Surgery For Femoroacetabular Impingement Research Articles

THE IMPACT OF SOCIOECONOMIC STATUS ON OUTCOMES FROM TREATMENT FOR FEMOROACETABULAR IMPINGEMENT

There is little known about how patient socioeconomic status impacts clinical outcomes in hip preservation surgery. The aim of this study was to evaluate the relationship between indices of multiple deprivation, funding provider (NHS Funded or Private Funded) and clinical outcomes following surgery for femoroacetabular impingement (FAI)The study analysed the data of 5590 patients recorded in the NAHR who underwent primary hip arthroscopic treatment for FAI between November 2013 and July 2023. Records were matched to the UK National index of multiple deprivation using the lower layer super output area. Using iHOT12 score, patient reported outcome measures were analysed at base line and 1 year following surgery.2358 records were matched to LLSOA deciles. Between the lowest (most deprived) 3 deciles and the highest (least deprived) the average baseline iHOT12 score was 28.98 (n=366) and 35.33 (n=821). The proportion of patients receiving treatment through NHS funding compared to independent funding for the most deprived, 292 (90%) 37 (10%) respectively compared to the least deprived 515 (70%) and 244 (30%) respectively. At 1year, iHOT12 scores for each group were 51.64 (29.1 SD) compared to 61.5 (28.06 SD) respectively.The study demonstrates that patients from lower socioeconomic backgrounds had poorer baseline and one-year post-surgery iHOT12 scores compared to those from higher socioeconomic strata. Furthermore, a higher reliance on NHS funding was observed among the most deprived, while more affluent patients predominantly opted for private funding. These findings underscore the significant influence of socioeconomic status on both the quality of healthcare received and recovery outcomes in hip preservation surgery, calling attention to the need for more equitable healthcare solutions.

Relationship Between Hip Capsular Thickness and Instability After Previous Hip Arthroscopic Surgery: A Matched-Cohort Analysis.

Thinner anterior hip capsules are associated with hip laxity, but there is little known about the impact of capsular thickness on the development of instability after primary hip arthroscopic surgery. To investigate the relationship between hip capsular thickness as measured on preoperative magnetic resonance imaging (MRI) and the development of hip instability after hip arthroscopic surgery for femoroacetabular impingement. Case-control study; Level of evidence, 3. We reviewed revision hip arthroscopic procedures performed between January 1, 2019, and May 1, 2021, at a single institution. Inclusion criteria were preoperative MRI/magnetic resonance arthrography, completion of the study traction protocol, and asymmetric distraction between the hips of ≥3 mm on examination under anesthesia. A comparison group of patients treated for femoroacetabular impingement with primary hip arthroscopic surgery who did not develop capsular instability were matched 1:1 to the patients with instability. Superolateral hip capsular thickness was measured on MRI before index surgery. Analysis was conducted using independent-samples t tests and multivariable linear regression. A total of 44 patients were included, with 22 patients each in the instability and no-instability groups. The mean capsular thickness was lower in the patients with hip instability than in those without (1.9 ± 0.6 vs 3.4 ± 1.1 mm, respectively; P < .001). Decreased capsular thickness was significantly associated with hips with instability versus no-instability (β = -1.468 [95% CI, -2.049 to -0.887]; P < .001). Thinner preoperative hip capsules in the region of the iliofemoral ligament were seen in patients who subsequently underwent revision arthroscopic surgery for hip instability compared to patients who underwent primary hip arthroscopic surgery without subsequent revision. Patients at a higher risk for the development of postoperative hip instability had a superolateral hip capsular thickness of <2 mm.

Hip Arthroscopy Improves Sexual Function in Receptive Partners with Femoroacetabular Impingement Syndrome.

Hip Arthroscopy Improves Sexual Function in Receptive Partners with Femoroacetabular Impingement Syndrome.

Mini-open Femoroacetabular Osteoplasty in Patients With Tönnis Grade 2 or Higher Osteoarthritis is Associated With a Higher Risk of Subsequent Conversion to THA.

The severity of degenerative changes of the hip is known to adversely impact the outcomes of the treatment of femoroacetabular impingement (FAI). Although the operative indications for FAI have expanded to include patients with moderate degrees of hip osteoarthritis, the exact stage of hip osteoarthritis at which surgery for FAI can offer clinical benefits is still uncertain. (1) How does the survivorship free from conversion to THA and survivorship free from revision differ between patients with preexisting Tönnis Grades 2 or 3 changes and those without advanced degenerative changes (Tönnis Grade 0 or 1) after mini-open femoroacetabular osteoplasty? (2) What are the differences in hip-specific and general-health outcome scores between the two groups after mini-open femoroacetabular osteoplasty? From December 2003 to April 2019, we treated 901 patients for FAI, and their clinical data were systematically recorded in a longitudinally maintained database. Mini-open femoroacetabular osteoplasty was our preferred surgical approach because of the surgeon's extensive experience with the technique. Among the entire dataset, 6% of patients (51 individuals) had Tönnis Grade 2 or higher hip osteoarthritis, while the remaining 94% (850 patients) had no or mild degenerative changes (Tönnis Grade 0 or 1). In the Tönnis Grade 2 or 3 group, three patients were lost before the minimum 2-year follow-up duration, leaving 4% (48 patients) who qualified for inclusion in the study. For the matched group with Tönnis Grade 0 or 1, 5% (45 patients) were excluded because of incomplete data, and a further 7% (58 patients) were excluded because they did not have 2 years of follow-up, leaving 83% (747 patients) who were eligible for the matching process. Matching was based on patient age (within 1 year), gender, and BMI (within one unit). Matching resulted in the inclusion of 144 randomly selected control patients in this retrospective, comparative study. General indications for femoroacetabular osteoplasty included symptoms of pain and restricted hip motion in young, active patients with signs of FAI evident on physical examination and radiographs. Patient demographics, medical history, radiographic parameters, and intraoperative findings were compared between the two groups to establish baseline differences and identify potential confounding variables. There was no difference in the mean ± standard deviation age between the cohort of interest and control group (39 ± 10 years and 38 ± 11 years, respectively; p = 0.67). There was no difference in the mean follow-up duration (7 ± 3 years versus 8 ± 2 years; p = 0.25) or the preoperative symptomatic period between the study and control groups (2 ± 2 years versus 3 ± 6 years; p = 0.09). There was no difference in the prevalence of dysplasia, slipped capital femoral epiphysis, Perthes disease, or avascular necrosis of the hip between the two groups. Intraoperatively, the groups did not differ in terms of labral repair (65% [31 of 48] versus 78% [113 of 144]; p = 0.08) and labral transplantation (2%; p > 0.99 for both); however, labral resection was performed more frequently in the study group (63% [30 of 48] versus 42% [60 of 144]; p = 0.002). At a minimum of 2 years of follow-up, survivorship free from conversion to THA and survivorship free from revision surgeries, as well as the latest clinical and functional outcome scores (SF-36, Hip Disability and Osteoarthritis Outcome Score, and modified Harris hip score), were compared between groups. Survivorship free from conversion to THA at 5 years was lower among patients with preexisting Tönnis Grades 2 or 3 changes than it was among patients matched for age, gender, and BMI who did not have advanced degenerative changes (Tönnis Grade 0 or 1) after mini-open femoroacetabular osteoplasty (75% [95% confidence interval 64% to 88%] versus 92% [95% CI 87% to 96%]; p < 0.001). No patients in either group underwent reoperation other than conversion to THA. Although the groups did not differ at baseline in terms of their outcomes scores, the group with more visible arthritis had lower postoperative Hip Disability and Osteoarthritis Outcome Scores than the control group (60 ± 21 points versus 86 ± 11 points, mean difference 26 points [95% CI 10 to 41]; p =0.004). There were no other between-group differences in outcome scores after surgery. In our study, approximately 25% of patients undergoing mini-open femoroacetabular osteoplasty with Tönnis Grade 2 or higher osteoarthritis underwent conversion to THA within 5 years. Some postoperative functional scores were lower in patients with advanced arthritis than in matched patients with no or mild arthritis. We emphasize the importance of exercising caution when considering femoroacetabular osteoplasty in patients in whom advanced arthritis is already evident at the time of presentation. Level III, therapeutic study.

Hip Arthroscopy for Femoroacetabular Impingement Is Associated With Improved Sexual Function And Quality of Life

PurposeThe purpose of this study was to investigate changes in sexual function and activity following arthroscopic hip surgery for femoroacetabular impingement using the United Kingdom Non-Arthroplasty Hip Registry dataset. Sub-analyses were performed between males and females, and patients over 40 and under 40 years old. MethodsPatients who had arthroscopic hip surgery between 1st January 2012 and 31st October 2020, were aged over 16, and completed the relevant PROMs were included. Question 9 of the iHOT-12 (SAQ) refers to problems with sexual activity, and responses to this were compared pre-operatively and at 6-months and 12-months post-operatively. Sub-analyses were also performed, including SAQ scores by patients’ sex or age. SAQ scores were correlated with EQ-5D-5L scores using Spearman’s rank coefficient. ResultsSAQ was answered by 2547 patients pre-operatively and at 6-months post-operatively (62.3% female, median age 36.2, IQR 29-44 years) and by 2314 at 12-months (61.9% female, median age 36.2, IQR 29-44 years). Scores for sexual activity increased from 35.0 pre-operatively to 70.0 at 6-months (p<0.001), maintained at 12-months (p<0.001). Female patients demonstrated a significantly greater improvement in their scores for sexual function from pre-operatively (median 30.0, IQR 14-50) to 6-months (median 60, IQR 28-86, p<0.001) and 12-months (median 62.0, IQR 29-90, p<0.001), compared to male patients (pre-operative median 50.0, IQR 25-84; 6-month median 80, IQR 45-97; 12-month median 80, IQR 41-98). The effect of age on improvements in sexual function did not demonstrate a significant difference. A significant positive correlation was found between improvements in sexual function and quality of life, as measured by the EQ-5D-5L, at 6-months and 12-months (p<0.001). ConclusionHip arthroscopy for symptomatic FAI produces an improvement in sexual function and activity. Scores for sexual function improved regardless of patient age or sex; however, female patients experienced a greater improvement in sexual function than males.

Are degenerative findings detected on traction MR arthrography of the hip associated with failure of arthroscopic femoroacetabular impingement surgery?

To identify preoperative degenerative features on traction MR arthrography associated with failure after arthroscopic femoroacetabular impingement (FAI) surgery. Retrospective study including 102 patients (107 hips) undergoing traction magnetic resonance arthrography (MRA) of the hip at 1.5T and subsequent hip arthroscopic FAI surgery performed (01/2016 to 02/2020) with complete follow-up. Clinical outcomes were assessed using the International Hip Outcome Tool (iHOT-12) score. Clinical endpoint for failure was defined as an iHOT-12 of < 60 points or conversion to total hip arthroplasty. MR images were assessed by two radiologists for presence of 9 degenerative lesions including osseous, chondrolabral/ligamentum teres lesions. Uni- and multivariate Cox regression analysis was performed to assess the association between MRI findings and failure of FAI surgery. Of the 107 hips, 27 hips (25%) met at least one endpoint at a mean 3.7 ± 0.9years follow-up. Osteophytic changes of femur or acetabulum (hazard ratio [HR] 2.5-5.0), acetabular cysts (HR 3.4) and extensive cartilage (HR 5.1) and labral damage (HR 5.5) > 2h on theclockface were univariate risk factors (all p < 0.05) for failure. Three risk factors for failure were identified in multivariate analysis: Acetabular cartilage damage > 2h on the clockface (HR 3.2, p = 0.01), central femoral osteophyte (HR 3.1, p = 0.02), and femoral cartilage damage with ligamentum teres damage (HR 3.0, p = 0.04). Joint damage detected by preoperative traction MRA is associated with failure 4years following arthroscopic FAI surgery and yields promise in preoperative risk stratification. Evaluation of negative predictors on preoperative traction MR arthrography holds the potential to improve risk stratification based on the already present joint degeneration ahead of FAI surgery. • Osteophytes, acetabular cysts, and extensive chondrolabral damage are risk factors for failure of FAI surgery. • Extensive acetabular cartilage damage, central femoral osteophytes, and combined femoral cartilage and ligamentum teres damage represent independent negative predictors. • Survival rates following hip arthroscopy progressively decrease with increasing prevalence of these three degenerative findings.

Utility of 3D Planning Software in Understanding Residual Proximal Femoral Deformity for Planning of Revision Hip Arthroscopy

Background: During the early evolution of femoroacetabular impingement (FAI) treatment, undercorrection of femoral deformity was a leading cause of hip arthroscopy failures. As the pendulum has swung, overresection of femoral deformity has increased in prevalence as a cause of persistent hip pain after arthroscopy. Computed tomography (CT) scans are increasingly being used in hip arthroscopy for preoperative planning purposes and may allow for improved 3-dimensional (3D) assessment of complex femoral deformities after previous femoroplasty. Purpose: To assess whether CT scans provide additional utility over standard radiographs in understanding proximal femoral morphology in patients being evaluated for revision hip arthroscopy after previous femoroplasty in the setting of FAI. Study Design: Cohort study (Diagnosis); Level of evidence, 3. Methods: Preoperative CT scans and standard radiographs were obtained in 80 patients who underwent revision hip arthroscopy for FAI. The anteroposterior and Dunn radiographic views were used to assess patients for residual proximal femoral deformity and were compared with the CT scan views using a commercially available software program. Determinations of underresection were made using alpha angle, while overresection was determined according to a previously described technique. Chi-square tests were performed to determine statistical significance between radiographic and CT classifications of overresection, underresection, and concomitant over- and underresection. A kappa value was calculated to determine the agreement between measurements on the radiographs and CT scans. Results: There were 30 patients (37.5%) for whom the CT scans revealed information about femoral morphology that was not detected on the radiographs. The kappa value of agreement was 0.28 between CT and radiographic measurements. Underresected cams were detected in 30 patients (37.5%) on CT scans versus 17 patients (21.3%) on radiographs (P = .024). Overresected cams were detected in 31 patients (38.8%) on CT scans versus 14 patients (17.5%) on radiographs (P = .0049). Concomitant areas of under- and overresection were detected in 12 patients (15.0%) on CT scans versus 3 patients (3.8%) on radiographs (P = .027). Conclusion: CT scans with 3D planning software may be more sensitive than traditional radiographic views at detecting aberrant proximal femoral anatomy in the setting of failed FAI surgery. The use of 3D planning software may be considered as an adjunctive tool to better understand complex deformity in the proximal femur for the planning of revision hip arthroscopy.

Poster 112: Epigenetic Dysregulation during the OA Progression in Hip FAI

Objectives: Femoroacetabular impingement (FAI) is considered a leading cause of early hip OA, but initial molecular mechanisms that lead FAI patients to OA progression remains to be elucidated. Recent articles revealed that epigenetic changes are associated with OA progression, specifically, DNA methyltransferase 3B (DNMT3B) plays a critical role on cartilage homeostasis by attenuating catabolic gene expression. This study aimed to examine the catabolic state of articular chondrocyte (ACs) during OA progression in hip FAI disease, particularly the expressions of DNMT3B and 4-aminobutyrate aminotransferase (ABAT, downstream of DNMT3B), to assess how epigenetic dysregulation contributes to OA progression. Methods: Full-thickness cartilage samples were collected from the impingement zone. In total, twelve patients underwent hip preservation surgery for cam FAI (early-FAI) and twelve patients underwent total hip replacement for advanced OA secondary to cam FAI (late FAI-OA) were included in this study. As a non-disease (ND) group, five healthy samples were procured from hip joint cadavers. The explants were cultured in unstimulated conditions or catabolic stimulus (IL1β). Histological analyses was performed with safranin-O/fast-green. Gene expression was analyzed via qPCR for GAPDH, DNMT3B, ABAT, MMP-13, and COL10A1. Protein expression was analyzed by western blotting analysis for DNMT3B and ABAT. Methylation specific PCR was performed to assess the methylation status at ABAT promoter (epigenetic change). Results: The early FAI group included younger subjects with lower Tönnis grade than the late FAI OA group; however, there were no significant differences in gender, BMI, and α-angle between groups. Cartilage samples in early-FAI and late FAI-OA showed a histological OA phenotype (Figure 1A). RT-PCR confirmed increased expression of MMP-13 and COL10A1 in early and late FAI-OA (Figure 1B), confirming cartilage degeneration, catabolism, and chondrocyte hypertrophy when compared to ND group. Interestingly, RT-PCR revealed that expression of DNMT3B gradually declined as the disease progressed (ND vs early p&lt;0.001, early vs late p=0.016), while ABAT increased as the disease progressed (ND vs early p&lt;0.001, early vs late p=0.035, Figure 1B). IF staining confirmed that DNMT3B was abundantly expressed in chondrocytes of normal cartilage but the expression gradually decreased with disease progression, contrary ABAT expression gradually increased as the disease progressed (Figure 1C). These results were supported by protein expression in western blotting analysis (Figure 1D). In MSP analysis, the human ABAT promoter is characterized by a typical CpG island (Figure 2A, blue area). Additionally, there was hypomethylation at the ABAT promoter during end stage of disease (ND vs early p=0.022, early vs late p=0.042) (Figure 2B). Catabolic stimulus with IL1β for early FAI and late FAI-OA, accentuated the ABAT promoter hypomethylation (early FAI: nontreatment vs IL1β p=0.056, late FAI-OA: nontreatment vs IL1β p=0.015, Figure 2C) and resulted in further overexpression of ABAT and catabolic markers and decreased expression of DNMT3B (Figure 3A-C). These findings are supported by protein expression in western-blotting analysis (Figure 3D). Conclusions: In the present study, histological findings were similar in early and late FAI, but DNMT3B expression levels gradually decreased with OA progression, while ABAT and catabolic marker expression levels increased, suggesting a less catabolic phenotype in the early stage of disease. MSP analysis confirmed ABAT promoter hypo-methylation (epigenetically dysregulation) as hip OA progresses. Notably, in the current study, the inflammatory stimulus with IL1β further reduced DNA methylation at the ABAT promoter and resulted in a concomitant excessive increase of ABAT and catabolic markers in human hip OA ACs. This study suggests, for the first time, that cartilage degeneration in the impingement zone in hip FAI is progressive at the molecular level and may be controlled in part by an epigenetic dysregulation. Understanding the mechanism of OA disease in hip FAI will potentially provide concomitant interventional treatment to hip pre-OA disease.

Poster 113: Epigenetic Regulation of PPARγ Rescues Articular Chondrocytes from Catabolic State Suggesting PPARγ as a Potential Target to Slow Down Progression of OA in Hip FAI

Objectives: Hip Femoroacetabular impingement (FAI) has a high prevalence of chondral lesions, and the severity of chondral damage is associated with an increased risk of postoperative OA progression, but the mechanisms of cartilage degeneration in OA progression remains unclear. Peroxisome proliferator- activated receptor-gamma (PPARγ) is widely expressed in healthy articular chondrocytes (ACs) and plays an essential role in cartilage homeostasis. Recent investigations into OA pathogenesis have revealed that hyper or hypomethylation (by DNMTs) of OA susceptibility genes are involved in OA progression, especially downregulation of PPARγ has been linked to OA progression. This study aimed to investigate the expression of PPARγ and DNA methyltransferases enzymes (DNMT1 and DNMT3A) during progression of hip disease and 2) methylation changes in the PPARγ promoter area during progression of hip disease. Methods: Full-thickness cartilage samples were collected from the impingement zone. Twelve patients underwent hip preservation surgery for cam FAI (early FAI) and twelve patients underwent total hip replacement for advanced OA secondary to cam FAI (late FAI-OA) were included. As a non-disease (ND) group, six healthy samples were procured from hip joint cadavers. Cartilage explants were cultured in unstimulated conditions or catabolic stimulus (IL1β) with or without DNA demethylating agent 5-Aza-2’- deoxycytidine (5Aza). Histological analysis was performed with safranin O/fast green. Gene expression was analyzed via qPCR for GAPDH, DNMT1, DNMT3A, PPARγ, MMP13, and COL10A1. Methylation specific PCR (MSP) was performed to assess the methylation status at PPARγ promoter site. Chromatin immunoprecipitation (ChIP) assay was performed to confirm an interaction between DNMT3A and the PPAR promoter region. Results: The early FAI group included younger subjects than the late FAI OA group. Cartilage samples in early and late FAI-OA displayed a histological OA phenotype (Figure 1A). ACs in early and late FAI-OA displayed increased expression of catabolism and chondrocyte hypertrophy markers ( MMP13: ND vs early p&lt;0.001, ND vs late p&lt;0.001, COL10A1: ND vs early p&lt;0.001, ND vs late p&lt;0.001, Figure. 1B). Contrary, expression of PPARγ gradually declined as the disease progressed (ND vs early p=0.001, early vs late p=0.003, Figure. 1B). IF analysis also displayed a gradual decrease of the PPARγ expression during disease progression (ND vs early p=0.001, early vs late p=0.041, Figure 1C). In the assessment of the epigenetic mechanisms of aberrant DNA methylation in OA progression, overexpression of DNMT1 and DNMT3A levels was observed with disease progression in RT-PCR ( DNMT1: ND vs early p&lt;0.001, early vs late p=0.041, DNMT3A: ND vs early p=0.015, early vs late p=0.053,Figure 2A) and IF analysis ( DNMT1: ND vs early p&lt;0.001, early vs late p&lt;0.001, DNMT3A: ND vs early &lt;0.001, early vs late p=0.008, Figure 2B). Next, in MSP analysis, human PPARγ promoter was featured by typical CpG islands (Figure 3A). As the OA progresses, hypermethylation at PPARγ promoter (ND: 9%, Early-FAI: 34%, Late FAI-OA: 48%) was observed (Figure 3B), and ChIP assay confirmed DNMT3A interaction with the CpG PPARγ promoter area (Figure 3C). IL1β stimulus increased PPARγ promoter methylation for early (34% to 57%, p=0.016, Figure 3D) and late stages (48% to 79%, p=0.001, Figure 3D) resulting in suppression of PPARγ expression (P=0.073, Figure 3F). Contrary, treatment with 5Aza (a DNA demethylator) brought the level of methylation back to 37% for early FAI ( p=0.033, Figure 3D) and 46% for late FAI-OA (p&lt;0.001, Figure 3D), reversed the PPARγ suppression induced by IL1β (early- FAI p=0.009, and late FAI-OA ACs p&lt;0.001 Figure 3F) and decreased expression of MMP-13 and COL10A1 induced by IL1β (early-FAI p=0.009, Figure 4C and late FAI-OA ACs p&lt;0.001 Figure 3F). PPARγ inhibitor rescued cells from the catabolic phenotype. (Fig.3E, F), suggesting that restoration of PPARγ by 5Aza contributes significantly to the cartilage protective effect. Conclusions: This current study demonstrates that PPARγ expression was gradually suppressed via promoter hypermethylation during OA progression in hip FAI. Moreover, the inflammatory stimulus with IL1β further increased catabolic markers and enhanced PPARγ suppression via promoter excessive hypermethylation in human hip ACs. Notably, DNA demethylating agent (5 aza) prevents the IL1β induced PPARγ promoter hypermethylation rescuing PPARγ and alleviating cartilage degenerative damage. Certainly, for patients with symptomatic hip FAI, surgical correction should be prioritized to suppress inflammation, but our observations suggests that critical epigenetic dysregulation occurs during the progression of hip OA. Future investigations will be needed to confirm if regulation of these epigenetic changes could potentially complement surgical treatment to minimize OA progression in hip FAI.

Paper 12: Severity of Chondrolabral Junction Degeneration Predicts Conversion to Total Hip Arthroplasty after Arthroscopic Femoroacetabular Impingement Treatment at Minimum 10-Years Follow-Up

Objectives: To identify location and severity of intraoperative pathology at time of arthroscopic surgery for femoroacetabular impingement (FAI) as risk factors for conversion to total hip arthroplasty (THA) utilizing long-term follow-up (minimum 10 years). Methods: Retrospective study of prospectively collected data of adult patients (≥ 18 years) who underwent hip arthroscopy for FAI between 1998 and 2011 with minimum follow-up of 10 years. Location and severity of pathology at time of arthroscopic surgery were assessed as risk factors for later conversion to a primary outcome of THA. Patients with radiographic evidence of hip dysplasia and previous history of hip surgery were excluded. Patients were then grouped according to whether they had underwent THA. Differences in continuous variables including age, BMI, and center edge angle (CEA) were analyzed with independent t tests. Differences in categorical variables including type of treatment (debridement or repair), deformity (CAM vs pincer vs combined), Outerbridge grade, location of most severe chondral wear (anterosuperior acetabulum, posterosuperior acetabulum, femoral head), presence of chondral flap, and degree of chondrolabral degeneration (as measured by Beck classification) were analyzed with the Pearson’s Chi-squared test. For variables with greater than two levels (chondrolabral degeneration, etc.) adjusted residuals were calculated to determine which comparisons were statistically different, with a value of &gt;2 indicating a lack of fit with the null hypothesis of difference. A multivariable logistic regression model was constructed to estimate the influence of the exact location and severity of pathology on risk for conversion to THA. Model results are reported as odds ratios (OR) with corresponding 95% confidence intervals. Results: A total of 109 patients with a mean age of 39.41 ± 11.43 years and minimum follow-up of 10 years were eligible for inclusion in this study. The average follow-up was 12.29 ± 2.53 years. Average body mass index (BMI) was 26.19 ± 4.07 while average center edge angle (CEA) was 39.53 ± 7.24. 67 (61.5%) patients underwent debridement while 42 (38.5%) patients underwent labral repair. 32 (29.4%) patients subsequently converted to THA. BMI (1.7% difference, p = 0.072), CEA (0.3% difference, p = 0.832), sex (0.2% difference, p = 0.991), procedure type (11.8% difference, p = 0.565), and presence of a chondral flap (6.3% difference, p = 0.685) were not significantly associated with conversion to THA. FAI type, Outerbridge grade, chondrolabral junction degeneration, and location of most severe degenerative change were statistically significant, with adjusted residuals greater than 2 (Table 1). A multivariable logistic regression model demonstrated age (OR=1.08, 95% CI 1.03-1.14, p = 0.002), Grade 4 chondrolabral degeneration (OR = 3.26, 95% CI 1.16-9.17, p = 0.025) and combined FAI type (OR = 4.32, 95% CI 1.38 – 13.56, p = 0.012) as significant risk factors for conversion to THA. Conclusions: Grade 4 degeneration of the chondrolabral junction as well as combined FAI type and older age are significant risk factors for conversion to THA after arthroscopic treatment of FAI at minimum 10-years of follow-up. [Table: see text][Table: see text]

Paper 63: Return to Long Distance Running After Hip Arthroscopy for Femoroacetabular Impingement

Objectives: Arthroscopic hip surgery for femoroacetabular impingement (FAI) has shown high rates of return to different sports in athletes. No studies to date have focused on patients’ return to long- distance running, a running sport with unique characteristics and demands. The purpose of this study was to determine return to long-distance running rates and changes in running performance in long distance runners undergoing hip arthroscopic surgery for the treatment of FAI and to identify possible risk factors associated with not returning to long distance running. Methods: An institutional hip preservation registry was retrospectively reviewed for patients identified as long distance runners (half marathons and marathons) who underwent primary hip arthroscopies for FAI performed between March 2010 and January 2017. Patient demographics and injury characteristics as well as clinical and radiographic findings were recorded. All patients were contacted for return to running information using a running specific return to sport questionnaire. Multivariable logistic regression analysis was used to identify potential risk factors for not returning to long-distance running. Results: Sixty-eight long distance runners (78 hips) were included. Mean patient age and body mass index (BMI) were 37.8±8.9 years and 23.8±3.3 kg/m2, respectively. Thirty-eight (56%) were female runners. Mean weekly running milage prior to injury was 34.5±16.9 miles. Mean duration of hip symptoms prior to seeking medical evaluation was 77.3±16.9 weeks. Fifty-nine runners (87%) had to stop or modify their running for a mean duration of 44.3±45 weeks prior to surgery due to hip symptoms. Overall, 50 runners (74%) returned to any running, of which 25 runners (50%) returned to long distance running completing half/full marathons races after surgery. Most common reasons for not returning to running were pain or discomfort (50%) followed by fear of re-injury (22%) and additional different injuries (22%). Among runners who did not return to any running, 12 (67%) reported satisfaction from surgery. Multivariable logistic regression analysis revealed female runners (odds ratio [OR]=0.2; confidence interval [CI]=0.0 to 0.9; p=0.034) and hips with radiologic findings of higher alpha angles (OR=0.9; 95% CI=0.9 to 1.0; p=0.045) were less likely to return to long distance running. Conclusions: Hip arthroscopic treatment for FAI in symptomatic long-distance runners, a distinctive subgroup of runners, allowed most of them (74%) to return to running, however only 40% returned to long distance running races. Female runners and runners with radiologic findings of higher alpha angles were less likely to return to long-distance running. These data can better guide clinicians and long- distance runners with realistic expectations related to the arthroscopic management of symptomatic FAI.

Hip Arthroscopy for Femoroacetabular Impingement

Background: Femoroacetabular impingement (FAI) is pain due to shape mismatch at the hip joint commonly affecting young athletes, and there are 2 main types depending on which bone has the underlying deformity: cam (femoral) and pincer (acetabular). Hip arthroscopy is an invaluable technique in the sports surgeon repertoire, and there is a need for a comprehensive tutorial that elucidates the best practices and nuances. Indications: Pain with evidence of FAI and labral tear on imaging, and failing conservative treatment, warrants arthroscopy. Technique Description: FAI surgery requires anatomical labral repair, thorough osteoplasty to correct the underlying deformity and prevent labral retearing, and careful treatment of soft tissues and capsular closure. Results: Reduced pain and improved hip function are the goals of treatment, with approximately 90% of patients returning to sport at 6 to 8 months postoperatively. Discussion/Conclusion: Hip arthroscopy is a safe and effective treatment for patients with FAI who failed conservative therapy. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Poster 114: Viability and Expression of Chondrocytes Harvested During Arthroscopic Treatment of Femoroacetabular Impingement

Poster 114: Viability and Expression of Chondrocytes Harvested During Arthroscopic Treatment of Femoroacetabular Impingement

Pericapsular Nerve Group Block Leads to Small but Consistent Reductions in Pain Between 18 and 24 Hours’ Postoperatively in Hip Arthroscopy for Femoroacetabular Impingement Surgery: A Prospective, Randomized Controlled Clinical Trial

To investigate whether the use of a pericapsular nerve group (PENG) block would reduce perioperative pain after arthroscopic therapy for femoroacetabular impingement syndrome (FAIS) and to examine opioid requirements and occurrence of postoperative nausea and vomiting (PONV). Between May 2022 and October 2022, patients (N= 68) undergoing arthroscopic surgery for FAIS were randomly allocated into 2 groups. The first group received an ultrasound-guided PENG preoperatively with 20 mL of 0.375% ropivacaine and standardized postoperative oral medication. The second group received a sham block preoperatively with 20 mL of 0.9% saline and standardized postoperative oral medication. The primary end point was pain scores (visual analog score [VAS], 0-10) during the first 24 hours postoperatively. To quantify clinical significance of outcome achievement for the VAS pain score, the minimal clinically important difference (MCID) was calculated using the half standard deviation method. The incidence of PONV as well as opioid usage (converted to morphine equivalent) within the first 24 hours were secondary outcomes. Randomization and permission were successfully obtained from 68 participants. From the fifteenth postoperative hour, the PENG group reported significantly less postoperative pain than the control group (24th postoperative hour: VAS pain PENG group 1.3 ± 0.9 [0-3]; 95% confidence interval {CI} 0.4-1.2 vs the VAS pain control group 2.4 ± 1.6 [0-5]; 95% CI 1.4-4.7; P= .009). The VAS pain score threshold for achieving the MCID at 24 hours postoperative was defined as a decrease of 1.1. 27 patients (79%) in the PENG group and 22 patients (65%) in the control group were able to achieve MCID (P= .009). Opioid dosage and postoperative nausea did not differ significantly between groups (P=.987 and P= .655, respectively). Concomitant complications such as falls, hematomas, or weakened muscles did not occur in either group. According to this study, a PENG block minimally reduced pain after arthroscopic treatment for FAIS between the 18th and 24th postoperative hours. The PENG group achieved significantly more often the pain VAS MCID. However, there was no proof that the PENG group consumed fewer opioids than the control group. Overall, PONV was found at a low and comparable rate. Level I, randomized controlled trial.

Biomechanical Analysis of Hip Braces after Hip Arthroscopic Surgery for Femoroacetabular Impingement Syndrome: An Observational Study.

Currently, hip braces are recommended and typically worn by femoroacetabular impingement (FAI) patients after hip arthroscopic surgery. However, there is currently a lack of literature regarding the biomechanical effectiveness of hip braces. The purpose of this study was to investigate the biomechanical effect of hip braces after hip arthroscopic surgery for FAI. Overall, 11 patients who underwent arthroscopic FAI correction and labral preservation surgery were included in the study. Standing-up and walking tasks in unbraced and braced conditions were performed at 3 weeks postoperatively. For the standing-up task, videotaped images of the hip's sagittal plane were recorded while patients stood from a seated position. After each motion, the hip flexion-extension angle was calculated. For the walking task, acceleration of the greater trochanter was measured using a triaxial accelerometer. For the standing-up motion, the mean peak hip flexion angle was found to be significantly lower in the braced condition than in the unbraced condition. Furthermore, the mean peak acceleration of the greater trochanter was significantly lower in the braced condition than in the unbraced condition. Patients undergoing arthroscopic FAI correction surgery would benefit from usage of a hip brace in terms of protecting repaired tissues during early postoperative recovery.

Hip Arthroscopy Trends: Increasing Patient Out-of-Pocket Costs, Lower Surgeon Reimbursement, and Cost Reduction With Utilization of Ambulatory Surgery Centers

To (1) report on trends in immediate procedure reimbursement, patient out-of-pocket expenditures, and surgeon reimbursement in hip arthroscopy (2) compare trends in ambulatory surgery centers (ASC) versus outpatient hospitals (OH) utilization; (3) quantify the cost differences (if any) associated with ASC versus OH settings; and 4) determine the factors that predict ASC utilization for hip arthroscopy. The cohort for this descriptive epidemiology study was any patient over 18 years identified in the IBM MarketScan Commercial Claims Encounter database who underwent an outpatient hip arthroscopy, identified by Current Procedural Terminology codes, in the United States from 2013 to 2017. Immediate procedure reimbursement, patient out-of-pocket expenditure, and surgeon reimbursement were calculated, and a multivariable model was used to determine the influence of specific factors on these outcome variables. Statistically significant P values were less than .05, and significant standardized differences were more than 0.1. The cohort included 20,335 patients. An increasing trend in ASC utilization was observed (P= .001), and ASC utilization for hip arthroscopy was 32.4% in 2017. Patient out-of-pocket expenditures for femoroacetabular impingement surgery increased 24.3% over the study period (P= .003), which was higher than the rate for immediate procedure reimbursement (4.2%; P= .007). ASCs were associated with $3,310 (28.8%; P= .001) reduction in immediate procedure reimbursement and $47 (6.2%; P= .001) reduction in patient out-of-pocket expenditure per hip arthroscopy. ASCs provide a significant cost difference for hip arthroscopy. Although there is an increasing trend toward ASC utilization, it remains relatively low at 32.4% in 2017. Thus, there are opportunities for expanded ASC utilization, which is associated with significant immediate procedure reimbursement difference of $3,310 and patient out-of-pocket expenditure difference of $47 per hip arthroscopy case, ultimately benefiting healthcare systems, surgeons, and patients alike. Level III, retrospective comparative trial.

The Relationship Between the Joint Space and Outcomes After Hip Arthroscopic Surgery for Femoroacetabular Impingement: Reevaluating the 2-mm Rule

Background: A limited joint space (<2 mm) is associated with poorer outcomes and conversion to total hip arthroplasty (THA) after hip arthroscopic surgery. As indications for hip arthroscopic surgery expand, it is important to reevaluate established risk factors among large patient populations. Purpose: To reevaluate the relationship between the radiographic joint space and outcomes after hip arthroscopic surgery and to assess the validity of a joint space of 2 mm as the accepted cutoff for successful hip arthroscopic surgery. Study Design: Cohort study; Level of evidence, 3. Methods: Patients aged 18 to 50 years who underwent hip arthroscopic surgery for femoroacetabular impingement between January 2008 and December 2016 and had a minimum 2-year follow-up were included. Patients with previous ipsilateral hip surgery, a history of hip fractures, dysplasia (lateral center-edge angle <20°), or osteoarthritis (Tonnis grade >2) were excluded. The joint space was categorized as diminished (≤2 mm), borderline (>2 to ≤3 mm), or preserved (>3 mm). Minimum 2-year patient-reported outcomes (modified Harris Hip Score [mHHS], Hip Outcome Score–Activities of Daily Living [HOS-ADL], Hip Outcome Score–Sports-Specific Subscale [HOS-SSS]), revision rates, and rates of conversion to THA were compared between groups. Results: A total of 699 patients (782 hips) with a mean age of 33.8 ± 10.1 years met 2-year inclusion criteria. The mean follow-up time was 4.2 ± 2.1 years. Overall, 51 hips (6.5%) had a diminished joint space, 297 (38.0%) had a borderline joint space, and 434 (55.5%) had a preserved joint space. Patients with a diminished joint space had larger femoral and acetabular defects compared with those with larger joint spaces. All groups had improved patient-reported outcome scores compared with baseline (P < .001 for all), and there were no differences between the groups in the percentage of patients who reached the minimal clinically important difference or patient acceptable symptom state. There were also no differences between the groups in revision rates (P = .95). A greater number of hips with a diminished joint space converted to THA (n = 8 [15.7%]) compared with those with a borderline (n = 9 [3.0%]) or preserved (n = 9 [2.1%]) joint space (P < .001). Considering joint space as a continuous variable, adjusted logistic regression showed that for every millimeter decrease in the joint space, the odds of conversion to THA increased by a factor of 2.5 (odds ratio, 2.5 [95% CI, 1.6-3.8]). Conclusion: This study demonstrated that patients with a diminished joint space were at a higher risk of conversion to THA. Although 2 mm should not serve as a strict cutoff, patients should be counseled based on their preoperative radiographic findings accordingly.

Long-term Outcomes After Arthroscopic Treatment of Femoroacetabular Impingement for Patients With Borderline Dysplasia

Background: Outcomes after isolated hip arthroscopic surgery for patients with dysplasia have been unfavorable. Results have included iatrogenic instability and conversion to total hip arthroplasty at a young age. However, patients with borderline dysplasia (BD) have shown more favorable results at short- and medium-term follow-up. Purpose: To assess long-term outcomes after hip arthroscopic surgery for femoroacetabular impingement in patients with BD (lateral center-edge angle [LCEA] = 18°-25°) compared with a control group of patients without dysplasia (LCEA = 26°-40°). Study Design: Cohort study; Level of evidence, 3. Methods: We identified a group of 33 patients (38 hips) with BD who were treated for FAI between March 2009 and July 2012. An age- and sex-matched control group of 83 patients (96 hips) was also identified. Patient-reported outcome scores were collected preoperatively and subsequently at a mean of 9.6 years postoperatively. Results: The mean LCEA and Tönnis angle were 22.42°± 2.02° and 6.27°± 3.23° in the BD group, respectively, and 31.71°± 3.52° and 2.42°± 3.02° in the control group, respectively (P < .001). At a mean follow-up of 9.6 years (range, 8.2-11.6 years), there was a significant improvement in all patient-reported outcome scores in both groups (P < .001). There were no significant differences between preoperative and postoperative scores or rates of achieving the minimal clinically important difference between the BD and control groups. Bilateral surgery was noted to be a risk factor for any revision during the follow-up period (P < .001). There were 2 hips (5.3%) that underwent revision surgery in the BD group and 10 hips (10.4%) in the control group; of these, 1 patient in the BD group underwent total hip arthroplasty, and 1 patient who had undergone bilateral surgery in the control group underwent bilateral hip resurfacing. Conclusion: Durable outcomes (>9 years) with low revision rates can be expected after hip arthroscopic surgery with an approach that involves labral preservation where possible and careful attention to capsular closure in patients with BD. The observed outcomes were similar to those of a femoroacetabular impingement group with normal coverage. These results highlight the importance of classifying patients into impingement or instability categories and tailoring treatment appropriately with arthroscopic surgery or periacetabular osteotomy, respectively.

Radiographic Predictors of Reoperation in Adolescents Undergoing Hip Preservation Surgery for Femoroacetabular Impingement

Background: Femoroacetabular impingement (FAI) is a condition caused by repetitive abutment of a morphologically abnormal proximal femur and/or acetabulum that may result in chondral and labral pathology. An understanding of radiographic parameters associated with successful primary surgery has not been well established. Purpose: To determine preoperative radiographic parameters that predict reoperation for FAI and correlate radiographic measurements with outcomes in these patients. Study Design: Case-control study; Level of evidence, 3. Methods: A prospectively collected institutional registry of adolescent patients (age, <19 years) who underwent surgery for FAI (arthroscopic/open) was reviewed. Preoperative standing anteroposterior pelvic radiographs were analyzed for femoroepiphyseal acetabular roof (FEAR) index, as well as lateral center-edge angle (LCEA) and alpha, Tönnis, and Sharp angles. Patient-reported outcomes (PROs) (modified Harris Hip Score, Hip disability and Osteoarthritis Outcome Score) were analyzed preoperatively and at 1- and 2-year followup. Radiographic indication of risk for reoperation was evaluated using receiver operating characteristic (ROC) analysis. Spearman correlation was calculated between radiographic measurements and PROs at 2 years postoperatively. Results: A total of 81 patients (91 hips) underwent primary surgery (57 surgical dislocations vs 34 arthroscopies) for FAI. The mean age at time of primary operation was 16.23 years (range, 10.4-19.6 years) (73.6% female). Eleven hips (12.1%) underwent reoperation at a mean of 20.6 months from primary surgery. The LCEA, FEAR index, Tönnis angle, and Sharp angle before index surgery were significantly different (P < .05) between patients who underwent reoperation and those who did not. ROC analysis indicated that LCEA <22°, FEAR index >–8.7°, Tönnis angle >6.0°, and Sharp angle >44° were predictors for increased risk of reoperation. Using the cutoff values from the ROC analysis in this series, 43% of patients with an LCEA ≤22° had a repeat procedure, while only 8% of those with an LCEA >22° had a repeat procedure. Similar trends were seen with the other aforementioned acetabular radiographic measurements (FEAR index, Tönnis angle, Sharp angle). Patients who did not require a reoperation demonstrated significant improvement in all PRO categories from their preoperative to 2-year postoperative visits (P < .0001). Conclusion: In patients undergoing treatment for FAI, a reoperation was associated with radiographic signs of hip dysplasia, indicating that patients with a shallower acetabulum are at risk for a repeat operation.

Effect of Changes in Iliocapsularis Cross-sectional Area on Hip Arthroscopy Outcomes: Clinical and Magnetic Resonance Imaging Follow-up.

The function of the iliocapsularis (IC) muscle is still unclear. Previous studies have reported that the cross-sectional area of the IC may be useful in identifying borderline developmental dysplasia of the hip (BDDH). To evaluate the pre- to postoperative changes in IC cross-sectional area in patients with femoroacetabular impingement (FAI) and to determine if there are any associations with clinical outcomes after hip arthroscopy. Cohort study; Level of evidence, 3. The authors retrospectively evaluated patients who underwent arthroscopic surgery for FAI at a single institution between January 2019 and December 2020. Patients were divided into 3 groups according to lateral center-edge angle: BDDH group (20°-25°), control group (25°-40°), and pincer group (>40°). Supine anteroposterior hip radiographs, 45° Dunn view radiographs, computed tomography scans, and magnetic resonance imaging (MRI) scans were obtained for all patients preoperatively and postoperatively. The cross-sectional areas of the IC and the rectus femoris (RF) were measured on an axial MRI slice at the level of the femoral head center. Preoperative and final follow-up scores on the visual analog scale for pain and the modified Harris Hip Score (mHHS) were compared between groups with the independent-samples t test. A total of 141 patients (mean age, 38.5 years; 64 male, 77 female) were included. The preoperative IC-to-RF ratio of the BDDH group was significantly higher than that of the pincer group (P < .05). In the BDDH group, there was significant pre- to postoperative decrease in IC cross-sectional area and the IC-to-RF ratio (P < .05 for both) as well as a significant correlation between the preoperative IC cross-sectional area and the postoperative mHHS (r = 0.434; P = .027). Patients with BDDH had a significantly higher preoperative IC-to-RF ratio than patients with pincer morphology. A higher preoperative IC cross-sectional area was associated with better postoperative patient-reported outcomes after arthroscopy for the treatment of FAI combined with BDDH.