Cohort profile: Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) - an international consortium of prospective cohort studies with individual participant data on hip osteoarthritis.

PURPOSE: Hip osteoarthritis (OA) is a major cause of pain and disability worldwide. Lack of effective therapies may reflect poor knowledge on its aetiology and risk factors, and result in the management of end-stage hip OA with costly joint replacement. The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium was established to pool and harmonise individual participant data from prospective cohort studies. The consortium aims to better understand determinants and risk factors for the development and progression of hip OA, to optimise and automate methods for (imaging) analysis, and to develop a personalised prediction model for hip OA. PARTICIPANTS: World COACH aimed to include participants of prospective cohort studies with ≥200 participants, that have hip imaging data available from at least 2 time points at least 4 years apart. All individual participant data, including clinical data, imaging (data), biochemical markers, questionnaires and genetic data, were collected and pooled into a single, individual-level database. FINDINGS TO DATE: World COACH currently consists of 9 cohorts, with 38 021 participants aged 18-80 years at baseline. Overall, 71% of the participants were women and mean baseline age was 65.3±8.6 years. Over 34 000 participants had baseline pelvic radiographs available, and over 22 000 had an additional pelvic radiograph after 8-12 years of follow-up. Even longer radiographic follow-up (15-25 years) is available for over 6000 of these participants. FUTURE PLANS: The World COACH consortium offers unique opportunities for studies on the relationship between determinants/risk factors and the development or progression of hip OA, by using harmonised data on clinical findings, imaging, biomarkers, genetics and lifestyle. This provides a unique opportunity to develop a personalised hip OA risk prediction model and to optimise methods for imaging analysis of the hip.

Operative or Nonoperative Treatment is Predicted Accurately for Patients Who Have Hip Complaints Consulting an Orthopedic Surgeon Using Machine Learning Algorithms Trained With Prehospital Acquired History-Taking Data.

BACKGROUND: Increasing numbers of patients suffering from hip osteoartritis will lead to increased orthopaedic health care consumption. Artificial intelligence might alleviate this problem, using Machine learning (ML) to optimize orthopaedic consultation workflow by predicting treatment strategy (non-operative or operative) prior to consultation. The purpose of this study was to assess ML accuracy in clinical practice, by comparing ML predictions to the outcome of clinical consultations. METHODS: In this prospective clinical cohort study, adult patients referred for hip complaints between January 20th to February 20th 2023 were included. Patients completed a computer-assisted history taking (CAHT) form and using these CAHT answers, a ML-algorithm predicted non-operative or operative treatment outcome prior to in-hospital consultation. During consultation, orthopaedic surgeons and physician assistants were blinded to the prediction in 90 and unblinded in 29 cases. Consultation outcome (non-operative or operative) was compared to ML treatment prediction for all cases, and for blinded and unblinded conditions separately. Analysis was done on 119 consultations. RESULTS: Overall treatment strategy prediction was correct in 101 cases (accuracy 85%, P < .0001). Non-operative treatment prediction (n = 71) was 97% correct versus 67% for operative treatment prediction (n = 48). Results from unblinded consultations (86.2% correct predictions,) were not statistically different from blinded consultations (84.4% correct, P > .05). CONCLUSIONS: Machine Learning algorithms can predict non-operative or operative treatment for patients with hip complaints with high accuracy. This could facilitate scheduling of non-operative patients with physician assistants, and operative patients with orthopaedic surgeons including direct access to pre-operative screening, thereby optimizing usage of health care resources.

Pincer Morphology Is Not Associated With Hip Osteoarthritis Unless Hip Pain Is Present: Follow-Up Data From a Prospective Cohort Study.

OBJECTIVE: The objective of this study was to assess the relationship between pincer morphology and radiographic hip osteoarthritis (RHOA) over 2, 5, 8, and 10 years' follow-up and to study the interaction between pincer morphology and pain. METHODS: Individuals from the prospective Cohort Hip and Cohort Knee study were drawn. Anteroposterior pelvic and false profile radiographs were obtained. Hips free of definite RHOA (Kellgren and Lawrence [KL] grade 0 or 1) at baseline were included. Pincer morphology was defined as a lateral or anterior center edge angle or both ≥40° at baseline. Incident RHOA was defined as KL ≥ 2 or total hip replacement at follow-up. Multivariable logistic regression with generalized estimating equations estimated the associations at follow-up. Associations were expressed as unadjusted odds ratios (ORs) and adjusted ORs with 95% confidence intervals (CIs). An interaction term was added to investigate whether pincer morphology had a different effect on symptomatic hips. RESULTS: Incident RHOA developed in 69 hips (5%) at 2 years' follow-up, in 178 hips (14%) at 5 years' follow-up, in 279 hips (24%) at 8 years' follow-up, and in 495 hips (42%) at 10 years' follow-up. No significant associations were found between pincer morphology and incident RHOA (adjusted OR 0.35 [95% CI 0.06-2.15]; adjusted OR 1.50 [95% CI 0.94-2.38]). Significant interactions between pain and anterior pincer morphology in predicting incident RHOA were found at 5, 8, and 10 years' follow-up (OR 1.97 [95% CI 1.03-3.78]; OR 3.41 [95% CI 1.35-8.61]). CONCLUSION: No associations were found between radiographic pincer morphology and incident RHOA at any follow-up moment. Anteriorly located pincer morphology with hip pain, however, was significantly associated with incident RHOA. This highlights the importance of studying symptoms and hip morphology simultaneously.

Hip dysplasia as risk factor for clinically relevant and radiographic hip osteoarthritis: 10-year results from the CHECK cohort.

OBJECTIVES: To investigate hip dysplasia as a risk factor for clinically relevant and incident radiographic hip osteoarthritis. METHODS: From a prospective cohort (CHECK) of 1002 middle-aged, new consulters for hip and/or knee pain, 468 hips (251 individuals) were selected based on hip pain, available lateral center edge angle (LCEA) and absence of definite radiographic hip OA (Kellgren and Lawrence grade (KL) <2) at baseline, as well as available follow-up measures. Clinically relevant hip OA was defined by an expert diagnosis based on clinical and radiographic data obtained between year 5-10 from baseline. Incident radiographic hip OA was defined by KL grade ≥2 or a total hip replacement at the 10-year follow-up. Associations between hip dysplasia (LCEA ≤20°) and outcomes were expressed in odds ratios (OR) adjusted for age, sex and BMI. RESULTS: At baseline, participants had a mean age of 55.5 years (SD 5.4), 88% were female and, on hip level, the prevalence of hip dysplasia was 3.6% (n = 17). After 10 years, hip dysplasia was associated with an increased risk for clinically relevant hip OA (OR 2.80 (95% CI 1.15, 6.79), but not for incident radiographic hip OA (OR 0.78 (95% CI 0.26, 2.30)). CONCLUSION: In the long term, baseline hip dysplasia was associated with an increased risk for clinically relevant hip OA, but not for incident radiographic hip OA. With this in mind, we suggest that future research investigating the link between hip dysplasia and OA strive to include a definition for OA that is clinically relevant.

Arthritis Foundation/HSS Workshop on Hip Osteoarthritis, Part 1: Epidemiology, Early Development, and Cohorts From Around the World.

Far more publications are available for osteoarthritis of the knee than of the hip. Recognizing this research gap, the Arthritis Foundation, in partnership with the Hospital for Special Surgery, convened an in-person meeting of thought leaders to review the state of the science of and clinical approaches to hip osteoarthritis. This article summarizes the recommendations and clinical research gaps gleaned from 5 presentations given in the "how hip osteoarthritis begins" session of the 2023 Hip Osteoarthritis Clinical Studies Conference, which took place on February 17 and 18, 2023, in New York City.

Risk Factors and Population-Attributable Fractions for Incident Hip Osteoarthritis.

Background: Despite the huge burden of hip osteoarthritis (OA) and the lack of effective treatment, research into the primary prevention of hip OA is in its infancy. Purpose: We sought to evaluate risk factors for incident clinical and incident radiographic hip OA among middle-aged and older adults, to evaluate the importance of risk factors from a preventive perspective, and to estimate the percentage of new cases attributable to these risk factors. Methods: We retrospectively reviewed data from the Rotterdam study, an open-population cohort study of individuals aged 55 years or older. Data including baseline age, sex, body mass index, smoking status, education level, diagnosis of diabetes, C-reactive protein (CRP), cam morphology, acetabular dysplasia, radiographic thumb OA, radiographic hip OA, and hip pain were assessed for their association with incident clinical hip OA and incident radiographic hip OA separately, after 11 years of follow-up. The population-attributable fractions (PAFs) of statistically significant modifiable risk factors were calculated, as well. Results: New onset of clinical hip OA was seen in 19.9% (544 of 2729) and incident radiographic hip OA in 9.9% (329 of 3309). Female sex, education level below average (PAF 21.4%), and radiographic hip OA (PAF 3.4%) were statistically significantly associated with incident clinical hip OA. Female sex, age, overweight (PAF 20.0%), cam morphology (PAF 7.9%), acetabular dysplasia (PAF 3.6%), and radiographic thumb OA (PAF 4.7%) were statistically significantly associated with radiographic hip OA. Conclusions: Our retrospective analysis suggests that, from a primary prevention perspective, the most important modifiable risk factors among middle-aged and older individuals may be low educational level for incident clinical hip OA and overweight for incident radiographic hip OA. Further study is warranted.

Radiographic assessment of the pubic symphysis in elite male adolescent football players: Development and reliability of the Maturing Adolescent Pubic Symphysis (MAPS) classification.

INTRODUCTION: The pubic symphysis is susceptible to growth related injuries long after the adolescent growth spurt. Our study describes the radiographic maturation of the pubic symphysis on pelvic radiographs in adolescent football players and introduces the Maturing Adolescent Pubic Symphysis classification (MAPS classification). METHODS: Anteroposterior pelvic radiographs of 105 healthy adolescent male football players between 12 and 24 years old were used to develop the classification system. The radiological scoring of the symphyseal joint was developed over five rounds. The final MAPS classification items were scored in random order by two experienced readers, blinded to the age of the participant and to each other's scoring. The inter- and intra-rater reliability were examined using weighted kappa (κ). RESULTS: We developed a classification system with descriptive definitions and an accompanying pictorial atlas. The symphyseal joint was divided into three regions: the superior corners, and the upper and lower regions of the joint line. Inter-rater reliability was substantial to almost perfect: superior region: κ = 0.70 (95% CI 0.60---0.79), upper region of the joint line: κ = 0.89 (95% CI 0.86---0.92), lower region of the joint line: κ = 0.65 (95% CI 0.55---0.75). The intra-observer reliability showed similar results. CONCLUSION: The Maturing Adolescent Pubic Symphysis classification (MAPS classification) is a reliable descriptive classification of the radiographic maturation of the pubic symphysis joint in athletic males. The stages can provide a basis for understanding in clinical practice and will allow future research in this field.

Football Players With Hip Dysplasia: The Relationship Between Muscle Strength, Functional Performance, Self-reported Sport and Recreation, Cartilage Defects, and Sex. A Cross-sectional Study.

OBJECTIVE: In symptomatic football players with hip dysplasia, we aimed to explore the relationships between self-reported sport and recreation ability and (1) hip muscle strength, (2) functional performance, and investigate if these relationships were modified by sex or cartilage defects. METHODS: In this cross-sectional study, football players (n = 50) with longstanding (>6 months) hip and/or groin pain, a positive flexion/adduction/internal rotation test, and a lateral-center-edge angle <25° were included. Hip muscle strength and functional performance were assessed. Self-reported sport and recreation ability was quantified using the sports and recreational subscales from the International Hip Outcome Tool-33 (iHOT-Sport) and the Copenhagen Hip and Groin Outcome Score (HAGOS-Sport). Relationships were evaluated using regression models with sex and cartilage defects as potential effect modifiers. RESULTS: There was a positive linear relationship between the one-leg-rise test and the iHOT-Sport subscale (ß = 0.61; 95% CI: 0.09, 1.14). A polynomial (concave) relationship was found between peak eccentric adduction strength and the HAGOS-Sport subscale (ß = -30.88; 95% CI: -57.78, -3.99). Cartilage defects modified the relationship between peak isometric adduction strength and HAGOS-Sport, with those with cartilage defects having a polynomial (convex) relationship (ß = 36.59; 95% CI: 12.74, 60.45), and those without cartilage defects having no relationship. CONCLUSION: One-leg-rise performance and adduction strength were associated with self-reported sport and recreation ability, indicating a possible relationship between physical function, hip joint structure, and sport and recreation ability in football players with hip dysplasia. J Orthop Sports Phys Ther 2023;53(10):1-8. Epub: 8 September 2023. doi:10.2519/jospt.2023.12026.

Does hip muscle strength and functional performance differ between football players with and without hip dysplasia?

OBJECTIVE: To compare hip muscle strength and functional performance in football players with and without hip dysplasia and investigate if the relationships were modified by sex. DESIGN: Cross-sectional study. METHODS: This study compared football players with hip dysplasia (HD group) and without hip dysplasia (control group). Hip muscle strength (Nm/kg) and functional task performance were assessed in both groups. Linear regression with generalized estimating equations were used to assess differences between groups. Sex was assessed as a potential effect modifier. RESULTS: 101 football players were included (HD group, n = 50, control group, n = 51). There was no difference in hip muscle strength or functional performance between the HD group and the control group. Results ranged from hip extension strength (Estimate -0.13.95%CI: 0.29 to 0.02, P = 0.087) to hip external rotation strength (Estimate 0.00.95%CI: 0.05 to 0.05, P = 0.918). No relationships were modified by sex or age. CONCLUSIONS: Similar levels of hip muscle strength and functional performance were found in active football players with and without hip dysplasia. These findings differ from other studies. This may be due to our cohort having less advanced hip dysplasia than the surgical populations that have been previously investigated, or due to a beneficial effect of football participation on muscle strength and functional performance in people with hip dysplasia.

Cam morphology is strongly and consistently associated with development of radiographic hip osteoarthritis throughout 4 follow-up visits within 10 years.

OBJECTIVE: To determine the association between cam morphology and the development of radiographic hip osteoarthritis (RHOA) at four time points within 10-year follow-up. DESIGN: The nationwide prospective Cohort Hip and Cohort Knee study includes 1002 participants aged 45-65 years with 2-, 5-, 8-, and 10-year follow-ups. The associations of cam morphology (alpha angle >60°) and large cam morphology (alpha angle >78°) in hips free of osteoarthritis at baseline (Kellgren & Lawrence (KL) grade <2) with the development of both incident RHOA (KL grade≥2) and end-stage RHOA (KL grade≥3) were estimated using logistic regression with generalized estimating equation at each follow-up and using Cox regression over 10 years, adjusted for age, sex, and body mass index. RESULTS: Both cam morphology and large cam morphology were associated with the development of incident RHOA at all follow-ups with adjusted Odd Ratios (aORs) ranging from 2.7 (95% Confidence interval 1.8-4.1) to 2.9 (95% CI 2.0-4.4) for cam morphology and ranging from 2.5 (95% CI 1.5-4.3) to 4.2 (95% CI 2.2-8.3) for large cam morphology. For end-stage RHOA, cam morphology resulted in aORs ranging from 4.9 (95% CI 1.8-13.2) to 8.5 (95% CI 1.1-64.4), and aORs for large cam morphology ranged from 6.7 (95% CI 3.1-14.7) to 12.7 (95% CI 1.9-84.4). CONCLUSIONS: Cam morphology poses the hip at 2-13 times increased odds for developing RHOA within a 10-year follow-up. The association was particularly strong for large cam morphology and end-stage RHOA, while the strength of association was consistent over time.

Prevalence and radiological definitions of acetabular dysplasia after the age of 2 years: a systematic review.

Acetabular dysplasia is one of the most common causes of early hip osteoarthritis and hip replacement surgery. Recent literature suggests that acetabular dysplasia does not always originate at infancy, but can also develop later during childhood. This systematic review aims to appraise the literature on prevalence numbers of acetabular dysplasia in children after the age of 2 years. A systematic search was performed in several scientific databases. Publications were considered eligible for inclusion if they presented prevalence numbers on acetabular dysplasia in a general population of healthy children aged 2-18 years with description of the radiological examination. Quality assessment was done using the Newcastle-Ottawa score. Acetabular dysplasia was defined mild when: the center-edge angle of Wiberg (CEA-W) measured 15-20°, the CEA-W ranged between -1 to -2SD for age, or based on the acetabular index using thresholds from the Tönnis table. Severe dysplasia was defined by a CEA-W < 15°, <-2SD for age, or acetabular index according to Tönnis. Of the 1837 screened articles, four were included for review. Depending on radiological measurement, age and reference values used, prevalence numbers for mild acetabular dysplasia vary from 13.4 to 25.6% and for severe acetabular dysplasia from 2.2 to 10.9%. Limited literature is available on prevalence of acetabular dysplasia in children after the age of 2 years. Prevalence numbers suggest that acetabular dysplasia is not only a condition in infants but also highly prevalent later in childhood.

Are hip biomechanics during running associated with symptom severity or cam morphology size in male football players with FAI syndrome?

BACKGROUND: Femoroacetabular impingement (FAI) syndrome is considered a motion-related condition. Little is known about the influence of symptom severity and cam morphology on hip biomechanics for individuals with FAI syndrome. RESEARCH QUESTION: Are hip biomechanics during running associated with symptom severity or cam morphology size in male football players with FAI syndrome? METHODS: Forty-nine male, sub-elite football (soccer or Australian football) players (mean age= 26 years) with FAI syndrome completed the International Hip Outcome Tool-33 (iHOT-33) and Copenhagen Hip and Groin Outcome Score (HAGOS) and underwent radiographic evaluation. Biomechanical data were collected during overground running (3-3.5 m∙s-1) using three-dimensional motion capture technology and an embedded force plate. Various discrete hip angles and impulses of joint moments were analysed during the stance phase. Linear regression models investigated associations between running biomechanics data (dependent variables) and iHOT-33 and HAGOS scores and cam morphology size (independent variables). RESULTS: Hip joint angles during running were not associated with symptom severity in football players with FAI syndrome. A positive association was found between the impulse of the hip external rotation moment and HAGOS-Sport scores, such that a smaller impulse magnitude occurred with a lower HAGOS-Sport score (0.026 *10-2 [95%CI <0.001 *10-2 to 0.051 *10-2], P = 0.048). Larger cam morphology was associated with a greater peak hip adduction angle at midstance (0.073 [95%CI 0.002-0.145], P = 0.045). SIGNIFICANCE: Hip biomechanics during running did not display strong associations with symptom severity or cam morphology size in male football players with FAI syndrome who were still participating in training and match play. Future studies might consider investigating associations during tasks that utilise end range hip joint motion or require greater muscle forces.

A 20 mg dose of dexamethasone does not reduce the proportion of joint replacement patients needing rescue analgesia: a matched cohort study.

Background: Consistent pain control after total joint replacement (TJR) has not yet been reached in all patients managed with a multimodal analgesia regime. Questions remain on dosage and timing of analgesics. Glucocorticoids such as dexamethasone are considered most powerful in reducing the surgery-induced inflammatory response with most pain studies using a 6-12 mg dose. Reviews agree that additional glucocorticoids may provide more analgesia, but a dose-finding analysis is limited. The primary aim of this study was to determine if a high, single preoperative dose of dexamethasone resulted in a reduced need for rescue analgesics during the first 24 hours after TJR when compared to a standard 8 mg dose of dexamethasone. Methods: A cohort study in which 59 patients who received 20 mg dexamethasone intravenously just prior to incision were matched 1:1 to patients who received a standard 8 mg dose. Consecutive elective hip and knee replacement patients managed by one anaesthesiologist were included in the high dose group between June 2019 and March 2020. Patients were matched for arthroplasty type, gender, age, anaesthesia type and pre-operative pain. Patients with opioid use before surgery or with diabetes mellitus were excluded. Oxynorm rescues analgesics (number of times given and dosage) usage during hospitalization was retrieved from the electronic nursing files. Results: There were no significant differences between groups in gender distribution, mean age and body mass index (BMI), in American Society of Anesthesiologists (ASA), type of arthroplasty, anaesthesia type and pre-operative pain score. In the 20 mg group 54 patients (91.5%) needed oxynorm during hospitalization versus 58 (98.3%) in the 8 mg group (P=0.09). High dose group patients received a median of 5 mg [interquartile range (IQR): 0] oxynorm versus 5 mg (IQR: 0) in the standard dose group (P=0.70). Conclusions: In this matched cohort study there was no difference in the proportion of patients needing rescue analgesics during hospitalization between the group of patients who preoperatively received 20 mg dexamethasone and the group of patients who received 8 mg. Future blinded randomized controlled trials are needed to further investigate the effect of different glucocorticoids dosages on pain after joint replacement surgery.

Adding false-profile radiographs improves detection of developmental dysplasia of the hip, data from the CHECK cohort.

The aim of this study was to determine the additional value of the false-profile (FP) view radiograph in the diagnosis of developmental dysplasia of the hip (DDH), as compared with an anteroposterior (AP) pelvic radiograph only, and evaluate the correlation between the Wiberg-lateral center edge angle (W-LCEA) and Wiberg-anterior center edge angle (W-ACEA). We used baseline data from a nationwide prospective cohort study (Cohort Hip and Cohort Knee). DDH was quantified on AP pelvic and FP hip radiographs using semi-automatic measurements of the W-LCEA and W-ACEA. A threshold of <20° was used to determine DDH for both the W-LCEA and the W-ACEA. The proportion of DDH only present on the FP view determined the FP view additional value. The correlation between the W-LCEA and W-ACEA was determined. In total 720 participants (1391 hips) were included. DDH was present in 74 hips (5.3%), of which 32 were only present on the FP view radiograph (43.2%). The Pearson correlation coefficient between W-LCEA and W-ACEA of all included hips was 0.547 (95% confidence interval: 0.503-0.591) and 0.441 (95% confidence interval: 0.231-0.652) in hips with DDH. A mean difference of 9.4° (SD 8.09) was present between the W-LCEA and the W-ACEA in the hips with DDH. There is a strong additional value of the FP radiograph in the diagnosis of DDH. Over 4 out of 10 (43.2%) individuals' DDH will be missed when only using the AP radiograph. In hips with DDH a moderate correlation between W-LCEA and W-ACEA was calculated indicating that joints with normal acetabular coverage on the AP view can still be undercovered on the FP view.

A prospective cohort study on cam morphology and its role in progression of osteoarthritis.

BACKGROUND: Cam morphology contributes to the development of hip osteoarthritis (OA) but is less studied in the general population. This study describes its associations with clinical and imaging features of hip OA. METHODS: Anteroposterior hip radiographs of 1019 participants from the Tasmanian Older Adult Cohort (TASOAC) were scored at baseline for α angle (cam morphology) in both hips. Using the Altman's atlas, radiographic hip OA (ROA) was assessed at baseline. Hip pain and right hip structural changes were assessed on a subset of 245 magnetic resonance images (MRI) at 5 years. Joint registry data for total hip replacement (THR) was acquired 14 years from baseline. RESULTS: Of 1906 images, cam morphology was assessed in 1016 right and 890 left hips. Cross-sectionally, cam morphology modestly associated with age (prevalence ratio [PR]: 1.02 P = .03) and body mass index (BMI) (PR: 1.03-1.07, P = .03) and strongly related to male gender (PR: 2.96, P < .001). Radiographically, cam morphology was prevalent in those with decreased joint space (PR: 1.30 P = .03) and osteophytes (PR: 1.47, P = .03). Longitudinally, participants with right cam and high BMI had more hip pain (PR: 17.9, P = .02). At the end of 5 years of follow-up these participants were also more likely to have structural changes such as bone marrow lesions (BMLs) (PR: 1.90 P = .04), cartilage defects (PR: 1.26, P = .04) and effusion-synovitis at multiple sites (PR: 1.25 P = .02). Cam morphology at baseline in either hip predicted up to threefold risk of THR (PR: 3.19, P = .003) at the end of 14 years. CONCLUSION: At baseline, cam morphology was linked with age, higher weight, male gender, early signs of radiographic OA such as joint space narrowing (JSN) and osteophytes (OST). At follow-up, cam predicted development of hip BMLs, hip effusion-synovitis, cartilage damage and THR. These findings suggest that cam morphology plays a significant role in early OA and can be a precursor or contribute to hip OA in later life.

Does Femoroacetabular Impingement Syndrome Affect Self-Reported Burden in Football Players With Hip and Groin Pain?

BACKGROUND: It is unknown if football players with femoroacetabular impingement (FAI) syndrome report worse burden than those with other causes of hip/groin pain, and to what extent this is mediated by cartilage defects and labral tears. HYPOTHESIS: Football players with FAI syndrome would report worse burden than other symptomatic players, with the effect partially mediated by cartilage defects and/or labral tears. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 4. METHODS: Football (soccer and Australian football) players (n = 165; 35 women) with hip/groin pain (≥6 months and positive flexion-adduction-internal rotation test) were recruited. Participants completed 2 patient-reported outcome measures (PROMs; the International Hip Outcome Tool-33 [iHOT-33] and Copenhagen Hip and Groin Outcome Score [HAGOS]) and underwent hip radiographs and magnetic resonance imaging (MRI). FAI syndrome was determined to be present when cam and/or pincer morphology were present. Cartilage defects and labral tears were graded as present or absent using MRI. Linear regression models investigated relationships between FAI syndrome (dichotomous independent variable) and PROM scores (dependent variables). Mediation analyses investigated the effect of cartilage defects and labral tears on these relationships. RESULTS: FAI syndrome was not related to PROM scores (unadjusted b values ranged from -4.693 (P = 0.23) to 0.337 (P = 0.93)) and cartilage defects and/or labral tears did not mediate its effect (P = 0.22-0.97). CONCLUSION: Football players with FAI syndrome did not report worse burden than those with other causes of hip/groin pain. Cartilage defects and/or labral tears did not explain the effect of FAI syndrome on reported burden. CLINICAL RELEVANCE: FAI syndrome, cartilage defects, and labral tears were prevalent but unrelated to reported burden in symptomatic football players.

Are cam morphology size and location associated with self-reported burden in football players with FAI syndrome?

Cam morphology size and location might affect the severity of reported burden in people with femoroacetabular impingement (FAI) syndrome. We investigated the relationship between cam morphology size (i.e., alpha angle) and self-reported hip/groin burden (i.e., scores for the International Hip Outcome Tool-33 (iHOT-33) and Copenhagen Hip and Groin Outcome Score (HAGOS)), examined separately for the anteroposterior pelvis (AP) and Dunn 45° radiographs in football players with FAI syndrome. In total, 118 (12 women) subelite football (soccer or Australian football) players with FAI syndrome with cam morphology (alpha angle ≥60°) participated. One blinded assessor quantified superior and anterosuperior cam morphology size by measuring alpha angles for the AP and Dunn 45° radiographs, respectively. Linear regression models investigated relationships between alpha angle (continuous independent variable, separately measured for the AP and Dunn 45° radiographs) and iHOT-33 and HAGOS scores (dependent variables). Larger anterosuperior cam morphology (seen on the Dunn 45° radiograph) was associated with lower (i.e., worse) scores for the iHOT-Total, iHOT-Symptoms, iHOT-Job, and iHOT-Social subscales (unadjusted estimate range -0.553 to -0.319 [95% confidence interval -0.900 to -0.037], p = 0.002 to 0.027), but not the iHOT-Sport (p = 0.459) nor any HAGOS scores (p = 0.110 to 0.802). Superior cam morphology size (measured using the AP radiograph) was not associated with any iHOT-33 or HAGOS scores (p = 0.085 to 0.975). Larger anterosuperior cam morphology may be more relevant to pain and symptoms in football players with FAI syndrome than superior cam morphology, warranting investigation of its effects on reported burden and hip disease over time.

The Size and Prevalence of Bony Hip Morphology Do Not Differ Between Football Players With and Without Hip and/or Groin Pain: Findings From the FORCe Cohort.

OBJECTIVE: To compare the size and prevalence of bony hip morphology in football players with and without hip and/or groin pain. DESIGN: Case-control. METHODS: We recruited 184 soccer and Australian football players with self-reported hip and/or groin pain of greater than 6 months in duration and a positive flexion, adduction, and internal rotation (FADIR) test (290 hips, 21% women), and 55 football players with no pain and a negative FADIR test (110 hips, 26% women) as a control group. Bony hip morphology was identified by the alpha angle and lateral center-edge angle (LCEA) on anteroposterior pelvis and Dunn 45° radiographs. The alpha angle and LCEA were analyzed as continuous measures (size) and dichotomized using threshold values to determine the presence of bony hip morphology (cam, large cam, pincer, and acetabular dysplasia). Regression analyses estimated differences in the size and prevalence of bony hip morphology between football players with and without pain. RESULTS: In all football players and in men, the size and prevalence of bony hip morphology did not differ between those with and without hip and/or groin pain. Cam morphology was evident in 63% of hips in players without pain and 71% of symptomatic hips in players with hip and/or groin pain. In female football players with hip and/or groin pain compared to those without pain, larger alpha angle values were observed on the Dunn 45° view (5.9°; 95% confidence interval: 1.2°, 10.6°; P = .014). CONCLUSION: The size and prevalence of bony hip morphology appear to be similar in football players with and without hip and/or groin pain. J Orthop Sports Phys Ther 2021;51(3):115-125. Epub 25 Dec 2020. doi:10.2519/jospt.2021.9622.