Differences between race and sex in measures of hip morphology: a population-based comparative study.

OBJECTIVE: This paper aims to (i) identify differences in measures of hip morphology between four racial groups using anteroposterior (AP) hip x-rays, and (ii) examine whether these differences vary by sex. METHODS: 912 hip x-rays (456 individuals) from four racial groups (European Caucasians, American Caucasians, African Americans and Chinese) were obtained. Males and females (45-75 years) with no radiographic hip OA (Kellgren and Lawrence < Grade 2 or Croft < Grade 1) were included. Eleven features of hip joint morphology were analysed. Linear regression with generalised estimating equations (GEE) was used to determine race and sex differences in hip morphology. Post-hoc Bonferroni procedure was used to adjust for multiple comparisons. RESULTS: The final analysis included 875 hips. Chinese hips showed significant differences for the majority of measures to other racial groups. Chinese were characterised by more shallow and narrow acetabular sockets, reduced femoral head coverage, smaller femoral head diameter, and a lesser angle of alignment between the femoral neck and shaft. Variation was found between other racial groups, but with few statistically significant differences. The average of lateral centre edge angle, minimum neck width and neck length differed between race and sex (p-value for interaction < 0.05). CONCLUSIONS: Significant differences were found in measures of morphology between Chinese hips compared to African Americans or Caucasian groups; these may explain variation in hip OA prevalence rates between these groups and the lower rate of hip OA in Chinese. Sex differences were also identified, which may further explain male-female prevalence differences for OA.

Harmonising measures of knee and hip osteoarthritis in population-based cohort studies: an international study.

OBJECTIVE: Population-based osteoarthritis (OA) cohorts provide vital data on risk factors and outcomes of OA, however the methods to define OA vary between cohorts. We aimed to provide recommendations for combining knee and hip OA data in extant and future population cohort studies, in order to facilitate informative individual participant level analyses. METHOD: International OA experts met to make recommendations on: 1) defining OA by X-ray and/or pain; 2) compare The National Health and Nutrition Examination Survey (NHANES)-type OA pain questions; 3) the comparability of the Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) scale to NHANES-type OA pain questions; 4) the best radiographic scoring method; 5) the usefulness of other OA outcome measures. Key issues were explored using new analyses in two population-based OA cohorts (Multicenter Osteoarthritis Study; MOST and Osteoarthritis Initiative OAI). RESULTS: OA should be defined by both symptoms and radiographs, with symptoms alone as a secondary definition. Kellgren and Lawrence (K/L) grade ≥2 should be used to define radiographic OA (ROA). The variable wording of pain questions can result in varying prevalence between 41.0% and 75.4%, however questions where the time anchor is similar have high sensitivity and specificity (91.2% and 89.9% respectively). A threshold of 3 on a 0-20 scale (95% CI 2.1, 3.9) in the WOMAC pain subscale demonstrated equivalence with the preferred NHANES-type question. CONCLUSION: This research provides recommendations, based on expert agreement, for harmonising and combining OA data in existing and future population-based cohorts.

Do foot & ankle assessments assist the explanation of 1 year knee arthroplasty outcomes?

OBJECTIVE: Whilst a number of risk factors for poor patient reported outcome measures (PROMs) following knee arthroplasty (KA) have been identified, unexplained variability still remains. The role of pre-operative foot and ankle status on such outcomes has not been investigated. The aim of this study was therefore to determine the association of clinical foot and ankle assessments with patient reported outcomes 1 year following KA. DESIGN: One hundred and fifteen participants from the Clinical Outcomes in Arthroplasty Study (COASt), underwent detailed foot and ankle assessments at baseline, prior to KA (2012-2014) and were followed up for self-reported outcomes 1 year after surgery. RESULTS: Thirty nine percent of subjects reported foot pain at baseline. Mean pre-operative Oxford Knee Score (OKS; 0 [worst] to 48 [best outcome]) was 21 and post-operative OKS score was 38. In fully adjusted analysis pre-operative foot pain was significantly associated with 1 year outcome (risk ratio [RR] 0.78 95% confidence interval [95% CI] 0.62, 0.98). No significant association was observed between ankle dorsiflexion or foot posture and outcome. CONCLUSIONS: Patients with pre-operative foot pain are more likely to have poorer clinically important outcomes 1 year following KA than patients without foot pain. Static ankle dorsiflexion and foot posture do not further explain post-operative KA outcomes. Consideration should also be given to address pre-operative foot pain when attempting to achieve a good clinical outcome for KA.

Bone density and body composition in newly licenced professional jockeys.

The primary objective is the description of bone mineral density (BMD) and body composition in newly licensed jockeys. One in three male, flat jockeys has a very low bone mineral density. Further research is needed to assess the short-term risk of fractures and long-term health implications of these findings. INTRODUCTION: Describe bone mineral density (BMD) and body composition in entry-level male and female, flat and jump jockeys in Great Britain. METHODS: Data was collected on jockeys applying for a professional jockey license between 2013 and 2015. Areal BMD at the spine, femoral neck (FN), total hip and body composition were assessed by dual-energy X-ray absorptiometry (DXA) scan. We examined differences between BMD and body composition by gender and race type (flat or jump). Volumetric bone mineral apparent density (BMAD) of the spine and FN was also calculated to account for group differences in bone size. RESULTS: Seventy-nine male flat jockeys (age 18.5 ± 1.9, BMI 19.0 ± 1.4), 69 male jump (age 20.7 ± 2.0, BMI 20.6 ± 1.3) and 37 female flat jockeys (age 19.3 ± 2.0, BMI 20.8 ± 1.7) took part in this study. Spine BMD Z-scores ≤-2 for male flat, male jump and female flat jockeys were 29, 13 and 2.7%, respectively. Spine BMD was lower in male than female flat jockeys (p<0.001). All BMD scores were lower in male flat compared to male jump jockeys (p<0.001). Body fat percent (BF %) was lower in male flat jockeys compared to male jump and female flat jockeys (p<0.05). Lean mass index (LMI) was lower in male flat compared to male jump jockeys (p<0.001). CONCLUSIONS: Male flat jockeys had a significantly lower BMD, LMI and BF% compared to jump jockeys and female flat jockeys. Male flat jockeys had lower spine BMD scores than females. Individual bone maturation may influence these findings. Further investigation into the relevance of low BMD and altered body composition on jockey health is required.

Painful knee but not hand osteoarthritis is an independent predictor of mortality over 23†years follow-up of a population-based cohort of middle-aged women.

UNLABELLED: To assess whether joint pain or radiographic osteoarthritis (ROA) of the knee and hand is associated with all-cause and disease-specific mortality in middle-aged women. METHODS: Four subgroups from the prospective community-based Chingford Cohort Study were identified based on presence/absence of pain and ROA at baseline: (Pain-/ROA-; Pain+/ROA-; Pain-/ROA+; Pain+/ROA+). Pain was defined as side-specific pain in the preceding month, while side-specific ROA was defined as Kellgren-Lawrence grade ≥2. All-cause, cardiovascular disease (CVD) and cancer-related mortality over the 23-year follow-up was based on information collected by the Office for National Statistics. Associations between subgroups and all-cause/cause-specific mortality were assessed using Cox regression, adjusting for age, body mass index, typical cardiovascular risk factors, occupation, past physical activity, existing CVD disease, glucose levels and medication use. RESULTS: 821 and 808 women were included for knee and hand analyses, respectively. Compared with the knee Pain-/ROA- group, the Pain+/ROA- group had an increased risk of CVD-specific mortality (HR 2.93 (95% CI 1.47 to 5.85)), while the knee Pain+/ROA+ group had an increased HR of 1.97 (95% CI 1.23 to 3.17) for all-cause and 3.57 (95% CI 1.53 to 8.34) for CVD-specific mortality. We found no association between hand OA and mortality. CONCLUSION: We found a significantly increased risk of all-cause and CVD-specific mortality in women experiencing knee pain with or without ROA but not ROA alone. No relationship was found between hand OA and mortality risk. This suggests that knee pain, more than structural changes of OA is the main driver of excess mortality in patients with OA.

A comparison of radiographic anatomic axis knee alignment measurements and cross-sectional associations with knee osteoarthritis.

OBJECTIVE: Malalignment is associated with knee osteoarthritis (KOA), however, the optimal anatomic axis (AA) knee alignment measurement on a standard limb radiograph (SLR) is unknown. This study compares one-point (1P) and two-point (2P) AA methods using three knee joint centre locations and examines cross-sectional associations with symptomatic radiographic knee osteoarthritis (SRKOA), radiographic knee osteoarthritis (RKOA) and knee pain. METHODS: AA alignment was measured six different ways using the KneeMorf software on 1058 SLRs from 584 women in the Chingford Study. Cross-sectional associations with principal outcome SRKOA combined with greatest reproducibility determined the optimal 1P and 2P AA method. Appropriate varus/neutral/valgus alignment categories were established using logistic regression with generalised estimating equation models fitted with restricted cubic spline function. RESULTS: The tibial plateau centre displayed greatest reproducibility and associations with SRKOA. As mean 1P and 2P values differed by >2°, new alignment categories were generated for 1P: varus <178°, neutral 178-182°, valgus >182° and for 2P methods: varus <180°, neutral 180-185°, valgus >185°. Varus vs neutral alignment was associated with a near 2-fold increase in SRKOA and RKOA, and valgus vs neutral for RKOA using 2P method. Nonsignificant associations were seen for 1P method for SRKOA, RKOA and knee pain. CONCLUSIONS: AA alignment was associated with SRKOA and the tibial plateau centre had the strongest association. Differences in AA alignment when 1P vs 2P methods were compared indicated bespoke alignment categories were necessary. Further replication and validation with mechanical axis alignment comparison is required.

Association of metabolic syndrome with knee and hand osteoarthritis: A community-based study of women.

OBJECTIVE: It is unclear whether the association between osteoarthritis (OA) and metabolic syndrome (MetS) varies with the site of the affected joint and the presence of pain. Our aim was to describe the association between MetS and radiographic OA (ROA) affecting the knee or the hand in the presence or absence of concurrent joint pain. METHODS: Cross-sectional data of 952 women, aged 45-65years from the Chingford study, a population-based longitudinal cohort of middle-aged women initiated in 1988-1989 in London (UK), was analysed. MetS was defined using the National Cholesterol Education Program Treatment Panel III criteria. Data was collected on components of MetS: waist circumference, triglycerides, high-density lipoprotein (HDL), blood pressure and blood glucose. The outcome was four knee and hand OA groups: painful ROA, ROA only, pain only and neither ROA nor pain (reference category). Multinomial logistic regression models adjusted for age and body mass index (BMI) were used to evaluate the effect of presence of MetS and its individual components on OA subgroups for knee and hand separately. RESULTS: 952 eligible women, aged 45-65years was analysed. A significant association was observed between the presence and the number of MetS with painful knee ROA when adjusted for age; however, this association disappeared when BMI was included in the model. In contrast, the presence and the number of MetS were associated with painful interphalangeal (IPJ) OA after adjusting for both age and BMI. Four out of the five MetS components, including triglycerides, HDL-c, hypertension and glucose, were associated with painful IPJ OA. CONCLUSIONS: MetS is associated with painful IPJ OA but not with knee OA once BMI is taking into consideration. Further attention to MetS and OA at different sites is needed to understand the metabolic phenotype in OA.

Development and validation of a clinical prediction model for patient-reported pain and function after primary total knee replacement surgery.

To develop and validate a clinical prediction model of patient-reported pain and function after undergoing total knee replacement (TKR). We used data of 1,649 patients from the Knee Arthroplasty Trial who received primary TKR across 34 centres in the UK. The external validation included 595 patients from Southampton University Hospital, and Nuffield Orthopaedic Centre (Oxford). The outcome was the Oxford Knee Score (OKS) 12-month after TKR. Pre-operative predictors including patient characteristics and clinical factors were considered. Bootstrap backward linear regression analysis was used. Low pre-operative OKS, living in poor areas, high body mass index, and patient-reported anxiety or depression were associated with worse outcome. The clinical factors associated with worse outcome were worse pre-operative physical status, presence of other conditions affecting mobility and previous knee arthroscopy. Presence of fixed flexion deformity and an absent or damaged pre-operative anterior cruciate ligament (compared with intact) were associated with better outcome. Discrimination and calibration statistics were satisfactory. External validation predicted 21.1% of the variance of outcome. This is the first clinical prediction model for predicting self-reported pain and function 12 months after TKR to be externally validated. It will help to inform to patients regarding expectations of the outcome after knee replacement surgery.

Serum Lipid Levels and Risk Of Hand Osteoarthritis: The Chingford Prospective Cohort Study.

The development of hand osteoarthritis (HOA) could be linked to hyperlipidaemia. No longitudinal studies have addressed the relationship between serum lipid profile and HOA. The study aim was to determine the association between serum lipid profile and the incidence of radiographic hand osteoarthritis (RHOA). All women in a prospective population-based cohort from the Chingford study with available baseline lipid measurements and without RHOA on a baseline were included. Study outcome was the incidence of RHOA in year 11 of follow-up. Serum lipid profile variables were analysed as continuous variables and categorised into quartiles. The association between serum lipid profile and RHOA was modeled using multivariable logistic regression. Overall RHOA incidence was 51.6% (45.7-57.4%). An inverse association between HDL cholesterol levels and the incidence of RHOA was observed by quartile: OR of 0.36 [95%CI 0.17-0.75], 0.52 [95%CI 0.26-1.06], and 0.48 [95%CI 0.22-1.03]. Triglycerides levels showed a significant trend. No relationship was found with total or LDL cholesterol. Higher levels of HDL cholesterol appear to protect against RHOA after 11 years of follow-up. More research is needed to elucidate HOA risk factors, the mechanisms related to the lipid pathway, and the effects of lipid-lowering agents on reducing the incidence of OA.

Walking speed and high blood pressure mortality risk in a Spanish elderly population.

This study analyzed the relationship between blood pressure and all-cause mortality according to objectively measured walking speed in a Mediterranean population-based sample of older persons. We used data from the longitudinal 'Peñagrande' Cohort Study, initiated in 2008 in a sex- and age-stratified random sample of 1250 people aged ⩾65 years living in Madrid (Spain). A total of 814 individuals participated in the first study wave. The average of two standardized blood pressure readings was used. Walking speed was measured over a 3-m walk and classified as faster (⩾0.8 m s(-1)) or slower. A total of 314 individuals were slower walkers, 475 were faster walkers and 25 did not complete the walk test. Cox proportional hazards models stratified by walking speed were used to assess the association between blood pressure and all-cause death. Non-linear relationship between BP and mortality was explored by a restricted cubic spline analysis. There were 171 deaths from study entry through 31 March 2013. Systolic blood pressure <140 mm Hg and diastolic blood pressure <90 mmHg were associated with higher mortality than blood pressure values above 140 and 90 mm Hg, respectively, but this association reached statistical significance only for systolic blood pressure and only in the slower walkers. In conclusion, systolic blood pressure levels <140 mm Hg were found associated with higher risk of total mortality among slower walkers in an old Spaniard population cohort.