Association between hip muscle strength/function and hip cartilage defects in sub-elite football players with hip/groin pain.

OBJECTIVE: To explore associations between hip muscle strength and cartilage defects (presence and severity) on magnetic resonance imaging (MRI) in young adults with hip/groin pain participating in sub-elite football. DESIGN: Sub-elite football players with hip/groin pain (>6 months) completed assessments of isometric hip strength and functional task performance. Hip cartilage defects were assessed using the Scoring Hip Osteoarthritis with MRI tool. This exploratory, cross-sectional study used logistic and negative binomial models to assess the relationships between hip muscle strength or functional task performance and hip cartilage defects, controlling for body mass index, age, testing site and cam morphology, incorporating sex-specific interaction terms. RESULTS: One hundred and eighty-two (37 women) sub-elite (soccer or Australian football) players with hip/groin pain (age 26 ± 7 years) were included. Greater hip extension strength was associated with higher cartilage total score (adjusted incidence rate ratio [aIRR] 1.01, 95%CI: 1.0 to 1.02, p = 0.013) and superolateral cartilage score (adjusted odds ratio (aOR) 1.03, 95% confidence interval (CI): 1.01 to 1.06, p < 0.01). In female sub-elite football players, greater hip external rotation strength was associated with lateral cartilage defects (aOR 1.61, 95%CI: 1.05 to 2.48, p = 0.03) and higher cartilage total score (aIRR 1.25, 95%CI: 1.01 to 1.66, p = 0.042). A one-repetition increase in one-leg rise performance was related to lower odds of superomedial cartilage defects (aOR 0.96, 95%CI: 0.94 to 0.99, p < 0.01). CONCLUSIONS: Overall, there were few associations between peak isometric hip muscle strength and overall hip cartilage defects. It is possible that other factors may have relevance in sub-elite football players. Additional studies are needed to support or refute our findings that higher one leg rise performance was associated with reduced superomedial cartilage defect severity and greater hip extension strength was related to higher cartilage defect severity scores.

The association between hip/groin pain and hip strength in football players: An exploratory analysis of the FORCe cohort.

OBJECTIVES: Explore associations between peak hip strength in football players with hip/groin pain and healthy controls. DESIGN: Cross-sectional study. METHODS: Male and female sub-elite football players (soccer and Australian football) with hip/groin pain >6-month duration and players without hip/groin pain were recruited across Melbourne and Brisbane, Australia. Demographic information and two questionnaires; the Copenhagen Hip and Groin Outcome Score and the International Hip Outcome Tool 33 were collected. Hand-held dynamometry was used to measure isometric hip strength for flexion, extension, abduction, adduction, internal rotation, and external rotation. Linear mixed effects models were used to compare strength measures between groups. RESULTS: 190 football players with hip/groin pain (mean ±â€¯standard deviation age, 27.8 ±â€¯6.3 years) and 64 controls (age, 27.3 ±â€¯5.6 years) were included in this study. Of these, 291 symptomatic limbs and 128 control limbs were used for analyses. Symptomatic players had lower peak hip adduction (adjusted mean difference = -0.18: 95 % confidence interval -0.27 to -0.08, P : 0.001), external rotation (-0.06: 95 % confidence interval -0.09 to -0.02, P : 0.003), and internal rotation strength (-0.06: 95 % confidence interval -0.10 to -0.03, P : 0.001) compared to controls. A sport-specific interaction was observed for hip abduction strength. When separated by football code, abduction strength was lower in symptomatic Australian football players compared to their same sport peers (-0.20: 95 % confidence interval -0.33 to -0.06, P : 0.004), but not in symptomatic soccer players (-0.05: 95 % confidence interval -0.15 to 0.06, P : 0.382). CONCLUSIONS: Hip adduction, internal rotation, and external rotation strength appears lower in football players with hip/groin pain independent of sex and football code. Hip abduction strength was lower in symptomatic Australian football players but not in soccer players.

Is running good or bad for your knees? A systematic review and meta-analysis of cartilage morphology and composition changes in the tibiofemoral and patellofemoral joints.

BACKGROUND: The general health benefits of running are well-established, yet concern exists regarding the development and progression of osteoarthritis. AIM: To systematically review the immediate (within 20 min) and delayed (20 min-48 h) effect of running on hip and knee cartilage, as assessed using magnetic resonance imaging (MRI). METHOD: Studies using MRI to measure change in hip or knee cartilage within 48 h pre- and post-running were identified. Risk of bias was assessed using a modified Newcastle-Ottawa Scale. Percentage change in cartilage outcomes were estimated using random-effects meta-analysis. Certainty of evidence was evaluated with the Grading of Recommendations Assessment, Development and Evaluation tool. RESULTS: Twenty-four studies were included, evaluating 446 knees only. One third of studies were low risk of bias. Knee cartilage thickness and volume decreased immediately after running, with declines ranging from 3.3% (95% confidence interval [CI]: 2.6%, 4.1%) for weight-bearing femoral cartilage volume to 4.9% (95% CI: 4.43.6%, 6.2%) for patellar cartilage volume. T1ρ and T2 relaxation times were also reduced immediately after running, with the largest decline being 13.1% (95% CI: -14.4%, -11.7%) in femoral trochlear cartilage. Tibiofemoral cartilage T2 relaxation times recovered to baseline levels within 91 min. Existing cartilage defects were unchanged within 48 h post-run. CONCLUSIONS: There is very low certainty evidence that running immediately decreases the thickness, volume, and relaxation times of patellofemoral and tibiofemoral cartilage. Hip cartilage changes are unknown, but knee changes are small and appear transient suggesting that a single bout of running is not detrimental to knee cartilage.

The association between statistical shape modeling-defined hip morphology and features of early hip osteoarthritis in young adult football players: Data from the femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study.

Objective: To explore the relationship between radiographic hip shape and features of early hip osteoarthritis (OA) on magnetic resonance imaging (MRI) in young male and female football players without radiographic hip OA. Design: We used baseline data from a cohort of symptomatic and asymptomatic football players aged 18-50 years. Hip shape was assessed on anteroposterior radiographs with statistical shape modeling (SSM) for men and women separately. Cartilage defects and labral tears were graded using the Scoring Hip Osteoarthritis with MRI (SHOMRI) system. We used logistic regression with generalized estimating equations to estimate associations between each hip shape variant, called shape modes, and cartilage defects or labral tears. Results: We included 229 participants (446 hips, 77.4% male). For each sex, 15 shape modes were analyzed. In men, three shape modes were associated with cartilage defects: adjusted odds ratios (aOR) 0.75 (95%CI 0.58-0.97) per standard deviation (SD) for mode 1; 1.34 (95%CI 1.05-1.69) per SD for mode 12; and 0.61 (95%CI 0.48-0.78) per SD for mode 15; and one also with labral tears: aOR 1.30 (95%CI 1.01-1.69) per SD for mode 12. These modes generally represented variations in the femoral neck and subtypes of cam morphology, with and without pincer morphology. For women, there was no evidence for associations with the outcomes. Conclusions: Several hip shape variants were associated with cartilage defects on MRI in young male football players. Specifically, one subtype of cam morphology was associated with both cartilage defects and labral tears. Hip shape was not associated with early OA features in women.

Does land-based exercise-therapy improve physical activity in people with knee osteoarthritis? A systematic review with meta-analyses.

PRIMARY OBJECTIVE: Investigate the effects of land-based exercise-therapy on physical activity in people with knee osteoarthritis (KOA). DESIGN: Systematic review and meta-analysis of randomised or quasi-randomised trials investigating land-based exercise-therapy on physical activity, fitness, and general health in people with KOA. We updated a 2013 Cochrane review search on exercise-therapy for KOA in April 2021 and applied the Cochrane Risk-of-Bias Tool 1.0 to included articles. Standardised mean differences (SMDs) and 95% confidence intervals (CI) were calculated. GRADE was used to assess certainty of the evidence. RESULTS: Twenty-eight randomised controlled trials (2,789 participants) evaluating the effects of resistance-training (n = 10), walking (n = 6) and mixed-exercise programs (n = 7) were identified. Low to moderate certainty evidence indicated small increases in physical activity for exercise-therapy compared to non-exercise interventions in the short-term (SMD, 95% CI = 0.29, 0.09 to 0.50), but not the medium- (0.03, -0.11 to 0.18) or long-term (-0.06, -0.34 to 0.22). Low certainty evidence indicated large increases in physical activity for walking programs (0.53, 0.11 to 0.95) and mixed-exercise programs (0.67, 0.37 to 0.97) compared to non-exercise interventions in the short-term. Low certainty evidence indicated moderate and small increases in physical activity for resistance-training combined with education focused on pain coping skills and self-efficacy compared to education alone at medium-term follow-up (0.45, 0.19 to 0.71). CONCLUSION: Walking and mixed-exercise, but not resistance-training, may improve physical activity in people with KOA in the short-term. Combining resistance-training with education may increase physical activity in the medium-, but not the long-term, highlighting the potential importance of developing more effective longer-term interventions for people with KOA. Future studies evaluating land-based exercise-therapy are encouraged to include physical activity outcomes and longer-term follow-up to increase the certainty of evidence.

Should return to pivoting sport be avoided for the secondary prevention of osteoarthritis after anterior cruciate ligament reconstruction? A prospective cohort study with MRI, radiographic and symptomatic outcomes.

OBJECTIVE: To evaluate if returning to pivoting sport following anterior cruciate ligament reconstruction (ACLR) is associated with longitudinal structural and symptomatic osteoarthritis outcomes. DESIGN: Eighty-one adults aged 18-50 years were followed prospectively 1- to 5-years post-ACLR. Return to pivoting sport was assessed at 1-, 3- and 5-years. Longitudinal changes in osteoarthritis features were evaluated from 1- and 5-year magnetic resonance imaging (MRI)s using MRI Osteoarthritis Knee Score (MOAKS). Radiographic osteoarthritis and self-reported knee symptoms, function and quality of life were assessed using the Osteoarthritis Research Society International (OARSI) atlas and Knee injury Osteoarthritis Outcome Score (KOOS), respectively, at 5 years post-ACLR. Generalised linear models (adjusted for baseline characteristics) assessed whether returning to pivoting sport was associated with risk of worsening osteoarthritis features on MRI, radiographic osteoarthritis and KOOS. RESULTS: Thirty participants returned to pivoting sport 1-year post-ACLR and 50 returned at any time (i.e., 1-, 3- or 5-years). Returning to pivoting sport was not associated with worsening of any MRI osteoarthritis feature (risk ratio (RR) range: 0.59-2.91) or 5-year KOOS (ß range: -2.73-3.69). Returning to pivoting sport at 1-year and up to 5-years post-ACLR was associated with a 50% (RR 0.49, 95%CI 0.10-2.37) and 40% (RR 0.60, 95%CI 0.16-2.17) reduced risk of radiographic osteoarthritis, respectively, but these risk reductions were inconclusive due to wide confidence intervals. CONCLUSION: After ACLR, returning to pivoting sport was not associated with increased risk of worsening knee osteoarthritis features on MRI, radiographic osteoarthritis or knee symptoms. Participation in pivoting sport need not be avoided as part of osteoarthritis secondary prevention strategies.

Immediate outcomes following the GLA:D® program in Denmark, Canada and Australia. A longitudinal analysis including 28,370 patients with symptomatic knee or hip osteoarthritis.

OBJECTIVE: To report outcomes across three countries for patients with symptomatic knee or hip OA attending the evidence-based education and exercise therapy program Good Life with osteoArthritis from Denmark (GLA:D®). DESIGN: GLA:D® is a structured treatment program including 2-3 patient education sessions and 12 supervised exercise sessions delivered over 8 weeks by certified health care practitioners. The program was introduced in Denmark in 2013, in Canada 2015 and in Australia 2016. Absolute mean change in pain intensity, number of chair stands in 30 s, 40 m walk test time and Knee injury and Osteoarthritis Outcome Score (KOOS)/Hip dysfunction and Osteoarthritis Outcome Score (HOOS) QOL subscale scores from baseline to immediately after treatment were reported as means and 95 % CIs and proportion of responders for each country. RESULTS: Patients from the three countries improved 26-33% in mean pain intensity, 8-12% in walking speed, 18-30% in chair stand ability and 12-26% in joint-related quality of life from baseline to immediately after treatment, with no clinically relevant differences between patients with hip and knee OA. These improvements correspond with moderate to large within-group effect sizes and 43-47 % of the patients experienced clinically relevant pain reductions. CONCLUSION: About half or more of patients across the three countries were categorized as responders for pain and objective function following the implementation of GLA:D®. These findings indicate positive patient outcomes associated with GLA:D® participation across varying health care systems from implementation of guideline-based patient education and exercise therapy for knee and hip OA.

Prevalence of early hip OA features on MRI in high-impact athletes. The femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study.

OBJECTIVE: To compare early hip osteoarthritis (OA) features on magnetic resonance imaging (MRI) in high-impact athletes with and without hip and/or groin pain, and to evaluate associations between early hip OA features, the International Hip Outcome Tool (iHOT33) and Copenhagen Hip and Groin Outcome Score (HAGOS). DESIGN: This case-control study evaluated data of the femoroacetabular impingement and hip osteoarthritis cohort (FORCe). One hundred and eighty-two symptomatic (hip and/or groin pain >6 months and positive flexion-adduction-internal-rotation (FADIR) test) and 55 pain-free high-impact athletes (soccer or Australian football (AF)) without definite radiographic hip OA underwent hip MRI. The Scoring Hip Osteoarthritis with MRI (SHOMRI) method quantified and graded the severity of OA features. Each participant completed the iHOT33 and HAGOS. RESULTS: Hip and/or groin pain was associated with higher total SHOMRI (0-96) (mean difference 1.4, 95% CI: 0.7-2.2), labral score (adjusted incidence rate ratio (aIRR) 1.33, 95% CI: 1.1-1.6). Differences in prevalence of cartilage defects, labral tears and paralabral cysts between symptomatic and pain-free participants were inconclusive. There was a lower prevalence of effusion-synovitis in symptomatic participants when compared to pain-free participants (adjusted odds ratio (aOR) 0.46 (95% CI: 0.3-0.8). Early hip OA features were not associated with iHOT33 or HAGOS. CONCLUSIONS: A complex and poorly understood relationship exists between hip and/or groin pain and early hip OA features present on MRI in high-impact athletes without radiographic OA. Hip and/or groin pain was associated with higher SHOMRI and labral scores.

Co-creation of a sport-specific anterior cruciate ligament injury risk reduction program for women: A concept mapping approach.

OBJECTIVES: To engage physiotherapists experienced in female elite sport and athletes to co-create a sport-specific anterior cruciate ligament (ACL) injury risk reduction program. DESIGN: Concept Mapping. METHODS: The Concept Systems Global MAX™ web platform was used to collect and analyse data from 27 context and content experts (22 physiotherapists, 5 athletes). Participants brainstormed statements representing the critical elements that should be included in an ACL injury risk reduction program for women playing elite Australian Football (AF). RESULTS: Twenty-two participants brainstormed 56 statements that were synthesised and edited to 62 statements. Statements were sorted into clusters by twenty-three participants and rated on importance and feasibility using six-point scales. Multidimensional scaling and cluster analysis identified a 5-cluster solution as follows: Football-specific preparation (15 statements); Movement skills (17 statements); Strength and conditioning (15 statements); Individual preparation (7 statements); and Education (8 statements). Calculation of mean ratings for each cluster and statement identified the Movement skills cluster as most important (mean=3.61 out of 5) and the Football-specific preparation cluster as most feasible (3.75 out of 5). By contrast, the Individual preparation cluster was rated the least important (mean=2.9 out of 5), and the least feasible (3.12 out of 5), to include in the program. CONCLUSIONS: The five clusters of critical elements to include in an ACL injury risk reduction program for women playing elite AF, in order of most to least importance were: movement skills, football-specific preparation, education, strength and conditioning and individual preparation.

Muscle size and composition in people with articular hip pathology: a systematic review with meta-analysis.

OBJECTIVE: To synthesise and evaluate the current evidence investigating muscle size and composition in non-inflammatory articular hip pathology. METHODS: A systematic review of five electronic databases, using three concepts; articular hip pathology (e.g., osteoarthritis (OA)); hip muscles; and outcomes (e.g., muscle size and adiposity) was undertaken. Studies addressing non-inflammatory or non-traumatic articular hip pain, using measures of muscle size and adiposity were included and appraised for risk of bias. Data was extracted to calculate standardised mean differences (SMD) and pooled where possible for meta-analysis. RESULTS: Thirteen cross-sectional studies were included; all studies measured muscle size and 5/13 measured adiposity. In OA, there was low to very low quality evidence of no difference in hip muscle size, compared with matched controls. In unilateral OA, there was low to very low quality evidence of smaller size in gluteus minimus (SMD -0.38; 95% confidence interval (CI) -0.74, -0.01), gluteus medius (-0.44; 95% CI: -0.83, -0.05) and gluteus maximus (-0.39; 95% CI: -0.75, -0.02) muscles in the symptomatic limb. Individual studies demonstrated non-uniform changes in muscle size in OA. No significant difference was observed in muscle size in other pathologies or in adiposity for any group. CONCLUSION: There is some low quality evidence that specific hip muscles are smaller in unilateral hip OA. Variation in the magnitude of differences indicate changes in size are not uniform across all muscles or stage of pathology. Studies in larger cohorts investigating muscle size and composition across the spectrum of articular pathologies are required to clarify these findings.

Hip abductor muscle volumes are smaller in individuals affected by patellofemoral joint osteoarthritis.

OBJECTIVE: The aims of this study were twofold: firstly, to compare hip abductor muscle volumes in individuals with patellofemoral joint (PFJ) osteoarthritis (PFJ OA) against those of healthy controls; and secondly, to determine whether hip muscle volumes and hip kinematics during walking are related in individuals with PFJ OA and healthy controls. METHODS: Fifty-one individuals with PFJ OA and thirteen asymptomatic, age-matched healthy controls ≥40 years were recruited. Volumes of the gluteus medius, gluteus minimus and tensor fasciae latae were obtained from magnetic resonance (MR) images. Video motion capture was used to measure three-dimensional hip joint kinematics during overground walking. RESULTS: Significantly smaller gluteus medius (P = 0.017), gluteus minimus (P = 0.001) and tensor fasciae latae (P = 0.027) muscle volumes were observed in PFJ OA participants compared to controls. Weak correlations were observed between smaller gluteus minimus volume and larger hip flexion angle at contralateral heel strike (CHS) (r = -0.279, P = 0.038) as well as between smaller gluteus minimus volume and increased hip adduction angle at CHS (r = -0.286, P = 0.046). CONCLUSION: Reduced hip abductor muscle volume is a feature of PFJ OA and is associated with increased hip flexion and adduction angles during the late stance phase of walking for PFJ OA participants and healthy controls.

Relation of meniscus pathology to prevalence and worsening of patellofemoral joint osteoarthritis: the Multicenter Osteoarthritis Study.

OBJECTIVE: To determine the relationship of meniscal damage to magnetic resonance imaging (MRI) features of compartment-specific patellofemoral joint (PFJ) osteoarthritis (OA) at baseline and 2 years later. METHOD: Individuals from a prospective cohort of individuals aged 50-79 with or at risk of knee OA were included. At the 60-month and 84-month study visit, Whole-Organ MRI Score (WORMS) was used to assess meniscal tears and extrusions as well as cartilage damage and bone marrow lesions (BMLs) in the medial and lateral patella and trochlea. Worsening of structural features was defined as any increase in WORMS score from 60 to 84 months. Logistic regression was used to determine the cross-sectional and longitudinal relation of meniscus damage to features of compartment-specific PFJ OA. RESULTS: Relative to knees without lateral meniscal pathology at baseline, those with grades 3-4 lateral meniscal tear and extrusion had greater risk of worsening of cartilage damage in the lateral PFJ 2 years later (Risk ratio: 1.7 [95% CI: 1.1-2.7) and (1.7 [1.2-2.5]), respectively. Relative to those without medial meniscal pathology at baseline, those with grades 1-2 (0.6 [0.4-0.9]) and 3-4 (0.7 [0.5-1.0]) medial meniscal tears had lower risk of worsening of BMLs in the medial PFJ 2 years later. CONCLUSION: Meniscal tear and extrusion are associated with increased risk of medial and lateral PFJ OA and more severe meniscal pathology is associated with worsening of PFJ OA 2 years later. Lateral meniscal pathology appears to be more detrimental to the lateral PFJ.

Patellofemoral morphology and alignment: reference values and dose-response patterns for the relation to MRI features of patellofemoral osteoarthritis.

OBJECTIVE: We aimed to (1) determine reference values for trochlear morphology and patellofemoral (PF) alignment in adults without magnetic resonance imaging (MRI)-defined PF full thickness cartilage damage or knee pain; and (2) evaluate dose-response patterns for these measures with prevalent MRI-defined PF structural damage and/or knee pain. DESIGN: The Framingham Community Cohort is a population-based sample of ambulatory adults aged ≥50 years. We evaluated six morphology and alignment measures using MRI (n = 985), and reported reference values (mean ± 2SD) in a subsample without MRI-defined PF full thickness cartilage damage or knee pain (n = 563). With restricted cubic spline Poisson regression, we evaluated dose-response patterns of each of the six measures with prevalent MRI-defined PF structural damage or joint pain. Our primary outcome was full thickness cartilage damage. RESULTS: For dose-response curves, prevalence ratios (PR) increased monotonically for all measures except patellar tilt, which rose with both lateral and medial tilt. Associations were generally strongest in the lateral PF compartment. PR for the strongest predictors of full thickness cartilage damage reached clinical relevance (PR > 1.5) at sulcus angle (SA) ≥135.0°; patellar tilt angle at ≤1.0° and ≥15.0°; and bisect offset ≥57.0%. Lateral trochlear inclination (LTI) achieved PR > 1.5 at ≤23.0° for full thickness cartilage damage with pain. CONCLUSIONS: SA, patellar tilt, and bisect offset were most strongly associated with full thickness cartilage damage. LTI, patellar tilt and bisect offset had stronger associations with the addition of pain. These findings contribute to better identifying a subset of patients who may benefit from mechanically based interventions.

Return to sport matters-longer-term quality of life after ACL reconstruction in people with knee difficulties.

Many individuals experience long-term quality of life (QOL) impairment following anterior cruciate ligament reconstruction (ACLR). Factors contributing to poor QOL and psychological health >5 years after ACLR remain unclear. This study aimed to describe QOL and psychological health outcomes in people with knee difficulties (pain, symptoms, or functional limitations) 5-20 years following ACLR and identify factors explaining variability in these outcomes. Participants with knee difficulties 5-20 years following ACLR completed a battery of validated patient-reported outcomes [including the Knee injury and Osteoarthritis Outcome Score (KOOS), ACL-QOL, and the Assessment of QOL (AQoL-8D) instrument]. Multivariable linear regression was used to identify factors explaining variability in outcomes. One hundred sixty-two participants aged 38 ± 9 (mean ± SD) years completed questionnaires 9 ± 4 (range 5-20) years following ACLR. Thirty-nine percent of participants returned to competitive sport, 28% returned to a lower level, and 32% did not return to sport after ACLR. Not returning to sport after ACLR was associated with worse KOOS-QOL (ß = 0.29, P = 0.001 [mean ± SD (55 ± 20)], ACL-QOL [ß = 0.48, P < 0.001; (57 ± 21)], and AQoL-8D [ß = 0.22, P = 0.02 (0.80 ± 0.14)]) scores. Increased body mass index (56% were overweight/obese) was related to worse QOL and more depressive symptoms. Subsequent knee surgery and contralateral ACLR were also associated with poorer QOL outcomes in these individuals.

Anterior knee pain following anterior cruciate ligament reconstruction does not increase the risk of patellofemoral osteoarthritis at 15- and 20-year follow-ups.

OBJECTIVE: To prospectively evaluate the relationship between the presence or persistence of anterior knee pain (AKP) during the first 2-years following anterior cruciate ligament reconstruction (ACLR) and patellofemoral osteoarthritis (PFOA) at 15- and 20-years. DESIGN: This study was ancillary to a long-term prospective cohort study of 221 participants following bone-patellar-tendon-bone ACLR. AKP was assessed at 1- and 2-years post-ACLR using part of the Cincinnati knee score with an additional pain location question (persistence defined as presence at both follow-ups). Radiographic PFOA (definite patellofemoral osteophyte) and symptomatic PFOA (patellofemoral osteophyte, with knee pain during past 4 weeks) was assessed at 15- and 20-years follow-up. We used generalized linear models with Poisson regression to assess the relationship between AKP and PFOA. RESULTS: Of the 181 participants (82%) who were assessed at 15-years post-ACLR (age 39 ± 9 years; 42% female), 36 (24%) and 33 (22%) had AKP at 1- and 2-years, respectively, while 14 (8%) reported persistent AKP. Radiographic and symptomatic PFOA was observed at 15-years in 130 (72%) and 70 (39%) participants, respectively, and at 20-years in 115 (80%) and 60 (42%) participants, respectively. Neither the presence nor persistence of AKP at 1- and/or 2-years post-ACLR was associated with significantly higher risk of radiographic or symptomatic PFOA at 15- or 20-years (risk ratios <2.1). CONCLUSIONS: Although AKP and PFOA were prevalent, AKP does not appear to be associated with long-term PFOA following ACLR.

Achilles tendon material properties are greater in the jump leg of jumping athletes.

PURPOSE: The Achilles tendon (AT) must adapt to meet changes in demands. This study explored AT adaptation by comparing properties within the jump and non-jump legs of jumping athletes. Non-jumping control athletes were included to control limb dominance effects. METHODS: AT properties were assessed in the preferred (jump) and non-preferred (lead) jumping legs of male collegiate-level long and/or high jump (jumpers; n=10) and cross-country (controls; n=10) athletes. Cross-sectional area (CSA), elongation, and force during isometric contractions were used to estimate the morphological, mechanical and material properties of the ATs bilaterally. RESULTS: Jumpers exposed their ATs to more force and stress than controls (all p≤0.03). AT force and stress were also greater in the jump leg of both jumpers and controls than in the lead leg (all p<0.05). Jumpers had 17.8% greater AT stiffness and 24.4% greater Young's modulus in their jump leg compared to lead leg (all p<0.05). There were no jump versus lead leg differences in AT stiffness or Young's modulus within controls (all p>0.05). CONCLUSION: ATs chronically exposed to elevated mechanical loading were found to exhibit greater mechanical (stiffness) and material (Young's modulus) properties.

Knee kinematics and kinetics are associated with early patellofemoral osteoarthritis following anterior cruciate ligament reconstruction.

OBJECTIVE: Patellofemoral osteoarthritis (PFOA) commonly occurs following anterior cruciate ligament reconstruction (ACLR). Our study aimed to compare knee kinematics and kinetics during a hop-landing task between individuals with and without early PFOA post-ACLR. DESIGN: Forty-five individuals (mean ± SD 26 ± 5 years) 1-2 years post-ACLR underwent 3T isotropic MRI scans and 3D biomechanical assessment of a standardised forward hop task. Knee kinematics (initial contact, peak, excursion) in all three planes and sagittal plane kinetics (peak) were compared between 15 participants with early PFOA (MRI-defined patellofemoral cartilage lesion) and 30 participants with no PFOA (absence of patellofemoral cartilage lesion on MRI) using analysis of covariance (ANCOVA), adjusted for age, BMI, sex and the presence of early tibiofemoral OA. RESULTS: Compared to participants without PFOA, those with early PFOA exhibited smaller peak knee flexion angles (mean difference, 95% confidence interval [CI]: -5.2°, -9.9 to -0.4; P = 0.035) and moments (-4.2 Nm/kg.m, -7.8 to -0.6; P = 0.024), and greater knee internal rotation excursion (5.3°, 2.0 to 8.6; P = 0.002). CONCLUSIONS: Individuals with early PFOA within the first 2-years following ACLR exhibit distinct kinematic and kinetic features during a high-load landing task. These findings provide new information regarding common post-ACLR biomechanical patterns and PFOA. Since management strategies, such as altering knee load, are more effective during the early stages of disease, this knowledge will help to inform clinical management of early PFOA post-ACLR.

Factors that predict a poor outcome 5-8†years after the diagnosis of patellofemoral pain: a multicentre observational analysis.

BACKGROUND: Patellofemoral pain (PFP) has traditionally been viewed as self-limiting, but recent studies show that a large proportion of patients report chronic knee pain at long-term follow-up. We identified those patients with an unfavourable recovery ('moderate improvement' to 'worse than ever' measured on a Likert scale) and examined whether there is an association between PFP and osteoarthritis (OA) at 5-8-year follow-up. METHODS: Long-term follow-up data were derived from 2 randomised controlled trials (n=179, n=131). Patient-reported measures were obtained at baseline. Pain severity (100 mm visual analogue scale (VAS)), function (Anterior Knee Pain Scale (AKPS)) and self-reported recovery were measured 5-8 years later, along with knee radiographs. Multivariate backward stepwise linear regression analyses were used to evaluate the prognostic ability of baseline pain duration, pain VAS and AKPS on outcomes of pain VAS and AKPS at 5-8 years. RESULTS: 60 (19.3%) participants completed the questionnaires at 5-8-year follow-up (45 women, mean age at baseline 26 years) and 50 underwent knee radiographs. No differences were observed between responders and non-responders regarding baseline demographics, and 3-month and 12-month pain severity and recovery. 34 (57%) reported unfavourable recovery at 5-8 years. 48 out of 50 participants (98%) had no signs of radiographic knee OA. Multivariate models revealed that baseline PFP duration (>12 months; R(2)=0.22) and lower AKPS (R(2)=0.196) were significant predictors of poor prognosis at 5-8 years on measures of worst pain VAS and AKPS, respectively. SUMMARY AND CONCLUSION: More than half of participants with PFP reported an unfavourable recovery 5-8 years after recruitment, but did not have radiographic knee OA. Longer PFP duration and worse AKPS score at baseline predict poor PFP prognosis. Education of health practitioners and the general public will provide patients with more realistic expectations regarding prognosis.

Quality of life in anterior cruciate ligament-deficient individuals: a systematic review and meta-analysis.

BACKGROUND: Physical and psychological impairments impacting quality of life (QOL) are common following ACL reconstruction. Rehabilitation alone is an effective alternative to reconstruction for some patients, warranting the investigation of QOL in ACL-deficient individuals. PURPOSE: To report and compare QOL in ACL-deficient individuals with population norms and ACL-reconstructed groups, and investigate relationships between participant characteristics and QOL. STUDY DESIGN: Systematic review and meta-analysis. METHODS: We systematically identified and methodologically appraised all studies reporting QOL in ACL-deficient individuals ≥5 years following ACL rupture. Knee-related and health-related QOL scores in ACL-deficient cohorts were compared to ACL-reconstructed groups using a random-effects meta-analysis. Descriptive comparisons were made with population norms. RESULTS: Eleven studies reported QOL in 473 ACL-deficient individuals, a mean of 10 (range 5-23) years following ACL rupture. Eight studies reported knee-related QOL using the Knee injury and Osteoarthritis Outcome Score QOL subscale (KOOS-QOL); scores (mean±SD) ranging from 54±17 to 77±22 were impaired compared to population norms. Health-related QOL, measured with the SF-36 domain scores in five studies, was similar to population norms, but impaired compared to physically active populations. Meta-analysis revealed no significant differences in KOOS-QOL (mean difference (95% CI) 2.9 (-3.3 to 9.1)) and SF-36 scores (for all SF-36 domains except Vitality) between ACL-deficient and ACL-reconstructed groups. CONCLUSIONS: This systematic review found impaired knee-related QOL in ACL-deficient individuals ≥5 years after ACL rupture, compared to population norms. Meta-analysis revealed similar knee-related QOL in ACL-deficient and ACL-reconstructed groups, and no difference in health-related QOL scores for seven of the eight SF-36 domains.