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.

Physical impairments in Adults with Developmental Dysplasia of the Hip (DDH) undergoing Periacetabular osteotomy (PAO): A Systematic Review and Meta-Analysis.

Background: Developmental dysplasia of the hip (DDH) is a condition associated with hip pain and impairments. Periacetabular osteotomy (PAO) is a common surgical treatment for DDH. Outcomes following PAO have historically been based on radiology or patient reported outcomes, and not physical impairments. Objective: To investigate differences in physical impairments in adults with DDH undergoing PAO compared with asymptomatic participants, and to investigate pre- to post-PAO changes in physical impairments. Design: Systematic review with meta-analysis. Methods: A literature search was performed in five databases (MEDLINE, CINAHL, EMBASE, Sports Discuss, and PsychINFO), using the PRISMA checklist. Studies were considered eligible if patients were aged 15 years and older, treated with PAO for DDH and if they included a physical impairment outcome measure. Two independent reviewers performed data extraction and assessed methodological quality, using a modified version of the Downs and Black checklist. Results: Of 5,017 studies, 24 studies were included with 2190 patients. The methodological quality scores ranged from 39% to 88%. With low level of evidence, meta-analysis showed 58% of patients had a positive anterior impingement test (95%CI: 39-76%), prior to PAO and one to three years after PAO. Five years after PAO, the proportion fell to 17% (95%CI: 11-24%). Prior to PAO, patients with DDH walked with a lower peak hip extension angle, compared to asymptomatic participants (SMD 0.65 (95%CI 0.21-1.10). Best evidence synthesis of non-pooled data showed limited evidence of increased walking velocity, stride length and improved hip flexion and extension moment 18-months post-PAO compared to pre-op. Cadence, hip abduction and hip flexion strength did not change. Conclusion: Most patients with DDH have a positive hip impingement test, pre-PAO. Compared to asymptomatic participants, patients with DDH demonstrate physical impairments during walking which appear to improve after surgery. Hip abduction and flexion strength did not change pre- to post-PAO. Level of Evidence: 1b.

Feasibility and acceptability of a six-month exercise and patient education intervention for patients with hip dysplasia: A mixed methods study.

BACKGROUND AND OBJECTIVES: To evaluate the feasibility and acceptability of exercise and patient education for patients with hip dysplasia not receiving surgery. DESIGN: Feasibility study. METHODS: The participants received exercise instruction and patient education over six months. Feasibility covered recruitment, retention, and mechanisms of change (MC). MC were measured with Hip and Groin Outcome Score (HAGOS), muscle strength tests, Y-balance test, and hop for distance test (HDT) over six months. Acceptability covered adherence, expectations, perceptions, benefits, and harms. RESULTS: Thirty of 32 were recruited (median age: 30 years); six were lost to follow-up. Twenty-four participants improved by a mean of 11 (95%CI: 5-17) HAGOS pain points, improvements in all subscales were 1-11 points. Mean hip abduction strength improved 0.2 (95%CI: 0.04-0.4) Nm/kg, similar to flexion and extension. Median Y-balance test improvements: anterior: 70 (IQR: 64-74) to 75 (IQR: 72-80) centimetres; posteromedial: 104 (IQR: 94-112) to 119 (IQR: 112-122) centimetres and posterolateral: 98 (IQR: 89-109) to 116 (IQR: 108-121) centimetres (p < .001). Median improvement in HDT was: 37 (IQR: 30-44) to 52 (IQR: 45-58) centimetres (p < .001). Participants adhered to 84% of scheduled sessions (1,581:1,872), expectations were met, and perceptions were characterized by high self-efficacy for exercise. Benefits were reported with no serious harms. CONCLUSION: Patients with hip dysplasia are willing to be recruited for exercise and patient education, with acceptable retention. MC were observed through improvements in pain, strength and function with high acceptance of the exercise and patient education intervention. Thus, it seems feasible to conduct a full-scale randomised controlled trial.

Do changes in outcomes following primary and revision hip replacement differ and relate to markers of socioeconomic status? A 1-year population-based cohort study.

BACKGROUND AND PURPOSE: There is little evidence on improvement after revision total hip replacement (THR). Moreover, improvements may be associated with socioeconomic status (SES). We investigated whether changes in Harris Hip Score (HHS) differ among patients undergoing primary and revision THR, and their association with markers of SES. PATIENTS AND METHODS: We conducted a populationbased cohort study on 16,932 patients undergoing primary and/or revision THR from 1995 to 2018 due to hip osteoarthritis. The patients were identified in the Danish Hip Arthroplasty Registry. Outcome was defined as mean change in HHS (0-100) from baseline to 1-year follow-up, and its association with SES markers (education, cohabiting, and wealth) was analyzed using multiple linear regression adjusting for sex, age, comorbidities, and baseline HHS. RESULTS: At 1-year follow-up, HHS improved clinically relevant for patients undergoing both primary THR: mean 43 (95% CI 43-43) and revision THR: mean 31 (CI 29-33); however, the increase was 12 points (CI 10-14) higher for primary THR. For primary THR, improvements were 0.9 points (CI 0.4-1.5) higher for patients with high educational level compared with low educational level, 0.4 points (CI 0.0-0.8) higher for patients cohabiting compared with living alone, and 2.6 points higher (CI 2.1-3.0) for patients with high wealth compared with low wealth. INTERPRETATION: Patients undergoing primary THR achieve higher improvements on HHS than patients undergoing revision THR, and the improvements are negatively related to markers of low SES. Health professionals should be aware of these characteristics and be able to identify patients who may benefit from extra rehabilitation to improve outcomes after THR to ensure equality in health.

Does Daily Physical Activity Differ Between Patients with Femoroacetabular Impingement Syndrome and Patients with Hip Dysplasia? A Cross-Sectional Study in 157 Patients and 60 Healthy Volunteers.

BACKGROUND: The clinical presentation of femoroacetabular impingement syndrome (FAIS) and acetabular hip dysplasia (HD) are similar. However, the groups seem to differ regarding physical activity (PA) and sport. PURPOSE: The aim was to compare PA between three groups; patients with FAIS, patients with HD, and healthy volunteers. A secondary purpose was to compare self-reported function in sport and recreation (sport/recreation) between patients with FAIS and HD. STUDY DESIGN: This study is a cross-sectional study on 157 patients with FAIS or HD and 60 healthy controls. METHODS: PA was measured with accelerometer-based sensors, and sport/recreation was measured with the Copenhagen Hip and Groin Outcome Score (HAGOS). Data on patients with FAIS or HD and healthy volunteers were collected in other studies and merged for comparison in this study. RESULTS: Fifty-five patients with FAIS (20 males; mean age 36 years), 97 patients with HD (15 males; mean age 30 years) and 60 healthy volunteers (24 males; mean age 31 years) were included. Compared with patients with HD, patients with FAIS spent more time on very low intensity PA (mean 73 minutes (95% CI: 45;102)) and less time on low intensity PA per day (mean -21 minutes (95% CI: -37;-6)). Both groups spent less time on high intensity PA per day compared with healthy volunteers (p≤0.03). However, sport/recreation did not differ between the two groups (FAIS: median 34 points (IQR: 22;50) and HD: median 38 points (IQR: 25;53), p=0.16). CONCLUSION: Patients with FAIS appear to be less physical active compared with patients with HD. However, both groups seem to perform less high intensity PA compared with healthy volunteers. This is interesting, as self-reported function in sport/recreation does not differ between patients with FAIS and HD. Thus, high intensity PA seems to be a key outcome in the management of patients with FAIS and HD. LEVEL OF EVIDENCE: Level 2b.

Hypermobility among patients with greater trochanteric pain syndrome.

INTRODUCTION: Greater trochanteric pain syndrome (GTPS) is a common and disabling hip condition. Hypermobility has been suggested as a possible cause of GTPS. The purpose of this study was to report the prevalence of hypermobility and to investigate its impact on hip-related function and awareness in patients with GTPS. METHODS: This cross-sectional study was based on a cohort of patients diagnosed with GTPS in the 2013-2015 period. Hypermobility was investigated with the Beighton Score and defined by a cut-off score ≥ 5. Data on patients' current hip function and awareness were collected with the questionnaires the Copenhagen Hip and Groin Outcome Score and the Forgotten Joint Score. RESULTS: A total of 612 patients with GTPS were identified based on the diagnosis system; out of those, 390 patients were assessed for eligibility, and 145 (37%) were included. The prevalence of hypermobility within this cohort was estimated to be 11% (95% confidence interval (CI): 3-26%) for males and 25% (95% CI: 17-34%) for females. No significant association was found between hypermobility and self-reported hip function and awareness. CONCLUSIONS: The prevalence of hypermobility in patients with GTPS was high, but the prevalence of hypermobility did not influence hip function and awareness. The results were based on a very low response rate and should be interpreted with this in mind. FUNDING: none. TRIAL REGISTRATION: not relevant.

Isokinetic dynamometry and gait analysis reveal different hip joint status in patients with hip dysplasia.

BACKGROUND:: Objective assessment of hip dysplasia patients' functional hip joint status routinely involves gait analysis or isokinetic dynamometry. However, these methods have shown equivocal results and have not been employed in the same groups of patients and controls. PURPOSE:: To assess hip flexor and abductor moments by isokinetic dynamometry in the dysplasia patient and controls, for which we previously reported smaller flexor and slightly larger abductor moments during gait in patients compared to controls. METHODS:: The study was designed as a prospective cohort study (Level of Evidence II) and conducted in a biomechanics laboratory at Aarhus University, Denmark, during 2011. Participants comprised 32 dysplasia patients and 32 age and gender matched controls. Outcome measures were static peak hip flexion moment at 15, 45 and 75° hip flexion; dynamic eccentric and concentric peak hip flexion moment at 60° and 120°/second; dynamic eccentric and concentric hip abductor moment at 30° and 60°/second. RESULTS:: Hip dysplasia patients had smaller eccentric peak flexion moments and smaller eccentric and concentric peak abduction moments at all tested velocities. CONCLUSION:: Although dysplasia patients have weaker hip flexion and abductor muscles than controls, their abductor muscles are sufficiently strong to ensure normal function during gait. Hence, gait analysis alone might not reveal the true, subnormal hip joint status in dysplasia patients. We suggest that comprehensive assessment of hip joint function in dysplasia patients should include more strenuous activities than gait, particularly in young(er) patients who are likely to prefer a more active lifestyle.

Progressive resistance training in patients with hip dysplasia: A feasibility study.

OBJECTIVES: To examine whether progressive resistance training is feasible in patients with symptomatic hip dysplasia scheduled for periacetabular osteotomy. A secondary objective was to investigate patient-reported outcomes, functional performance and hip muscle strength. DESIGN: Feasibility study. PATIENTS AND METHODS: Seventeen patients (median age 28 years, range 22-40 years) performed 8 weeks (20 sessions) of supervised sessions of progressive resistance training. Training-adherence, number of dropouts and adverse events, and visual analogue scale scores on pain were registered. Patients completed the Hip and Groin Outcome Score, performed 2 hop-tests, and hip peak torque was assessed by isokinetic dynamometry. RESULTS: Training-adherence was 90.3±9%. Few and minor adverse events were observed, one patient dropped out and acceptable pain levels were reported during the intervention. Scores on 4 out of 6 subscales on patient-reported outcome improved (p <0.05), as did standing distance jump (12.2%, 95% confidence interval (CI) [1.3, 23.0]), countermovement jump (25.1%, 95% CI [1.3, 48.8]). Isokinetic concentric hip flexion peak torque showed significant improvements (16.6%, 95% CI [4.6, 28.6]) on the affected side while isometric hip flexion (10.9%, 95% CI [0.3, 21.6]) improved on the non-affected side. CONCLUSION: Supervised progressive resistance training is feasible in patients with hip dysplasia. The intervention may improve pain levels, patient-reported outcomes, functional performance and hip flexion muscle strength.

Joint kinematics and kinetics during walking and running in 32 patients with hip dysplasia 1 year after periacetabular osteotomy.

BACKGROUND AND PURPOSE: Hip dysplasia can be treated with periacetabular osteotomy (PAO). We compared joint angles and joint moments during walking and running in young adults with hip dysplasia prior to and 6 and 12 months after PAO with those in healthy controls. PATIENTS AND METHODS: Joint kinematics and kinetics were recorded using a 3-D motion capture system. The pre- and postoperative gait characteristics quantified as the peak hip extension angle and the peak joint moment of hip flexion were compared in 23 patients with hip dysplasia (18-53 years old). Similarly, the gait patterns of the patients were compared with those of 32 controls (18-54 years old). RESULTS: During walking, the peak hip extension angle and the peak hip flexion moment were significantly smaller at baseline in the patients than in the healthy controls. The peak hip flexion moment increased 6 and 12 months after PAO relative to baseline during walking, and 6 months after PAO relative to baseline during running. For running, the improvement did not reach statistical significance at 12 months. In addition, the peak hip extension angle during walking increased 12 months after PAO, though not statistically significantly. There were no statistically significant differences in peak hip extension angle and peak hip flexion moment between the patients and the healthy controls after 12 months. INTERPRETATION: Walking and running characteristics improved after PAO in patients with symptomatic hip dysplasia, although gait modifications were still present 12 months postoperatively.

The gait pattern is not impaired in subjects with external snapping hip: a comparative cross-sectional study.

BACKGROUND: Symptomatic external snapping hip is a painful condition, where pain in the trochantor region and limitations of daily activity dominate clinical findings. The aetiology of symptomatic external snapping hip is elusive, but previous studies have suggested that weakness of the hip abductors and an altered walking pattern may play a role in the development of symptomatic external snapping hip. The aim of this study was to compare the walking pattern and muscular activity of the hip muscles between subjects with symptomatic external snapping hip and healthy subjects. METHODS: Thirteen subjects with diagnosed symptomatic external snapping hip (age: 25.5 years) were matched with 13 healthy subjects (age: 25.6 years). Joint kinematics and kinetics of the lower extremity were quantified by the peak hip adduction angle; the average knee rotation range of motion (ROM) and the peak valgus knee angle after data recording using a Vicon 612 motion capture system. Muscle activity was recorded bilaterally using surface electromyography (sEMG) on five muscles: gluteus maximus, gluteus medius, tensor fascia latae, rectus femoris and biceps femoris. A paired t-test was used to evaluate differences between the two groups. RESULTS: No significant differences were found between the groups concerning the peak hip adduction angle, the average knee rotation ROM, and the static valgus knee angle. No significant between-group differences were found concerning all other kinematics, kinetics or muscle activity. In subjects with symptomatic external snapping hip activity of the gluteus medius muscle during the acceptance phase of walking was 0.58 ± 0.19 whereas the activity was 0.68±0.07 in the asymptomatic group (p=0.115). CONCLUSIONS: No significant differences in the walking pattern were found between subjects with symptomatic external snapping hip and healthy subjects. This suggest that subjects with symptomatic external snapping hip does not have an impaired gait pattern.

Changes in walking and running in patients with hip dysplasia.

BACKGROUND AND PURPOSE: Earlier studies have suggested that the hip extension angle and the hip flexor moment in walking are affected by hip dysplasia, but to our knowledge there have been no reports on running or evaluations of self-reported health. We evaluated differences in walking, running, and self-reported health between young adults with symptomatic hip dysplasia and healthy controls. PATIENTS AND METHODS: Walking and running in 32 patients with hip dysplasia, mean 34 (18-53) years old, was compared with walking and running in 32 controls, mean 33 (18-54) years old. Joint kinematics and kinetics-quantified by the peak hip extension angle and the peak net joint moment of hip flexion during walking and running-were recorded using a motion-capture system, and health was evaluated using the Copenhagen Hip and Groin Outcome Score (HAGOS). RESULTS: The peak hip extension angle during walking was less in the patients than in the controls (-10.4 (SD 4.8) degrees vs. -13.2 (SD 4.5) degrees; p = 0.02). Similarly, the peak net joint moment of hip flexion during walking was lower in the patients than in the controls (0.57 (SD 0.13) N*m/kg vs. 0.70 (SD 0.22) N*m/kg; p = 0.008). In all dimensions of HAGOS, the patients scored lower than the controls. Furthermore, the hip extension angle and the net joint moment of hip flexion correlated with the HAGOS subscales pain and physical function in sport and recreation. INTERPRETATION: Patients with symptomatic hip dysplasia do modify walking and running, and we therefore suggest that the impairment found in this study should play an important role in the evaluation of later operative and training interventions.