The two-year incidence of hip osteoarthritis after arthroscopic hip surgery for femoroacetabular impingement syndrome

Reliability of pre-operative symptoms, radiographs, and MRI for the assessment of cartilage loss in patients with femoroacetabular impingement syndrome with intra-operative correlation

OBJECTIVE

To assess the correlation of pre-operative symptoms, pre-operative diagnostic imaging for cartilage loss, and intra-operative cartilage findings in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome.

MATERIALS AND METHODS

Three radiologists performed retrospective independent reviews of pre-operative MRIs in 96 hips for acetabular/femoral cartilage loss utilizing a simplified "high-low" classification and the International Cartilage Repair Society grading system. Severity of supra-foveal central femoral head cartilage loss was separately noted. Pre-operative radiographs were graded using the Tonnis and Kellgren-Lawrence systems and for central joint space narrowing. Pre-operative patient symptoms were prospectively gathered utilizing the Nonarthritic Hip Score and the modified Harris Hip Score. Intra-operatively, cartilage loss was recorded using the Outerbridge system.

RESULTS

A moderate-to-strong positive correlation between pre-operative radiographic and MR cartilage loss was observed (0.21 ≤ Τ ≤ 0.53, T = Kendall's tau) for all readers/scales. Weak-to-moderate positive correlation was found between intra-operative cartilage grading and radiographic grading (0.10 ≤ Τ ≤ 0.30). Weak-to-moderate positive correlation between MRI and intra-operative cartilage grading was found for all readers/grading systems (0.17 ≤ Τ ≤ 0.43). Cartilage defects were slightly under-reported on MRI, reaching statistical significance at the femoral head. There was moderate-to-strong positive correlation between radiographic central joint narrowing and MRI central femoral head cartilage loss (0.35 ≤ Τ ≤ 0.55) for all readers. Inter-reader reliability was fair-to-moderate for radiographs, but poor for MRI. Clinical scores demonstrated very weak negative to no correlation with radiographic/MR cartilage findings and weak positive correlation with intra-operative cartilage findings.

CONCLUSION

Despite MRI underestimation of cartilage loss, the very weak-to-weak correlation of clinical symptoms with pre-operative imaging and intra-operative findings emphasizes the importance of MRI in pre-operative evaluation.

Osteochondroplasty with or without labral repair is more cost-effective than arthroscopic lavage with or without labral repair for treatment of young adults with femoroacetabular impingement: A cost-utility analysis based on data from a randomized controlled trial

OBJECTIVES

The objective of this study was to conduct a cost-utility analysis of osteochondroplasty with or without labral repair compared to arthroscopic lavage with or without labral repair for femoroacetabular impingement (FAI) from a Canadian public payer perspective.

METHODS

A Markov model was constructed to compare the lifetime quality-adjusted life years (QALYs) and costs of the two treatment strategies. The target population was surgical FAI patients aged 36 years. The primary data source was patient-level data from the Femoroacetabular Impingement Randomised Controlled Trial, which evaluated the efficacy of the surgical correction of FAI via arthroscopic osteochondroplasty with or without labral repair compared to arthroscopic lavage with or without labral repair in Canada. Long-term data were extrapolated using a generalized gamma model. The primary outcome was the incremental cost-effectiveness ratio, calculated by dividing the difference in costs by the difference in QALYs between osteochondroplasty and lavage, with or without labral repair. Probabilistic sensitivity analyses and one-way sensitivity analyses were used to characterize uncertainty of model parameters and assumptions.

RESULTS

Over a lifetime horizon, osteochondroplasty, with or without labral repair, had a greater expected benefit (0.63 QALYs gained per patient) and lower costs ($955.89 saved per patient), as compared with lavage with or without labral repair. Probabilistic sensitivity analyses demonstrated that the probability of osteochondroplasty, with or without labral repair, being cost-effective was 90.5% at a commonly used willingness-to-pay threshold of $50,000/QALY in Canada. Across all one-way sensitivity analyses, osteochondroplasty with or without labral repair remained a cost-effective option.

CONCLUSION

Over a lifetime time horizon, osteochondroplasty, with or without labral repair, is a cost-effective treatment strategy for young adults with FAI. Future research involving real-word data is needed to further validate these findings.

LEVEL OF EVIDENCE

III.

Femoroacetabular Impingement and the Effect of Osteochondroplasty on Hip Osteoarthritis Prevention: The Pandora's Box Opening Process

OBJECTIVE

This study was conducted to assess the effect of osteochondroplasty on osteoarthritis (OA) prevention, comparing radiological evolution between identical hips from the same patient who had undergone unilateral surgery.

DESIGN

We retrospectively reviewed radiological evolution between hips with similar shape from the same patient who had undergone unilateral surgery. In all, 56 FAI patients (112 hips) with a mean age of 42.18 ± 9.16 years and had undergone unilateral arthroscopy treatment have been included. Four independent researchers measured Wiberg, Acetabular and Alpha angles, Extrusion index, and Tönnis classification preoperatively to verify that operated and non-operated hips had the same shape. OA evolution was assessed by joint space width (JSW) in 3 different articular points and Tönnis classification.

RESULTS

No preoperative anatomical differences were present between groups (P > 0.05). At the end of follow-up (31.9 months), a decrease of JSW in the 3 points measured was found in OP hips (OP vs. N-OP; P < 0.01). These results were correlated with changes in the proportion of patients who progressed to grade III in Tönnis classification (from 1.3% preoperative to 23.2% at the end of follow-up).

CONCLUSIONS

Osteochondroplasty and labrum procedures were not associated with OA prevention. The OP hips showed a faster OA degeneration, which was not seen in the N-OP. These results will encourage hip surgeons to perform further investigations to avoid the "Pandora's Box Opening Process."

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.

Non-operative Management and Outcomes of Femoroacetabular Impingement Syndrome

PURPOSE

To serve as a guide for non-operative physicians in the management of femoroacetabular impingement syndrome and provide an algorithm as to when to refer patients for potential surgical management.

RECENT FINDINGS

Supervised physical therapy programs that focus on active strengthening and core strengthening are more effective than unsupervised, passive, and non-core-focused programs. There is promising evidence for the use of intra-articular hyaluronic acid and PRP as adjunct treatment options. Recent systematic reviews and meta-analyses have found that in young active patients, hip arthroscopy demonstrates improved short-term outcomes over physical therapy. The decision for the management of FAIS is complex and should be specific to each patient. Consideration of the patient's age, timing to return to sport, longevity of treatment, hip morphology, and degree of cartilage degeneration is required to make an informed decision in the treatment of these patients.

Patient-Perceived Outcomes Improve Faster Than Hip Strength in Recovery After Surgical Correction for Symptomatic Femoroacetabular Impingement

Background: Patients with symptomatic femoroacetabular impingement (FAI) have hip strength deficits, instability, and increased risk for concomitant injury. While surgical intervention is an effective method of treatment for FAI, more information is needed about the recovery process. Purposes: We sought to understand how patients with FAI recover from surgical correction in the short term. Do patients' perceptions of improvement correspond with measured improvements in hip strength? Methods: We conducted a prospective cohort study of 17 patients (11 male, age range: 16-38 years) who were diagnosed with symptomatic FAI at a single surgeon's practice. Hip strength (flexion, extension, and abduction) was measured preoperatively and at 14, 26, and 52 weeks postoperatively. Patient-reported outcomes using the modified Harris Hip Score (mHHS) and Hip Outcome Osteoarthritis Score (HOOS) subscales were measured at the same time points and at 2 weeks postoperatively. Results: Compared with preoperative values, there was a significant increase in postoperative values at 26 and 52 weeks in normalized isokinetic hip extension (29% and 38%, respectively) and normalized hip abduction (48% and 55%, respectively). No differences in strength were observed at 14 weeks. Modified Harris Hip Score and all HOOS subscales were decreased by 2 weeks postoperatively, and by 14 weeks mHHS improved by 21%, and HOOS subscales improved as well (activities of daily living by 18%, pain by 34%, quality of life by 69%, sport and recreation by 36%, and symptoms by 28%). Conclusion: We observed that patient-reported outcomes including symptoms, function, and satisfaction improved at 14 weeks, while objective measures of hip strength improved at 26 weeks following surgical correction of FAI. More rigorous study is indicated.

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.

Comparison of Walking Biomechanics After Physical Therapist-Led Care or Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Secondary Analysis From a Randomized Controlled Trial

BACKGROUND

Femoroacetabular impingement syndrome is characterized by chondrolabral damage and hip pain. The specific biomechanics used by people with femoroacetabular impingement syndrome during daily activities may exacerbate their symptoms. Femoroacetabular impingement syndrome can be treated nonoperatively or surgically; however, differential treatment effects on walking biomechanics have not been examined.

PURPOSE

To compare the 12-month effects of physical therapist-led care or arthroscopy on trunk, pelvis, and hip kinematics as well as hip moments during walking.

STUDY DESIGN

Secondary analysis of multi-centre, pragmatic, two-arm superiority randomized controlled trial subsample; Level of evidence, 1.

METHODS

A subsample of 43 participants from the Australian Full randomised controlled trial of Arthroscopic Surgery for Hip Impingement versus best cONventional (FASHIoN trial) underwent gait analysis and completed the International Hip Outcome Tool (iHOT-33) at both baseline and 12 months after random allocation to physical therapist-led care (personalized hip therapy; n = 22; mean age 35; 41% female) or arthroscopy (n = 21; mean age 36; 48% female). Changes in trunk, pelvis, and hip biomechanics were compared between treatment groups across the gait cycle using statistical parametric mapping. Associations between changes in iHOT-33 and changes in hip kinematics across 3 planes of motion were examined.

RESULTS

As compared with the arthroscopy group, the personalized hip therapy group increased its peak hip adduction moments (mean difference = 0.35 N·m/body weight·height [%] [95% CI, 0.05-0.65]; effect size = 0.72; P = .02). Hip adduction moments in the arthroscopy group were unchanged in response to treatment. No other between-group differences were detected. Improvements in iHOT-33 were not associated with changes in hip kinematics.

CONCLUSION

Peak hip adduction moments were increased in the personalized hip therapy group and unchanged in the arthroscopy group. No biomechanical changes favoring arthroscopy were detected, suggesting that personalized hip therapy elicits greater changes in hip moments during walking at 12-month follow-up. Twelve-month changes in hip-related quality of life were not associated with changes in hip kinematics.

Inconclusive and Contradictory Evidence for Outcomes After Hip Arthroscopy in Patients With Femoroacetabular Impingement and Osteoarthritis of Tönnis Grade 2 or Greater: A Systematic Review

PURPOSE

To investigate whether hip arthroscopy (HA) is effective in patients with femoroacetabular impingement and concomitant hip osteoarthritis (OA) of Tönnis grade 2 or greater.

METHODS

This review was registered in the International Prospective Register for Systematic Reviews and Meta-analysis (PROSPERO, CRD42020210936). It followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines and included multiple databases: MEDLINE, Embase, Web of Science Core Collection, and Cochrane Library. All studies in English or German from database inception to December 1, 2020, that investigated outcomes of HA in patients with OA of Tönnis grade 2 or greater were considered eligible. The risk of bias was assessed using the MINORS (Methodological Index for Non-randomized Studies) tool. Data heterogeneity was explored using the I² test in a random-effects model.

RESULTS

Eleven studies met the eligibility criteria. The MINORS (Methodological Index for Non-randomized Studies) score averaged 68% (range, 46%-81%). A total of 616 hips, consisting of 247 hips of interest (Tönnis grade 2 or greater) and 369 controls, were included. The weighted estimated follow-up averaged 29.1 months (range, 12-84 months). Data on patient-reported outcome measures (PROMs) could be extracted for 6 of 11 studies, and date on conversion to total hip arthroplasty were available for 8 of 11. Four studies reported an overall improvement in PROMs after HA, and 2 highlighted a failure of improvement in PROMs. Failure of HA with conversion to total hip arthroplasty was observed at a rate of 0% to 9% in 4 studies, as opposed to proportions as high as 35% to 70% in the other 4 studies. There was a high level of heterogeneity, with a calculated I² value of 89%.

CONCLUSIONS

There is currently contradictory and insufficient evidence regarding the efficacy of HA for hips with femoroacetabular impingement and concomitant OA of Tönnis grade 2 or greater. This is in the context of data with low levels of evidence, mainly consisting of retrospective case series (Level IV) with a high risk of bias and high heterogeneity (I² of approximately 90%).

LEVEL OF EVIDENCE

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

[Treatment options for femoroacetabular impingement syndrome and osteoarthritis]

Femoroacetabular impingement syndrome (FAIS) is a prearthritic deformity. Many patients with FAIS show signs of osteoarthritis at the time of initial presentation. Ideally, surgical correction of FAIS should stop the progression of osteoarthritis. However, biological changes in the joint, inflammatory processes, and patient-specific factors, which are not influenced by surgery, show a role in the progression of joint degeneration. Thus, it is not surprising that the results of joint-preserving surgery in FAIS and osteoarthritis Tönnis grade 2 and higher are bad, and patients often need to undergo total hip replacement (THR).Even in patients with initial osteoarthritis (Tönnis grade 1) the results of joint-preserving surgery are significantly worse in comparison to in patients without osteoarthritis. As this pathology occurs mainly in young patients, efforts should be made to avoid THR, as the risk of loosening and revision surgery is increased. Analysis of risk factors that lead to worse outcome in joint-preserving surgery can be helpful. Age > 45 years, adiposity, high alpha angle, CE angle < 25° and female sex are risk factors that lead to worse outcome in patients with risk factors and osteoarthritis Tönnis grade 1, the success rate of joint-preserving surgery after 5 years is below 50%. Therefore, we recommend non-surgical treatment. Promising is the use of mesenchymal progenitor cells (MPCs), even if their routine use has not been established. If conservative therapy is not successful, THR is indicated. With the use of modern bearings, a survival rate of THR of more than 90% after 15 years is reported in patients < 50 years. Patient satisfaction after THR is higher than after joint-preserving surgery.The combination of treatment modalities like joint-preserving surgery in combination with the application of MPCs to both correct the mechanical conflict and also influence progression of osteoarthritis is promising the from a biological point of view.

Comparison of the Effect of MFAT and MFAT + PRP on Treatment of Hip Osteoarthritis: An Observational, Intention-to-Treat Study at One Year

Hip osteoarthritis (OA) is a major contributor to reduced quality of life and concomitant disability associated with lost working life months. Intra-articular injection of various biological materials has shown promise in alleviating symptoms and potentially slowing down the degenerative process. Here, we compared the effects of treatment of a cohort of 147 patients suffering from grade 1–4 hip OA; with either micro-fragmented adipose tissue (MFAT), or a combination of MFAT with platelet-rich plasma (PRP). We found significant improvements in both the visual analogue score for pain (VAS) and Oxford hip score (OHS) that were similar for both treatments with over 60% having an improvement in the VAS score of 20 points or more. These results suggest a positive role for intra-articular injection of MFAT + PRP as a treatment for hip osteoarthritis which may be important particularly in low body mass index (BMI) patients where the difficulty in obtaining sufficient MFAT for treatment could be offset by using this combination of biologicals.

Changes in Hip Capsule Morphology after Arthroscopic Treatment for Femoroacetabular Impingement Syndrome with Periportal Capsulotomy are Correlated With Improvements in Patient-Reported Outcomes

PURPOSE

To assess the correlation between changes in hip capsule morphology with improvements in patient-reported outcome (PRO) scores after arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) using the periportal capsulotomy technique.

METHODS

Twenty-eight patients with cam morphology FAIS (without arthritis, dysplasia, or hypermobility) were prospectively enrolled before arthroscopic labral repair and femoroplasty through periportal capsulotomy (anterolateral/midanterior portals) without closure. Patients completed the Hip Disability and Osteoarthritis Outcomes Score (HOOS) and had nonarthrographic 3T magnetic resonance imaging (MRI) scans of the affected hip before and 1 year after surgery. Anterior capsule thickness, posterior capsule thickness, anterior-posterior capsule thickness ratio, and proximal-distal anterior capsule thickness ratio were measured on axial-oblique MRI sequences. Pearson correlation coefficients were calculated to determine the association between hip capsule morphology and PRO scores.

RESULTS

Postoperative imaging showed that for all 28 patients (12 female), labral repairs and capsulotomies had healed within 1 year of surgery. Analysis revealed postoperative decreases in anterior hip capsule thickness (1395.4 ± 508.4 mm³ vs 1758.4 ± 487.9 mm³; P = .003) and anterior-posterior capsule thickness ratio (0.92 ± 0.33 vs 1.12 ± 0.38; P = .02). Higher preoperative anterior-posterior capsule thickness ratio correlated with lower preoperative scores for HOOS pain (R = -0.43; P = .02), activities of daily living (ADL) (R = -0.43; P = .02), and sport (R = -0.38; P = .04). Greater decrease from preoperative to postoperative anterior-posterior capsule thickness ratio correlated with greater improvement for HOOS pain (R = -0.40; P = .04), ADL (R = -0.45; P = .02), and sport (R = -0.46; P = .02).

CONCLUSIONS

Periportal capsulotomy without closure demonstrates capsule healing by 1 year after arthroscopic FAIS treatment. Changes in hip capsule morphology including decreased anterior-posterior capsule thickness ratio after surgery may be correlated with improvements in patient pain, function, and ability to return to sports.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Prior hip arthroscopy does not affect 1-year patient-reported outcomes following total hip arthroplasty: a register-based matched case-control study of 675 patients

Background and purpose - Femoroacetabular impingement syndrome (FAIS) is a common cause of hip pain and may contribute to the development of osteoarthritis. We investigated whether a prior hip arthroscopy affects the patient-reported outcomes (PROMs) of a later total hip arthroplasty (THA).Patients and methods - Patients undergoing hip arthroscopy between 2011 and 2018 were identified from a hip arthroscopy register and linked to the Swedish Hip Arthroplasty Register (SHAR). A propensity-score matched control group without a prior hip arthroscopy, based on demographic data and preoperative score from the EuroQoL visual analogue scale (EQ VAS) and hip pain score, was identified from SHAR. The group with a hip arthroscopy (treated group) consisted of 135 patients and the matched control group comprised 540 patients. The included PROMs were EQ-5D and EQ VAS of the EuroQoL group, and a questionnaire regarding hip pain and another addressing satisfaction. Rate of reoperation was collected from the SHAR. The follow-up period was 1 year.Results - The mean interval from arthroscopy to THA was 27 months (SD 19). The EQ-5D was 0.81 and 0.82, and EQ VAS was 78 and 79 in the treated group and the matched control group respectively. There were no differences in hip pain, and reported satisfaction was similar with 87% in the treated group and 86% in the matched control group.Interpretation - These results offer reassurance that a prior hip arthroscopy for FAIS does not appear to affect the short-term patient-reported outcomes of a future THA and indicate that patients undergoing an intervention are not at risk of inferior results due to their prior hip arthroscopy.

Comparison Between Hip Arthroscopic Surgery and Periacetabular Osteotomy for the Treatment of Patients With Borderline Developmental Dysplasia of the Hip: A Systematic Review

Background:

The treatment for borderline developmental dysplasia of the hip (BDDH) has historically been arthroscopic surgery or periacetabular osteotomy (PAO). As orthopaedic surgery is constantly evolving, a lack of comparison of outcomes for these 2 treatment methods could potentially be stalling the progression of treatment for patients with BDDH.

Purpose:

To evaluate the existing literature on patient characteristics, procedures, clinical outcomes, and failure rates for patients with BDDH and to determine whether PAO or hip arthroscopic surgery is a better treatment method for patients with BDDH.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Studies included were found using the following search words: “hip” and “borderline dysplasia,” “osteotomy” or “arthroscopy,” and “outcome” or “procedure.” Articles were included if they detailed participants of all sexes and ages, reported on isolated hips, and had patients diagnosed with BDDH.

Results:

A search was conducted across 3 databases, resulting in 469 articles for consideration, from which 12 total studies (10 on arthroscopic surgery and 2 on PAO) were chosen for a review. There were 6 studies that included patients with a lateral center-edge angle of 18° to 25°, while the remainder included patients with a lateral center-edge angle of 20° to 25°. All the studies reviewing arthroscopic surgery reported concomitant/accessory procedures, while the articles on the topic of PAO did not. It was determined that, whether treated using arthroscopic surgery or PAO, outcomes improved across all patient-reported outcome measures. Revision surgery was also common in both procedures.

Conclusion:

There is a lack of consensus in the literature on the best treatment option for patients with BDDH. Preoperative patient characteristics and concomitant injuries should be considered when evaluating which surgical procedure will result in the most favorable outcomes.

Risk Factors for Conversion of Hip Arthroscopy to Total Hip Arthroplasty: A Large Closed-Cohort Study

Purpose

To evaluate risk factors for conversion of hip arthroscopy to total hip arthroplasty (THA) within 2 years in a closed patient cohort.

Methods

This study was a case series of consecutive hip arthroscopy procedures from September 2008 to November 2018 in the electronic medical record of Kaiser Permanente Northern California. Patients were included with minimum 2-year follow-up or if they had conversion to THA within 2 years (the primary outcome) regardless of follow-up time. Patient characteristics at the time of the index arthroscopy were extracted; characteristics of patients who experienced the outcome event versus those who did not were compared by use of multivariable logistic regression models and receiver operating characteristic (ROC) curves.

Results

The mean follow-up time was 4.9 years (median 4.6, range 0.6 to 11.6). The mean age was 37.2 years (range 10 to 88), and 57% were female. During the follow-up period, 82 patients underwent a THA within 2 years of their arthroscopies (5.3%, 95% confidence interval 4.3% to 6.5%) after a median time of 9 months (interquartile range 5.9 to 14.4) after the initial arthroscopy. Increasing age was highly predictive of early THA conversion (area under the ROC curve = 0.78, P < .001). Although other predictors showed significant bivariable associations with early failure, body mass index (BMI), race, sex, and prior arthroscopy did not add meaningful independent predictive information.

Conclusions

The risk of conversion to THA within 2 years after hip arthroscopy increased substantially with patient age at the time of the procedure. BMI, race, sex, and prior arthroscopy were not important independent predictors of conversion beyond the information contained in patient age.

Level of Evidence

Level IV, therapeutic case series.

Achieving a Perfectly Spherical Femoroplasty: Pearls, Pitfalls, and Optimal Surgical Technique

Femoroacetabular impingement describes a pathologic interaction between the bony femoral head/neck junction and acetabulum. Cam-type femoroacetabular impingement results from an aspherical femoral head architecture, which increases early contact along the acetabular surface during hip range of motion. Errant arthroscopic femoroplasty recently has been discussed within the literature to describe a preventable etiology of failed hip arthroscopy, most notably cam over- and under-resection. We present an arthroscopic surgical technique for achieving the perfectly spherical femoroplasty, meant to minimize complications and improve postoperative outcomes.