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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.

Conventional polyethylene (CPE) was used widely in the past as a bearing surface in total hip arthroplasty (THA). As CPE THAs age and the revision burden continues to grow, it is increasingly important to understand the durability and failure mechanisms of this bearing material. Currently, such long-term data remain limited, particularly in younger, more active patients in whom wear issues are of greater concern.We retrospectively reviewed 90 hips (77 patients) that underwent primary THA with CPE bearings on cobalt chrome femoral heads at age ≤50 years at 20-year minimum follow-up (mean 21.6 [20-23]). We analyzed polyethylene wear rates, clinical outcomes (modified Harris Hip Score, University of California, Los Angeles Activity Score), and implant survivorship.Wear analysis revealed a median linear wear rate of 0.113 mm/y (95% CI 0.102-0.148) and a median volumetric wear rate of 41.20 mmWear-related issues developed at increasingly high rates after 15 years, suggesting the need for surveillance after this time. The long-term wear and survivorship data of this study may be used as a benchmark when evaluating the performance of contemporary bearings in young, active THA patients.

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.

Young adult patients with symptomatic acetabular dysplasia and marginal secondary osteoarthritis can be faced with the decision to either undergo periacetabular osteotomy (PAO) to relieve symptoms and slow osteoarthritis progression or wait until progression to more advanced disease and undergo total hip arthroplasty (THA). The decision can be difficult, and contemporary literature to guide these decisions is sparse. Therefore, we retrospectively assessed complication rate, survivorship and patient-reported clinical outcomes [modified Harris Hip score (mHHS), UCLA Activity score] in two, consecutive cohorts of patients aged 18–40 years that underwent either PAO for symptomatic acetabular dysplasia (mean age 28.9 years) or THA for advanced secondary osteoarthritis (32.5 years). PAO patients were followed for a mean of 10.5 years (8–19) and THA patients for 11.9 (8–17) years. Between PAO and THA groups, there were no differences in overall complication rate (4.7% versus 4.7%), non-revision reoperation rate (5.9% versus 2.3%, P = 0.37) or end-revision rate [7 (8.2%) PAOs converted to THA at mean 10.8 years versus 3 (7.0%) THAs revised at 6.2 years, P = 0.80]. Latest scores remained significantly improved from baseline in both the PAO (mHHS 86.1 versus 63.3, P 70) at latest follow-up without end-revision] was achieved in 81.2% of PAO hips and 83.7% of THA hips (P = 0.72).

Background: Femoroacetabular impingement (FAI) is a leading cause of hip pain in young adults and often leads to degenerative osteoarthritis (OA). A small animal model of hip deformities is crucial for unraveling the pathophysiology of hip OA secondary to FAI. Purposes: To (1) characterize a new minimally invasive surgical technique to create a proximal femoral head–neck deformity in a skeletally immature rabbit model and (2) document the effect of an injury to the medial proximal femoral epiphysis on head–neck morphology at 28 days after the injury. Study Design: Controlled laboratory study. Methods: Six-week-old New Zealand White rabbits (n = 10) were subjected to right hip surgery, with the left hip used as a control. An epiphyseal injury in the medial femoral head was created using a 1.6-mm drill. Hips were harvested bilaterally at 28 days after surgery. Alpha and epiphyseal shaft angles were measured on radiographs. Alpha angles at the 1- and 3-o’clock positions were measured on the oblique axial plane of micro–computed tomography images. Bone bar formation secondary to growth plate injuries was confirmed using alcian blue hematoxylin staining. Results: All hips in the study group showed a varus–type head-neck deformity, with lower epiphyseal shaft angles on anteroposterior radiographs versus those in the control group (133°± 8° vs 142°± 5°, respectively; P = .022) and higher epiphyseal shaft angles on lateral radiographs (27°± 12° vs 10°± 7°, respectively; P < .001). The mean alpha angles in the study group were higher at both the 1- (103°± 14° vs 46°± 7°, respectively; P < .002) and 3-o’clock (99°± 18° vs 35°± 11°, respectively; P < .002) positions than those in the control group. Alcian blue hematoxylin staining of all hips in the study group indicated that the injured physis developed a bony bar, leading to growth plate arrest on the medial femoral head. Conclusion: The proposed model led to growth arrest at the proximal femoral physis, resulting in a femoral head–neck deformity similar to human FAI. Clinical Relevance: Our novel small animal model of a femoral head–neck deformity is a potential platform for research into the basic mechanisms of FAI disease progression and the development of disease–modifying therapies.

Femoroacetabular impingement (FAI) is an important trigger of hip osteoarthritis (OA). Epigenetic changes in DNA methyltransferase 3B (DNMT3B) attenuate catabolic gene expression in cartilage hemostasis. This study aimed to examine the articular chondrocyte catabolic state and DNMT3B and 4-aminobutyrate aminotransferase promoter (ABAT) expression during OA progression in FAI. Cartilage samples were collected from the impingement zone of twelve patients with cam FAI (early-FAI) and twelve patients with advanced OA secondary to cam FAI (late-FAI-OA). Five healthy samples were procured from cadavers (ND: non-diseased). Explants were cultured under unstimulated conditions, catabolic stimulus (IL1β), or anabolic stimulus (TGFβ). Histology was performed with safranin-O/fast-green staining. Gene expression was analyzed via qPCR for GAPDH, DNMT3B, ABAT, MMP-13, COL10A1. Methylation specific PCR assessed methylation status at the ABAT promoter. Cartilage samples in early-FAI and late-FAI-OA showed a histological OA phenotype and increased catabolic marker expression (MMP13/COL10A1, ND vs early-FAI, p=0.004/p0.001, ND vs late-FAI-OA, p0.001/p0.001). RT-PCR confirmed DNMT3B underexpression (ND vs early-FAI, p0.001, early-FAI vs late-FAI-OA, p=0.016) and ABAT overexpression (ND vs early-FAI, p0.001, early vs late-FAI-OA, p=0.035) with advanced disease. End-stage disease showed ABAT promoter hypomethylation. IL1β stimulus accentuated ABAT promoter hypomethylation and led to further ABAT and catabolic marker overexpression in early-FAI and late-FAI-OA while TGFβ normalized these alterations in gene expression. Catabolic and epigenetic molecule expression suggested less catabolism in early-stage disease. Sustained inflammation induced ABAT promoter hypo-methylation causing a catabolic phenotype. Suppression of ABAT by methylation control could be a new target for therapeutic intervention to prevent OA progression in hip FAI. This article is protected by copyright. All rights reserved.

BACKGROUND: Mental health is becoming increasingly important in patient outcomes. The patient reported outcome measurement information system (PROMIS) was developed by the NIH to collect outcome data in rapid dynamic fashion on electronic platforms. The potential role of PROMIS in monitoring young total hip arthroplasty (THA) patients is under-investigated. The purpose of this study is to investigate correlations between PROMIS Depression or Anxiety with SF-12 mental component score. METHODS: We identified 223 hips (200 patients) who underwent primary THA over a 30-month period at a single institution. Patients without preoperative PROMIS or SF-12 mental scores, or >50yo were excluded. All data was collected preoperatively and included age, sex, BMI, ASA, PROMIS Depression, PROMIS Anxiety, and SF-12 Mental component score. We considered floor and ceiling effects as significant if >15% of patients responded with the lowest or highest possible score, respectively. Relationships between SF-12 and PROMIS were investigated using correlation (R), and were considered strong if R>0.7. RESULTS: Mean age was 41-years-old, mean ASA category was 2, mean BMI was 30kg/m2, and 54% were female. None of the PROMs showed any floor/ceiling effects at baseline. PROMIS Depression showed a strong correlation to SF-12 Mental (R=-0.72) while PROMIS Anxiety showed a moderate correlation to SF-12 Mental (R=-0.58). Negative linear relationships were observed because a lower PROMIS Depression/Anxiety values indicates less depressive/anxious feelings (inverse of SF-12). CONCLUSION: PROMIS Anxiety and Depression correlate well with SF-12 mental. These PROMIS domains may be attractive alternatives to legacy mental health instruments in young THA patients. Level of Evidence: III

The clinical success of periacetabular osteotomy (PAO) for the treatment of symptomatic acetabular dysplasia is well-documented. Conflicting evidence exists regarding the correlation of age with clinical outcomes. Hip disability and Osteoarthritis Outcome Score - global (HOOSglobal) is a recently validated patient-reported outcome measure following PAO. The purpose of this study is to asses HOOSglobal and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores at early follow-up based on age at the time of PAO.A prospective multicenter cohort of 391 patients undergoing PAO with minimum 2-year follow-up (average 4.71 years) were identified. Patients were categorized into 4 age groups:20 years (N = 131), 20-29 (N = 102), 30-39 (N = 65), and ≥40 (N = 34). A 4 × 2 repeated measures analysis of variance (Age Group × Time) was used to compare preoperative and postoperative HOOSglobal and WOMAC scores between age groups. A multiple linear regression was used to identify predictors of postoperative HOOSglobal scores.HOOSglobal and WOMAC scores increased across all age groups; however, a statistically greater increase in preoperative to postoperative HOOSglobal and WOMAC scores was found in those ≥40 years compared to those20 (P.002), 20-29 (P = .01), and 30-39 years (P = .02). Higher preoperative HOOSglobal scores were predictive of greater postoperative HOOSglobal scores (P.001) but age (P = .65), gender (P = .80), body mass index (P = .50), and Tönnis Classification (P = .07) were not independent predictors of 1-year outcomes.The absence of differences in early postoperative patient-reported outcomes across multiple age ranges emphasizes that PAO in the setting of symptomatic acetabular dysplasia can be successful regardless of patient age alone. Therefore, age alone might not be an appropriate selection criterion when evaluating surgical candidates for PAO.II.

Background The Patient-Reported Outcomes Measurement Information System (PROMIS) was developed by the National Institutes of Health to collect outcome data in rapid dynamic fashion on electronic platforms. The potential role of PROMIS in monitoring pain and function in young total hip arthroplasty (THA) patients has been under-investigated. The purpose of this study is to investigate correlation between PROMIS Physical Function (PF) and PROMIS Pain Interference (PI) and legacy scores with similar considerations. Methods We identified 298 hips who underwent primary THA over 40 months. Patients without preoperative PROMIS or legacy scores, or >50 years were excluded. Demographic data included age, gender, and body mass index. Outcome data included PF, PI, modified Harris Hip Score (mHHS), Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) domains, and Short Form 12 components. Floor/ceiling effects were considered to be significant if ≥15% of patients responded with the lowest or highest possible score. Spearman correlation (R) was performed to investigate correlation between legacy scores and PROMIS domains. Results Mean age was 40 years, mean body mass index was 30.1 kg/m2, and 55% were female. None of the patient-reported outcome measures showed any floor/ceiling effects. PI showed moderate correlation to mHHS (R = −0.60), WOMAC Pain (R = −0.62), and WOMAC PF (R = −0.60). PF showed moderate correlation to mHHS (R = 0.66) and WOMAC PF (R = 0.55). Mean PF and PI scores differed significantly from the general population mean of 50 (36.7, 65.4, respectively; both P Conclusion PROMIS is an attractive alternative to legacy scoring measures, showing moderate correlations between PROMIS physical domains and legacy PROMs of WOMAC and mHHS in young patients undergoing THA.

This study aimed to (1) measure acetabular sector angle (ASA) from proximal to distal positions along the axial femoral head axis, (2) identify acetabular deficiency patterns, and (3) correlate ASA at different axial positions with other radiological measurements in acetabular dysplasia. We identified 30 hips with dysplasia (lateral center edge angle [LCEA] 20°) and 30 hips without dysplasia (LCEA 25°) from a retrospective cohort. Anterior and posterior ASA (AASA, PASA) were measured in the axial computed tomography plane through the femoral head center (equatorial) and two axial positions above the equatorial line (intermediate and proximal). Deficiency patterns were identified using ASA cut-off values determined from receiver operating characteristic curves. Pearson's coefficients were used for correlations. Compared to non-dysplastic hips, AASA in dysplastic hips was significantly smaller in all levels: equatorial (46.1 ± 7.3 vs. 54.9 ± 8.5,° p 0.001), intermediate (62.1 ± 11.2 vs. 69.0 ± 10.6,° p = 0.02), and proximal (102.9 ± 14.2 vs. 128.3 ± 23.0,° p 0.001). According to proximal ASA (Pro-ASA) cut-off values in dysplastic hips, global deficiency was most prevalent (19/30, 63.3%), followed by anterior (6/30, 20%) and posterior (3/30, 10%) deficiency. There were strong correlations between acetabular anteversion and Eq-AASA (r = -0.74, p 0.001) and LCEA and pro-PASA (r = 0.82, p 0.001). Clinical significance: Acetabular sector angle provides insight into acetabular morphology and patterns of deficiency, providing essential information for precise acetabular reorientation.

The purpose of this exploratory analysis was to compare the impact of movement pattern training (MoveTrain) and standard strength and flexibility training (Standard) on muscle volume, strength and fatty infiltration in patients with hip-related groin pain (HRGP). We completed a secondary analysis of data collected during an assessor-blinded randomized control trial. Data was used from 27 patients with HRGP, 15 to 40 years, who were randomized into MoveTrain or Standard groups. Both groups participated in their training protocol (MoveTrain, n = 14 or Standard, n = 13) which included 10 supervised sessions over 12 weeks and a daily home exercise program. Outcome measures were collected at baseline and immediately after treatment. Magnetic resonance images (MRI) data was used to determine muscle fat index (MFI) and muscle volume. A hand-held dynamometer was used to assess isometric hip abductor and extensor strength. The Standard group demonstrated a significant post-treatment increase in gluteus medius muscle volume compared to the MoveTrain group. Both groups demonstrated an increase in hip abductor strength and reduction in gluteus minimus and gluteus maximus MFI. The magnitude of change for all outcomes were modest. Statement of Clinical Significance: Movement pattern training or a program of strength/flexibility training may be effective at improving hip abductor strength and reducing fatty infiltration in the gluteal musculature among those with HRGP. Further research is needed to better understand etiology of strength changes and impact of muscle volume and MFI in HRGP and the effect of exercise on muscle structure and function. This article is protected by copyright. All rights reserved.

Background Venous thromboembolism (VTE) is a serious complication of total hip arthroplasty (THA) and total knee arthroplasty (TKA). Apixaban is approved for VTE prophylaxis. This study seeks to ascertain the risk of VTE and bleeding complications in patients undergoing primary THA and TKA receiving apixaban for postoperative VTE prophylaxis for one of the following indications: high risk for VTE, previously on apixaban, and contraindication to the use of aspirin. Methods This is a retrospective cohort study of patients who underwent primary THA or TKA over a 17-month period and were prescribed apixaban for thromboprophylaxis postoperatively. Results 230 patients were included in the study, 110 TKA and 120 THA. The primary reasons for high-risk VTE status included personal and family history of VTE, and 13% were taking apixaban preoperatively for atrial fibrillation. 1 patient (0.43%) who underwent TKA had a DVT with PE. 2.6% of patients had wound complications requiring operative treatment, and 0.87% of THA patients underwent revision arthroplasty. Conclusion The use of apixaban for VTE prophylaxis after primary THA and TKA in patients at high risk for VTE, in patients previously on apixaban, and in patients with a contraindication to the use of aspirin is associated with a low risk of VTE and bleeding complications.

Aims The direct anterior approach (DAA) for total hip arthroplasty (THA) has potential advantages over other approaches and is most commonly performed with the patient in the supine position. We describe a technique for DAA THA with the patient in the lateral decubitus position and report the early clinical and radiological outcomes, the characteristics of the learning curve, and perioperative complications. Methods All primary DAA THAs performed in the lateral position by a single surgeon over a four-year period from the surgeon’s first case using the technique were identified from a prospectively collected database. Modified Harris Hip Scores (mHHS) were collected to assess clinical outcome, and routine radiological analysis was performed. Retrospective review of the medical records identified perioperative complications, the characteristics of the learning curve, and revisions. Results A total of 257 patients were included in the study. Their mean age was 60 years (SD 9.0). A total of 164 (64%) were female. The mean mHHS improved significantly from 52.1 (SD 16.2) preoperatively to 94.4 (SD 11) at a follow-up of one year (p < 0.001), with 212 of 225 patients (94%) achieving a minimal clinically important difference (MCID) (> 8 points). Radiological evaluation showed a mean leg length discrepancy of 2.6 mm (SD 5.9) and a mean difference in femoral offset of 0.2 mm (SD 4.9). A total of 234/243 acetabular components (96.3%) were positioned within Lewinnek’s safe zone. Analysis of operating time, blood loss, the position of the components, and complications did not identify a learning curve. A total of 14 patients (5.4%) had a major perioperative complication and three (1.2%) required revision THA. There were no major neurovascular complications and no dislocations. Conclusion We have described and analyzed a surgical technique for undertaking DAA THA in the familiar lateral decubitus position using a routine operating table, positioning devices, and instrumentation, and shown that it can be performed safely and effectively under these circumstances. Cite this article: Bone Joint J 2021;103-B(7 Supple B):53–58.

Aims The purpose of this study was to determine the access to and ability to use telemedicine technology in adult patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), and to determine associations with the socioeconomic characteristics of the patients, including age, sex, race, and education. We also sought to understand the patients’ perceived benefits, risks, and preferences when dealing with telemedicine. Methods We performed a cross-sectional survey involving patients awaiting primary THA and TKA by one of six surgeons at a single academic institution. Patients were included and called for a telephone-administered survey if their surgery was scheduled to be between 23 March and 2 June 2020, and were aged > 18 years. Results The response rate was 52% (189 of 363 patients). A total of 170 patients (90.4%) reported using the internet, 177 (94.1%) reported owning a device capable of videoconferencing, and 143 (76.1%) had participated in a video call in the past year. When asked for their preferred method for a consultation, 155 (82.8%) and 26 (13.9%) ranked in-person and a videoconference as their first choice, respectively. The perceived benefits of telemedicine consultations included reduced travel to appointments (165 (88.2%) agreed) and reduced cost of attending appointments (123 (65.8%) agreed). However, patients were concerned that they would not establish the same patient-physician connection (100 (53.8%) agreed), and would not receive the same level of care (52 (33.2%) agreed) using telemedicine consultations compared with in-person consultations. Conclusion Most patients undergoing arthroplasty have access to and are capable of using the technology required for telemedicine consultations. However, they still prefer in-person consultations due to concerns that they will not establish the same patient-physician connection and will not receive the same level of care, despite the benefits of reducing the time spent in travelling and the cost of attending appointments, and the appointments being easier to attend. Cite this article: Bone Joint J 2021;103-B(7 Supple B):98–102.

After treatment with in situ stabilization, slipped capital femoral epiphysis (SCFE) patients have variable degrees of deformity that can contribute to femoroacetabular impingement (FAI). To evaluate the severity of residual deformity most physicians currently use biplanar radiographs of an anteroposterior pelvis which profiles the lateral head-neck deformity and a frog lateral view which profiles the anterior head-neck deformity. However, the assessment of FAI morphology commonly relies on the 45-degree Dunn view to profile the anterolateral head-neck junction where FAI deformity is maximal. Therefore, the purpose of this study was to compare the magnitude of residual SCFE deformity detected on the frog lateral radiograph to the 45-degree Dunn radiograph.A retrospective review of radiographic images of 50 hips (47 patients) diagnosed with SCFE at a single academic institution from 2014 to 2018 was performed. The group included 25 hips evaluated postoperatively after fixation (Group 1) and 25 hips presenting with residual symptomatic SCFE deformity after previous pinning (Group 2). The alpha angle was assessed on both the 45-degree Dunn and frog lateral views for comparison. The modified Southwick slip angle was assessed on the frog lateral view only as a measure of SCFE severity.The Dunn view showed the maximal residual SCFE deformity as measured by the alpha angle in 88% (44/50) of cases. Overall, the mean alpha angle (70.7 degree vs. 60.1 degree, P0.001) was significantly larger on the Dunn view as compared with frog lateral. Subgroup analysis showed a larger alpha angle on Dunn view compared with frog lateral in both immediate postoperative and residual SCFE deformities as well: Group 1 (69.5 degree vs. 60.9 degree, P0.001) and Group 2 (71.9 degree vs. 59.3 degree, P0.001).In patients with SCFE, the maximal residual deformity of the proximal femur can typically be seen on the 45-degree Dunn view, rather than on the frog lateral view. Our findings suggest the 45-degree Dunn view may be beneficial part of the postoperative assessment of SCFEs to quantify the true maximal deformity present.Level IV.

BACKGROUND Slipped capital femoral epiphysis (SCFE) is a common hip problem in children. The resulting deformity can cause impingement similar to cam-type idiopathic femoroacetabular impingement (FAI). Although there are similarities between FAI and SCFE, deformity patterns, severity, and time of onset of symptoms varies, which may impact management. The purpose of this study was to describe patterns of articular cartilage damage in patients undergoing surgical hip dislocation for sequelae of SCFE in comparison to patients undergoing arthroscopic surgery for primary FAI. METHODS Patients were identified who underwent surgical treatment for hip pain due to primary FAI (cam type) or sequelae of SCFE. Clinical data and radiographic measurements were recorded. Cartilage was assessed intraoperatively. Severity was classified using the modified Beck classification, while location was classified into 6 sectors. Statistical analysis was performed to test for differences in demographic and radiographic characteristics between the SCFE and FAI patients. χ2 or Fisher exact tests were used to evaluate trends in patterns of acetabular and femoral cartilage wear between SCFE and FAI groups. RESULTS The SCFE group had 28 hips compared with 304 in the FAI group. SCFE patients were younger (19 vs. 32, P

Evidence related to physical therapist-led intervention for patients with chronic hip-related groin pain (HRGP) is limited. The purpose was to assess sustainability of treatment effects for people with HRGP undergoing two physical therapist-led interventions. We completed an ancillary analysis of a pilot multicenter, randomized clinical trial (RCT). Forty-six patients with chronic HRGP, 15-40 years, were enrolled. Patients were randomized to participate in 10 sessions over 12 weeks of either movement pattern training (MoveTrain) or traditional strength/flexibility (Standard). Participants completed self-report questionnaires before treatment and 6 and 12 months after treatment completion. Outcome measures included Hip disability and Osteoarthritis Outcome Score (HOOS), Patient Specific Functional Scale (PSFS) and Numeric Pain Rating Scale (NPRS) for average and worst pain. Continuous data were analyzed with mixed model repeated measures analysis of variance (RM-ANOVA) within each group. NPRS was analyzed using multinomial generalized estimating equations (GEE) with a cumulative logit. Reported p-values are from statistical contrasts within the RM-ANOVAs and GEEs testing a priori hypotheses regarding change from pretest to month 6, and pretest to month 12. 43/46 (93.5%) participants completed treatment, 40 (87.0%) completed 6 and 38 (82.6%) completed 12 month questionnaires. At 6 and 12 months, both groups demonstrated clinically significant improvements, compared to pretest, in all subscales of HOOS (P

Several bundled payment plans, like the Bundled Payment for Care Improvement (BPCI) initiative for total joint arthroplasty, have been introduced to decrease costs and improve clinical care. Measuring clinical outcomes with efficient, standardized methodologies is essential to determine the relative value of total joint arthroplasty care. We investigated feasibility and responsiveness of the recently developed Patient-Reported Outcomes Measurement Information System (PROMIS) in total knee arthroplasty (TKA) patients.We included patients with preoperative and 1-year PROMIS Physical Function (PF), Pain Interference (PI), and Depression (DEP) scores who received unilateral primary TKA. Burden was assessed using the number of questions and time required for PROMIS completion. The minimum clinically important difference was defined as 5. Floor/ceiling effects were noted if more than 15% of patients responded with the lowest/highest possible score, respectively. Wilcoxon rank-sum test was used to compare categorical data. Analysis of variance was used for PROMIS comparisons.In total, 172 knees (54 BPCI) were included. Floor effects were identified for DEP at baseline (non-BPCI) and follow-up (both groups), and for PI at follow-up only (BPCI). Patients required 140 seconds and 16 questions to answer all 3 PROMIS domains. Sixty-seven percent, 60%, and 44% of knees achieved minimum clinically important difference in PI, PF, and DEP scores respectively, with no significant difference between groups. The BPCI cohort was older (P.001) with a higher American Society of Anesthesiologists score (P = .028). There were no significant differences in scores between BPCI and non-BPCI patients.PROMIS is feasible and time-efficient in BPCI patients undergoing primary TKA. There were no significant differences in outcomes between BPCI and non-BPCI knees.Level III.

Developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI) are common hip pathologies and important risk factors for osteoarthritis, yet the disease mechanisms differ. DDH involves deficient femoral head coverage and a shortened abductor moment arm, so this study hypothesized that the cross-sectional area (CSA) of the gluteus medius/minimus muscle complex and the stabilizing iliocapsularis muscle would be larger in DDH versus FAI, without increased fatty infiltration. A longitudinal cohort identified prearthritic patients with DDH or FAI who underwent imaging before surgery. Patients with DDH and FAI (Cam, Pincer, or Mixed) were 1:1 matched based on age, sex, and body mass index. Magnetic resonance imaging was used to measure the gluteus medius/minimus complex and iliocapsularis in two transverse planes. Amira software was used to quantify muscle and noncontractile tissue. Paired samples t-tests were performed to compare muscle size and composition (p 0.05). There were no differences in the iliocapsularis muscle. Patients with DDH had significantly larger CSA of the gluteus medius/minimus complex at both transverse planes, and the noncontractile tissue proportion did not differ. The mean difference in overall muscle CSA at the anterior inferior iliac spine was 4.07 ± 7.4 cm

Background: Given the lack of established, externally validated criteria for the diagnosis of unstable hips, the Femoro-Epiphyseal Acetabular Roof (FEAR) index has been proposed as a useful tool for identifying hips with instability in the setting of borderline acetabular dysplasia. Purposes: To (1) determine the external performance of the FEAR index in identifying hips with a clinical diagnosis of instability in the setting of borderline dysplasia and (2) assess the performance of the FEAR index compared with acetabular inclination or physeal scar angle alone. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: The authors reviewed 176 patients with borderline acetabular dysplasia (lateral center-edge angle, 20°-25°). A positive FEAR index was defined as ≥5°. An alternative threshold ≥2° was also assessed. Significant instability was determined by the senior surgeon based on the combination of patient and radiographic features; unstable hips were treated with periacetabular osteotomy (with or without hip arthroscopy), and stable hips were treated with isolated hip arthroscopy. Results: Only 18% of borderline hips had a positive FEAR index. The ≥5° positive FEAR index threshold had a sensitivity of 33% (23/70) and specificity of 92% (98/106) in predicting the clinical diagnosis of instability. The ≥2° FEAR index threshold had a sensitivity of 39% (27/70) and specificity of 89% (94/106) in predicting the clinical diagnosis of instability. No alternative threshold for the FEAR index resulted in high levels of sensitivity and specificity. A threshold of –5° was required to reach an adequate sensitivity of 74%. The FEAR index remained a significant predictor of hip instability even after controlling for acetabular inclination (odds ratio, 1.12; P < .001) or physeal scar angle (odds ratio, 1.6; P < .001). Conclusion: In the current study, a positive FEAR index was generally indicative of the presence of clinical instability, but the FEAR index alone remained inadequate to fully define the instability of a given hip, as it demonstrated low sensitivity (only 33%) in the external validation. The FEAR index is best used in the context of other clinical and radiographic features.

BACKGROUND The anterior inferior iliac spine (AIIS) prominence is increasingly recognized in the setting of femoroacetabular impingement (FAI). The AIIS prominence may contribute to decreased hip flexion after acetabular reorientation in patients with acetabular dysplasia. AIIS morphologies have been characterized in numerous populations including asymptomatic, FAI, and athletic populations, but the morphology of the AIIS in patients with symptomatic acetabular dysplasia undergoing periacetabular osteotomy (PAO) has not been studied. In acetabular dysplasia, deficiency of the anterosuperior acetabular rim is commonly present and may result in the AIIS being positioned closer to the acetabular rim. Understanding morphological variation of the AIIS in patients with symptomatic dysplasia, and its relationship to dysplasia subtype and severity may aid preoperative planning, surgical technique, and evaluation of postoperative issues after PAO. QUESTIONS/PURPOSES In this study, we sought to determine: (1) the variability of AIIS morphology types in hips with symptomatic acetabular dysplasia and (2) whether the differences in the proportion of AIIS morphologies are present between dysplasia pattern and severity subtypes. METHODS Using our hip preservation database, we identified 153 hips (148 patients) who underwent PAO from October 2013 to July 2015. Inclusion criteria for the current study were (lateral center-edge angle [LCEA] < 20°), Tonnis Grade of 0 or 1 on plain AP radiographs of the pelvis, preoperative low-dose CT scan, and no prior surgery, trauma, neuromuscular, ischemic necrosis, or Perthes-like deformity. A total of 50 patients (50 hips) with symptomatic acetabular dysplasia undergoing evaluation for surgical planning of PAO remained for retrospective evaluation; we used these patients' low-dose CT scans for analysis. The median (range) age of patients in the study was 24 years (13 to 49). Ninety percent (45 of 50) of the hips were in female patients, whereas 10% (5 of 50) were in male patients. The morphology of the AIIS was classified on three-dimensional CT reconstructions according to a previously published classification to define the relationship between the AIIS and the acetabular rim. The morphology of the AIIS was classified as Type I (AIIS well proximal to acetabular rim), Type II (AIIS extending to level of acetabular rim), or Type III (AIIS extending distal to acetabular rim). Acetabular dysplasia subtype was characterized according to a prior protocol as either predominantly an anterosuperior acetabular deficiency, a posterosuperior acetabular deficiency, or a global acetabular deficiency. Acetabular dysplasia severity was distinguished as mild (LCEA 15° to 20°) or moderate/severe (LCEA < 15°). To answer our first question, regarding the proportions of each AIIS morphology in the dysplasia population, we calculated proportions and 95% CI estimates. To answer our second question, regarding the proposition of AIIS type between subtypes of dysplasia type and severity, we used a chi-square test or Fisher's exact test to compare categorical variables. A p value of < 0.05 was considered significant. RESULTS Seventy-two percent (36 of 50; 95% CI 58% to 83%) of patients had a Type II or III AIIS morphology. Type I AIIS morphology was found in 28% of patients (14 of 50; 95% CI 18% to 42%), Type II AIIS morphology in 62% (31 of 50; 95% CI 48% to 74%), and Type III AIIS/morphology in 10% (5 of 50; 95% CI 4% to 21%). A Type I AIIS was seen in seven of 15 of patients with anterosuperior acetabular deficiency, three of 18 of patients with global deficiency, and four of 17 patients with posterosuperior deficiency (p = 0.08). There was no difference in the variability of AIIS morphologies between the different subtypes of acetabular dysplasia pattern and no difference in AIIS morphology variability between patients with mild versus moderate/severe dysplasia. CONCLUSIONS The morphology of the AIIS in patients with acetabular dysplasia is commonly prominent, with 72% of hips having Type II or Type III morphologies. CLINICAL RELEVANCE The AIIS is often prominent in patients with acetabular dysplasia undergoing PAO, regardless of dysplasia pattern or severity. Prominent AIIS morphologies may affect hip flexion ROM after acetabular reorientation. AIIS morphology is a variable that should be considered during preoperative planning for PAO. Future studies are needed to assess the clinical significance of a prominent AIIS on intraoperative findings and postoperative status after PAO.

BACKGROUND Periacetabular osteotomy (PAO) increases acetabular coverage of the femoral head and medializes the hip's center, restoring normal joint biomechanics. Past studies have reported data regarding the degree of medialization achieved by PAO, but measurement of medialization has never been validated through a comparison of imaging modalities or measurement techniques. The ilioischial line appears to be altered by PAO and may be better visualized at the level of the inferior one-third of the femoral head, thus, an alternative method of measuring medialization that begins at the inferior one-third of the femoral head may be beneficial. QUESTIONS/PURPOSES (1) What is the true amount and variability of medialization of the hip's center that is achieved with PAO? (2) Which radiographic factors (such as lateral center-edge angle [LCEA] and acetabular inclination [AI]) correlate with the degree of medialization achieved? (3) Does measurement of medialization on plain radiographs at the center of the femoral head (traditional method) or inferior one-third of the femoral head (alternative method) better correlate with true medialization? (4) Are intraoperative fluoroscopy images different than postoperative radiographs for measuring hip medialization? METHODS We performed a retrospective study using a previously established cohort of patients who underwent low-dose CT after PAO. Inclusion criteria for this study included PAO as indicated for symptomatic acetabular dysplasia, preoperative CT scan, and follow-up between 9 months and 5 years. A total of 333 patients who underwent PAO from February 2009 to July 2018 met these criteria. Additionally, only patients who were between 16 and 50 years old at the time of surgery were included. Exclusion criteria included prior ipsilateral surgery, femoroacetabular impingement (FAI), pregnancy, neuromuscular disorder, Perthes-like deformity, inadequate preoperative CT, and inability to participate. Thirty-nine hips in 39 patients were included in the final study group; 87% (34 of 39) were in female patients and 13% (5 of 39 hips) were in male patients. The median (range) age at the time of surgery was 27 years (16 to 49). Low-dose CT images were obtained preoperatively and at the time of enrollment postoperatively; we also obtained preoperative and postoperative radiographs and intraoperative fluoroscopic images. The LCEA and AI were assessed on plain radiographs. Hip medialization was assessed on all imaging modalities by an independent, blinded assessor. On plain radiographs, the traditional and alternative methods of measuring hip medialization were used. Subgroups of good and fair radiographs, which were determined by the amount of pelvic rotation that was visible, were used for subgroup analyses. To answer our first question, medialization of all hips was assessed via measurements made on three-dimensional (3-D) CT hip reconstruction models. For our second question, Pearson correlation coefficients, one-way ANOVA, and the Student t-test were calculated to assess the correlation between radiographic parameters (such as LCEA and AI) and the amount of medialization achieved. For our third question, statistical analyses were performed that included a linear regression analysis to determine the correlation between the two radiographic methods of measuring medialization and the true medialization on CT using Pearson correlation coefficients, as well as 95% confidence intervals and standard error of the estimate. For our fourth question, Pearson correlation coefficients were calculated to determine whether using intraoperative fluoroscopy to make medialization measurements differs from measurements made on radiographs. RESULTS The true amount of medialization of the hip center achieved by PAO in our study as assessed by reference-standard CT measurements was 4 ± 3 mm; 46% (18 of 39 hips) were medialized 0 to 5 mm, 36% (14 hips) were medialized 5 to 10 mm, and 5% (2 hips) were medialized greater than 10 mm. Thirteen percent (5 hips) were lateralized (medialized < 0 mm). There were small differences in medialization between LCEA subgroups (6 ± 3 mm for an LCEA of ≤ 15°, 4 ± 4 mm for an LCEA between 15° and 20°, and 2 ± 3 mm for an LCEA of 20° to 25° [p = 0.04]). Hips with AI ≥ 15° (6 ± 3 mm) achieved greater amounts of medialization than did hips with AI of < 15° (2 ± 3 mm; p < 0.001). Measurement of medialization on plain radiographs at the center of the femoral head (traditional method) had a weaker correlation than using the inferior one-third of the femoral head (alternative method) when compared with CT scan measurements, which were used as the reference standard. The traditional method was not correlated across all radiographs or only good radiographs (r = 0.16 [95% CI -0.17 to 0.45]; p = 0.34 and r = 0.26 [95% CI -0.06 to 0.53]; p = 0.30), whereas the alternative method had strong and very strong correlations when assessed across all radiographs and only good radiographs, respectively (r = 0.71 [95% CI 0.51 to 0.84]; p < 0.001 and r = 0.80 [95% CI 0.64 to 0.89]; p < 0.001). Measurements of hip medialization made on intraoperative fluoroscopic images were not found to be different than measurements made on postoperative radiographs (r = 0.85; p < 0.001 across all hips and r = 0.90; p < 0.001 across only good radiographs). CONCLUSION Using measurements made on preoperative and postoperative CT, the current study demonstrates a mean true medialization achieved by PAO of 4 mm but with substantial variability. The traditional method of measuring medialization at the center of the femoral head may not be accurate; the alternate method of measuring medialization at the lower one-third of the femoral head is a superior way of assessing the hip center's location. We suggest transitioning to using this alternative method to obtain the best clinical and research data, with the realization that both methods using plain radiography appear to underestimate the true amount of medialization achieved with PAO. Lastly, this study provides evidence that the hip center's location and medialization can be accurately assessed intraoperatively using fluoroscopy. LEVEL OF EVIDENCE Level III, diagnostic study.

Background Hip dysplasia is one of the most common causes of hip arthritis. Its incidence is estimated to be between 3.6 and 12.8% (Canadian Institute for Health Information, Hip and knee replacements in Canada, 2017–2018: Canadian joint replacement registry annual report, 2019; Jacobsen and Sonne-Holm, Rheumatology 44:211–8, 2004). The Periacetabular Osteotomy (PAO) has been used successfully for over 30 years (Gosvig et al., J Bone Joint Surg Am 92:1162–9, 2010), but some patients continue to exhibit symptoms post-surgery (Wyles et al., Clin Orthop Relat Res 475:336–50, 2017). A hip arthroscopy, performed using a small camera, allows surgeons to address torn cartilage inside the hip joint. Although both procedures are considered standard of care treatment options, it is unknown whether the addition of hip arthroscopy improves patient outcomes compared to a PAO alone. To delay or prevent future joint replacement surgeries, joint preservation surgery is recommended for eligible patients. While previous studies found an added cost to perform hip arthroscopies, the cost-effectiveness to Canadian Health care system is not known. Methods Patients randomized to the experimental group will undergo central compartment hip arthroscopy prior to completion of the PAO. Patients randomized to the control group will undergo isolated PAO. Patient-reported quality of life will be the primary outcome used for comparison between the two treatment groups as measured by The International Hip Outcome Tool (iHOT-33) (Saberi Hosnijeh et al., Arthritis Rheum 69:86–93, 2017). Secondary outcomes will include the four-square step test and sit-to-stand (validated in patients with pre-arthritic hip pain) and hip-specific symptoms and impairment using the HOOS; global health assessment will be compared using the PROMIS Global 10 Score; health status will be assessed using the EQ-5D-5L and EQ VAS questionnaires (Ganz et al., Clin Orthop Relat Res 466:264–72, 2008) pre- and post-operatively. In addition, operative time, hospital length of stay, adverse events, and health services utilization will be collected. A sub-group of patients (26 in each group) will receive a T1rho MRI before and after surgery to study changes in cartilage quality over time. A cost-utility analysis will be performed to compare costs and quality-adjusted life years (QALYs) associated with the intervention. Discussion We hypothesize that (1) concomitant hip arthroscopy at the time of PAO to address central compartment pathology will result in clinically important improvements in patient-reported outcome measures (PROMs) versus PAO alone, that (2) additional costs associated with hip arthroscopy will be offset by greater clinical improvements in this group, and that (3) combined hip arthroscopy and PAO will prove to be a cost-effective procedure. Trial registration ClinicalTrials.gov NCT03481010. Registered on 6 March 2020. Protocol version: version 3.

Background: The molecular mechanism of how femoroacetabular impingement (FAI) morphology leads to hip osteoarthritis (OA) is yet to be determined. The expression and location of inflammation-related molecules during early- and late-stage FAI have not been previously described. Moreover, the characterization of intra-articular inflammation away from the cam deformity as well as the nature of adjacent synovial tissue have also not been extensively reported. Hypothesis: Early-stage FAI has a similar expression of inflammation-related markers in the head-neck and acetabular cartilage but less synovitis than late-stage FAI. Study Design: Controlled laboratory study. Methods: Head-neck cartilage, acetabular cartilage, and synovial samples were obtained from patients undergoing hip preservation surgery for the treatment of symptomatic cam FAI (early FAI group; n = 15) and advanced OA secondary to cam FAI (late FAI group; n = 15). Samples procured from healthy young adult donors served as the control group (n = 7). Cartilage degeneration was assessed by histology, and the expression of inflammation-related proteins (interleukin–1 beta [IL-1β], matrix metalloproteinase–13 [MMP-13], a disintegrin and metalloproteinase with thrombospondin motifs–4 [ADAMTS-4], type II collagen [COL2], and aggrecan neoepitope [NITEGE]) was measured by immunostaining. Synovial samples in the early and late FAI groups were examined for synovitis and the expression of IL-1β. Results: Head-neck cartilage in the early FAI group showed significantly more degeneration than the control group and an increased expression of inflammation-related proteins (IL-1β: 69.7% ± 18.1% vs 20.2% ± 4.9%, respectively; MMP-13: 79.6% ± 12.6% vs 25.3% ± 9.5%; ADAMTS-4: 83.9% ± 12.2% vs 24.3% ± 11.1%; NITEGE: 89.7% ± 7.7% vs 39.8% ± 20.5%) ( P < .001). Head-neck and acetabular cartilage in the early and late FAI groups showed a similar degree of degeneration. Moreover, a similar expression of inflammation-related proteins was observed between the early and late FAI groups for head-neck cartilage (IL-1β: 69.7% ± 18.1% vs 72.5% ± 13.2%; MMP-13: 79.6% ± 12.6% vs 71.4% ± 18.8%; ADAMTS-4: 83.9% ± 12.2% vs 82.6% ± 12.5%; COL2: 93.6% ± 3.9% vs 92.5% ± 5.8%; NITEGE: 89.7% ± 7.7% vs 95.7% ± 4.7%) and acetabular cartilage (IL-1β: 83.3% ± 24.8% vs 80.7% ± 15.6%; MMP-13: 94.3% ± 9.7% vs 85.2% ± 12.3%; ADAMTS-4: 98.5% ± 2.3% vs 98.4% ± 3.4%; COL2: 99.8% ± 0.7% vs 99.7% ± 1.1%; NITEGE: 96.7% ± 6.7% vs 99.2% ± 2.2%). In contrast, synovitis was minimal with a low expression of IL-1β in the early FAI group compared with the late FAI group. Conclusion: Hip cartilage exhibited an OA phenotype in patients with early-stage FAI, similar to what was observed in hip OA secondary to FAI. Severe synovitis was only evident with late-stage FAI. Clinical Relevance: This study supports the concept that early hip impingement is associated with cartilage degeneration and catabolism.

Background: Surgical treatment of symptomatic femoroacetabular impingement (FAI) and dysplasia requires careful characterization of acetabular morphology. The lateral center-edge angle (LCEA) is often used to assess lateral acetabular anatomy. Previous work has questioned the LCEA as a surrogate for acetabular contact/articular cartilage surface area because of the variable morphology of the lunate fossa. Hypothesis: We hypothesized that weightbearing articular cartilage of the acetabulum would poorly correlate with LCEA secondary to significant variation in the size of the lunate fossa. Study Design: Cohort study (Diagnosis); Level of evidence, 3. Methods: Patients with 3D CT imaging undergoing either hip arthroscopy or periacetabular osteotomy for FAI or symptomatic hip instability were retrospectively identified. The LCEA and femoral head diameter were measured on an anteroposterior pelvis radiograph. Patients were grouped according to their lateral acetabular coverage as undercoverage (LCEA, 40°). Patients were randomly identified until each group contained 20 patients. The articular surface area was measured from preoperative 3D CT data. Linear regression analysis was performed to examine the relationship between articular surface area and LCEA. Continuous and categorical data were analyzed utilizing analysis of variance and chi-square analysis. Statistical significance was set at P < .05. Results: No difference in age ( P = .52), body mass index (BMI) ( P = .75), or femoral head diameter ( P = .66) was noted between groups. A significant difference in articular surface area was observed between patients with undercoverage and those with overcoverage (20.4 cm2 vs 24.5 cm2; P = .01). No significant difference was identified between the undercoverage and normal groups (20.4 cm2 vs 23.3 cm2; P = .09) or the normal and overcoverage groups (23.3 cm2 vs 24.5 cm2; P = .63). A moderate positive correlation was observed between LCEA and articular surface area across all patients ( r = 0.38; P = .002) but not when patients with undercoverage were excluded ( r = 0.02; P = .88). Significant variation in surface area was observed within each group such that no patient in any group was outside of 2 SDs of the means of the other groups. When patients were categorized into quartiles established by the articular surface area for the entire population, 40% of patients with overcoverage were observed in the first or second quartile (lower area). Conclusion: Lateral acetabular undercoverage based on the LCEA (25°), however, is not predictive of increased, normal, or decreased acetabular surface area.

OBJECTIVE: To compare 3D hip kinematics during single leg squat (SLsquat) and step down, between patients with hip-related groin pain (HRGP) and asymptomatic participants. To assess relationships among hip kinematics, muscle strength and bony morphology. DESIGN: Controlled laboratory cross-sectional study. METHODS: 40 patients with HRGP and 40 matched, asymptomatic participants, 18–40 years. Hand-held dynamometry was used to assess hip abductor and external rotator strength. An 8-camera motion analysis system was used to quantify 3D kinematics during SLSquat and step down. MRI was used to quantify bony morphology. Independent t-tests and Mann-Whitney U tests were used to assess between-group differences. Pearson coefficient correlations were used to assess relationships. RESULTS: Patients with HRGP had smaller peak hip flexion angles, smaller knee flexion angles and lesser squat depth compared to asymptomatic participants during SLSquat. Among patients with HRGP, smaller hip flexion angles during SLSquat were associated with hip abductor weakness (r=.47, P =

The Patient-Reported Outcomes Measurement Information System (PROMIS) is increasingly used to assess patient health. The Bundled Payment for Care Improvement (BPCI) initiative for total hip arthroplasty (THA) was introduced to decrease costs and improve clinical care. We investigated differences between BPCI and non-BPCI THA patients and their PROMIS scores, along with its feasibility and responsiveness in these populations.We included all consecutive patients receiving unilateral primary THA who also had preoperative and one-year postoperative PROMIS physical function (PF), PROMIS pain interference (PI), and PROMIS depression (DEP) scores. Demographics and PROMIS scores were compared. Test burden was assessed using the number of questions and time required for PROMIS completion. The minimum clinically important difference was defined as 5. Floor and ceiling effects were noted if more than 15% of patients responded with the lowest or highest possible score, respectively. Wilcoxon rank-sum test was used to compare categorical data. ANOVA was used for PROMIS comparisons.290 hips (86 BPCI, 30%) were included. The BPCI cohort was older (P.001) with a higher American Society of Anesthesiologists physical status classification system (P = .0045). There were significant differences in baseline scores of PF and DEP between BPCI and non-BPCI (P = .046 and P = .048, respectively). Both groups showed significant improvement at follow-up in all scores (all P.001). Significantly more non-BPCI patients achieved minimum clinically important difference at follow-up in PI and PF (P = .047 and P = .023, respectively). Floor effects were identified for DEP at baseline and follow-up and for PI at follow-up only.PROMIS is feasible and time-efficient in BPCI patients undergoing primary THA. There were significant differences between BPCI and non-BPCI hips.Level III.

Developmental dysplasia of the hip (DDH) in adolescents and young adults can cause notable pain and dysfunction and is a leading cause of progressive hip osteoarthritis in affected patients. Recognition of the clinical symptoms and radiographic presentation of DDH in adolescents and young adults are paramount for early management. Plain radiographs are critical for making proper diagnosis, whereas three-dimensional imaging including MRI and/or CT detects intra-articular pathology and better characterizes hip morphology. Management of early, symptomatic DDH includes nonsurgical modalities and open joint preservation techniques. Arthroscopic management can be used as an adjunct for symptomatic treatment and for addressing intra-articular pathology, but it alone does not correct the underlying osseous dysplasia and associated instability. The periacetabular osteotomy has become the mainstay of efforts to redirect the acetabulum and preserve the articular integrity of the hip; however, the proximal femur is also a potential source of pathology that should be considered. Open hip procedures are technically demanding yet provide the opportunity for pain relief, improved function, and preservation of the hip joint.

Background: No previous study has investigated how the Patient-Reported Outcomes Measurement Information System (PROMIS) performs compared with legacy patient-reported outcome measures in patients with symptomatic acetabular dysplasia treated with periacetabular osteotomy (PAO). Purpose: To (1) measure the strength of correlation between the PROMIS and legacy outcome measures and (2) assess floor and ceiling effects of the PROMIS and legacy outcome measures in patients treated with PAO for symptomatic acetabular dysplasia. Study Design: Cohort study (Diagnosis); Level of evidence, 2. Methods: This study included 220 patients who underwent PAO for the treatment of symptomatic acetabular dysplasia. Outcome measures included the Hip disability and Osteoarthritis Outcome Score (HOOS) pain, HOOS activities of daily living (ADL), modified Harris Hip Score (mHHS), PROMIS pain, and PROMIS physical function subsets, with scores collected preoperatively and/or postoperatively at a minimum 12-month follow-up. The change in mean scores from preoperatively to postoperatively was calculated only in a subgroup of 57 patients with scores at both time points. Distributions of the PROMIS and legacy scores were compared to evaluate floor and ceiling effects, and Pearson correlation coefficients were calculated to evaluate agreement. Results: The mean age at the time of surgery was 27.7 years, and 83.6% were female. The mean follow-up time was 1.5 years. Preoperatively, neither the PROMIS nor the legacy measures showed significant floor or ceiling effects. Postoperatively, all legacy measures showed significant ceiling effects, with 15% of patients with a maximum HOOS pain score of 100, 29% with a HOOS ADL score of 100, and 21% with an mHHS score of 100. The PROMIS and legacy instruments showed good agreement preoperatively and postoperatively. The PROMIS pain had a moderate to strong negative correlation with the HOOS pain ( r = −0.66; P < .0001) and mHHS ( r = −0.60; P < .0001) preoperatively and the HOOS pain ( r = −0.64; P < .0001) and mHHS ( r = −0.64; P < .0001) postoperatively. The PROMIS physical function had a moderate positive correlation with the HOOS ADL ( r = 0.51; P < .0001) and mHHS ( r = 0.49; P < .0001) preoperatively and a stronger correlation postoperatively with the HOOS ADL ( r = 0.56; P < .0001) and mHHS ( r = 0.56; P < .0001). Conclusion: We found good agreement between PROMIS and legacy scores preoperatively and postoperatively. PROMIS scores were largely normally distributed, demonstrating an expanded ability to capture variability in patients with improved outcomes after treatment.

Developmental dysplasia of the hip (DDH) causes hip instability and early-onset osteoarthritis. The focus on pathomechanics in DDH has centered on the shallow acetabulum, however there is growing awareness of the role of femoral deformities in joint damage. The objective of this study was to determine the influence of femoral version (FV) on the muscle and joint reaction forces (JRFs) of dysplastic hips during gait. Magnetic resonance images, in-vivo gait data, and musculoskeletal models were used to calculate JRFs and simulate changes due to varying FV deformities. Rotation about the long axis of the femur was added in the musculoskeletal models to simulate FV values from -5° (relative retroversion) to + 35° (increased anteversion). In our simulations, FV deformities caused the largest changes to the anteroposterior and resultant JRFs. From a normal FV of 15°, a 15° increase in femoral anteversion caused JRFs to be less posterior in early stance (Δ = 0.43 ± 0.22 xbodyweight) and more anterior in late stance (Δ = 0.60 ± 14 xbodyweight). Relative retroversion caused anteroposterior changes that were similar to anteversion in early stance but opposite in late stance. Resultant JRFs experienced the largest changes during late stance where anteversion raised the peak by 0.48 ± 0.15 xbodyweight and relative retroversion lowered the peak by 0.32 ± 0.30 xbodyweight. Increasing anteversion increased hip flexor and abductor muscle forces, which caused the changes in JRFs. Identifying how FV deformities influence hip joint loading can elucidate their role in the mechanisms of hip degeneration in patients with DDH.

Residual Legg-Calvé-Perthes (LCP) deformities represent one of the most challenging disorders in hip reconstructive surgery. In complex cases, both instability (acetabular dysplasia) and multifocal femoroacetabular impingement (FAI) (proximal femoral deformities) require correction. We assessed intermediate-term patient-reported outcome measures, radiographic correction, complications, and survivorship for combined surgical dislocation (SD) and periacetabular osteotomy (PAO) for the treatment of complex LCP deformities.A retrospective cohort study was performed on 31 hips with complex LCP deformities undergoing combined SD and PAO for concurrent instability and FAI. Treatment included femoral head reshaping, trochanteric advancement and relative femoral neck lengthening, management of intra-articular lesions, and PAO. Twenty-seven hips (87%) had a minimum follow-up of 5 years. The mean age was 19.8 years, 56% of patients were female, and 44% of patients had undergone a previous surgical procedure.At a mean of 8.4 years, 85% of hips (23 of 27) remained preserved (no conversion to total hip arthroplasty). The survivorship estimates were 93% at 5 years and 85% at 10 years. The median (and interquartile range) increased from 64 points (55, 67 points) to 92 points (70, 97 points) (p0.001) for the modified Harris hip score (mHHS) and from 60 points (45, 75 points) to 86 points (75, 100 points) (p = 0.001) for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score. Symptoms (mHHS70 points) were reported for an additional 19% of hips (n = 5) at the final follow-up. The University of California Los Angeles (UCLA) activity score increased from a median of 8 points (6, 10 points) to 9 points (7, 10 points) (p = 0.207). Structural correction included mean improvement (and standard deviation) of 15.3° ± 7.6° for acetabular inclination, 20.7° ± 10.8° for the lateral center-edge angle, 23.4° ± 16.3° for the anterior center-edge angle, and 18 ± 10 mm for trochanteric height (p0.001 for all). Complications occurred in 2 hips (7%), including 1 deep wound infection and 1 superficial wound infection. There was 1 reoperation due to complication, but there were no nerve palsies, thromboembolic events, fractures, or nonunions.At an intermediate follow-up of combined SD and PAO for complex LCP deformities, 85% of hips were preserved. This procedure provides reliable deformity correction, major pain relief, improved function, and acceptable complication and failure rates.Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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 (R

There is considerable disparity in institutional practices surrounding routine pathologic examination of femoral heads removed during total hip arthroplasty (THA). Multiple groups have studied the merits of routine femoral head pathology in THA, without clear consensus. We sought to further investigate the existing evidence on routine pathologic examination of femoral heads retrieved during THA to determine if this practice provides additional clinical value and is cost-effective.To conduct a systematic review of the literature, a medical librarian was consulted to develop and perform comprehensive searches in PubMed (1809-present), Embase (embase.com 1974-present), CINAHL (EBSCO, 1937-present), and the Cochrane Central Register of Controlled Trials (Wiley). Final searches resulted in 727 references. Through multiple reviewer screenings and assessments of eligible full-text articles, we included 14 articles for review.Our systematic review yielded pathologic examination results from 17,388 femoral head specimens collected during THA. In 0.85% of cases, the pathologic diagnosis differed in a meaningful way from the preoperative clinical diagnosis. Routine pathology changed patient management in approximately 0.0058% of cases. The average cost for pathologic examination of each specimen was $126.38.Routine pathologic examination of femoral heads retrieved during THA has limited impact on patient management. With an estimated 500,000 THAs performed in 2019, the economic feasibility of routine femoral head pathology is limited at an annual cost of up to $63,000,000 and cost per quality-adjusted life-year approaching infinity. However, surgeon discretion on a patient-specific or practice-specific basis should be used to make the final determination on the need for femoral head pathology.

BACKGROUND: This study aimed: (1) to compare the transcriptome profile of articular cartilage in cam-FAI (early stage) to advanced OA secondary to cam-FAI (late stage) and (2) to investigate epigenetic changes through the expression of DNA methylation enzymes DNMT3B, DNMT1, and DNMT3A and peroxisome proliferator-activated receptor gamma (PPARγ) in human cartilage samples during the progression of hip OA. METHODS: Full-thickness cartilage samples were collected from the anterolateral head-neck junction (impingement zone) of 22 patients (9 early-FAI and 13 late-FAI). RNA sequencing and in vitro cartilage cultures with histological analysis and immunohistochemistry staining for PPARγ and DNMT3B were performed. Target gene validation was confirmed with RT-PCR. RESULTS: Fifty genes and 42 pathways were identified differentially between early and late-FAI (fold change 1.5, P < .01). PPARγ and DNMT3B were gradually suppressed with disease progression. Contrarily, disease progression induced expression of DNMT1/3A. CONCLUSION: By comparing comprehensive gene expression in early and late stage hip degeneration at the whole-genome level, distinct transcriptome profiles for early and late stage disease were identified along with key molecular contributors to the progression of hip OA. Preservation of endogenous PPARγ may have therapeutic potential to delay or prevent hip OA.

Hips with developmental dysplasia (DDH) are at a heightened risk of premature hip osteoarthritis, which is often expedited by mechanically induced articular tissue damage. A prevalent form of damage in DDH is labral tears caused by abnormal loading at the shallow acetabular edge. Although the majority of reported DDH-related labral tears occur in the antero-superior acetabulum, posterior labral tears are prevalent in individuals whose lifestyle involves frequent high hip flexion tasks such as squatting. To better understand region-specific risks for chondrolabral damage during high hip flexion, we used image-based musculoskeletal models to compare acetabular edge loading (AEL) during double-legged squat between hips with symptomatic DDH (n = 10) and healthy controls (n = 10). Compared to controls, hips with DDH had higher instantaneous posterior AEL at the lowest point of squat (2.6 vs. 1.8 ×BW, p ≤ 0.04), and higher accumulative loading across the duration of the squatting motion (2.6 vs. 1.9 ×BW*s, p ≤ 0.04). Elevated posterior AEL coincided with increased net hip extension moments and posterior joint reaction forces, and was correlated with the severity of DDH acetabular deformity. Our findings suggest that posterior AEL is elevated in hips with symptomatic DDH during double-legged squat, which may contribute to chondrolabral damage in individuals who often perform such high hip flexion tasks. Clinical evaluation of DDH should consider patient-specific anatomy and lifestyle factors when establishing diagnoses and planning personalized treatment.

Complex deformities of the hip requiring intra-articular and proximal femoral correction are challenging with regard to surgical access and complication risk. Combined surgical dislocation and proximal femoral osteotomy (SD/PFO) is a surgical strategy that provides unrestricted access to the joint with the capability for adjunctive PFO. Although providing excellent surgical access, concerns over a potentially high risk of postoperative complications remain, and published information on the safety of this technique remain scarce. In this study, we defined the early complication profile of combined surgery across 48 hips with a variety of complex deformities using a standardized, validated complication grading scheme for hip preservation surgery. Patients were mean age 19.1 years 13–33 years and 60% had previous surgery. At the early mean follow-up of 2.9 years, considerable improvement was seen across all outcome scores. Major complications (Grade III or higher) occurred at a rate of 4.2% (n = 2). Both were osteotomy non-unions, and both were treated successfully with revision PFO and bone grafting at mean 1.1 years. To our knowledge, the current series of combined SD-PFO surgeries represents the largest to date for which detailed complication data have been reported. Given the complexity of these disorders, a major complication rate of 4.2% is acceptable. Our complication rates were comparable to those reported for isolated SD and PFO procedures. These rates did not vary significantly across morphologic variants or patient-specific characteristics. Additionally, our complication risk profile is consistent with previous, smaller reports, which supports the generalizability of these results among appropriately experienced surgeons.

Objectives: Full-thickness cartilage injury is not uncommon in patients undergoing primary treatment of Femoroacetabular impingement (FAI). Treatment of these lesions with microfracture is commonly performed. However, the outcomes of these procedures relative to other patients undergoing FAI surgery is not well established and the literature on this topic is limited to small, retrospective single surgeon studies. The purpose of the present study was to evaluate outcomes of patients who underwent concurrent FAI correction and acetabular microfracture and to identify predictors treatment failure. Methods: A prospective multicenter cohort study of the treatment of FAI was performed. A total of 760 hips undergoing primary FAI surgery were enrolled. Inclusion criteria were primary FAI surgery, Tonnis 0 or 1 osteoarthritis grade, and age between 16 and 55 years. A total of 61 hips underwent treatment of full-thickness acetabular cartilage lesions with microfracture, with 55 (90.2%) having follow-up greater than 1 year (mean 4.0 years). This group had a mean age of 35.0+10.1 years, BMI of 27.2+4.2, and included 81.8% (45/55) males. A comparison cohort of 492 hips undergoing primary FAI surgery without treatment of acetabular full-thickness cartilage was utilized. Baseline, intraoperative, and follow-up data was recorded including the modified Harris hip score (mHHS) and HOOS domains of pain, ADLs, sports and recreation, symptoms, and quality of life. Composite failure was characterized by reoperation [total hip arthroplasty (THA) or revision surgery] or clinical failure (failure to meet either MCID or PASS for mHHS). Age was assessed in 5 year intervals. Students t-test was used for continuous variables and chi squared were used for categorical variables. A p value less than 0.05 was considering significant. Results: Hips undergoing acetabular microfracture were more likely (compared to comparison cohort) to be male (81.8% vs. 40.9%, p40 years* of age was 0%, 20.0%, and 22.7% p=.016*), while the rate of composite failure in these groups was 17.4%, 20.0% and 45.5%, respectively (p=.029*). Hips greater than 35 years of age demonstrated inferior HOOS outcomes for domains of pain, ADLs, sports and recreation, QOL, and symptoms and SF-12 physical component scores(Table 1). Conclusions: The results of acetabular microfracture in patients undergoing FAI surgery at a mean follow-up of 4.0 years postoperatively are strongly correlated with age. Patients under 35 years of age demonstrate excellent outcomes with low rates of revision or progression to THA. Acetabular microfracture should have a limited to absent role in patients over the age of 40.