Symptomatic Femoroacetabular Impingement Research Articles

Accelerated Bilateral Hip Arthroscopy (1 Week Apart): Outcomes Compared With Delayed Bilateral Procedure (4-12 Weeks) and Case-Control Matched Unilateral Arthroscopy

Background: Staged bilateral hip arthroscopy is an option for athletes who have symptomatic bilateral femoroacetabular impingement; however, the optimal timing of the second procedure is unknown. Purpose: To evaluate minimum 2-year outcomes for patients undergoing accelerated bilateral arthroscopy against those undergoing (1) delayed bilateral and (2) unilateral arthroscopy. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review was performed of prospectively collected data from patients undergoing bilateral primary hip arthroscopy for femoroacetabular impingement between 2009 and 2022. Inclusion criteria entailed competitive athletes with concurrent bilateral symptoms at initial presentation. Exclusion criteria (either hip) were Tönnis grade >1, dysplasia (lateral center-edge angle <25°), Perthes disease, protrusio acetabuli, and avascular necrosis. Two groups were established based on the duration between procedures: within 7 days (accelerated group) and within 4 to 12 weeks (delayed group). Patients from the accelerated group were matched in a 1:2 ratio with patients undergoing unilateral surgery based on age ±2 years, sex, and athletic status. Minimum 2-year postoperative patient-reported outcomes (PROs) (including modified Harris Hip Score, University of California Los Angeles activity scale, 36-Item Short Form Health Survey, and Western Ontario and McMaster Universities Osteoarthritis Index), rates of achieving the minimal clinically important difference, rates of continuing to play main sport, and satisfaction were compared between groups. Results: A total of 131 athletes (262 hips) with bilateral femoroacetabular impingement were included: 91 in the accelerated group and 40 in the delayed group. Duration between surgeries was 0.99 ± 0.02 and 6.35 ± 2.18 weeks, respectively. All accelerated athletes were each successfully matched to 2 athletes with unilateral procedures (N = 182). All 3 groups demonstrated significant improvement from baseline across all PROs (P < .001 for all). Acquired change in PROs was similar and not significantly different between groups (P > .05). Satisfaction with relief from pain was achieved by 85.9% of patients in the accelerated group compared with 83.1% in the delayed group (P = .053) and 87.3% in the unilateral group (P = .933). The minimal clinically important difference for the modified Harris Hip Score was achieved by 84.9% of patients in the accelerated group compared with 91.5% in the delayed group (P = .212) and 87.6% in the unilateral group (P = .456). At 2 years postoperatively, the continue-to-play rate was 73.6% for the accelerated group compared with 77.1% for the delayed group (P = .577) and 73.0% for the unilateral group (P = .903). There were no increased complications associated with the accelerated group. Conclusion: Accelerated bilateral hip arthroscopy 1 week apart was a safe and effective treatment option for athletes with bilateral symptoms. Improvement in PROs and continue-to-play rates were comparable with those after a delayed duration between procedures and with those case-control matched athletes undergoing unilateral arthroscopy.

Relationship between Spinopelvic Parameters and Hip Function in Patients with Femoroacetabular Impingement at Diagnosis: A Cross-Sectional Study.

The aim of this study was to determine correlation between the spinopelvic parameters in sitting and standing positions (sacral slope [SS], lumbar lordosis [LL], spinopelvic tilt [SPT], pelvic incidence [PI], and pelvic femoral angle [PFA]), with hip function assessed using the modified Harris hip scores (mHHs) in patients with symptomatic femoroacetabular impingement (FAI) at diagnosis. A retrospective study of 52 patients diagnosed with symptomatic FAI was conducted. Evaluation of the spinopelvic complex in terms of SS, LL, SPT, PI and PFA was performed using lateral radiographs of the pelvis and lumbosacral spine in standing and sitting positions. Assessment of hip function at diagnosis was performed using the mHHs. Calculation of spinopelvic mobility was based on the difference (Δ) between measurements performed in standing and sitting position. The median time of pain evolution was 11 months (interquartile range [IQR], 5-24 months) with a median mHHs of 66.0 points (IQR, 46.0-73.0) at diagnosis. The mean change of LL, SS, SPT, and PFA was 20.9±11.2°, 14.2±8.6°, 15.5±9.0°, and 70.7±9.5°, respectively. No statistically significant correlation was observed between spinopelvic parameters and the mHHs (P>0.05). Radiological parameters of the spinopelvic complex did not show correlation with hip function at the time of diagnosis in patients with symptomatic FAI. Conduct of further studies will be required in the effort to understand the effect of the spinopelvic complex and its compensatory mechanics, primarily between the hip and spine, in patients with FAI before and after hip arthroscopy.

The Effect of a Formal Nonoperative Management Program Combining a Hip Injection With Structured Adjunctive Exercise Rehabilitation in Patients With Symptomatic Femoroacetabular Impingement Syndrome

Background: Although the initial treatment recommendations for femoroacetabular impingement syndrome (FAIS) may include nonsurgical therapies such as injections and rehabilitation, many patients undergo isolated injections or a rudimentary exercise regimen. Purpose: To investigate the benefit of an intra-articular hip injection and concomitant structured exercise rehabilitation program in patients with symptomatic FAIS ≥6 months. Study Design: Case series; Level of evidence, 4. Methods: For this study we recruited 49 patients with a mean age of 32.8 years (range, 16-56 years) and symptoms ≥6 months (range, 6-250 months) associated with FAIS, as confirmed via magnetic resonance imaging and radiography. After a guided intra-articular injection of corticosteroid and local anesthetic, patients underwent a structured 12-week rehabilitation program. Patients were assessed before and after injection (8 weeks and 4, 6, 12, and 24 months) with a range of patient-reported outcome measures (PROMs), including the 33-item International Hip Outcome Tool, Hip Outcome Score, modified Harris Hip Score, the Tegner Activity Score, a visual analog scale assessing the frequency and severity of hip pain, and a Global Rating of Change scale. Range of motion, peak isometric hip strength, and hop tests were assessed. Absolute scores and limb symmetry indices were calculated. The percentage of patients transitioning toward surgery over the period was evaluated. Results: Of the 44 patients who underwent the injection and completed the initial 8-week rehabilitation component, 14 (31.8%) progressed toward surgical intervention over the 24-month postinjection period owing to dissatisfaction and/or symptom recurrence. Patients who progressed toward surgery, as compared with those who did not, reported significantly worse (P < .05) PROMs presurgery and more pain within the first 4 weeks after injection. In the nonoperative cohort, a significant improvement (P < .05) in all PROMs was observed, with 93% of these patients satisfied overall. The Global Rating of Change did not improve, although this was measured only after the injection, reflecting no further significant perceived global change from 8 weeks to 24 months. A significant increase (P < .05) in all hip range of motion and most isometric strength measures was observed at 8 weeks after injection, with these improvements largely sustained until 24 months. Bilateral improvements in hop capacity were observed, with hop test LSIs significantly improving for the single (p = 0.009), triple (p = 0.029) and triple crossover (p = 0.005) hop tests for distance. Conclusion: Although 32% of patients progressed toward surgery, significant improvement in hip pain, symptoms, and physical function was observed in the majority of patients with symptomatic FAIS as a result of a targeted nonoperative management pathway consisting of an intra-articular injection and a structured exercise program.

Unravelling the hip-spine dilemma from the CHECK-cohort: is sagittal pelvic morphology linked to radiographic signs of femoroacetabular impingement?

To date the aetiology of femoroacetabular impingement (FAI) is still not completely understood. There are mechanical theories that suggest symptomatic FAI is linked to sagittal pelvic morphology and spinopelvic-femoral dynamics. The aim of this study is to evaluate the relation of sagittal pelvic morphology and orientation to radiographic signs of FAI. Additionally, we test whether the relation between FAI and spinopelvic parameters differs in osteoarthritic hips. From a prospective, observational cohort study, 1002 patients between 45 and 65 years old with a first episode of knee or hip pain were followed for 8 years. All patients who had lateral lumbar radiographs and clinical and radiographic follow-up of the hips were included in the present study. Range of internal rotation of the hip as well as radiographic signs of FAI (alpha and Wiberg angle) and presence of hip osteoarthritis (Kellgren and Lawrence) were systematically measured at baseline. Pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS)) were measured at 8-year follow-up. Associations between PI, PT, SS and FAI parameters were tested using generalised estimating equations. 421 subjects, 842 hips, were included. No significant relations between PI, PT or SS and alpha or Wiberg angle were found. Comparison of hips with and without radiological sign(s) of FAI showed no differences in PI, PT or SS. There was no relation between range of internal rotation of the hip and spinopelvic parameters. Sagittal pelvic morphology and orientation are not related to the presence of radiological signs of FAI in this study population.

Does Femoral Osteoplasty Improve Long-term Clinical Outcomes and Survivorship of Hip Arthroscopy? A 15-Year Minimum Follow-up Study

Background: Although femoral osteoplasty is common practice in treating cam-type femoroacetabular impingement (FAI), long-term data are lacking that support the ability of this procedure to optimize outcomes and alter natural history. Purpose: To compare long-term clinical outcomes and survivorship of treatment for symptomatic FAI via arthroscopic correction of labral or chondral pathology with and without femoral osteoplasty. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective cohort study was performed across 2 consecutive cohorts of patients with isolated cam-type FAI who underwent hip arthroscopic treatment of labral or chondral pathology without femoral osteoplasty (HS group) or with femoral osteoplasty (HS-OST group). These unique cohorts were established at a distinct transition time in our practice before and after adoption of femoral osteoplasty for treatment of FAI. Clinical outcomes were measured using the modified Harris Hip Score (mHHS). Kaplan-Meier analysis was used to assess for total hip arthroplasty (THA)–free and reoperation-free survivorship. Results: The final HS group included 17 hips followed for 19.7 ± 1.2 years, and the final HS-OST group included 23 hips followed for 16.0 ± 0.6 years. No significant patient or morphological differences were found between groups. Compared with the HS group, the HS-OST group had significantly higher final mHHS (82.7 vs 64.7 for HS-OST vs HS, respectively; P = .002) and mHHS improvement (18.4 vs 6.1; P = .02). The HS-OST group also had significantly greater 15-year THA-free survivorship versus the HS group (78% vs 41%, respectively; P = .02) and reoperation-free survivorship (78% vs 29%; P = .003). Conclusion: This study demonstrated superior long-term clinical outcomes and survivorship with combined arthroscopy and femoral osteoplasty compared with hip arthroscopy alone. These long-term data strongly support the practice of femoral osteoplasty in patients with cam FAI morphologies and suggest that this treatment alters the natural history of FAI at long-term follow-up.

Moderate and High Sport Specialization Level in Ice Hockey Athletes Is Associated With Symptomatic Cam Deformity.

There is a known association between ice hockey and cam deformity in growing athletes. Similarly, the association between sport specialization and overuse injury in youth athletes has been well established. Limited research exists examining the relationship between cam deformity and sport specialization. Our hypothesis was that there would be a positive association with cam deformity and sport specialization category. Retrospective chart review and cross-sectional questionnaire study. Level 4. Study participants included athletes aged 15 to 25 years with symptomatic femoroacetabular impingement (FAI) and considered ice hockey as their primary sport. All participants had completed Dunn lateral radiographs or hip magnetic resonance imaging as part of their clinical evaluation. All participants completed a survey regarding sport specialization level. Multivariable linear regression analysis controlling for sex was used to analyze the association between degree of sport specialization, age of sport specialization, position played, and level played. Comparisons in radiographic parameters across ice hockey groups were conducted using Student t tests and chi-square tests. Sixty-six ice hockey participants made up the cohort. The majority reported high sport specialization (41/66, 62%). The mean age of sport specialization was 10.7 years (SD 3.5). Participants with moderate specialization had 25 times the odds of a cam deformity (odds ratio [OR] 25.2; 95% CI 1.5-410.7; P = 0.02) and those with high specialization had 9 times the odds of cam deformity (OR 9.3; 95% CI 1.2-74.2; P = 0.04) compared with those with a low degree of specialization, controlling for patient sex. No association was detected between the age of specialization and the likelihood of cam deformity when controlling for patient sex. Level of sport specialization was associated with a cam deformity in this cohort of youth ice hockey athletes. This study suggests that an association exists.

Factors Associated With Disease Progression in the Contralateral Hip of Patients With Symptomatic Femoroacetabular Impingement: A Minimum 5-Year Analysis

Background: Femoroacetabular impingement (FAI) is one of the most common causes of hip osteoarthritis, yet the factors controlling disease progression are poorly understood. Purpose: To investigate rates of initial and subsequent symptoms in the contralateral hip of patients with FAI, and identify predictors of disease progression (symptom development and surgical intervention) in the contralateral hip. Study Design: Cohort study; Level of evidence, 2. Methods: This prospective study included a minimum 5-year follow-up of the contralateral hip in 179 patients undergoing FAI surgery. Symptoms (moderate pain) and surgical progression were monitored. Univariate and multivariate analyses compared patient-specific and imaging characteristics of symptomatic patients with those who remained asymptomatic to identify factors associated with disease progression. Results: A total of 150 patients (84% follow-up) were followed for a mean of 7.1 years (range, 5-11 years). Thirty-nine of these patients (26% [39/150]) had contralateral hip symptoms at initial evaluation. Of those without contralateral hip symptoms at initial evaluation, 32% (36/111) had developed contralateral hip symptoms by latest follow-up. Those who developed symptoms during the study period had a lower anteroposterior head-neck offset ratio (0.153 vs 0.165; P = .005), decreased total arc of rotation in 90° of flexion (39.9° vs 51.1°; P = .005), and decreased external rotation in 90° of flexion (28.6° vs 37.1°; P = .003) compared with those who never developed symptoms. Age, sex, body mass index, alpha angle, lateral center-edge angle, internal rotation in flexion, and University of California, Los Angeles (UCLA), activity score were similar between these groups. Those with contralateral symptoms at initial evaluation progressed to contralateral surgery at a rate of 41% (16/39) and those who developed contralateral symptoms during the study period progressed to contralateral surgery at a rate of 28% (10/36). Among those with contalateral hip symptoms (either present initially or developed during study period)), younger age (24.6 vs 34.1 years; P < .001) and baseline UCLA activity score ≥9 (P = .003) were associated with progression to surgery. By Kaplan-Meier analysis, 64%, 54%, and 48% of patients remained free of contralateral hip symptoms at 2, 5, and 10 years. Conclusion: At a mean follow-up of 7.1 years, significant symptoms in the contralateral hip of patients with FAI were present in approximately 50% of patients. FAI disease progression (symptom development and surgical intervention) was associated with decreased hip rotation arc, decreased external rotation, and decreased head-neck offset ratio. In symptomatic patients, younger age and UCLA activity score ≥9 were associated with progression to surgery. These findings represent important factors for patient counseling and risk modeling in FAI.

Characteristics of Biomechanical and Physical Function According to Symptomatic and Asymptomatic Acetabular Impingement Syndrome in Young Adults.

Femoroacetabular impingement (FAI) is caused by hip joint anomalies. Although asymptomatic and symptomatic FAI have been reported in young adults, information on biomechanical and functional characteristics of FAI is rare. We compared the subjective hip score, range of motion (ROM), dynamic balance, and hip strength between symptomatic FAI (FAIsym) and asymptomatic FAI (FAIasym) groups and healthy controls. Participants (n = 307; men: 155, women: 152) were classified according to morphological abnormalities and hip joint symptoms, comprising symptomatic FAI, asymptomatic FAI, and healthy controls. The Copenhagen Hip and Groin Outcome Score (HAGOS), hip ROM, Y-balance test (YBT), and isokinetic hip strength were measured. The types of FAI were not significantly differenent in both men and women. FAIsym exhibited significantly reduced HAGOS, whereas FAIasym showed no significant difference compared to the healthy group (men: healthy 91.7 vs. FAIasym 87.2 vs. FAIsym 49.9, women: healthy 91.7 vs. FAIasym 86.2 vs. FAIsym 53.9). Hip flexion, adduction, and internal and external rotation ROMs were only significantly reduced in symptomatic FAI. Asymptomatic and symptomatic FAI groups displayed significantly lower YBT scores than healthy controls (men healthy: 84.9 vs. FAIasym: 69.0 vs. FAIsym 58.7, women healthy 79.2 vs. FAIasym 64.0 vs. FAIsym 55.5). Isokinetic hip flexion, adduction, and abduction strengths were significantly lower in FAIsym. In conclusion, FAIasym showed no decrease in muscle strength but displayed reduced dynamic balance. Subjective satisfaction, ROM, muscle strength, and dynamic balance were lower in FAIsym compared to FAIasym and healthy groups.

Hip arthroscopy for femoroacetabular impingement is associated with significant improvement in early patient reported outcomes: analysis of 4963 cases from the UK non-arthroplasty registry (NAHR) dataset

PurposeResults from recent randomised controlled trials demonstrate the superiority of surgery over physiotherapy in patients with femoroacetabular impingement (FAI) of the hip in early follow-up. However, there is paucity of evidence regarding which factors influence outcomes of FAI surgery, particularly notable is the lack of information on the effect of impingement subtype (cam or pincer or mixed) on patient reported outcomes measures (PROMs). This study aims to evaluate the early outcomes of hip arthroscopy for FAI, and their determinants.MethodsThis is a retrospective analysis of prospectively collected data from the UK Non-Arthroplasty Hip Registry (NAHR) of patients undergoing arthroscopic intervention for FAI between 2012 and 2019. The null hypothesis was that there is no difference in PROMs, based on morphological subtype of FAI treated or patient characteristics, at each follow-up timepoint. The outcome measures used for the study were the iHOT-12 score and the EQ5D Index and VAS 6- and 12-month follow-up.ResultsA cohort of 4963 patients who underwent arthroscopic treatment of FAI were identified on the NAHR database. For all FAI pathology groups, there was significant improvement from pre-operative PROMs when compared to those at 6 and 12 months. Overall, two-thirds of patients achieved the minimum clinically important difference (MCID), and almost half achieved substantial clinical benefit (SCB) for iHOT-12 by 12 months. Pre-operatively, and at 12-month follow-up, iHOT-12 scores were significantly poorer in the pincer group compared to the cam and mixed pathology groups (p < 0.01). Multivariable analysis revealed PROMS improvement in the setting of a higher-grade cartilage lesion.ConclusionThis registry study demonstrates that hip arthroscopy is an effective surgical treatment for patients with symptomatic FAI and results in a statistically significant improvement in PROMs which are maintained through 12 months follow-up.Level of evidenceIII.

Poster 197: Understanding the Biological Pathway of Progression of Hip OA Disease through Transcriptome Analysis

Poster 197: Understanding the Biological Pathway of Progression of Hip OA Disease through Transcriptome Analysis

Poster 196: Articular Chondrocytes in Hip Femoroacetabular Impingement Present a Less Catabolic Phenotype than Late Stage of Disease

Objectives:Pathophysiologic mechanisms during osteoarthritis (OA) have been primarily identified using tissues harvested from end stage of disease. However, it is likely that the disease-initiating molecular changes have already occurred in early-stage diseased joints. Femoroacetabular impingement (FAI) has an etiologic role in up to 50% of hip osteoarthritis (OA) and offers a unique opportunity to study molecular changes during early stage OA. Cartilage samples from the impingement zone of FAI patients express catabolic inflammatory molecules. Previously, we have confirmed that DNA methyltransferase 3B (DNMT3B) regulates post-natal articular cartilage homeostasis and 4 aminobutyrate aminotransferase (ABAT) is a downstream target for DNMT3B and attenuates catabolic gene expression. The purpose of the present study is to examine the catabolic state of ACs during progression of disease in hip FAI, specifically, to investigate the catabolic phenotype and to assess the expression levels of DNMT3B and ABAT during early (FAI) and late stage disease (OA-FAI).Methods:Full-thickness cartilage samples were collected from the anterolateral head-neck junction (impingement zone) of 11 patients. 5 patients underwent hip preservation surgery for symptomatic cam FAI (early stage OA- FAI) and 6 patients underwent total hip replacement for advanced OA secondary to cam FAI (late stage FAI-OA). As a non-disease (ND) group, 4 healthy samples were procured from hip joint cadavers. A liberator was used to harvest full thickness tissue samples for cartilage explant cultures. The cartilage tissues were washed several times using antibiotics and incubated at 37 °C and 5% CO2 for 24h. Subsequently, the explants were cultured in unstimulated conditions (no-treatment), under anabolic (TGFβ) and catabolic stimulus (IL-1β) for 48h. After culture, sections were stained with safranin O and fast green for histological analysis and cartilage degeneration was graded based on the Mankin score. RNA was isolated from explants, gene expression was analyzed via qPCR for the following specific markers: GADPH (housekeeping gene), DNMT3B, ABAT, MMP-13, and Type X collagen (COL10A1) (Figure-1). Comparisons among three groups were performed using one-way analysis of variance followed by the post hoc Bonferroni correction test.Results:Histological Mankin-scores are shown in Figure-2. Cartilage samples without treatment in ND group showed normal hyaline cartilage. However, reduction in safranin-O staining with significant increase of Mankin-score was observed under catabolic stimulus of IL-1β (Figure-2A). Contrary, in early FAI and late FAI-OA group, degenerative changes including superficial irregularities with some clefts, cell cloning, and reduced staining was observed in unstimulated conditions and became more pronounced when treated with IL-1β (Figure-2A and B). Degenerative changes were alleviated by anabolic stimulus with TGFβ1 (Figure-2B). qPCR revealed that compared to ND group, the expression levels of ABAT, MMP-13 and COL10A1 were increase in the early-FAI and late FAI-OA confirming a catabolic phenotype. Contrary, expression of DNMT3B gradually declined as the disease progressed showing significant differences between early-FAI and late FAI-OA (Figure-3B). Remarkably, although histological findings were similar between early and late stage FAI, catabolic molecule expression varied between early and late stage of disease suggesting a more catabolic phenotype state for late stage of disease.Conclusions:This current study provides initial data regarding the catabolic state of human ACs in early and late stage of hip FAI disease and characterized a catabolic phenotype of ACs from impingement zone in FAI. Importantly, although histological findings were similar between early and late stage FAI, catabolic molecule expression varied suggesting a less catabolic phenotype for early stage of disease. Most interestingly, the expression of DNMT3B gradually decrease as the disease progresses, and ABAT expression increase. Identification of these changes of methylation profiles during disease progression can distinguish pre- and early disease states from end diseased state and could provide a potential intervention to stop the OA progression in the near future. Future interventional therapies will confirm if ACs from early stage of disease can be rescued to a normal phenotype.

Paper 44: Does femoral osteoplasty enhance clinical outcomes and survivorship of FAI surgery at long-term follow-up beyond fifteen years?

Objectives:Cam-type femoroacetabular impingement (FAI) is now well-established as a risk factor for intra-articular damage (labrum and articular cartilage) and secondary osteoarthritis. Long-term studies of FAI surgery are critical in understanding clinical outcomes, refining surgical treatments and predicting osteoarthritis progression. Nevertheless, studies beyond 15 years are uncommon. Although femoral osteoplasty is now common practice in treating cam FAI, long-term data supportive of this procedure and its ability to alter the natural history of FAI are not available. The purpose of this study was to analyze the long-term clinical outcomes and survivorship of symptomatic FAI treatment by arthroscopic correction of labral pathology alone or in combination with femoral osteoplasty (structural FAI correction).Methods:A retrospective comparative study was performed on two consecutive, longitudinal cohorts of patients with isolated cam-type FAI that underwent surgical treatment of labral pathology either with femoral osteoplasty (HSLO group, 23 hips) or without femoral osteoplasty (HS group, 17 hips). These cohorts were captured immediately prior to and after implementation of femoral osteoplasty into our practice and have been previously reported on at mean 2-year followup. The current study investigated clinical outcomes and survivorship at minimum 15-year followup. Patients with pincer or combined cam-pincer morphologies were excluded. Clinical outcomes were measured with the modified Harris hip score (mHHS). Kaplan-Meier survival was assessed for THA-free and reoperation-free survivorship.Results:The HSLO group included 23 hips followed for a mean of 16.0 ±0.6 years, and the HS group 17 hips followed for 19.7 ±1.2. The HSLO group had a significantly higher final mHHS (82.7 vs. 64.7, p=0.002) and mHHS improvement (18.4 vs. 6.1, p=0.02) compared to the HS group. The rate of THA conversion (22% vs. 59%, P=0.02) and overall reoperation (22% vs. 70%, P=0.003) were significantly lower in the HSLO group. THA conversion occurred at a mean of 5.8 ±2.5 years postoperatively in the HSLO group, and 7.1 ±4.0 years in the HS group. The HSLO group had significantly greater 15-year THA-free survivorship (78% vs 41%, p=0.02) and reoperation-free survivorship (78% vs. 29%, p=0.003) by Kaplan-Meier analysis.Conclusions:This study demonstrates better long-term clinical outcomes and survivorship with combined arthroscopy and femoral osteoplasty compared to arthroscopy alone. These long-term data strongly support the current practice of femoral osteoplasty in patients with cam FAI morphologies and suggest that this treatment alters the natural history of FAI.Figure 1.Comparative Survival

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

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

Hip–Spine Syndrome in the Nonarthritic Patient

Hip–spine syndrome refers to concurrent hip and spine pathology with overlapping symptoms. Most of the literature has studied it in relation to total hip arthroplasty literature and has been shown to increase dislocation risk. Lumbar spine and pelvic mobility have been studied less frequently in relation to nonarthritic pathologic hip states. Understanding the biomechanical relationship between the lumbar spine, pelvis, and hip can help elucidate how hip–spine syndrome affects the nonarthritic hip and how it impacts outcomes of hip arthroscopy. Changes in lumbar spine motion may be the reason certain predisposed patients develop symptomatic femoroacetabular impingement (FAI) or ischiofemoral impingement. Some athletes may be “hip users” with a low pelvic incidence, making them more reliant on hip motion due to less-intrinsic lumbopelvic motion. When these patients have FAI morphology, their increased reliance on hip motion makes them prone to experiencing femoroacetabular contact and concurrent symptoms. Other athletes may be “spine users,” with larger pelvic incidence and more baseline lumbopelvic motion, making them less reliant on hip motion and therefore less prone to experiencing hip impingement even with hip FAI morphology. Hip–spine syndrome also appears to have an impact on patient selection, role of nonoperative treatment, and hip arthroscopy surgical outcomes. Identifying patients with concurrent pathology may allow surgeons to recommend targeted physical therapy or counsel patients better on their expectations after surgery.

Sagittal Plane Mobility in Adolsents with Femoroacetabular Impingment

Background:Femoroacetabular impingement (FAI) is a dynamic degradative condition of the hip joint characterized by classic physical exam findings in combination with abnormal radiographs and/or MRI. Although this abnormal morphologic relationship contributes to FAI, the role of physical therapy to mitigate symptoms by improving strength and mobility of the hip remains the first line treatment. Despite this common treatment algorithm, limited knowledge exists on the effects of sagittal balance, lumbopelvic mobility, and its role in the development of treatment for symptomatic FAI.Hypothesis/Purpose:To review lumbopelvic mobility from standing to sitting position in adolescent athletes who present with clinical signs of FAI.Methods:Pelvic radiographic measurements in the sagittal plane were performed on a retrospective series of consecutive patients who presented with clinical diagnosis of FAI at a pediatric sports medicine institution from April 2019-March 2021. Standardized EOS dynamic lateral pelvic images were performed in standing and sitting positions to evaluate the differences in sacral slope, pelvic tilt, and pelvic incidence. Data from bi-positional radiographs were combined with standard measurements for FAI obtained on AP pelvis (lateral center edge angle, acetabular inclination) and 45 degree Dunn views (alpha angle), and patient reported outcomes (PROs) (mHHS, HOOS, UCLA). Differences in sacral slope from pre-treatment radiographs were used to determine comparison groups: those with a change vs. those with limited change between a sitting and standing position.Results:76 adolescent patients (mean age 15.7 years [12-24]; 71.5% females) with sitting/standing lateral pelvis radiographs and a clinical diagnosis of FAI were identified. Between sitting and standing positions, there was no change in pelvic incidence, while significant differences were noted in sacral slopes and pelvic tilt (Table 1). Variability in sacral slope differences between sitting and standing were identified with 10 (13.9%) patients having minimal (<10o) change, while 8 (11.1%) demonstrated changes > 40o (Figure 1). Adolescent patients with FAI who demonstrated more mobility from sitting to standing position had a higher sacral slope in the standing position. No correlations were noted between pelvic incidence or sacral slope and radiographic measures associated with FAI, PROs or differences in those with variable changes in sacral slope from sitting to standing position.Conclusion:Lateral pelvic imaging may be an important tool for understanding dynamic hip impingement. In adolescent patients signs and symptoms with clinical FAI, significant variability exists in lumbopelvic mechanics, regardless of the severity of radiographic values.Table 1.Radiographic measurements performed on a sitting and standing lateral pelvic radiographs using EOS. Values listed are mean (standard deviation; range).Figure 1.Sitting and Standing lateral pelvic images from 2 patients. Top row: Standing lateral pelvis (A) and sitting lateral pelvis (B) with a significant change in sacral angle and pelvic tilt with no changes in pelvic incidence. Not the change in lumbar lordosis in this patient. Bottom row: Standing lateral pelvic (A) and sitting lateral pelvic (B) without significant change in lumbosacral position.

Risk factors for early symptomatic femoroacetabular impingement following in situ fixation of slipped capital femoral epiphysis

In situ fixation of slipped capital femoral epiphysis (SCFE) results in residual deformity that can cause femoroacetabular impingement (FAI). It is unknown what factors could help differentiate patients who are more likely to become symptomatic. We performed a retrospective review of 55 hips treated with in situ pinning for SCFE and subsequent secondary deformity correction procedure for symptomatic FAI and compared them to 39 asymptomatic hips with SCFE deformity using multivariable analysis. Case patients were slightly older than controls (12.6 vs 11.3 years, p = 0.0002) but had similar BMI. The mean epiphyseal-diaphyseal angle was 56° in cases versus 44° in controls (p = 0.0019). Cases were significantly more likely to have obligate external rotation with hip flexion, external foot progression, flexion <90°, antalgic limp, and Trendelenburg lurch. On radiographs, most cases had a head-neck offset ≤0 mm, a distinct metaphyseal corner prominence, acetabular retroversion, and an alpha angle ≥60°. Most controls also had head-neck offset ≤0 mm. Pre-pinning, older age (OR = 1.98 per year, p = 0.0016) and initial epiphyseal-diaphyseal angle (OR = 1.04 per degree, p = 0.018) significantly increased the odds of having symptomatic FAI. Post-pinning, external foot progression increased the odds of symptomatic FAI by 10.48 (p = 0.017), and an alpha angle ≥60° resulted in 11.4 times higher odds of symptomatic FAI (p = 0.011). The linear correlation between epiphyseal-diaphyseal and alpha angle was poor (r = 0.28). Older age and initial epiphyseal-diaphyseal pre-pinning mildly increased the odds of eventual symptomatic FAI. This information can help the surgeon to predict which patients may develop symptomatic FAI.

Incidence of Symptomatic Femoroacetabular Impingement: A 4-Year Study at a National Collegiate Athletic Association Division I Institution.

Background:Femoroacetabular impingement (FAI) is an increasingly recognized cause of hip pain in young athletes. Although there are multiple studies that describe the radiographic prevalence of FAI in athletes, its true incidence within this population is unknown.Purpose:To report on the overall and sport-specific incidence of symptomatic FAI in National Collegiate Athletic Association (NCAA) Division I athletes. Return-to-sport times were reported for patients treated operatively.Study Design:Cohort study; Level of evidence, 3.Methods:A retrospective review was conducted to identify all reported hip injuries within a large, multisport NCAA Division I institution. Hip injuries were stratified into FAI, general pain/dysfunction, musculotendinous, ligament, bursitis, bone stress, contusion, and other. FAI was diagnosed based on history, physical examinations, imaging, and symptomatic relief after a diagnostic injection. Descriptive statistics were used to calculate the overall and sport-specific incidence, and chi-square analysis was performed to identify contingency data.Results:In a 3-year period, a total of 5319 musculoskeletal injuries occurred in 1072 athletes. There were 491 (9.2%) hip injuries that occurred in 288 athletes, of which 40 injuries were FAI. The overall incidence of symptomatic FAI was 3.0% of the total population, 3.7% of all injured athletes, and 13.9% of athletic hip injuries. There were no statistically significant differences in FAI rates among male and female athletes overall or among male and female athletes within similar sports. Of the 19 athletes who were treated nonoperatively, 2 failed to return to play: 1 secondary to multiple musculoskeletal injuries and 1 related to cardiac issues. There were 21 hips in 20 patients that were treated operatively, with 1 athlete failing to return to sport. Return to play occurred at a mean of 202 days (range, 81-360 days) after hip arthroscopic surgery.Conclusion:In this large, multisport NCAA Division I cohort, the overall incidence of symptomatic FAI was 3.0% and represented 13.9% of hip injuries. The successful management of FAI with return to play was achieved by both nonoperative and operative treatment methods. The relatively low incidence of symptomatic FAI, despite reports of a high prevalence of FAI morphology in athletes, serves to emphasize the importance of clinical evaluations in treating patients with FAI.

Characterizing femoroacetabular impingement in professional Nordic Skiers

ABSTRACT Objective Studies have shown a high prevalence of femoroacetabular impingement (FAI) among elite athletes yet there is a paucity of data on FAI in Nordic skiers. The purpose of this study was to determine the prevalence of radiographic FAI in professional Nordic Combined Skiers and Ski jumpers compared to controls and assess functional outcomes including hip range of motion (ROM) and pain in patients with radiographic evidence of FAI compared to those without it. Methods A cohort of elite Nordic Skiers underwent medical history, physical examination, and pelvic radiographs at their visit with a fellowship-trained sports medicine physician. On pelvis radiographs, Alpha angle>55 degrees was deemed cam-positive, and positive crossover signs, Tönnis<0, or LCEA>40 were deemed pincer positive. Further stratification was performed by sex, ski event type, hip pain, presence of cam lesions, and presence of pincer lesions. Spearman correlation matrix was performed to measure the association between radiographic measurements and ROM. Results Nineteen Nordic skiers and nineteen age, sex, and BMI matched controls were included in the study. There were no significant differences in age, sex, BMI, and hip pain between groups. While Nordic skiers demonstrated decreased ROM bilaterally on external rotation compared to controls, skiers had larger ROM bilaterally on extension, abduction, adduction compared to controls. Skiers were significantly more likely to have bilateral crossover sign and alpha angles>55 compared to controls. Subgroup analysis showed that Cam positive patients had higher flexion and adduction ROM and pincer positive patients had significantly higher flexion and abduction ROM compared to patients without cam and pincer lesions respectively. Patients with hip pain had significantly lower right hip abduction ROM compared to patients without hip pain. No significant correlations were seen between radiographic measurements and ROM. Conclusion Similar to other elite ‘hip heavy’ sport athletes, Nordic skiers gave a notably higher prevalence of radiographic cam and pincer type morphology and significantly higher ROM compared to nonathletic controls. Clinicians evaluating Nordic skiers should be aware of these baseline findings with respect to a possible elevated long-term risk of symptomatic FAI in these athletes as well as other conditions related to radiographic FAI.

Multifactorial pathomechanism of hip dysplasia and femoroacetabular impingement in young adults: the diamond concept.

Hip dysplasia (DDH) as well as femoroacetabular impingement (FAI) are common causes of hip pain in young adults and lead to premature osteoarthritis (OA). However, not all patients with radiographic features of DDH or FAI develop symptoms and degenerative changes, which indicates that various factors play a role in the disease process. Here we use a diamond concept to illustrate anatomical factors that play a role in the pathomechanism of symptomatic DDH and FAI. This concept may help clinicians in the diagnosis of hip pain in young adults. For DDH, the following factors are included: (1) acetabular and (2) femoral morphology, (3) pelvic shape and geometry, (4) spinopelvic alignment and (5) soft tissue properties. For FAI, the following factors are included: (1) intraarticular acetabular and (2) intraarticular femoral morphology, (3) extraarticular pelvic and (4) extraarticular femoral morphology, (5) spinopelvic alignment and (6) soft tissue properties. Knowledge of these factors can help to identify an adequate treatment. Surgical treatment options include (1) extraarticular acetabular, (2) extraarticular femoral, (3) intraarticular acetabular and (4) intraarticular femoral procedures. Further research is warranted on the specific role and the interaction of the parameters presented in the diamond concept in the disease process of hip joint degeneration.

Chronically elevated contact stress exposure correlates with intra-articular cartilage degeneration in patients with concurrent acetabular dysplasia and femoroacetabular impingement.

Hip dysplasia is known to lead to premature osteoarthritis. Computational models of joint mechanics have documented elevated contact stresses in dysplastic hips, but elevated stress has not been directly associated with regional cartilage degeneration. The purpose of this study was to determine if a relationship exists between elevated contact stress and intra-articular cartilage damage in patients with symptomatic dysplasia and femoroacetabular impingement. Discrete element analysis was used to compute hip contact stresses during the stance phase of walking gait for 15 patients diagnosed with acetabular dysplasia and femoral head-neck offset deformity. Contact stresses were summed over the duration of the walking gait cycle and then scaled by patient age to obtain a measure of chronic cartilage contact stress exposure. Linear regression analysis was used to evaluate the relationship between contact stress exposure and cartilage damage in each of six acetabular subregions that had been evaluated arthroscopically for cartilage damage at the time of surgical intervention. A significant correlation (R2 = 0.423, p < 0.001) was identified between chondromalacia grade and chronic stress-time exposure above both a 1 MPa damage threshold and a 2 MPa-years accumulated damage threshold. Furthermore, an over-exposure threshold of 15% regional contact area exceeding the 1 and 2 MPa-years threshold values resulted in correct identification of cartilage damage in 83.3% (55/66) of the acetabular subregions loaded during gait. These results suggest corrective surgery to alleviate impingement and reduce chronic contact stress exposures below these damage-inducing thresholds could mitigate further cartilage damage in patients with hip dysplasia.