is a Lifetime Discipline

As hip arthroscopy use grows, so does resident and fellow exposure, providing more "hands-on" learning opportunities. Nevertheless, hip arthroscopy is technically challenging, particularly noting that improved patient-reported outcomes and survivorship are reported after labral repair or reconstruction (vs debridement) as well as routine capsular closure. Undoubtedly a requisite number of cases is required to reach the saturation point of the "learning curve." A recent review shows that traction time, complication rates, and reoperation rates decrease with increasing case volumes, but there is a wide range of cases reported after which the learning curve "plateaus," ranging from 30 to 520 cases. A large database study shows that hip arthroscopy readmissions and complications are significantly lower in high-volume centers. However, large database studies may include biases requiring attention. First, the rates are relatively low across the entire cohort. Second, more younger patients were treated in the greater-volume centers, which may contribute to the difference in outcomes observed. Finally, older patients (often >50 years old) with concomitant osteoarthritis are also associated with greater complication, readmission, and reoperation rates. Such patients may not be selected as candidates for hip arthroscopy by greater-volume surgeons. The hip arthroscopy volume to competency learning curve debate is complicated. Learning when "enough is enough" is a lifetime discipline.

Adhesions in the setting of hip arthroscopy

With the growing number of primary arthroscopies performed, patients requiring revision hip arthroscopies for various issues is high including postoperative adhesion formation, a source of pain, mechanical symptoms, range of motion limitation, stiffness, and microinstability. Adhesions are a consequence of biological pathways that have been stimulated by injury or surgical interventions leading to an increased healing response. Preventative efforts have included surgical adjuncts during/after primary hip arthroscopy, biologic augmentation, and postoperative rehabilitation. Treatment options for adhesion formation includes surgical lysis of adhesions with or without placement of biologic membranes aimed at inhibiting adhesion reformation as well as systemic medications to further reduce the risk. Postoperative rehabilitation exercises have also been demonstrated to prevent adhesions as a result of hip arthroscopy. Ongoing clinical trials are further investigating pathways and prevention of adhesion formation.

Progression of Osteoarthritis at Long-term Follow-up in Patients Treated for Symptomatic Femoroacetabular Impingement With Hip Arthroscopy Compared With Nonsurgically Treated Patients

BACKGROUND

Femoroacetabular impingement (FAI) is a common cause of hip pain, especially in young patients. When left untreated, it has been demonstrated to be a risk factor for the onset or progression of osteoarthritis (OA) and has been identified as one of the main contributors leading to the need for total hip arthroplasty (THA) at a young age. While the short-term therapeutic potential of hip arthroscopy is widely recognized, little is known regarding its potential mid- to long-term preventive effect on the progression of hip OA.

PURPOSE

To (1) report clinical outcomes of arthroscopically treated FAI syndrome with a minimum 5-year follow-up and compare the results to a cohort with FAI treated nonsurgically and (2) determine the influence of hip arthroscopy on the onset and progression of hip OA in patients diagnosed with FAI.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who had hip pain and were diagnosed with FAI were included. Exclusion criteria were (1) previous or concomitant hip surgery, (2) <5 years of follow-up, and (3) insufficient radiographs. Patients treated with hip arthroscopy were compared with a cohort of patients with FAI who were treated nonsurgically. Kaplan-Meier estimates of failure (defined as conversion to THA) were performed. Bivariate analysis and Cox regression were used to identify factors associated with inferior clinical and radiographic outcomes.

RESULTS

A total of 957 patients (650 female, 307 male; 1114 hips) (mean age, 28.03 ± 8.9 years [range, 6.5-41.0 years]) with FAI were included. A total of 132 hips underwent hip arthroscopy and 982 hips were nonoperatively treated. The mean follow-up was 12.5 ± 4.7 years (range, 5.0-23.4 years). At the final follow-up, the rate of OA progression was 26.5% in the operative group and 35.2% in the nonoperative cohort (P < .01). Conversion to THA was performed in 6.8% of the surgical patients and 10.5% of the initially nonsurgical patients (P = .19). Additionally, there was no significant difference in the risk of failure between the operatively and nonoperatively treated patients. Male sex, increased age at initial diagnosis, presence of cam morphology, and increased initial Tönnis grade were risk factors for failure (male sex: hazard ratio [HR], 2.3; P < .01; per year of increased age: HR, 1.1; P < .01; presence of cam: HR, 3.5; P < .01; per Tönnis grade: HR, 4.0; P < .01).

CONCLUSION

At a mean follow-up of nearly 13 years, 7% of patients of the surgical group experienced progression to THA, compared with 11% of the nonoperative control group. While most of the operative group showed little to no OA at final follow-up, moderate OA (Tönnis grade 2) was present in 12% of the cohort compared with 22% of nonsurgical patients. Increased age at diagnosis, male sex, presence of a cam morphology, and presence of initial arthritic joint changes were found to be risk factors for failure. The results of this study demonstrated evidence for a preventive effect of hip arthroscopy on the development and progression of OA in young patients with FAI at mid- to long-term follow-up.

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.

Total Hip Arthroplasty in Patients Aged 40 to 60 years old: A Population-Based Study

INTRODUCTION

Contemporary total hip arthroplasty (THA) has resolved many implant longevity concerns in younger patients. Patients in their fourth and fifth decades of life are projected to be the fastest growing demographic of THA patients. We aimed to assess this demographic to evaluate the: 1) rate of THA over time; 2) cumulative incidence of revision; and 3) identify risk factors for revision.

METHODS

A retrospective population-based study of patients between 40 and 60 years old undergoing primary THA was conducted using administrative data from a large clinical data repository. A total of 28,414 patients were included for analysis with a mean age of 53 years (range, 40-60 years) and median follow up of 9 years (range, 0-17 years). Linear regressions were used to assess annual rates of THA in this cohort over time. Kaplan-Meier analysis was used to determine cumulative incidence of revision. Multivariate cox proportional hazards models were used to determine association of variables with revision risk.

RESULTS

The annual rate of THA in our population increased by 60.7% over the study period (P <0.0001). Cumulative incidence of revision was 2.9% at 5-years and 4.8% at 10-years. Younger age, women, non-osteoarthritis diagnosis, medical complications, and annual surgeon volume < 60 THA were associated with increased revision risk.

CONCLUSION

Demand for THA continues to dramatically increase in this cohort. Risk of revision was low but multiple risk factors were identified. Future studies will help delineate the effect of these variables on revision risk and assess implant survivorship beyond 10 years.

The HAR-index: a reliable method for evaluating the risk of total hip arthroplasty conversion after hip arthroscopy for femoroacetabular impingement

PURPOSE

Hip arthroscopy is a growing technique in the treatment of femoroacetabular impingement (FAI), but can sometimes lead to unsatisfactory results such as the early conversion to total hip arthroplasty (THA). The purpose of this study is to describe a new tool for assessing the preoperative risk of THA conversion after hip arthroscopy in patients with FAI.

METHODS

This study is a retrospective analysis of a prospective cohort of 584 patients with FAI who underwent hip arthroscopy at a single centre with a minimum 2 years follow-up. The preoperative variables of these patients were analysed to calculate the risk of each variable for THA. By selecting variables with an area under the receiver operating characteristic (ROC) curve greater than 0.7, a calculator was created to provide a risk index for each patient.

RESULTS

Four variables (age, body mass index, Tönnis score and ALAD) were associated with an increased risk of THA conversion. The optimal cut-off points for each variable were determined, and a risk index was created. The Hip-Arthroplasty-Risk Index (HAR-Index) is a 0-4 points scale obtained from four binary scores of 0 or 1 depending on whether the cut-off point for each variable was reached or not. The increased risk of THA for each HAR-Index value was 1.1%, 6.2%, 17.9%, 55.1% and 79.3% respectively. The HAR-Index showed a very good predictive capacity with an area under the ROC curve of 0.89.

CONCLUSION

The HAR-Index is a simple and practical tool for practitioners to make more informed decisions about performing hip arthroscopy in patients with FAI. With a very good predictive capacity, the HAR-Index can help to reduce the rate of conversion to THA.

LEVEL OF EVIDENCE

Level III.

Hip Arthroscopy in the Presence of Advanced Osteoarthritis Results in 57% Survivorship, With 78% Survivor Satisfaction, at 10 Years. A Matched-Control Study

PURPOSE

To (1) determine the 10-year survivorship (avoidance of total hip arthroplasty, THA) for patients with advanced osteoarthritis (OA) undergoing hip arthroscopy for femoroacetabular impingement, and (2) compare survivorship and patient-reported outcomes (PROs) with a matched-control group without OA.

METHODS

Advanced OA hips (Tönnis ≥2) were matched in a 1:1 ratio (age ± 5 years, sex) to hips with preoperative Tönnis grade ≤1. Exclusion criteria was dysplasia, age <18 years, previous hip conditions/surgeries, and bilaterally operated patients with OA on one side only. Survival was estimated by Kaplan-Meier analysis for levels of sex, age groups and Tönnis. Cox proportional hazards model estimated hazard ratios (HR) of undergoing THA conversion. Where THA was avoided, outcomes and proportion of cases achieving patient acceptable symptomatic state was determined RESULTS: 53 OA hips were matched with 53 control hips. Survival distributions were significantly different for: (1) Group: OA 57.1%, control 87.0% (P = .001); (2) Tönnis grade: Tönnis 0, 89.2%; Tönnis 1, 77.8%; Tönnis 2, 67.6%; Tönnis 3, 25.0% (P < .001); and (3) age: (OA: 75.0% vs 44.8%, control: 100%, vs 75.0%, for <35 and >35 years respectively) (P = .002). Conversion to THA was greater for increasing Tönnis: HR 1.9 (P = .450), 3.5 (P = .032), and 11.0 (P < .001) for Tönnis 1, 2, and 3 respectively, relative to no OA (Tönnis 0) and >35 years: HR 4.3 (95% confidence interval 1.6-11.3, P = .003). Patient acceptable symptomatic state achievement was similar for both groups (78% OA vs 91% control, P = .167). modified Harris Hip Score and Short Form-36 significantly improved within both groups from baseline to 10 years CONCLUSIONS: Arthroscopic correction of femoroacetabular impingement, in the presence of advanced OA results in 57% survivorship at 10 years (68% Tönnis 2, 25% Tönnis 3). Where THA was avoided, 78% considered their 10-year post-HA state to be satisfactory, with patient-reported outcomes similar to a matched non-OA cohort. Tönnis 2 in particular should be considered for arthroscopic hip preservation to avoid the need to prematurely replace the hip joint.

LEVEL OF EVIDENCE

IV, case series.

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.

Limited clinical utility of a machine learning revision prediction model based on a national hip arthroscopy registry

PURPOSE

Accurate prediction of outcome following hip arthroscopy is challenging and machine learning has the potential to improve our predictive capability. The purpose of this study was to determine if machine learning analysis of the Danish Hip Arthroscopy Registry (DHAR) can develop a clinically meaningful calculator for predicting the probability of a patient undergoing subsequent revision surgery following primary hip arthroscopy.

METHODS

Machine learning analysis was performed on the DHAR. The primary outcome for the models was probability of revision hip arthroscopy within 1, 2, and/or 5 years after primary hip arthroscopy. Data were split randomly into training (75%) and test (25%) sets. Four models intended for these types of data were tested: Cox elastic net, random survival forest, gradient boosted regression (GBM), and super learner. These four models represent a range of approaches to statistical details like variable selection and model complexity. Model performance was assessed by calculating calibration and area under the curve (AUC). Analysis was performed using only variables available in the pre-operative clinical setting and then repeated to compare model performance using all variables available in the registry.

RESULTS

In total, 5581 patients were included for analysis. Average follow-up time or time-to-revision was 4.25 years (± 2.51) years and overall revision rate was 11%. All four models were generally well calibrated and demonstrated concordance in the moderate range when restricted to only pre-operative variables (0.62-0.67), and when considering all variables available in the registry (0.63-0.66). The 95% confidence intervals for model concordance were wide for both analyses, ranging from a low of 0.53 to a high of 0.75, indicating uncertainty about the true accuracy of the models.

CONCLUSION

The association between pre-surgical factors and outcome following hip arthroscopy is complex. Machine learning analysis of the DHAR produced a model capable of predicting revision surgery risk following primary hip arthroscopy that demonstrated moderate accuracy but likely limited clinical usefulness. Prediction accuracy would benefit from enhanced data quality within the registry and this preliminary study holds promise for future model generation as the DHAR matures. Ongoing collection of high-quality data by the DHAR should enable improved patient-specific outcome prediction that is generalisable across the population.

LEVEL OF EVIDENCE

Level III.

Primary Arthroscopic Labral Management: Labral Repair and Complete Labral Reconstruction Both Offer Durable, Promising Results at Minimum 5-Year Follow-up

BACKGROUND

Increased understanding of the acetabular labrum's role in hip joint biomechanics has led to a greater focus on the conservation and restoration of normal labral anatomic characteristics; however, labral repair is often not possible in the setting of severe intrasubstance damage or deficiency.

PURPOSE

To compare 5-year postoperative patient-reported outcomes between hips treated with primary complete arthroscopic labral reconstruction and those treated with primary labral repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All hips that underwent primary labral repair or reconstruction by the senior surgeon between January 2015 and December 2015 were included. Hips that had undergone a previous intra-articular procedure were excluded. Visual analog scales and patient-reported outcome (PRO) instruments were completed by patients within 1 week before surgery as a baseline measurement, between 22 and 26 months postoperatively for 2-year outcomes, and between 58 and 62 months for 5-year outcomes. PRO scores collected included the modified Harris Hip Score (mHHS), the 12-Item International Hip Outcome Tool, and the visual analog scale for pain and satisfaction. Pain and satisfaction were assessed using visual analog scales.

RESULTS

A total of 68 primary labral repairs and 62 primary complete labral reconstructions were included in the final analysis. Patients in the reconstruction cohort were older (38.3 vs 29.9 years; P < .001), had a higher incidence of severe labral tearing (62.90% vs 5.88%; P < .001), required a greater number of concomitant procedures (P < .001), and were more likely to have Beck grade III or IV chondral damage (12.94% vs 1.47%; P < .001). Both groups demonstrated statistically significant increases in outcome scores at minimum 5-year follow-up. Patients who underwent labral reconstruction had a significantly greater increase in mHHS from the preoperative assessment to latest follow-up compared with patients undergoing labral repair (27.43 vs 17.13; P = .04). No statistically significant differences between the 2 cohorts were found in achievement of minimal clinically important difference, Patient Acceptable Symptom State, maximum outcome improvement, and substantial clinical benefit at latest follow-up (P > .05). In total, 2 patients in the repair cohort and 3 patients in the reconstruction cohort required revision arthroscopy (P = .574). Further, 1 patient from each group converted to arthroplasty (P = .947).

CONCLUSION

The results of this study suggest that primary complete labral reconstruction is a viable surgical option for hips with moderate to severe labral pathology. At minimum 5-year follow-up, labral reconstruction produced similar outcomes to labral repair despite less favorable preoperative patient characteristics in the reconstruction cohort.

Outcomes After Primary Hip Arthroscopy in Athletes Older Than 40 Years Compared With Nonathletes

BACKGROUND

Master athletes (MAs), or athletes older than 40 years, make up a patient population whose outcomes after primary arthroscopic hip surgery are largely unknown.

PURPOSE

To report minimum 2-year outcomes of MAs after primary hip arthroscopy and compare their results to a propensity-matched nonathlete (NA) control group.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected between February 2008 and April 2019 and retrospectively reviewed for all patients who underwent primary hip arthroscopy. Patients were included if they were older than 40 years and had preoperative data for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score-Sports Specific Subscale, and visual analog scale score for pain. MAs reported participating in organized sports competition within 1 year before surgery and were propensity matched to a control group of patients who did not report participating in organized sports competition (NAs). Patient characteristics, radiographic and intraoperative findings, surgical procedures performed, and patient-reported outcome measures (PROMs) were reported and compared between the groups. The rates of achieving the minimal clinically important difference and maximum outcome improvement satisfaction threshold were recorded.

RESULTS

A total of 366 hips were eligible; 328 (89.6%) had adequate follow-up data. 328 patients met inclusion criteria but 88 were not included due to the restrictions of the propensity score match ratio. Of these, 80 hips (76 patients) were classified as MAs (mean age, 48.9 ± 6.2 years) and were propensity matched 1:2 to an NA control group. Groups were comparable for baseline demographic and radiographic parameters, intraoperative findings, and procedures performed. MAs had significantly better baseline and minimum 2-year PROM scores (P < .05), higher satisfaction (P = .01), and higher rates of achieving clinically meaningful improvement across all the outcome tools used (P < .05). MAs, when compared with NAs, had lower rates of secondary arthroscopy (0% vs 7.5%, respectively; P = .001) and conversion to total hip arthroplasty (12.5% vs 26.9%, respectively; P = .011).

CONCLUSION

MAs demonstrated favorable outcomes after primary hip arthroscopy. When compared with a propensity score-matched control group of NA patients, MAs demonstrated better preoperative and postoperative PROMs, higher rates of clinically meaningful improvement, and lower rates of secondary arthroscopy and conversion to total hip arthroplasty. Absolute improvements in PROM scores were similar between the groups.

Two-Tiered Resection of Cam Lesions in Hip Femoroacetabular Impingement: Optimizing Femoral Head Sphericity

Hip arthroscopy is one of the most rapidly growing fields in orthopaedic surgery. One of the most frequent pathologies treated with hip arthroscopy remains femoroacetabular impingement, which is addressed by labral repair and femoral osteoplasty. The most commonly cited reason for failure of arthroscopic treatment of femoroacetabular impingement is under-resection of the cam lesion. Surgeons frequently use evaluations of preoperative images, intraoperative fluoroscopy, and dynamic range of motion to ensure adequate resection. In this article, we describe a reproducible and standardized technique to assist in appropriate resection. This is achieved by a 2-tiered resection technique: Tier 1 aims to set the depth of resection and restore the head-neck offset. Tier 2 then matches the depth of the resection set by tier 1 and allows for retention of appropriate transition of the proximal convexity to the distal concavity seen in more ideally shaped femoral heads. With this technique, we offer a tool to avoid under-resection in the area of maximal conflict while simultaneously minimizing the risk of proximal over-resection and thus compromising the fluid seal dynamics of the joint in deeper flexion angles.

Lower Center Edge Angle and Bioipolar Cartilage Lesions Are Associated With Conversion to Hip Arthroplasty Within 2 Years Following Hip Arthroscopy: A Matched Cohort Analysis

PURPOSE

The purpose of this study was to determine whether radiographic parameters, intraoperative findings, patient-reported outcome measures, or intraoperative interventions that were performed differentiate those patients with >2 mm of joint space who convert under two years to total hip arthroplasty (THA) after undergoing hip arthroscopy for femoroacetabular impingement (FAI) when compared to those converting after 2 years.

METHODS

Included in this study were patients who underwent conversion to THA within 2 years of primary hip arthroscopy from a prospectively collected patient registry from 2007 to 2017. Patients who underwent early conversions to arthroplasty were matched 1:1 with patients who converted after 2 years, based upon age and gender. Preoperative outcome scores were collected, including Short Form-12, modified Harris Hip Score, and Hip Outcome Score. Additionally, variables from the preoperative radiographic evaluation, surgical findings, and procedures performed were also compared.

RESULTS

Forty-nine patients were included in the early conversion group and were matched with 49 patients in the later conversion group. Patients with lateral center edge angles of less than 25° were more likely to be in the early failure group [OR: 3.9; 95% CI: 1.01 to 15]. Patients with unipolar chondral defects on either the femoral (P = .128) or acetabular side (P = .656) were not at increased odds for early conversion compared to later conversion; however, those with bipolar chondral lesions at the time of surgery had increased odds of early conversions [OR: 3.3; 95% CI: 1.4 to 8] (P = .01). Neither surgical treatment nor preoperative patient-reported outcome measures were associated with early conversion.

CONCLUSIONS

In patient with >2 mm of joint space, lateral center edge angles of less than 25° and those with bipolar articular cartilage lesions seen at the time of hip arthroscopy are at increased risk for conversion to total hip arthroplasty within two years.

LEVEL OF EVIDENCE

Level III, retrospective comparison study.

Post-Related Complications in Hip Arthroscopy Are Reported Significantly Greater in Prospective Versus Retrospective Literature: A Systematic Review

PURPOSE

To determine whether there are differences in (1) the incidence of post-related complications following hip arthroscopy between prospective and retrospective publications; and (2) between post-assisted and postless techniques.

METHODS

A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to characterize post-related complications following hip arthroscopy for central or peripheral compartment hip pathology, including femoroacetabular impingement syndrome and chondrolabral injury. Inclusion criteria were prospective and retrospective Level I-IV evidence investigations that reported results of hip arthroscopy performed in the supine position. Exclusion criteria included open or extra-articular endoscopic hip surgery. Post-related complications included pudendal nerve injury (sexual dysfunction, dyspareunia, perineal pain or numbness) or perineum/external genitalia soft-tissue injury.

RESULTS

Ninety-four studies (12,212 hips; 49% male, 51% female; 52% Level IV evidence) were analyzed. Prospective studies (3,032 hips) report a greater incidence of post-related complications compared with retrospective (8,116 hips) studies (7.1% vs 1.4%, P < .001). Three studies (1,064 hips) used a postless technique and all reported a 0% incidence of pudendal neurapraxia or perineal soft tissue injury. Most pudendal nerve complications were transient, resolving by 3 months, but permanent nerve injury was reported in 4 cases. Only 19%, 22%, 7%, and 4% of studies reported a total surgery time, traction time, traction force, and bed Trendelenburg angle for their study samples, respectively.

CONCLUSIONS

The incidence of post-related complications is 5 times greater in prospective (versus retrospective) hip arthroscopy literature. Postless distraction resulted in a 0% incidence of post-related injuries.

LEVEL OF EVIDENCE

IV, systematic review of Level I-IV evidence.

Effect of Osteochondroplasty on Time to Reoperation After Arthroscopic Management of Femoroacetabular Impingement: Analysis of a Randomized Controlled Trial

Background:

A subset of patients with femoroacetabular impingement (FAI) fail arthroscopic management. It is not clear which patients will fail surgical management; however, several surgical and patient factors, such as type of procedure and age, are thought to be important predictors.

Purpose:

This time-to-event analysis with a 27-month follow-up analysis compared the effect of (1) arthroscopic osteochondroplasty with or without labral repair versus (2) arthroscopic lavage with or without labral repair on the time to reoperation in adults aged 18 to 50 years with FAI.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

Eligible participants had been randomized in a previous study trial to a treatment of arthroscopic osteochondroplasty or arthroscopic lavage with or without labral repair. Using the comprehensive data set from the Multinational Femoroacetabular Impingement Randomized controlled Trial, all reoperations until 27 months after surgery were identified. The analysis was conducted using a Cox proportional hazards model, with percentage of patients with a reoperation evaluated in a time-to-event analysis as the outcome. The independent variable was the procedure, with age and impingement subtype explored as potential covariates. The effects from the Cox model were expressed as the hazard ratio (HR). All tests were 2-sided, with an alpha level of .05.

Results:

A total of 108 patients in the osteochondroplasty group and 106 patients in the lavage group were included. The mean age of the patients included in the study was 36 ± 8.5 years. Overall, 27 incident reoperations were identified within the 27-month follow-up, with an incidence rate of 6 per 100 person-years. Within the osteochondroplasty group, 8 incident reoperations were identified (incidence rate, 3.4 per 100 person-years), while within the lavage group, 19 incident reoperations were identified (incidence rate, 8.7 per 100 person-years). The hazard of reoperation for patients undergoing osteochondroplasty was 40% of that of patients undergoing lavage (HR, 0.40 [95% CI, 0.17-0.91] P = .029).

Conclusion:

This study demonstrated that for adults between the ages of 18 and 50 years with FAI, arthroscopic osteochondroplasty was associated with a 2.5-fold decrease in the hazard of reoperation at any point in time compared with arthroscopic lavage.

Registration:

NCT01623843 (ClinicalTrials.gov identifier).

Survivorship Rate and Clinical Outcomes 10 Years After Arthroscopic Correction of Symptomatic Femoroacetabular Impingement

BACKGROUND

Femoroacetabular impingement (FAI) is a common mechanical hip condition, prevalent in both the athletic and the general population. Surgical intervention is an effective treatment option that improves both symptoms and function in short- to medium-term follow-up. Few studies within the literature have reported the longer-term success of arthroscopic surgery.

PURPOSE

The aim of this study was to quantify the 10-year survivorship and clinical outcome for patients treated arthroscopically for symptomatic FAI.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients from our hip registry (n = 119) completed patient-reported outcome measures (PROMs) including the modified Harris Hip Score (mHHS), University of California Los Angeles (UCLA) activity scale, 36-Item Short Form Health Survey (SF-36), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at a minimum of 10 years after arthroscopy (range, 10-12 years). Results were compared with baseline scores using the Wilcoxon signed rank test. The associations among several prognostic factors, which included age, sex, Tönnis grade, and labral treatment, and subsequent conversion to total hip replacement (THR) or repeat hip arthroscopy (RHA) were analyzed using the chi-square analysis. Relationships between range of motion and radiological findings with clinical outcome were also examined using Pearson correlation analysis. Minimal clinically important difference (MCID) was calculated using a distribution method (0.5 standard deviation of the change score), and substantial clinical benefit (SCB) was determined using an anchor method. Finally, receiver operating characteristic curves with subsequent Youden index were used to determine cutoffs for PROMs, which equated to a Patient Acceptable Symptom State (PASS).

RESULTS

A total of 8.4% of cases required conversion to THR, and 5.9% required RHA. Statistically significant improvements in mHHS, SF-36, and WOMAC scores, with high satisfaction (90%), were observed 10 years after surgery. No significant change was seen in activity level (UCLA score) despite patients being 10 years older. A high percentage of patients achieved MCID for mHHS (88%), SF-36 (84%), and WOMAC (60%). The majority of patients also achieved PASS (62% for mHHS, 85% for UCLA, 78% for SF-36, and 84% for WOMAC) and SCB (74% for mHHS, 58% for UCLA, 52% for SF-36, and 56% for WOMAC).

CONCLUSION

Arthroscopic intervention is a safe and viable treatment option for patients with symptomatic FAI, and patients can expect long-term improvements and high satisfaction. Results indicated a high satisfaction (90%) and survivorship rate (91.6%), with excellent clinical outcome, 10 years after the initial procedure.

Hip Arthroscopy Volume and Reoperations in a Large Cross-Sectional Population: High Rate of Subsequent Revision Hip Arthroscopy in Young Patients and Total Hip Arthroplasty in Older Patients

PURPOSE

To report contemporary trends in hip arthroscopy case volume in the United States using a large cross-sectional cohort with accurate laterality tracking for assessment of revision surgery and rates of conversion to total hip arthroplasty (THA).

METHODS

Using Current Procedural Terminology codes, we queried the Mariner PearlDiver dataset for patients who underwent hip arthroscopy from 2010 to 2017. Patient demographics were recorded and subsequent hip arthroscopy procedures and THA conversion within 2 years after surgery were tracked using International Classification of Diseases, Tenth Revision codes to accurately identify laterality. Emergency department and hospital admission within 30 days after surgery were queried.

RESULTS

Of the 53,103 patients undergoing hip arthroscopy procedures, hip arthroscopy case volume increased 2-fold from 2010 to 2014 but remained relatively unchanged from 2014 to 2017. The most common age group undergoing surgery was 40 to 49 years, and female patients represented 70% of cases. Two-year subsequent surgery rate was 19%, with 15.1% undergoing a revision arthroscopy and 3.9% converting to THA. The most common revision arthroscopy procedures were femoroplasty (9.5%), labral repair (8.5%), and acetabuloplasty (4.3%). Younger patients were more likely to undergo revision arthroscopy (18% age 10-19 years; 15% age 20-29 years). Older patients had a significant risk for conversion to THA within 2 years (36% age 60-69 years; 28% age 50-59 years). Female patients also demonstrated a slightly greater rate of conversion to THA (4.1% female, 3.5% male, P <.0001). Patients 20 to 29 years had the greatest risk of emergency department admission (5.4%) and hospital admission (0.8%) within 30 days of surgery.

CONCLUSIONS

The rise in hip arthroscopy procedures may be starting to plateau in the United States. Cross-sectional data also indicate that there is a greater than previously reported rate of revision hip arthroscopy in patients younger than 30 years of age and conversion to THA in patients older than 50 years of age.

LEVEL OF EVIDENCE

III, cross-sectional study.

Use of a larger surface area tip on bipolar radiofrequency wands in hip arthroscopy is associated with significantly lower traction and total surgery times

Clinical outcomes in arthroscopic hip preservation surgery have improved over the past two decades due to many factors, including advancements in technique and instrumentation. Complications following hip arthroscopy are associated with increased traction and overall surgical times. The purpose of this study was to compare traction and surgical times during hip arthroscopy using two different radiofrequency ablation wands produced by the same manufacturer. The authors hypothesized that the wand with a larger surface area would result in significantly less traction and surgical times. This study was a retrospective comparative investigation on patients who underwent arthroscopic surgery of the central, peripheral, peritrochanteric and/or deep gluteal space compartments of the hip. Both wands are 50-degree-angled probes, but the tip and shaft diameters are 3 and 3.75 mm for Wand A (Ambient Super MultiVac 50; tip surface area 7.1 mm2) compared to 4.7 and 4.7 mm for Wand B (Ambient HipVac 50; tip surface area 17.3 mm2), respectively. There was no difference (P = 0.16) in mean age of Wand A patients (30 females, 20 males; 35.2 years) versus Wand B patients (31 females, 19 males; 32.7 years). Traction time was significantly less in the Wand B group (41 ± 6 versus 51 ± 18 min; P &lt; 0.001), as was surgical time (102 ± 13 versus 118 ± 17 min; P &lt; 0.001). There were no significant differences in the number of labral anchors used or Current Procedural Terminology codes performed between groups. In conclusion, it was observed that the use of a larger surface area wand was associated with significantly less traction and surgical times during hip arthroscopy.

The Natural Course of Recovery After Hip Arthroscopy for Femoroacetabular Impingement According to the International Hip Outcome Tool-12 and Hip Outcome Score Sports Subscale

BACKGROUND

A paucity of literature exists regarding trajectories of functional and sports-specific recovery after hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

PURPOSE

To determine if subgroups of patients exist based on the recovery trajectory of patient-reported outcomes (PROs) after hip arthroscopy for FAIS in the short-term period and to determine clinical predictors for these subgroups of patients.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A prospectively maintained repository was queried for patients who had undergone primary hip arthroscopy for the treatment of FAIS between January 2012 and May 2018. Patients who completed the preoperative, 1-year, and 2-year International Hip Outcome Tool-12 (iHOT-12) or the Hip Outcome Score Sports Subscale (HOS-SS) were included. The latent class growth analysis (LCGA) and growth mixture models (GMMs) were used to identify subgroups of patients based on trajectories of recovery for the iHOT-12 and the HOS-SS utilizing preoperative, 1-year, and 2-year follow-ups. LCGA and GMM models using 1 to 6 classes for each PRO were performed, and the best-fit model for each PRO was selected. After final model selection, a multivariable multinomial logistic regression was performed, with the largest class being the reference group to determine clinical predictors of subgroup membership.

RESULTS

A total of 443 and 556 patients were included in the iHOT-12 and HOS-SS analyses, respectively. For the iHOT-12, we identified the following 3 subgroups: early progressors (70%), late regressors (22.3%), and late progressors (7.7%). Predictors of late regression were workers' compensation status, psychiatric history, preoperative chronic pain, and lower preoperative iHOT-12 scores; and late progressors were less likely to participate in sports. For the HOS-SS, we identified the following 4 subgroups: early progressors (47.7%), late regressors (17.4%), late progressors (6.8%), and steady progressors (28.1%). Predictors of less favorable recovery trajectories (late regressors and late progessors) were older age, male sex, back pain, psychiatric history, preoperative chronic pain, greater alpha angle, and lower preoperative HOS-SS scores.

CONCLUSION

Using the growth mixture modeling, 3 natural courses of health-related quality of life (early progression, late regression, and late progression) and 4 natural courses of recovery of athletic function (steady progression, late regression, late progression, and early progression) were identified. Preoperative psychiatric conditions, chronic pain, workers' compensation status, and lower iHOT-12 scores were predictive of less than favorable trajectories of recovery according to the iHOT-12, and male sex, older age, back pain, preoperative narcotic use, and lower preoperative HOS-SS were predictors of less favorable recovery trajectories according to the HOS-SS.

The lateral joint space width is essential for the outcome after arthroscopically assisted mini-open arthrotomy for treatment of a femoroacetabular impingement: an analysis of prognostic factors for the success of this hip-preserving technique

PURPOSE

The purpose of this study was to analyze predicting factors for a conversion to a total hip replacement (THR) after mini-open arthrotomy for treatment of femoroacetabular impingement (FAI).

METHODS

Between 2011 and 2016, we identified 32 patients, who were treated for FAI with a mini-open arthrotomy and received after mean time of 2.1 ± 1.4 years a THR. These patients were compared to 47 cases who did not receive a THR (mean follow-up: 4.3 ± 0.7 years) to explore pre- and intra-operative factors associated with a conversion to THR. The results were presented in separated Kaplan-Meier curves with log rank test for significance and hazard ratios.

RESULTS

A lateral joint space width of > 4 mm showed a higher THR-free survival rate compared to < 4 mm (p = 0.001); analogously one-sided (acetabular/femoral) 3-4° cartilage damage had a comparable THR-free survival rate than 1-2° kissing lesions (p = 0.001). Furthermore, an intact labrum without treatment and good cartilage status, a refixed labrum after rim resection in case of a pincer type FAI, or a refixed teared labrum were associated with a longer THR-free time than an untreated labrum accompanied by a poor cartilage status or an ossified labrum (p = 0.002). The strongest independent factor for a conversion to THR was femoral cartilage damage grade 1 and higher (p = 0.046). However, the rate of available patients was 53.0%.

CONCLUSION

The success of a joint-preserving mini-open arthrotomy seems to be dependent on the status of the radiological joint space width and the intra-operative cartilage status of the lateral edge.

The Key Parts of Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Implications for the Learning Curve

Background:

Hip arthroscopy is a rapidly growing surgical approach to treat femoroacetabular impingement (FAI) syndrome with a significant learning curve pertaining to complication risk, reoperation rate, and total hip arthroplasty conversion. Hip arthroscopy is more frequently being taught in residency and fellowship training. The key, or critical, parts of the technique have not yet been defined.

Purpose:

To identify the key components required to perform arthroscopic treatment of FAI syndrome.

Study Design:

Consensus statement.

Methods:

A 3-question survey comprising questions on hip arthroscopy for FAI was sent to a convenience sample of 101 high-volume arthroscopic hip surgeons in the United States. Surgeon career length (years) and maintenance volume (cases per year) were queried. Hip arthroscopy was divided into 10 steps using a Delphi technique to achieve a convergence of expert opinion. A step was considered “key” if it could (1) avoid complications, (2) reduce risk of revision arthroscopy, (3) reduce risk of total hip arthroplasty conversion, or (4) optimize patient-reported outcomes. Based on previous literature, steps with >90% of participants were defined as key. Descriptive and correlation statistics were calculated.

Results:

A total of 64 surgeons (63% response rate) reported 5.6 ± 2.1 steps as key (median, 6; range, 1-9). Most surgeons (56.3%) had been performing hip arthroscopy for >5 years. Most surgeons (71.9%) had performed >100 hip arthroscopy procedures per year. Labral treatment (97% agreement) and cam correction (91% agreement) were the 2 key steps of hip arthroscopy for FAI. Pincer/subspine correction (86% agreement), dynamic examination before capsular closure (63% agreement), and capsular management/closure (63% agreement) were selected by a majority of respondents but did not meet the study definition of key. There was no significant correlation between surgeon experience and designation of certain steps as key.

Conclusion:

Based on a Delphi technique and expert opinion survey of high-volume surgeons, labral treatment and cam correction are the 2 key parts of hip arthroscopy for FAI syndrome.

Editorial Commentary: Virtual Reality Simulation Can Help Arthroscopic Hip Preservation Surgeons at All Levels of Training and Practice-This is How

Virtual reality (VR) simulation has enormous potential utility in technically demanding manual activities. Hip arthroscopy is a perfect example of a challenging surgical technique with an extensive learning curve. The literature has recently consistently demonstrated that both career and annual maintenance case volume significantly influences patient-reported outcomes and risk of revision surgery and complications. Current residency and fellowship programs do not sufficiently prepare trainees to meet or exceed experience thresholds, so augmentation of training is necessary. A significant strength of VR simulation includes its ability to practice without limits. Unfortunately, hip models are limited to simple tasks, without full surgery models yet available simulating routine arthroscopic hip preservation procedures like labral repair, cam and pincer correction, capsular repair. Advanced techniques like labral reconstruction or augmentation, protrusio acetabulae, extensive cam morphology, revision surgery, peritrochanteric space endoscopy, and deep gluteal space endoscopy are not yet available for simulation. VR simulation can probably achieve competence for most, if not all, surgeons; possibly achieve proficiency; and unlikely to achieve mastery. The use of machine learning and artificial intelligence can process vast quantities of photo and video data to generate high-fidelity, lifelike surgical simulation. The near future will incorporate and assimilate these technologies cost-effectively for training programs and surgeons. Our patients will benefit.

High Risk of Conversion to THA After Femoroacetabular Osteoplasty for Femoroacetabular Impingement in Patients Older than 40 Years

BACKGROUND

Femoroacetabular impingement (FAI) is a recognized cause of hip pain and decreased quality of life and has been linked to primary idiopathic hip osteoarthritis (OA). Although the operative indications for FAI have expanded to include older patients, we do not know whether there is an increased risk of conversion to THA after femoroacetabular osteoplasty (FAO) via the mini-open approach for FAI in patients older than 40 years compared with younger patients, after controlling for other confounding variables.

QUESTIONS/PURPOSES

(1) After matching for gender, BMI, preoperative symptomatic period, surgeon experience, Tönnis grade, and degree of chondral lesion, are patients older than 40 years who undergo FAO for FAI more likely to be revised to THA at a minimum of 2 years' follow-up than are patients younger than 40? (2) Is there a difference in delta (postoperative minus preoperative) improvement in functional outcome scores in those patients who did not go on to THA between patients older than and younger than 40 years?

METHODS

Between 2003 and 2017, one surgeon performed 281 FAOs via the mini-open approach in patients older than 40 years and 544 of the same procedure in patients younger than 40 years. During that period, the general indications for FAO were the same in both age groups: (1) history and physical exam consistent with FAI, (2) radiographic evidence of focal impingement (cam, pincer, or both), (3) evidence of labral or chondrolabral tears, and (4) minimal to no arthritic changes (all four criteria required). In general, age was not used as a contraindication for surgery. A total of 86% (241 of 281) of patients older than 40 and 91% (494 of 544) of those younger than 40 were available for minimum of 2 years' follow-up, had complete datasets (radiographs as well as preoperative and most recent patient-reported outcomes scores) at a minimum of 2 years after surgery, and were considered eligible for the match. Propensity score matching was used to match for BMI, gender, preoperative symptomatic period, surgeon experience, Tönnis grade, and degree of intraoperative chondral lesion. We matched at a 1:2 ratio 130 patients older than age 40 with 260 patients younger than age 40. The mean ± SD follow-up duration for both groups was 5 ± 2 years. The mean age of the cohort of interest was 47 ± 5 years compared with 28 ± 7 years in the control. Fifty-four percent (70 of 130) of patients older than 40 years were women and 46% (60 of 130) were men; for those younger than 40, 51% (133 of 260) of participants were women and 49% (127 of 260) were men. Tönnis grade distribution for patients older than 40 was as follows: 46% (60 of 130) had Grade 0, 42% (55 of 130) had Grade 1, and 12% (15 of 130) had Grade 2. In comparison, Tönnis grade for patients younger than 40 was as follows: 52% (136 of 260) had Grade 0, 38% (100 of 260) had Grade 1, and 9% (24 of 260) had Grade 2 (p = 0.49). Chondral lesion degree was determined intraoperatively as none, a partial-thickness tear, or a full-thickness tear. Tönnis grade was determined based on preoperative plain AP hip radiographs. We then compared the percentage of patients who converted to THA during the surveillance period (our primary study outcome). We also compared the difference in delta (preoperative minus postoperative) improvement in functional outcome scores using the modified Harris Hip Score (mHHS) between the groups, excluding those who had already been converted to THA.

RESULTS

In patients older than 40 years, 16% (21 of 130) converted to THA at a mean time to conversion of 2 ± 1 years compared with 7% (17 of 260) at a mean time of 2 ± 2 years in patients younger than 40 years (p = 0.01). At a mean of 5 ± 2 years after FAO, among those patients who had not undergone conversion to THA, the mean delta mHHS score for patients older than 40 was 11 ± 17, compared with 20 ± 26 for patients younger than 40 (p = 0.04).

CONCLUSION

Since approximately 1 in 6 patients older than 40 years in this series who underwent FAO for FAI opted for early conversion to THA at a mean time of 2 years after the osteoplasty procedure, and the remaining patients who did not undergo THA reported lower improvement in functional outcomes, we recommend surgeons avoid this procedure in patients in this age group until or unless we can better refine our indications. This is especially true because loss to follow-up causes us to believe that, if anything, our estimates of the risk of conversion to THA are conservative.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Editorial Commentary: Personalized Hip Arthroscopy Outcome Prediction Using Machine Learning-The Future Is Here

Machine learning and artificial intelligence are increasingly used in modern health care, including arthroscopic and related surgery. Multiple high-quality, Level I evidence, randomized, controlled investigations have recently shown the ability of hip arthroscopy to successfully treat femoroacetabular impingement syndrome and labral tears. Contemporary hip preservation practice strives to continually refine and improve the value of care provision. Multiple single-center and multicenter prospective registries continue to grow as part of both United States-based and international hip preservation-specific networks and collaborations. The ability to predict postoperative patient-reported outcomes preoperatively holds great promise with machine learning. Machine learning requires massive amounts of data, which can easily be generated from electronic medical records and both patient- and clinician-generated questionnaires. On top of text-based data, imaging (e.g., plain radiographs, computed tomography, and magnetic resonance imaging) can be rapidly interpreted and used in both clinical practice and research. Formidable computational power is also required, using different advanced statistical methods and algorithms to generate models with the ability to predict individual patient outcomes. Efficient integration of machine learning into hip arthroscopy practice can reduce physicians' "busywork" of data collection and analysis. This can only improve the value of the patient experience, because surgeons have more time for shared decision making, with empathy, compassion, and humanity counterintuitively returning to medicine.

Lower body mass index and age are predictive of improved pain and health utility scores following arthroscopic management of femoroacetabular impingement

PURPOSE

To identify patient factors associated with improved pain scores, functional hip scores, health-related quality of life, and re-operation rates after arthroscopic management of femoroacetabular impingement (FAI).

METHODS

Using the comprehensive dataset from the multinational Femoroacetabular Impingement Randomized Controlled Trial (FIRST), a total of 13 prognostic factors that were chosen a priori were identified that would be expected to predict post-surgical outcomes. The primary outcome was pain assessed using a Visual Analogue Scale (VAS) and secondary outcomes included hip function (Hip Outcome Score [HOS] and International Hip Outcome Tool [iHOT-12]), health-related quality of life (Short Form-12 [SF-12] and Euro-Qol 5 Dimensions [EQ-5D]), and re-operation rate. A multivariable linear regression was used to analyse the change questionnaire scores from baseline to 12 months post-surgery including all 13 prognostic factors as independent variables. A total of 27 re-operation events were analysed at 24 months using a multivariable logistic regression including only the treatment group variable.

RESULTS

Of the 154 patients that had VAS scores completed at 12 months, a lower BMI (adjusted mean difference [aMD], 4.48 for a 5-unit decrease in BMI; 95% confidence interval [CI] 0.33-8.63; p = 0.035) was significantly associated with less pain. There was a significant negative association between increasing age and 1-year EQ-5D scores (aMD, - 0.04 for every 10-year increase in age; 95% CI - 0.07 to - 0.006; p = 0.020). The degree of impingement, severity of osteoarthritis, type of procedure, and adjudicated quality of surgery were not significantly associated with improvement across all outcomes at 12 months. Furthermore, there was no significant association between the treatment variable and the incidence of re-operation at 24 months.

CONCLUSION

This study identified that lower BMI and age are predictive of improved pain and health utility scores, respectively, following arthroscopic management of FAI at 12 months post-surgery. These results may be a helpful adjunct in clinical decisions for this patient population when determining candidacy for surgical intervention.

LEVEL OF EVIDENCE

I.

Arthroscopic classification of intra-articular hip pathology demonstrates at best moderate interrater reliability

PURPOSE

The purpose of this study was to report several novel classification systems for intra-articular lesions observed during hip arthroscopy, and to quantify the interrater reliability of both these novel systems and existing classifications of intra-articular lesions when tested by a group of high-volume hip arthroscopists.

METHODS

Five hip arthroscopists deliberated over shortcomings in current classification systems and developed several novel grading systems with particular effort made to capture factors important to the treatment and outcomes of hip arthroscopy for labral injury. A video learning module describing the classifications was then developed from the video archive of surgeries performed by the senior author and reviewed by study participants. Following review of the module, a pilot study was completed using five randomly selected videos, after which participating surgeons met once more to discuss points of disagreement and to seek clarification. The final video collection for testing reliability was composed of 29 videos selected with the intent of capturing all sublevels of each classification scheme. Study participants recorded their assessments using each classification scheme, and interrater reliability was calculated by a study participant not involved in grading.

RESULTS

The average kappa coefficients for the classification schemes ranged from 0.38 to 0.54, with the interrater reliability of all classification schemes except labral degeneration qualifying as moderate. The percent of cases with absolute agreement ranged from 17.2% to 51.7% across the classification systems.

CONCLUSIONS

Even among a group of high-volume hip arthroscopists who engaged in several discussions about the proposed classification schemes, grades were found to have at best moderate interrater reliability. Moderate interrater reliability is demonstrated for novel grading systems for describing labral tear complexity, labral bruising, labral size, and extent of synovitis, and fair reliability is demonstrated for labral degeneration. Further development and refinement of multifactorial grading systems for describing labral injury are indicated. Evaluating the multifactorial nature of intra-articular lesions in the hip is an important part of intraoperative decision-making and defining reliable classifications for intra-articular lesions is a critical first step towards developing generalizable criteria for guiding treatment type.

LEVEL OF EVIDENCE

Level III.

Risk of Conversion to Arthroplasty After Hip Arthroscopy: Validation of a Published Risk Score Using an Independent, Prospectively Collected Database

BACKGROUND

Hip arthroscopy is rapidly advancing and increasingly commonly performed. The most common surgery after arthroscopy is total hip arthroplasty (THA), which unfortunately occurs within 2 years of arthroscopy in up to 10% of patients. Predictive models for conversion to THA, such as that proposed by Redmond et al, have potentially substantial value in perioperative counseling and decreasing early arthroscopy failures; however, these models need to be externally validated to demonstrate broad applicability.

PURPOSE

To utilize an independent, prospectively collected database to externally validate a previously published risk calculator by determining its accuracy in predicting conversion of hip arthroscopy to THA at a minimum 2-year follow-up.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 1.

METHODS

Hip arthroscopies performed at a single center between November 2015 and March 2017 were reviewed. Patients were assessed pre- and intraoperatively for components of the THA risk score studied-namely, age, modified Harris Hip Score, lateral center-edge angle, revision procedure, femoral version, and femoral and acetabular Outerbridge scores-and followed for a minimum of 2 years. Conversion to THA was determined along with the risk score's receiver operating characteristic (ROC) curve and Brier score calibration characteristics.

RESULTS

A total of 187 patients (43 men, 144 women, mean age, 36.0 ± 12.4 years) underwent hip arthroscopy and were followed for a mean of 2.9 ± 0.85 years (range, 2.0-5.5 years), with 13 patients (7%) converting to THA at a mean of 1.6 ± 0.9 years. Patients who converted to THA had a mean predicted arthroplasty risk of 22.6% ± 12.0%, compared with patients who remained arthroplasty-free with a predicted risk of 4.6% ± 5.3% (P < .01). The Brier score for the calculator was 0.04 (P = .53), which was not statistically different from ideal calibration, and the calculator demonstrated a satisfactory area under the curve of 0.894 (P < .001).

CONCLUSION

This external validation study supported our hypothesis in that the THA risk score described by Redmond et al was found to accurately predict which patients undergoing hip arthroscopy were at risk for converting to subsequent arthroplasty, with satisfactory discriminatory, ROC curve, and Brier score calibration characteristics. These findings are important in that they provide surgeons with validated tools to identify the patients at greatest risk for failure after hip arthroscopy and assist in perioperative counseling and decision making.

Femoroacetabular Impingement Syndrome

Femoroacetabular impingement (FAI) syndrome is one of the most rapidly evolving etiologies of hip pain. The 2016 Warwick Agreement consensus statement defined FAI syndrome as a triad of symptoms, signs, and radiographic findings. Cam morphology is more likely in athletes and is associated with repetitive hip loading in maximal flexion during adolescence. Much less is known about the development of pincer morphology. Physical therapy improves pain and function, justifying a trial before pursuing surgery. Musculoskeletal injections are utilized for FAI syndrome, but the evidence is limited. Arthroscopic surgery for FAI syndrome can correct the morphological changes and address the underlying soft tissue injuries. Recent studies evaluated reliable indicators of surgical outcomes, the most reliable of which is the presurgical presence of osteoarthritis. Recent studies demonstrate the efficacy of surgery, but with the risk of complication and no guarantee of a return to the same level of sport.

Minimum volume standards in day surgery: a systematic review

BACKGROUND

The aim was to find out if and for what indications are minimum volume standards (MVS) applied in the day surgery setting and whether the application of MVS improves patient relevant outcomes.

METHODS

We conducted a comprehensive systematic literature search in seven databases on July 12th, 2019. Concerning effectiveness and safety, the data retrieved from the selected studies were systematically extracted into data-extraction tables. Two independent researchers (MS, CS) systematically assessed the quality of evidence using the quality assessment tool for individual studies of the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) called Task Force Checklist for Quality Assessment of Retrospective Database Studies. No instances of disagreement occurred. No further data processing was applied.

RESULTS

The systematic literature search, together with hand search, yielded 595 hits. No prospective or controlled studies were found. Data from eight retrospective studies were used in the analysis of clinical effectiveness and safety on seven indications: anterior cruciate ligament reconstruction, cataract surgery, meniscectomy, thyroidectomy, primary hip arthroscopy, open carpal tunnel release, and rotator cuff repair. All interventions (except for carpal tunnel release and thyroidectomy) confirmed a volume-outcome relationship (VOR) with relation to surgeon/hospital volume, however, none established MVS for the respective interventions. Safety related data were reported without its relationship to surgeon/hospital volume.

CONCLUSIONS

This present paper provides some evidence in favor of the VOR, however, it based on low quality retrospective data-analyses. The present results cannot offer any clear-cut MVS thresholds for the day surgery setting and so the simple transition from inpatient results (that support MVS) to the day surgery setting is questionable. Further quality assuring policy approaches should be considered.

Comparison of Suction Seal and Contact Pressures Between 270° Labral Reconstruction, Labral Repair, and the Intact Labrum

PURPOSE

To biomechanically compare the suction seal, contact area, contact pressures, and peak forces of the intact native labrum, torn labrum, 12- to 3-o'clock labral repair, and 270° labral reconstruction in the hip.

METHODS

A cadaveric study was performed using 8 fresh-frozen hemipelvises with intact labra and without osteoarthritis. Intra-articular pressure maps were produced for each specimen using an electromechanical testing system under the following conditions: (1) intact labrum, (2) labral tear, (3) labral repair between the 12- and 3-o'clock positions, and (4) 270° labral reconstruction using iliotibial band allograft. Specimens were examined in neutral position, 20° of extension, and 60° of flexion. In each condition, contact pressure, contact area, and peak force were obtained. Repeated-measures analysis of variance was used to identify differences in biomechanical parameters among the 3 conditions. Qualitative differences in suction seal were compared between labral repair and labral reconstruction using the Fisher exact test.

RESULTS

Repeated-measures analysis of variance for contact area in neutral position, extension, and flexion showed statistically significant differences between the normalized study states (P < .05). Post hoc analysis showed significantly larger contact areas measured in labral repair specimens than in labral reconstruction specimens in the extension and flexion positions. Region-of-interest analysis for the normalized contact area in the extension and flexion positions, as well as normalized contact pressures in neutral position, showed statistically significant differences between the labral states (P < .05). Finally, 8 labral repairs (100%) versus only 1 labral reconstruction (12.5%) retained the manually tested suction seal (P < .001).

CONCLUSIONS

In this in vitro biomechanical model, 270° labral reconstruction resulted in decreased intra-articular contact area and loss of suction seal when compared with labral repair. Clinically, labral reconstruction may not restore the biomechanical characteristics of the native labrum as compared with labral repair.

CLINICAL RELEVANCE

Labral reconstruction may result in lower intra-articular hip contact area and loss of suction seal, affecting the native biomechanical function of the acetabular labrum. Further biomechanical studies and clinical studies are necessary to determine whether there are any long-term consequences of 270° labral reconstruction.

Hip Arthroscopy in Patients Aged 40 Years and Older: Greater Success With Labral Reconstruction Compared With Labral Repair

PURPOSE

To assess the outcomes of complete, primary, arthroscopic hip labral reconstruction among patients aged 40 years and older compared with those who underwent primary labral repair and compared with patients aged 30 to 39 years who underwent complete, primary labral reconstruction.

METHODS

We recruited all patients who underwent arthroscopic labral reconstruction between March 2010 and June 2015 and were aged 30 to 65 years or who underwent arthroscopic labral repair between June 2009 and June 2015 and were aged 40 to 65 years. The modified Harris Hip Score (mHHS), Lower Extremity Function Score, and visual analog scale score for average pain were collected preoperatively and at minimum 2-year follow-up. Failure was defined as the need for revision ipsilateral hip surgery. The rate of conversion to total hip arthroplasty (a subset of failure) was assessed separately.

RESULTS

A total of 363 hips in 343 patients met the inclusion criteria. Follow-up was available for 312 hips (86.0%), and the average time to follow-up was 4.2 years (range, 2.0-8.5 years). After adjustment for differences in follow-up time between groups, failure was 3.29 times more likely for hips in the repair group aged 40 years and older than for hips in the reconstruction group aged 40 years and older (relative rate, 3.29; 95% confidence interval, 1.25-8.69; P = .02), and there was no difference in the failure rate for hips in the reconstruction group aged 40 years and older compared with hips in the reconstruction group aged 30 to 39 years (relative rate, 0.58; 95% confidence interval, 0.18-1.89; P = .37). The rate of conversion to total hip arthroplasty was not meaningfully different between the 3 groups. Among hips for which treatment did not fail, average improvement in the mHHS measured 35 points and both labral reconstruction groups saw a greater mHHS improvement than the labral repair group of patients aged 40 years and older (P = .01 and P < .01).

CONCLUSIONS

Labral reconstruction led to a lower failure rate, greater average improvement in the mHHS, and equivalent postoperative patient-reported outcome scores compared with labral repair among patients aged 40 years and older in this study population, and the outcomes of labral reconstruction were similar between patients aged 40 years and older and those aged 30 to 39 years. Complete labral reconstruction may be particularly advantageous in patients aged 40 years and older.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Importance of Retaining Sufficient Acetabular Depth: Successful 2-Year Outcomes of Hip Arthroscopy for Patients With Pincer Morphology as Compared With Matched Controls

BACKGROUND

Patients with pincer-type femoroacetabular impingement are commonly treated with arthroscopic reduction of acetabular depth as measured by the lateral center-edge angle (LCEA). The optimal amount of rim reduction has not been established, although large resections may increase contact pressures through the hip. A recent publication demonstrated inferior surgical outcomes in patients with acetabular overcoverage as compared with normal acetabular coverage. Casual observation of our database suggested equivalent improvements, prompting a similar analysis.

PURPOSE

To analyze patient-reported outcomes after hip arthroscopy for femoroacetabular impingement in patients with acetabular overcoverage who were matched with controls with normal coverage, as well as to analyze associations with reduction in LCEA.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were collected prospectively from patients with a minimum 2-year follow-up after receiving hip arthroscopy for femoroacetabular impingement by a single surgeon. Cases were reviewed to identify those with pincer-type morphology (LCEA >40°) and matched according to sex, age, chondral damage, and surgery date in a 1:1 ratio with controls with an LCEA of 25° to 40°. The surgical goal was to reduce the LCEA to the upper end of the normal range with minimal rim resection, usually 35° to 37°. Radiographic measurements of coverage, intraoperative findings, procedures, and patient-reported outcomes were recorded, including the 12-Item International Hip Outcome Tool, Non-arthritic Hip Score, Hip Disability and Osteoarthritis Outcome Score, visual analog scale for pain, rates of revision or reoperation, and conversion to total hip arthroplasty.

RESULTS

A total of 114 hips (93 patients) for the pincer group were matched 1:1 from 616 hips (541 patients) for the control group. The pincer group (mean ± SD age, 34.5 ± 12.2 years) did not differ in age, body mass index, or follow-up from controls. LCEA was reduced in both groups pre- to postoperatively: the pincer group from 44.0° ± 2.8° to 34.2° ± 3.5° and the controls from 32.9° ± 3.9° to 31.0° ± 3.0°. No differences in improvement were observed: iHOT-12 improved by 35.7 points in both groups (P = .9 for analysis of variance interaction) and Nonarthritic Hip Score by 22.3 points (P = .6). From all eligible surgical procedures, 2-year follow up rates were 2.5% and 2.6% for the pincer and control cohorts, respectively, and 1.2% and 0.3% for conversion to total hip arthroplasty.

CONCLUSION

Arthroscopic management of acetabular overcoverage can achieve excellent results, equivalent to arthroscopy for other causes of symptomatic femoroacetabular impingement. A key finding was smaller rim resections producing a mean postoperative LCEA of 34.2° with a small standard deviation.

Is There a Gender Gap in Outcomes After Hip Arthroscopy for Femoroacetabular Impingement? Assessment of Clinically Meaningful Improvements in a Prospective Cohort

Background

Although patients have experienced significant improvements after hip arthroscopy for femoroacetabular impingement (FAI), prior studies suggest that women have worse outcomes than men. These previous studies lack comparisons of patient-reported outcome (PRO) scores based on gender with respect to clinical significance measurements, including the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS).

Purpose

To evaluate outcomes after hip arthroscopy for FAI based on patient gender by prospectively assessing changes in PRO scores, MCID, and PASS.

Study Design

Cohort study; Level of evidence, 2.

Methods

Women and men undergoing hip arthroscopy for FAI were prospectively enrolled, and preoperative radiographic and intraoperative findings were collected. Patients completed the following PRO surveys before surgery and 2 years postoperatively: modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score (HOOS), and 12-Item Short Form Health Survey. Mean scores and percentage of patients reaching MCID and PASS were analyzed.

Results

A total of 131 hips were included (72 women, 59 men). Women had smaller preoperative alpha angles (59.1° vs 63.7°, respectively; P < .001) and lower acetabular cartilage injury grade (6.9% vs 22.0% with grade 4 injury, respectively; P = .013). Both women and men achieved equivalent significant improvements in PRO scores after surgery (scores increased 18.4 to 45.1 points for mHHS and HOOS). Women and men reached PASS for mHHS at similar rates (76.4% and 77.2%, respectively; P = .915). MCID was also achieved at similar rates between women and men for all scores (range, 61.4%-88.9%) except the activities of daily living subscale of the HOOS, in which a greater percentage of women reached MCID compared with men (79.2% vs 62.7%, respectively; P = .037). Additional stratification by age group using the median cohort age of 34 years showed no significant differences in PRO improvement based on age group for each gender.

Conclusion

Women can achieve clinically meaningful improvements in PRO scores after hip arthroscopy for FAI. Compared with men, women demonstrated equivalent high rates of achieving MCID and PASS at 2 years after surgery.

Does failure to meet threshold scores for mHHS and iHOT-12 correlate to secondary operations following hip arthroscopy?

The purpose of this study was to determine (i) if failing to achieve a patient-reported outcome (PRO) threshold at 1 year was associated with secondary operations at minimum 2-year follow-up and (ii)what outcome measure and threshold has the highest association with future surgeries. Inclusion criteria for this study were cases of primary hip arthroscopy between July 2014 and April 2017. Included patients had recorded pre-operative and 1-year post-operative modified Harris Hip Score (mHHS) and 12-item international Hip Outcome Tool (iHOT-12) scores. Patients were classified based on their ability to achieve minimal clinical important difference (MCID), substantial clinical benefit (SCB) and patient acceptable symptom state (PASS) for each PRO and the status of secondary operations at minimum 2-year follow-up. The sensitivity, specificity, accuracy, positive likelihood ratio and negative likelihood ratio for these thresholds were calculated. Of 425 eligible cases, 369 (86.8%) had minimum 2-year follow-up. Of the included patients, 28 underwent secondary operations (7.59%), with 14 undergoing secondary arthroscopies (3.79%) and 14 converting to total hip arthroplasty (3.79%). For mHHS, 267 (72.4%), 173 (46.9%) and 277 (75.1%) hips met MCID, SCB and PASS, respectively. For iHOT-12, 234 (63.4%), 218 (59.1%) and 280 (75.9%) hips met the respective thresholds. The highest specificity, sensitivity and accuracy were identified as for iHOT-12 MCID (0.79), iHOT-12 PASS (0.79) and iHOT-12 MCID (0.77), respectively. Patients not attaining MCID and PASS for mHHS and iHOT-12 at 1-year post-operatively are at increased risk of secondary operation. The most accurate threshold associated with secondary operation (0.77) is not achieving iHOT-12 MCID. Level of evidence: retrospective case series: level IV.

Staged Bilateral Hip Arthroscopy Compared With a Matched Unilateral Hip Arthroscopy Group: Minimum 2-Year Follow-Up

PURPOSE

To determine the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS) at 2-year follow up in patients who underwent staged bilateral hip arthroscopy versus age-, sex-, and body mass index-matched patients who underwent unilateral hip arthroscopy.

METHODS

Patients who underwent staged bilateral primary hip arthroscopy between January 2007 and December 2017 for the indication of femoroacetabular impingement (FAI) with a minimum 2-year follow-up were identified. The control group comprised patients who underwent a unilateral hip arthroscopy for FAI. The mHHS and the NAHS were analyzed.

RESULTS

Forty-two patients (84 hips) in the bilateral group were matched with 84 patients (84 hips) in the unilateral group. Both groups had significantly improved mHHS and NAHS when comparing preoperative scores with postoperative scores (bilateral group mHHS: 45.5 ± 15.1 to 81.7 ± 17.6, P < .0001, bilateral group NAHS: 49.5 ± 13.8 to 83.6 ± 20.0, P < .0001, unilateral group mHHS 48.5 ± 13.8 to 83.6 ± 15.9, P < .0001, unilateral group NAHS 48.8 ± 12.0 to 85.0 ± 16.6, P < .0001). The patient-acceptable symptomatic state was achieved in 57 hips (68%) in the bilateral group versus 62 hips (74%) in the unilateral group, P = .4. Patients with bilateral hip arthroscopy who had <17 months between index procedure and contralateral hip arthroscopy had significantly better mHHS and NAHS (85.5 ± 18.4 vs 75.71 ± 14.4, P = .013 for mHHS and 88.1 ± 17.1 vs 76.2 ± 22.4, P = .0074 for NAHS).

CONCLUSIONS

Bilateral hip arthroscopy for the indication of FAI has improved mHHS and NAHS at 2 years of follow up compared to baseline. There was no difference in 2-year mHHS and NAHS in patients who underwent bilateral hip arthroscopy and unilateral hip arthroscopy. Patients in the bilateral hip arthroscopy group that had the contralateral surgery longer than 17 months from index procedure had lower 2 year follow up mHHS and NAHS scores than those that underwent the second surgery within 17 months of the index procedure.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Does hip preservation surgery prevent arthroplasty? Quantifying the rate of conversion to arthroplasty following hip preservation surgery

Hip arthroscopic surgery for femoroacetabular impingement and periacetabular osteotomy (PAO) for dysplasia is the most commonly used contemporary treatment for these conditions and has been shown to provide pain relief and restore function. What is less understood and perhaps of more interest to health economists, is the role of these procedures in preserving the hip joint and avoiding hip arthroplasty. The aim of this systematic review was to determine whether hip joint preservation surgery, indeed, preserves the hip joint by looking at conversion rates to total hip arthroplasty (THA). Two separate searches were undertaken, using PRISMA guidelines and utilizing PubMed and Open Athens search engines, identifying manuscripts that looked at conversion to THA following either hip arthroscopy (HA) or PAO. When considering HA, we found 64 eligible papers. Out of these studies, there were 59 430 hips with 5627 undergoing conversion to THA (9.47% [95% CI 9.23–9.71%]) with a mean conversion time of 24.42 months. Regarding PAO, there were 46 eligible papers including 4862 patients who underwent PAO with subsequent conversion to THA in 404 patients (8.31% [95% CI 7.54–9.12%]). with a mean conversion time of 70.11 months. Certain features were associated with increased conversion rates, including increasing age, worsening arthritis and joint space <2 mm. This study demonstrates that the mean conversion rates to be <10% for HA and PAO, during the mean follow-up periods of included manuscripts. Joint preserving surgery appears to defer or at least delay the need for THA.

Mid-term Patient-reported Outcomes of Hip Arthroplasty After Previous Hip Arthroscopy: A Matched Case-control Study With a Minimum 5-year Follow-up

BACKGROUND

Previous hip arthroscopy may affect the outcomes of subsequent hip arthroplasty. The purpose is to compare mid-term patient-reported outcomes (PROs) and complication rates in patients who had previous ipsilateral hip arthroscopy (PA) with those without a previous surgery.

METHODS

A minimum 5-year PROs, complications, and revision surgery rates were compared between total hip arthroplasty (THA) recipients who received PA and those without. Available intraoperative findings, procedures, and conversion time of arthroscopies were reported. The relative risk (RR) of complications and revision THAs were reported. A Kaplan-Meier analysis assessed survivorship of revision THA.

RESULTS

There were 34 cases (33 patients) of PA that were matched to 89 control cases (87 patients). Both cohorts reported similar scores for Harris hip score, Forgotten Joint Score, pain, and patient satisfaction. No differences in the outcomes were found based on the arthroplasty approach. A higher postoperative complication rate {RR, 2.617 (95% confidence interval [CI], 0.808 to 8.476)} and revision THA rate (RR, 13.088 [95% CI, 1.59 to 107.99]) were found in the PA group.

CONCLUSION

Patients with PA demonstrated similar levels of PROs as those without previous ipsilateral hip arthroscopy. There may, however, be a higher rate of complications and revision surgery in the PA group.

LEVEL OF EVIDENCE

III.

Return to Sport After Femoroacetabular Impingement Surgery and Sport-Specific Considerations: a Comprehensive Review

PURPOSE OF REVIEW

Recent advancements in surgical technology and techniques have improved functional results for operative treatment of femoroacetabular impingement syndrome (FAIS). Few studies have comprehensively evaluated the literature regarding return to sport criteria, timing, level, and rates. The purpose of this study was to review recent studies regarding return to play after surgical correction of FAIS. We will specifically evaluate the level of return to play and look to compare pre- and postoperative competition levels when available. We will also analyze timing of return to play from injury to surgery. Additionally, we will elucidate any sport-specific criteria that may determine readiness for return.

RECENT FINDINGS

Athletes with FAIS treated non-operatively have a low rate of return to sport and are often functionally limited in their level of performance. Surgical management of FAIS includes hip arthroscopy as well as open techniques. Current literature suggests a high rate of return to sport after contemporary surgery for FAIS at 87-93% overall. Rate of return to the same level of competition following surgery for FAIS is 55-83% in pooled studies. Limited evidence is available comparing postoperative rehabilitation protocols and timing of return among different sports. Operative treatment of FAIS results in high rates of return to sport and functional performance. The results of this study may help educate patients preoperatively in regard to the likelihood of functional return to sport and sport-specific considerations. Further research evaluating rehabilitation protocols and return criteria may better elucidate timing intervals for patients to maximize function while limiting complications.

Can Radiographic Joint Space Accurately Predict Chondral Damage During Hip Arthroscopy? A Cross-Sectional Analysis

PURPOSE

To examine how preoperative radiographic joint space correlated with intraoperative chondral damage as diagnosed during hip arthroscopy, in patients without radiographic evidence of osteoarthritis or joint space <2 mm.

METHODS

Patients younger than the age of 50 years without previous hip conditions who underwent hip primary arthroscopy had their joint space and intraoperative chondral damage compared. A narrow joint space group was defined as those in the lowest decile of the average joint space. The demographics and presence of intra-articular findings of chondral damage were compared. In addition, receiver operator characteristic (ROC) curves were used to assess joint space as a predictor of intraarticular damage.

RESULTS

There were 1892 in this analysis. The incidence of severe cartilage damage (Outerbridge III and IV) was not significantly different between the narrow and non-narrow groups. The ROC analysis for joint space at detecting chondral damage was poor. The ROC area under the curve for joint space detecting any chondral defect (acetabular or femoral head) was 0.536 (confidence interval 0.506-0.565), with low sensitivity (0.492), specificity (0.582), negative predictive value (0.720), and positive predictive value (0.340). Spearman correlation could not demonstrate a correlation between joint space and cartilage damage (⍴_Acetabular = 0.10, ⍴_{Femoral Head} = 0.04). Interestingly, a gradual widening was observed between the medial and lateral joint spaces, with more pronounced findings in hips without damage.

CONCLUSIONS

The results of this study demonstrate that in patients with Tönnis 0 and 1, narrower joint space may be an anatomic variant and cannot predict actual intraoperative cartilage damage. However, if the lateral joint space has relative narrowing compared with the medial joint space, this may indicate acetabular cartilage damage.

LEVEL OF EVIDENCE

III, retrospective diagnostic comparative study.

Identifying the Most Successful Procedures in Hip Arthroscopy

Hip arthroscopy for femoral and acetabular pathologies has increased dramatically. However, there is little literature analyzing procedures as predictors of revision arthroscopy or arthroplasty. From February 2008 to November 2015, patients undergoing hip arthroscopy for a labral tear with minimum 2-year follow-up and between 18 and 60 years old were retrospectively reviewed. Those with previous surgeries, Tönnis grade greater than 1, and previous hip conditions were excluded. Follow-up was obtained for 1118 patients (1249 hips; 81.7%) with a mean age of 38.7 years (range, 18.0-60.0 years), mean body mass index of 26.4 kg/m² (range, 16.3-48.9 kg/m²), and mean follow-up of 50.2 months (range, 24.0-111.9 months). A total of 122 (9.8%) patients converted to total hip arthroplasty (mean, 35.3 months; range, 1.4-95.2 months). Multivariate analysis for predictors of total hip arthroplasty found age at surgery (hazard ratio, 1.064/y; P<.05), body mass index (nonlinear; P<.05), labral debridement (HR, 1.558; P=.03), and notchplasty (HR, 2.128; P<.05), with trochanteric bursectomy (HR, 0.367; P<.05) identified as associated with higher survivorship. A total of 124 (9.9%) patients underwent revision hip arthroscopy at a mean of 21.7 months (range, 0.10-83.3 months). Multivariate analysis for predictors of revision surgery found workers' compensation (HR, 3.352; P<.05), capsular repair (HR, 1.950; P<.05), and femoral head microfracture (HR, 2.844; P=.04) to be significant, with age at date of surgery (HR, 0.973/y; P<.05) and femoral head chondroplasty (HR, 0.241; P=.05) associated with higher survivorship. Understanding risk factors for conversion to total hip arthroplasty or revision is paramount during discussions with patients. [Orthopedics. 2020;43(3):173-181.].

Routine Interportal Capsular Repair Does Not Lead to Superior Clinical Outcome Following Arthroscopic Femoroacetabular Impingement Correction With Labral Repair

PURPOSE

To evaluate the impact of routine capsular repair on clinical outcome in a consecutive series of patients undergoing arthroscopic correction of symptomatic femoroacetabular impingement.

METHODS

Between 2009 and 2015, patients were assigned to 1 of 2 groups based on whether a capsular repair was performed as part of their index hip arthroscopic procedure. Exclusion criteria included previous underlying hip conditions, Tönnis >1, age >45 years, and labrum not repaired. Patients were assessed preoperatively and 2-years postoperatively using patient-reported outcome measures (PROMs), including the modified Harris hip score (mHHS), UCLA activity scale, short form-36, Western Ontario and McMaster Universities Osteoarthritis Index score, and measures of range of hip movements. The incidence of any subsequent revision surgery within 2 years was recorded. Sex and age groups were specifically analyzed.

RESULTS

In total, 966 consecutive cases were included (96.4% follow-up rate): 508 in group A (no repair) and 458 in group B (repair). Average age for all cases was 28.1 ± 7.0 years (14.6-44.9). There were significant improvements in all PROMs following surgery for both groups (P < .001). Statistical significance between groups at 2 years was observed for Short Form-36 (P = .001) and WOMAC (P = .041), greater in group A. Both groups similarly met the minimal clinically important difference (mHHS P = .414 and .605; UCLA, P = .549 and .614; Short Form-36, P = .455 and .079; WOMAC, P = .425 and .750 for distribution and anchor-based methods, respectively). In total, 38 (7.8%) cases group A and 24 (5.4%) cases group B required repeat hip arthroscopy (HA) (P = .148); No (0%) cases in group A and 2 (0.45%) cases in group B required total hip replacement (P = .226). There was significantly lower rate of repeat HA among 25- to 34-year age group (8.6% vs 3.9%, P = .047) where capsular repair was performed. No significant difference in the rate of repeat HA between groups for male (P = .203) or female (P = .603) subjects. Adhesions were more common in the repair group (79.2%, 95% confidence interval [CI] 57.8-92.9 vs 55.3%, CI 38.3-71.4; P = .055), with further capsular repair/plication required more frequently in the unrepaired group (50%, CI 33.4-66.6 vs 25%, CI 10.8-44.3); however, differences between groups were not significant (P = .051). Internal rotation was larger in group A compared with group B at 2 years (36.2 vs 28.1, P = .000). Female patients with capsular repair had reduced PROM scores at 2 years compared with female patients without repair (WOMAC, P = .004, and mHHS, P = .037).

CONCLUSIONS

Arthroscopic correction of femoroacetabular impingement with labral repair results in significant improvements in patient-reported outcomes at 2-years postsurgery, irrespective of whether the capsule is repaired. Routine capsular repair in a consecutive series of patients did not lead to superior outcomes compared with a nonrepaired group; similar proportions of cases in both groups were able to achieve minimal clinically important difference. In female patients, routinely repairing the capsule may lead to statistically inferior clinical outcome at 2-years postsurgery, although this may not be clinically significant. Routine capsular repair, however, may be beneficial in the younger, active patient, where a significant reduction in repeat arthroscopy was observed.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Approach to a Failed Hip Arthroscopy

PURPOSE OF REVIEW

Hip arthroscopy has seen increasing utilization over the last decade. This is largely related to increased recognition and improved techniques for treating femoroacetabilar impingement (FAI). Though hip arthroscopy generally yields favorable outcomes, there are a subset of patients who have residual or recurrent symptoms that require reoperation. The current review discusses an algorithmic approach to evaluating patients following a failed hip arthroscopy including a framework for clinical and radiographic assessment, available treatment options, and associated outcomes in revision surgery.

RECENT FINDINGS

Residual FAI has been demonstrated to be the most common indication for revision arthroscopy. Other indications include residual or recurrent labral pathology, gross instability, microinstability, or adhesions. Appropriate history and imaging are important to determine the cause for residual symptoms. Novel techniques including labral and capsular reconstruction, and modified remplissage procedures have been developed to deal with complex revision cases. Though studies have shown improved outcomes after revision surgery, they have been shown to result in inferior outcomes compared to a matched cohort following primary hip arthroscopy. Management of a failed hip arthroscopy remains a complex problem. Focused history, cross-sectional imaging, and revision hip arthroscopy with novel techniques can improve outcomes, albeit to a lesser extent than patients undergoing successful primary hip arthroscopy. The information provided here can help guide treatment and set appropriate patient expectations for revision surgery.