Femoroacetabular Impingement Patients Research Articles

Mid-term results of autologous matrix-induced chondrogenesis for large chondral defects in hips with femoroacetabular impingement syndrome.

The purpose of this study was to evaluate the mid-term outcomes of autologous matrix-induced chondrogenesis (AMIC) for the treatment of larger cartilage lesions and deformity correction in hips suffering from symptomatic femoroacetabular impingement (FAI). This single-centre study focused on a cohort of 24 patients with cam- or pincer-type FAI, full-thickness femoral or acetabular chondral lesions, or osteochondral lesions ≥ 2 cm2, who underwent surgical hip dislocation for FAI correction in combination with AMIC between March 2009 and February 2016. Baseline data were retrospectively obtained from patient files. Mid-term outcomes were prospectively collected at a follow-up in 2020: cartilage repair tissue quality was evaluated by MRI using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Patient-reported outcome measures (PROMs) included the Oxford Hip Score (OHS) and Core Outcome Measure Index (COMI). Clinical examination included range of motion, impingement tests, and pain. A total of 12 hips from 11 patients were included (ten males, one female, mean age 26.8 years (SD 5.0), mean follow-up 6.2 years (SD 5.2 months)). The mean postoperative MOCART score was 66.3 (SD 16.3). None of the patients required conversion to total hip arthroplasty. Two patients had anterior impingement. External hip rotation was moderately limited in four patients. There was a correlation between MOCART and follow-up time (rs = -0.61; p = 0.035), but not with initial cartilage damage, age, BMI, or imaging time delay before surgery. PROMs improved significantly: OHS from 37.4 to 42.7 (p = 0.014) and COMI from 4.1 to 1.6 (p = 0.025). There was no correlation between MOCART and PROMs. Based on the reported mid-term results, we consider AMIC as an encouraging treatment option for large cartilage lesions of the hip. Nonetheless, the clinical evidence of AMIC in FAI patients remains to be determined, ideally in the context of randomized controlled trials.

Risk factors for hip osteoarthritis after arthroscopy in patients with femoroacetabular impingement

To investigate the risk factors of hip osteoarthritis（HOA） after hip arthroscopy in patients with femoro-acetabular impingement（FAI） syndrome, and to reduce and prevent HOA. From September 2018 to September 2020, 106 patients with FAI underwent hip arthroscopy, including 40 males and 66 females, aged from 20 to 55 years old with an average age of （33.05±10.19） years old. The mechanism of injury included 51 cases for sports injury, 36 for traffic accidents, and 19 for blunt object injury. The duration of the disease ranged from 5 to 19 days with an average of （12.02±3.69） days. All patients were followed up for 18 months. Patients were divided into HOA group （23 cases） and non-HOA group （83 cases） according to the occurrence of HOA. Multivariate Logistic regression was used to analyze the risk factors of HOA after hip arthroscopy in FAI patients. By univariate analysis, aged from 50 to 70 years old, female, body mass index（BMI）> 30 kg·m-2, physical labor, cam type, postoperative infection, last follow-up hip degree of motion （range of motion, ROM） （flexion, abduction, adduction, internal rotation） and Tönnis grade 1 and above of the HOA group were higher than those of the non-HOA group （P<0.05）, and the relative appendicular skeletal muscle index （RASM） was lower than that of non-HOA group（P<0.05）. By multiple Logistic regression analysis, cam type, BMI>30 kg·m-2, last follow-up hip internal rotation ROM and Tönnis grade 1 were risk factors for HOA after hip arthroscopy in FAI patients （P<0.05）. FAI classification, body mass index, hip ROM and Tönnis grade are all related to HOA after hip arthroscopy in FAI patients. Follow-up and intervention should be strengthened in high-risk FAI patients to reduce the occurrence of HOA.

Discrepancies in MR- and CT-Based Femoral Version Measurements Despite Strong Correlations

PurposeTo determine the correlation and classification consistency of femoral version measurements between MR and CT using four commonly used measurement methods. MethodsA retrospective study was performed on femoroacetabular impingement (FAI) patients who received preoperative CT and MR imaging assessment of the surgical hip and ipsilateral distal femur. Femoral version was measured using the Murphy method, the oblique method, the Reikerås method and the Lee method. Intra- and inter-rater agreements were calculated. Linear regression and Bland-Altman analysis were performed for measurements using different imaging modalities and measurement methods. Femoral version measurements within the lower quartile, the middle 2 quartiles and the upper quartile were classified into different groups based on their percentile within the sample population. Classification consistency rates between modalities and methods were calculated and compared. ResultsFifty-three patients (39.4 ± 9.1 years; 32 female) were included for analysis. Intra- and inter-rater reliability were high for all modalities and methods (intra-rater ICC range, 0.963-0.993; inter-rater ICC range, 0.871-0.960). MR- and CT-based femoral version measurements showed strong correlations for all methods, with the Lee method demonstrating the strongest association (r = 0.904), while the oblique method exhibited the lowest correlation (r = 0.684) (all P < .001). MR-based measurements were smaller than CT-based measurements with mean differences ranging from 4.5° to 10.3°. Classification consistency between MR and CT ranged from 51% to 74%, whereas the consistency between different measurement methods ranged from 68% to 85%. ConclusionsWhile strong correlations were observed between MR- and CT-based femoral version measurements, MR-based measurements were significantly smaller than their CT counterparts. Classification consistency between the modalities was moderate to high. Measurements between different methods showed strong correlations with high consistency rates. Level of EvidenceLevel III, retrospective case series.

UTE T2* cartilage mapping in the hip: a pilot study assessing cartilage in patients with femoroacetabular impingement.

UTE T2* cartilage mapping use in patients undergoing femoroacetabular impingement (FAI) has been lacking but may allow the detection of early cartilage damage. To assess the reproducibility of UTE T2* cartilage mapping and determine the difference in UTE T2* values between FAI and asymptomatic patients and to evaluate the correlation between UTE T2* values and patient-reported symptoms. Prospective evaluation of both hips (7 FAI and 7 asymptomatic patients). Bilateral hip 3-T MRI scans with UTE T2* cartilage maps were acquired. A second MRI scan was acquired 1-9 months later. Cartilage was segmented into anterosuperior, superior, and posterosuperior regions. Assessment was made of UTE T2* reproducibility (ICC). Mean UTE T2* values in patients were compared (t-tests) and correlation was made with patient-reported outcomes (Spearman's). ICCs of mean UTE T2* were as follows: acetabular, 0.82 (95% CI=0.50-0.95); femoral, 0.76 (95% CI=0.35-0.92). Significant strong correlation was found between mean acetabular UTE T2* values and iHOT12 (ρ = -0.63) and moderate correlation with mHHS (ρ = -0.57). There was no difference in mean UTE T2* values between affected vs. non-affected FAI hips. FAI-affected hips had significantly higher values in acetabulum vs. asymptomatic patients (13.47 vs. 12.55 ms). There was no difference in mean femoral cartilage values between the FAI-affected hips vs. asymptomatic patients. The posterosuperior femoral region had a higher mean value in non-affected FAI hips vs. asymptomatic patients (12.60 vs. 11.53 ms). UTE T2* cartilage mapping had excellent reproducibility. Affected FAI hips had higher mean acetabular UTE T2* values than asymptomatic patients. Severity of patient-reported symptoms correlates with UTE T2* acetabular cartilage values.

Return to Play After Femoroacetabular Impingement.

Femoroacetabular impingement (FAI) is a pathomechanical process whereby abnormal contact between proximal femur and acetabulum at end range of hip motion induces chondrolabral lesions within the hip joint. Surgery followed by a rehabilitation program or physical therapy with possible addition of an intra-articular corticosteroid injection are the two predominant treatments. The majority of authors recognize that a well-designed rehabilitation protocol is essential to achieve good outcomes with both nonoperative and surgical treatment. However, there is little evidence about what is the best rehabilitation protocol and most of the literature available is based on expert level opinion. This current review investigates the recent literature on nonoperative and postoperative rehabilitation protocol and return to play in FAI patients and describes our approach. Historically, rehabilitation protocols for treatment of FAI as well as return to play protocols were based on experts' opinion and low-level evidence studies. In order to improve standardization of protocols and to allow a better comparison in between different protocols, different authors have created standardized rehabilitation protocols with consensus building methods comparing them with other treatment options in high-level evidence trials (FASHIoN trial, etc.). Despite the excellent results reported after nonoperative and post-surgical rehabilitation, and the high RTP rate after FAI treatment, there is a significant variability in between protocols. Further high-level evidence studies are necessary in order to establish a gold standard in rehabilitation and RTP protocols.

Did COVID-19 restrictions affect post-operative rehabilitation of patients who underwent arthroscopic management of femoroacetabular impingement?

Objectives: This study aimed to evaluate the impact of a home-based exercise rehabilitation protocol for post-arthroscopy femoroacetabular impingement (FAI) patients compared to the routine physiotherapy protocol and investigate the effect of COVID-19 restrictions on patient rehabilitation and clinical outcomes. Methods: The study used a prospective cohort with a matched-pair comparison research design. The study group included 26 patients who underwent arthroscopic management of FAI through osteochondroplasty and suture anchor repair from July 2020 to June 2022. Thirty patients from the existing database who underwent arthroscopic management of FAI from June 2018 to June 2020 were included as a control group. Patient demographic and baseline data, the modified Harris Hip Score and the international Hip Outcome Tool-12 (iHOT-12) Score, the surgical satisfaction questionnaire, and the COVID-19 rehabilitation questionnaire were investigated for both groups. Patients in the study group received home-based exercise booklets. Results: The iHOT-12 score was significantly improved in the study group compared to the control group at 6 and 12 months (72 ± 22.33, 80.85 ± 13.46 vs. 58.03 ± 23.89, 62.1 ± 19.52, P = 0.029, P &lt; 0. 001, respectively). Conclusion: Home-based exercise protocols successfully managed to achieve better outcomes in the study group assessed through the iHOT-12 Score at 1 year postoperatively. However, patients’ satisfaction was lower in the study group than in the control group.

Increased asphericity of the femoral head-neck junction in professional breakers compared to hobby athletes – a retrospective case-control study

ABSTRACT Objective Breaking has gained public attention as a form of sports activity. The associated intense movements of the hip joints are possibly linked to the development of femoroacetabular impingement (FAI). Therefore, this study aimed to assess clinical and radiographic FAI measures in professional breakers compared to hobby athletes. Methods The study cohort consisted of professional breakers with persisting hip pain who were 1:1 matched to a cohort of FAI patients without professional sports careers from our outpatient clinic. The primary endpoint assessed on standardized plain radiographs was the alpha angle (AA). Further measures were the acetabular index (AI), lateral center-edge angle (LCEA), crossover sign, ischial spine sign, and femoral head extrusion index (FHEI). The modified Harris Hip Score (mHHS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were used to obtain patient-reported measures. Results We recruited ten professional breakers and matched them to ten hobby athletes. The median AA was significantly higher in the breakers compared with the hobby athletes (73° [IQR 66.5°, 84.2°]) vs. 61.8° [IQR 59.5°, 64.8°], p = 0.0004). There was a significant reduction in weekly training hours in breakers after diagnosis (13.0 hours [interquartile range [IQR] 9.5, 32.4] to 1.5 hours [IQR 0, 4.8], p = 0.0039). There were no inter-group differences regarding mHHS, WOMAC, and additional radiographic measurements. Conclusion Breakers have higher AA in cam-type FAI compared to nonprofessional athletes. The corresponding hip pain significantly reduced training hours and caused the end of their breaking career. The potentially high prevalence of FAI in breakers and the corresponding consequences need to be considered early when athletes present with hip pain.

The Influence of Compensatory Pelvic Tilt on Patient-reported Outcome Measurements in FAI Patients Who Received Arthroscopic Treatment.

Pelvic compensation is common in femoroacetabular impingement (FAI) patients to reduce symptoms and increase range of motion. However, little attention was given to the postoperative clinical effect of pelvic compensation. Therefore, this study aims to compare the outcomes between pelvic compensation and normal pelvic position in femoroacetabular impingement (FAI) patients after hip arthroscopy. The retrospective study was conducted from January 2019 to June 2022, recruited consecutive patients who were diagnosed with FAI and received subsequent arthroscopic treatment. All patients completed an X-ray in the anterior-posterior standing position before and 4 weeks after surgery. Patients with pelvic compensation were compared with those who did not. Functional outcomes included hip disability and osteoarthritis outcome score (HOOS), modified Harris (mHHS) score, and lower-extremity activity scale (LEAS). Secondary outcomes included the EuroQol Five Dimensions Questionnaire (EQ-5D) and patient satisfaction. The intraclass correlation coefficient (ICC) was used to analyze interobserver and intraobserver reliability. Ninety patients with a mean age of 39.40 years were included in the study. No significant compensation changes were noted within groups after the elimination of impingement. The functional scores showed no significant difference between groups (p(HOOS) = 0.352, p(mHHS) = 0.183, p(LEAS) = 0.865). The EQ-5D revealed statistically better performance in usual activities in the compensatory group (p = 0.044). There are no significant between-group differences in patients' satisfaction evaluations. As assessed by Patient-Reported Outcome Measures (PROMs), patients with compensatory pelvic tilt demonstrated similar clinical outcomes without extra adverse events to patients with normal pelvic positioning in short-term follow-ups. Furthermore, compensatory pelvic tilt did not significantly enhance the range of motion or functional outcome at short-term follow-ups.

Poster 116: Integrated scRNA-seq and spatial transcriptomics analysis uncovers distinct cellular populations and transcriptomes in human hip synovium between patients with femoroacetabular impingement and osteoarthritis.

Objectives: Osteoarthritis (OA) is a common degenerative joint disease marked by joint dysfunction and chronic pain. Previous studies have outlined a variety of complex factors associated with cartilage degradation, inflammation, and pathological changes in knee synovium. However, hip and knee OA have been established as immunologically distinct types of joint diseases due to unique cytokine profiles of synovial fluid, and data regarding hip OA synovium is scarce1. Evidence suggests that primary hip OA may result from cam-type femoroacetabular impingement (FAI). Thus, cam-type FAI has been considered a unique early-phase model of hip OA, allowing scientists to identify regulators implicated in hip OA development. Integrated single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (Spatial-seq) provides a powerful means to better understand unique genetic markers underlying signaling pathways and cellular interactions that may be involved in disease progression (i.e., FAI to hip OA). In this study, we hypothesize that FAI and hip OA patients have distinct transcriptomic profiles and signaling pathways in their synovial tissues. We aim to identify the underlying molecular mechanisms by using scRNA-seq, Spatial-seq, and bioinformatic analyses. Methods: De-identified human hip synovial tissues were harvested from patients diagnosed with cam- type FAI or with OA (and accompanying cam morphology) according to approved IRB protocols at the University of Rochester (UR). Tissue samples were digested for scRNA-seq and sectioned for Spatial-seq separately and submitted to UR Genomics Research Center (10X Genomics). Distinct cell populations and differentially expressed genes (DEGs) were identified using bioinformatic tools including Seurat2, Monocle3, RcisTarget4, and CellChat5 R packages. Functional analysis for identified cell subsets was annotated by Gene Ontology term6. Differentiation trajectories of non-hematopoietic cells and cell-cell crosstalk were also evaluated. Results: Unsupervised clustering of FAI and OA hip synovial cells identified four major conserved groups: NK cells, endothelial cells, myeloid cells, and non-hematopoietic cells. Sub-clustering of integrated FAI and OA non-hematopoietic cells further yielded 5 distinct cell types including lining, sublining and transitional fibroblast-like synoviocytes (FLS) as well as endothelial cells and pericytes (Fig. 1A). In comparison to FAI synovium, OA synovium exhibited 4.5-, 5- and 8.5-fold increase in IL11+/CD82+ sublining FLS (cluster 5), pericytes (cluster 7) and SPP1+/KDR+ capillary endothelial cells (cluster 9), respectively (Fig. 1B). To further investigate the origin of these populations, we performed pseudotime analysis and revealed that pericytes may differentiate from C34+/C3+/CXCL14+ sublining perivascular FLS (cluster 6) (Fig. 2A)6. To determine the putative transcription factors (TFs) regulating the differentiation process between these two cell populations, we identified that KLF4, SOX5 and CREB3L2 (CAMP Responsive Element Binding Protein 3 Like 2) are potential key regulators using DNA-binding motif analysis. We also observed an opposite trend in expression of KLF4 and CREB3L2, with the highest expression levels of KLF4 in sublining perivascular FLS (Fig. 2B). Importantly, by integrating scRNA-seq and Spatial-seq datasets, we were able to map spatial location of identified cell clusters in the hip joint synovium, allowing us to further interrogate cell-cell crosstalk. For example, we observed that pericytes are in close proximity to SPP1+/KDR+ capillary endothelial cells (cluster 9) and identified that VISFATIN- (ITGA5+ITGB1) and SPP1-CD44 are critical signaling pathways between these two cell populations in OA synovium (Fig. 3B). Conclusions: OA is the most prevalent degenerative joint disorder and is a primary cause of worldwide disability without any available disease modifying therapies. We believe that our findings will reveal key genetic markers related to hip OA progression and facilitate the development of targeted drug deliveries for future therapeutic applications. Our scRNA-seq analysis revealed unique transcriptomic patterns in the synovial cells between FAI and hip OA patients. Integration of non-hematopoietic cells revealed a significant increase in the number of pericytes and endothelial cells present in OA vs. FAI synovium. This is supported by the evidence of increased vasculature in OA, which in turn may promote enhanced infiltration of myeloid cells, cytokines and chemokines into the synovium, leading to an advanced joint inflammation and disease progression7. Furthermore, we identified that both pericytes and capillary endothelial cells can express visfatin (an adipokine) and may modulate synovial inflammation in OA via integrin-mediated signaling pathways8. This observation aligns with previous studies that highlight a significant contribution of endothelial cell-pericyte interactions to OA pathogenesis8. In addition, our finding of decreased expression of KLF4 in pericytes is consistent with previous reports showing that KLF4 inactivation enhances the expression of pericyte markers9. Our next step is to integrate our scRNA- seq and Spatial-seq datasets of non-hematopoietic cells with myeloid cells to further elucidate how altered cell-cell crosstalk and signaling pathways in synovium may lead to hip OA progression. Indeed, we have analyzed myeloid cells separately, and observed elevated accumulation of “hybrid” macrophages expressing pro- and anti-inflammatory markers (IL10+/IL1 +/IL1 +) in the hip OA compared to FAI synovium.

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.

Paper 66: Short-Term Outcomes in Hip Arthroscopy Patients Participating in Formal Physical Therapy vs a Home Exercise Program: A Prospectively Enrolled Cohort Analysis

Objectives: The treatment of femoroacetabular impingement (FAI) has evolved over the last two decades, transitioning from an open hip dislocation to a more minimally invasive arthroscopic approach as the gold standard for treatment. The non-surgical management of FAI has evolved as well, and a key mainstay of the treatment paradigm for FAI has become physical therapy, both in the preoperative and postoperative periods. Previous research has demonstrated the importance of physical therapy in reducing pain and improving function in patients with FAI. As FAI treatment has changed, the delivery of patient physical therapy and rehabilitation has similarly changed, specifically with the introduction of home exercise programs that are patient-driven methods of postoperative rehabilitation. While other areas of orthopaedic surgery, such as shoulder and knee arthroplasty, have demonstrated similar results when comparing formal physical therapy programs with home-based programs, a comparable study has yet to be conducted specifically in the hip arthroscopy patient population. Given this lack of investigation, the purpose of this study was to compare the short-term outcomes of a formal physical therapy program or a home exercise program (HEP) in FAI patients treated with hip arthroscopy. Our hypothesis was that individuals in both groups would report similar outcomes at short- term follow up and would be significantly improved from their preoperative baselines. Methods: Patients undergoing hip arthroscopy for the treatment of FAI at a single center from October 2020 to October 2021 were prospectively enrolled. Inclusion criteria were 1) completion of a preoperative survey, 2) age greater than 18 years at time of surgery, and 3) lack of previous hip surgery. Patients were allowed to self-select to a formal physical therapy (FPT) program, which consisted of a traditional physical therapy course, or a home exercise program (HEP). Patients were administered a survey preoperatively and at 1 month, 3 months, 6 months, and 12 months postoperatively. Included in the survey was a single assessment numeric evaluation (SANE), visual analogue scale (VAS) pain scores, the International Hip Outcome Tool-12 (iHOT-12), the Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF), and patient satisfaction of physical therapy and their overall care. Demographic characteristics were collected from the electronic medical record. Statistical analysis was conducted using descriptive statistics, unpaired and paired t-tests, and Chi Square and Fisher’s Exact tests for categorical variable comparisons. A p-value of &lt; 0.05 was used to indicate statistical significance. Results: A total of 147 patients were included in this study, with 61 in the FPT group and 86 in the HEP group. There were no significant differences regarding patient sex (p = 0.675) and body mass index (p = 0.188), though the HEP group was slightly older than the FPT group (33.6 ± 9.5 years vs 30.1 ± 11.4 years; p = 0.048). At 12 months postoperative, no significant differences were reported between the FPT and HEP groups regarding hip function rated as a percent of normal (p = 0.576), VAS pain scores at rest (p = 0.262) or during activities of daily living (p = 0.214) or during sport (p = 0.066), PROMIS PF scores (p = 0.426), and iHOT-12 scores (p = 0.421). Furthermore, no differences were reported in patient satisfaction (p &gt; 0.05). Outcome scores at 12 months postoperative were significantly improved from the preoperative baseline across all measures in both groups (p &gt; 0.05). Conclusions: For patients undergoing hip arthroscopy for the treatment of FAI, formal physical therapy and home exercise programs are similarly efficacious in terms of patient-reported outcomes of hip function, with both rehabilitation options resulting in significant patient improvement at short term follow-up from their preoperative baseline. [Table: see text][Table: see text]

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.

Feasibility of photon-counting CT for femoroacetabular impingement syndrome evaluation: lower radiation dose and improved diagnostic confidence.

The feasibility of low-dose photon-counting detector (PCD) CT to measure alpha and acetabular version angles of femoroacetabular impingement (FAI). FAI patients undergoing an energy-integrating detector (EID) CT underwent an IRB-approved prospective ultra-high-resolution (UHR) PCD-CT between 5/2021 and 12/2021. PCD-CT was dose-matched to the EID-CT or acquired at 50% dose. Simulated 50% dose EID-CT images were generated. Two radiologists evaluated randomized EID-CT and PCD-CT images and measured alpha and acetabular version angles on axial image slices. Image quality (noise, artifacts, and visualization of cortex) and confidence in non-FAI pathology were rated on a 4-point scale (3 = adequate). Preference tests of standard dose PCD-CT, 50% dose PCD-CT, and 50% dose EID-CT relative to standard dose EID-CT were performed using Wilcoxon Rank test. 20 patients underwent standard dose EID-CT (~ CTDIvol, 4.5mGy); 10 patients, standard dose PCD-CT (4.0mGy); 10 patients, 50% PCD-CT (2.6mGy). Standard dose EID-CT images were scored as adequate for diagnostic task in all categories (range 2.8-3.0). Standard dose PCD-CT images scored higher than the reference in all categories (range 3.5-4, p < 0.0033). Half-dose PCD-CT images also scored higher for noise and cortex visualization (p < 0.0033) and equivalent for artifacts and visualization of non-FAI pathology. Finally, simulated 50% EID-CT images scored lower in all categories (range 1.8-2.4, p < 0.0033). Dose-matched PCD-CT is superior to EID-CT for alpha angle and acetabular version measurement in the work up of FAI. UHR-PCD-CT enables 50% radiation dose reduction compared to EID while remaining adequate for the imaging task.

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

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

Arthroscopic Capsular Suture-Lifting Technique for Treating Femoroacetabular Impingement Patients With a High Risk of Postoperative Anterior Instability

With the increasing popularity of hip arthroscopy, postoperative iatrogenic instability due to bony and soft-tissue issues has been noted by more orthopaedic surgeons. Although there is a low risk of serious complications in patients with normal hip joint development even without suturing of the joint capsule, for patients with a preoperative high risk of anterior instability—including those with excessive anteversion of the acetabulum or femur, borderline dysplasia of the hip, and hip arthroscopic revision surgery with an anterior defect of the joint capsule—capsulotomy without repair will result in postoperative anterior instability of the hip joint and related symptoms. Capsular suturing techniques that provide anterior stabilization will be of great help for these high-risk patients and reduce the possibility of postoperative anterior instability. In this Technical Note, we introduce the arthroscopic capsular suture-lifting technique for treating femoroacetabular impingement (FAI) patients with a high risk of postoperative hip instability. In the past 2 years, the capsular suture-lifting technique has been used to treat FAI patients with borderline dysplasia of the hip and excessive femoral neck anteversion, and clinical results have shown that the suture-lifting technique provides a reliable and effective solution for FAI patients with a high risk of postoperative anterior hip instability.

Femoral impingement in maximal hip flexion is anterior-inferior distal to the cam deformity in femoroacetabular impingement patients with femoral retroversion

Femoroacetabular impingement (FAI) patients report exacerbation of hip pain in deep flexion. However, the exact impingement location in deep flexion is unknown. The aim was to investigate impingement-free maximal flexion, impingement location, and if cam deformity causes hip impingement in flexion in FAI patients. A retrospective study involving 24 patients (37 hips) with FAI and femoral retroversion (femoral version (FV) < 5° per Murphy method) was performed. All patients were symptomatic (mean age 28 years (SD 9)) and had anterior hip/groin pain and a positive anterior impingement test. Cam- and pincer-type subgroups were analyzed. Patients were compared to an asymptomatic control group (26 hips). All patients underwent pelvic CT scans to generate personalized CT-based 3D models and validated software for patient-specific impingement simulation (equidistant method). Mean impingement-free flexion of patients with mixed-type FAI (110° (SD 8°)) and patients with pincer-type FAI (112° (SD 8°)) was significantly (p < 0.001) lower compared to the control group (125° (SD 13°)). The frequency of extra-articular subspine impingement was significantly (p < 0.001) increased in patients with pincer-type FAI (57%) compared to cam-type FAI (22%) in 125° flexion. Bony impingement in maximal flexion was located anterior-inferior at femoral four and five o'clock position in patients with cam-type FAI (63% (10 of 16 hips) and 37% (6 of 10 hips)), and did not involve the cam deformity. The cam deformity did not cause impingement in maximal flexion. Femoral impingement in maximal flexion was located anterior-inferior distal to the cam deformity. This differs to previous studies, a finding which could be important for FAI patients in order to avoid exacerbation of hip pain in deep flexion (e.g. during squats) and for hip arthroscopy (hip-preservation surgery) for planning of bone resection. Hip impingement in flexion has implications for daily activities (e.g. putting on shoes), sports, and sex.Cite this article: Bone Joint Res2023;12(1):22-32.

A comparison between ultrasound-guided AIIS injection and radiography in the diagnosis of subspine impingement in patients with FAI

BackgroundSubspine impingement (SSI) does not have effective diagnostic criteria, especially in patients who also have femoroacetabular impingement (FAI). The classification of anterior inferior iliac spine (AIIS) morphology via three-dimensional CT is controversial.PurposeTo propose a method for ultrasound-guided AIIS injection as a way to diagnose SSI and evaluate the accuracy of radiography methods, including 3-D CT and MRI, as well as intraoperative findings.MethodsPatients diagnosed with FAI between September 2020 and December 2021 were evaluated in this prospective study. Those who met the criteria were included in the ultrasound-guided AIIS injection test. Whether the pain was relieved after injection was recorded in the radiology report. Patients who experienced significant relief of the anterior groin pain (more than 50%) after the AIIS injection were considered positive responders. Among these patients, radiography materials, including AIIS morphology as measured by 3-D CT as well as superior capsular oedema on MRI, were compared. The presence of congestion or bruising on the capsule side of the labrum corresponding to the AIIS during hip arthroscopy was recorded.ResultsA total of 73 patients with FAI underwent the ultrasound-guided AIIS injection test. Prevalence rates of 13.70% (10/73), 58.90% (43/73), 23.29% (17/73) and 4.11% (3/73) were recorded for Type I, Type IIA, Type IIB and Type III AIISs, respectively. Thirty-six patients had positive responses to injection, and 37 patients had negative responses to injection. None of the patients with Type I, 23 (53.49%) patients with Type IIA, 11 (64.71%) patients with Type IIB and 2 (66.7%) patients with Type III AIISs had positive responses to the injection. A total of 57.14% of patients with Type II or Type III AIIS had positive responses to the injection. The proportions of patients with superior capsular oedema on MRI in the Type I, Type IIA, Type IIB, and Type III AIIS groups was 0, 30.23, 29.41 and 0%, respectively. Among non-Type I AIIS patients, those who reported positive responses to the injection had a higher incidence of superior capsular oedema (38.89% vs. 14.81%, P = 0.036), but they had no significant differences in the proportion of congestion or bruising of the labrum (47.22% vs. 37.04%, P = 0.419). The results showed that no pairs of methods—ultrasound-guided injection, MRI, and intraoperative findings—achieved good consistency (κ = 0.222, κ = 0.098 and κ = − 0.116).ConclusionsRadiographic methods including 3-D CT and MRI as well as the intraoperative findings of the labrum cannot be considered an accurate and reliable basis for the diagnosis and treatment of SSI in FAI patients. It is suggested that ultrasound-guided AIIS injections be combined with radiography to better diagnose SSI.Level of EvidenceIV, case series.

Evolution of Hip Muscles Strength in Femoroacetabular Impingement Patients Treated by Arthroscopy or Surgical Hip Dislocation: A Retrospective Exploratory Study.

Hip arthroscopy and surgical hip dislocation (SHD) can be adequate surgical options for patients suffering from femoroacetabular impingement (FAI) syndrome, but there is to date no published data on their impact on hip muscles strength. The purpose of this retrospective study was, therefore, to evaluate it on a consecutive series of 50 FAI patients treated either by arthroscopy (n = 29, aged 27.4 ± 7.5 years, 76% of women) or SHD (n = 21, aged 25.9 ± 6.5 years, 38% of women) at La Tour Hospital between 2020 and 2021. The bilateral isometric strengths of eight hip-related muscles were evaluated before and three months after surgery (halfway through the rehabilitation program). For arthroscopy, a statistically significant (p &lt; 0.05) reduction in hip muscles strength could be noted on the operated hamstrings (1.49 ± 0.43 vs. 1.39 ± 0.38 Nm/kg), flexors (1.88 ± 0.46 vs. 1.73 ± 0.41 Nm/kg), abductors (1.97 ± 0.42 vs. 1.72 ± 0.40 Nm/kg) and external rotators (1.17 ± 0.40 vs. 1.04 ± 0.37 Nm/kg). The abductors were the most affected muscles, with 45% of the patients suffering from a strength reduction ≥15%. The non-operated external rotators were also affected but to a lesser extent (1.21 ± 0.38 vs. 1.10 ± 0.36 Nm/kg). For SHD, a statistically significant strength reduction could be noted on the operated extensors (2.28 ± 0.84 vs. 2.05 ± 0.70 Nm/kg), abductors (1.87 ± 0.49 vs. 1.65 ± 0.41 Nm/kg), quadriceps (2.96 ± 0.92 vs. 2.44 ± 0.89 Nm/kg), external rotators (1.16 ± 0.42 vs. 0.93 ± 0.36 Nm/kg) and internal rotators (1.26 ± 0.38 vs. 0.96 ± 0.30 Nm/kg). The internal rotators were the most affected muscles, with 75% of the patients suffering from a strength reduction ≥15%. To conclude, particular attention should be paid to operated abductors for patients treated by arthroscopy as well as operated internal/external rotators, abductors and quadriceps for those treated by surgical hip dislocation. It reinforces that a rehabilitation method based on isolated muscle reinforcement and functional exercises that goes beyond three postoperative months is needed.

Whole-genome RNAsequencing identifies distinct transcriptomic profiles in impingement cartilage between patients with femoroacetabular impingement and hip osteoarthritis.

Femoroacetabular impingement (FAI) has a strong clinical association with the development of hip osteoarthritis (OA); however, the pathobiological mechanisms underlying the transition from focal impingement to global joint degeneration remain poorly understood. The purpose of this study is to use whole-genome RNA sequencing to identify and subsequently validate differentially expressed genes (DEGs) in femoral head articular cartilage samples from patients with FAI and hip OA secondary to FAI. Thirty-seven patients were included in the study with whole-genome RNA sequencing performed on 10 gender-matched patients in the FAI and OA cohorts and the remaining specimens were used for validation analyses. We identified a total of 3531 DEGs between the FAI and OA cohorts with multiple targets for genes implicated in canonical OA pathways.Quantitative reverse transcription-polymerase chain reaction validation confirmed increased expression of FGF18 and WNT16 in the FAI samples, while there was increased expression of MMP13 and ADAMTS4 in the OA samples. Expression levels of FGF18 and WNT16 were also higher in FAI samples with mild cartilage damage compared to FAI samples with severe cartilage damage or OA cartilage. Our study further expands the knowledge regarding distinct genetic reprogramming in the cartilage between FAI and hip OA patients. We independently validated the results of the sequencing analysis and found increased expression of anabolic markers in patients with FAI and minimal histologic cartilage damage, suggesting that anabolic signaling may be increased in early FAI with a transition to catabolic and inflammatory gene expression as FAI progresses towards more severe hip OA.Clinical significance:Cam-typeFAI has a strong clinical association with hip OA; however, the cellular pathophysiology of disease progression remains poorly understood. Several previous studies have demonstrated increased expression of inflammatory markers in FAI cartilage samples, suggesting the involvement of these inflammatory pathways in the disease progression. Our study further expands the knowledge regarding distinct genetic reprogramming in the cartilage between FAI and hip OA patients. In addition to differences in inflammatory gene expression, we also identified differential expression in multiple pathways involved in hip OA progression.

Outcomes in Patients with Global Pincer Versus Focal Pincer Femoroacetabular Impingement Treated with Hip Arthroscopy: A Retrospective Study with a Minimum 2-Year Follow-Up.

Global pincer is a relatively rare form of pincer deformity and is typically associated with technical challenges during surgery. So far, controversy remains whether patients with global pincer have equivalent surgical outcomes compared to patients with focal pincer. This study compares the clinical outcomes of arthroscopic treatment between patients with global pincer femoroacetabular impingement (FAI) and focal pincer FAI in the Chinese population. Data were retrospectively collected from patients with global and focal pincer FAI who underwent hip arthroscopy with a minimum two-year follow-up between April 2016 and December 2018. Radiographic measurements, arthroscopic procedures, preoperative and postoperative patient-reported outcomes (PROs) including modified Harris hip score (mHHS), hip outcome score-activities of daily living (HOS-ADL), international hip outcome tool-12 (iHOT-12), and visual analogue scale (VAS) scores, rates of revision surgery and conversion to total hip arthroplasty (THA) were recorded. Achievement of minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) was compared for the VAS, mHHS, HOS-ADL, and iHOT-12 scores between groups. The total of 33 and 167 patients were included in the global and focal group, respectively. There were no intergroup differences in age, gender, body mass index or follow-up times. Lateral center-edge angle (LCEA) was reduced in both groups postoperatively. Both groups demonstrated significant improvements in PROs compared with preoperative levels at the final follow-up. The preoperative scores showed significant differences in terms of mHHS (60.34 vs 62.90, P=0.031) and HOS-ADL (61.45 vs 64.74, P=0.022) scores between two groups, and the improvement of HOS-ADL score was significantly higher in global group (P=0.027). However, the postoperative scores, including VAS, mHHS, HOS-ADL, and iHOT-12 scores, showed no significant differences between two groups. And there were no significant differences in the rate of meeting the PASS and MCID between groups. One (3.0%) in the global group and six (3.6%) patients in the focal group underwent revision arthroscopy respectively, with no significant difference (P=0.876). There were no conversions to THA in both groups. Arthroscopic management of global pincer FAI can achieve excellent functional scores at minimum 2-year follow-up. The outcomes were similar to focal pincer FAI patients with a low rate of secondary procedure.