Incidence Of Hip Osteoarthritis Research Articles

Stair Climbing Ability and Identification of the Nine Stairs Ascent and Descent Test Cut-Off Points in Hip Osteoarthritis Patients: A Retrospective Study.

Objectives As the prevalence and incidence of hip osteoarthritis (hip OA) continue to rise, measuring the impact of hip OA severity on a patient's functionality is essential. Stair walking is a particularly relevant task to assess hip OA patients, as difficulty with stair ascent is one of the driving factors in deciding to undergo a total hip arthroplasty. Although stairs tests often arise in post-arthroplasty measures, there is a lack of reported stairs performance time in hip OA patients. Therefore, this retrospective study aimed to report the stair performance time of hip OA patients categorized by disease severity and determine cut-off points that differentiate between severity grades. Materials and methods The patient selection was based on the review of de-identified data from our research laboratory database. 254 hip OA patients (aged ≥ 50 years)were divided according to the Kellgren-Lawrence classification system into three groups: Grade 2 (n=68), Grade 3 (n=109), and Grade 4 (n= 68). The stair-walking ability was evaluated using the 9S-A/D test. The time taken to ascendand descendthe stairs was measured separately, and the total time (9S-A/D) was also recorded. The one-way ANOVA model, Welch test, Games-Howell posthoc test, Chi-Square tests, and Two-Way ANOVA model were used for the statistical analysis of the data. The cut-off points were obtained by receiver operating curve (ROC) analysis. The statistical significance was set at p<0.05. Results Homogeneity was found between the three groups regarding demographic and clinical characteristics, except age and gender (p<0.001). The comparison of the variables (9S-ascent, 9S-descent, and 9S-A/D) between groups, adjusted for gender and age,showed significant differences: Grade 2 individuals had shorter performance times compared to those in Grade 3 and Grade 4 (p<0.005). Simultaneously, patients with Grade 3 hip OA have a shorter performance time than those with Grade 4 hip OA (p<0.005). Regarding ROC analysis of Grade 2 versus Grade 3: The AUCs of 9S-ascend, 9S-descent, and 9S-A/D were 0.742 (95%CI 0.67-0.81), 0.734 (95%CI 0.66-0.81), and 0.745 (95%CI 0.54-0.90), respectively (all p values <0.005). The cut-off points of 9S-ascend, 9S-descent, and 9S-A/D were 8.7 s (sensitivity 56%, specificity 88%), 7.1 s (sensitivity 58%, specificity 80%), and 16.25 s (sensitivity 54%, specificity 90%), respectively. Concerning ROC analysis of Grade 3 versus Grade 4: The AUCs of 9S-ascend, 9S-descent, and 9S-A/D were 0.702 (95%CI 0.62-0.78), 0.711 (95%CI 0.63-0.79), and 0.715 (95%CI 0.64-0.80), respectively (all p values <0.005). The cut-off points of 9S-ascend, 9S-descent, and 9S-A/D were 11.5 s (sensitivity 66%, specificity 65%), 8.3 s (sensitivity 71%, specificity 62%), and 19.05 s (sensitivity 71%, specificity 61%), respectively. Conclusions The study provides evidence that the progression of hip OA affected stair walking; the performance time of 9S-ascent, 9S-ascent, and 9S-A/D tests was significantly longer as the severity of hip OA worsened. ROC analysis results show tests' ability to distinguish the cut-off point between different hip OA grades. However, further research is required for the reporting and classification of stair performance time values in hip OA patients and to further investigate the ability of 9S-ascent, 9S-descent, and 9S-A/D tests to predict the grade of hip OA.

Associations Between Baseline and Longitudinal Semiautomated Quantitative Joint Space Width at the Hip and Incident Hip Osteoarthritis: Data From a Community-Based Cohort.

To evaluate quantitative joint space width (JSW) at 10-, 30-, and 50-degree locations in relation to incident radiographic and symptomatic hip osteoarthritis (HOA) in a community-based cohort. Data were from Johnston County OA Project participants with supine hip radiographs at each of 4 time points; all had Kellgren/Lawrence (K/L) grades and quantitative JSW. We assessed covariates (age, race, height, weight, body mass index [BMI]) associated with quantitative JSW and hip-level associations between quantitative JSW and HOA over time using sex-stratified and multivariable-adjusted linear mixed models. A cluster analysis with logistic regression estimated associations between quantitative JSW trajectory groups and incident radiographic HOA and symptomatic HOA. At baseline, 397 participants (784 hips, 41% men, 24% Black, mean age 57 years) had a mean BMI of 29 kg/m2 . Over a mean of 18 years, 20% and 12% developed incident K/L grade-defined radiographic HOA or symptomatic HOA, respectively. Quantitative JSW was more sensitive to changes over time at 50 degrees. Values were stable among men but declined over time in women. Heavier women lost more quantitative JSW; changes in quantitative JSW were not significantly associated with race, education, or injury in women or men. In women only, loss of quantitative JSW over time was associated with 2-3 times higher odds of radiographic HOA and symptomatic HOA; among women and men, narrower baseline quantitative JSW was associated with these outcomes. Hip quantitative JSW demonstrates marked differences in respect to sex, with significant loss over time only in women. Loss of quantitative JSW over time in women and narrower baseline quantitative JSW in men and women were associated with incident radiographic HOA and symptomatic HOA.

Global, regional, and national burdens of hip osteoarthritis from 1990 to 2019: estimates from the 2019 Global Burden of Disease Study

BackgroundHip osteoarthritis is a common disabling condition of the hip joint and is associated with a substantial health burden. We assessed the epidemiological patterns of hip osteoarthritis from 1990 to 2019 by sex, age, and socio-demographic index (SDI).MethodsAge-standardized rates (ASRs) were obtained for the incidence and disability-adjusted life years (DALYs) of hip osteoarthritis from 1990 to 2019 for 21 regions, encompassing a total of 204 countries and territories. The estimated annual percentage changes (EAPCs) of ASRs were calculated to evaluate the trends in the incidence and DALYs of hip osteoarthritis over these 30 years.ResultsGlobally, from 1990 to 2019, the age-standardized incidence rate (ASIR) of hip osteoarthritis increased from 17.02 per 100,000 persons to 18.70 per 100,000 persons, with an upward trend in the EAPC of 0.32 (0.29–0.34), whereas the age-standardized DALY rate increased from 11.54 per 100,000 persons to 12.57 per 100,000 persons, with an EAPC of 0.29 (0.27–0.32). In 2019, the EAPCs of the ASIR and age-standardized DALY rate of hip osteoarthritis were positively associated with the SDI of hip osteoarthritis. In 1990 and 2019, the incidence of hip osteoarthritis was unimodally distributed across different age groups, with a peak incidence in the 60–64-year-old age group, whereas the DALYs increased with age.ConclusionsThe incidence and DALYs of hip osteoarthritis have been increasing globally. The EAPCs of the ASIR and age-standardized DALY rate were particularly significant in developed regions and varied across nations and regions, indicating the urgent need for governments and medical institutions to increase the awareness regarding risk factors, consequences of hip osteoarthritis.

Nocturnal pain and fatigue in middle-aged persons with hip complaints suspected for osteoarthritis – 10-year follow-up (check-study)

Purpose: The prevalence and incidence of hip osteoarthritis (OA) will increase the coming decades; the lifetime risk for symptomatic hip OA already is 25%. Many patients with OA experience elevated levels of fatigue. Yet, little is known about what affects fatigue in persons with early signs of hip OA. A possible mechanism for fatigue could be nocturnal pain. Nocturnal pain is difficult to treat conservatively and was highlighted as a key concern by patients of focus groups. Nocturnal (knee) pain was earlier shown to be related to sleep problems, and poor sleep was significantly linked to fatigue among people with hip and knee OA.

Improving the accuracy of clinical risk prediction for hip and knee osteoarthritis by a polygenic risk score

Purpose: Osteoarthritis (OA) as a late-onset disease presents a considerable burden on ageing societies, with over 300 million people affected diagnosed worldwide. Osteoarthritis is a complex degenerative disease with an estimated genetic component of ∼50%. Risk prediction for OA typically includes clinical and environmental factors, but genetic factors are not yet used. Individual genetic risk factors identified by GWAS may be combined in so-called polygenic risk scores (PRS). This study tests the clinical utility of PRS for predicting prevalent and incident hip OA or knee OA as part of the “Genotyping On All Patients (GOALL)” project at Erasmus MC.

Characteristics associated between the incidence of hip osteoarthritis and early hip complaints (CHECK study) within 10 years.

ObjectiveTo determine which baseline characteristics, especially clinically variables like pain, stiffness, physical functioning and disease variables, are associated with incident hip OA within 10 years in first presenters with hip complaints. Rheumatology key messagesHistory taking and not physical exam variables are associated with incident hip osteoarthritis.Specific questions about daily life activities are associated with incident hip OA.These questions are about pain while walking/shopping, difficulties putting socks on/off and rising from bed. MethodsData were obtained from the nationwide prospective Cohort Hip and Cohort Knee (CHECK) study (n = 1002). Incident hip OA was defined as fulfilling the clinical ACR criteria for hip OA, a Kellgren and Lawrence score ≥2 with hip pain, or received a hip replacement during follow-up. Baseline measurements were used of participants with hip complaints and without hip OA. Principal component analysis (PCA) was used to reduce the number of correlated variables. Associations between baseline characteristics (including PCA components) and incident hip OA were investigated using logistic regression analysis, adjusted for age, sex and BMI.ResultsIn total, 312 participants (85% female and 98% Caucasian) were included, 181 developed hip OA. PCA resulted in four components. Incident hip OA was associated with (i) component 1 (general presence of pain and symptoms) [odds ratio (OR) = 1.46 (95%CI: 1.08, 1.98)], (ii) component 3 (relatively high levels of pain during shopping/walking combined with less difficulty with putting socks on/off and rising from bed) [OR = 1.58 (95%CI: 1.18, 2.12)] and (iii) knee pain [OR = 0.34 (95% CI: 0.17, 0.66)].ConclusionIn first presenters with hip complaints, use of a few history-taking variables might allow better recognition of those at higher odds for incident hip OA within 10 years.

Effectiveness of a home-based telerehabilitation system in patients after total hip arthroplasty: study protocol of a randomized controlled trial

BackgroundThe demand for total hip arthroplasty (THA) is quickly rising given the escalating global incidence of hip osteoarthritis, and it is widely accepted that the post-surgery rehabilitation is key to optimize outcomes. The overall objective of this study is to evaluate the effectiveness of a new telerehabilitation solution, ReHub, for the physical function and clinical outcome improvement following THA. The specific aims of this manuscript are to describe the study design, protocol, content of interventions, and primary and secondary outcomes and to discuss the clinical rehabilitation impact of the expected experimental results.Methods/designThis prospective, randomized, controlled, parallel-group trial will include 56 patients who had undergone primary THA. Patients are randomized to a control group (standard rehabilitation during the 2-week stay in the rehabilitation clinic followed by 3 weeks of unsupervised home-based rehabilitation) or an experimental group (standard rehabilitation during the 2-week stay in the rehabilitation clinic followed by 3 weeks of home-based ReHub-assisted telerehabilitation). The primary outcome is physical performance assessed through the Timed Up-and-Go (TUG) test. Secondary outcomes include independence level, pain intensity, hip disability, hip range of motion, muscle strength, and patient’s perception of clinical improvement.DiscussionProving the clinical and cost-effectiveness of a home-based telerehabilitation program for physical and muscle function following THA could support its systematic incorporation in post-surgical rehabilitation protocols, which should be tailored to the individual and collective needs.Trial registrationClinicalTrial.gov NCT04176315. Registered on 22 November 2019

Unravelling the knee-hip-spine trilemma from the CHECK study.

The aetiologies of common degenerative spine, hip, and knee pathologies are still not completely understood. Mechanical theories have suggested that those diseases are related to sagittal pelvic morphology and spinopelvic-femoral dynamics. The link between the most widely used parameter for sagittal pelvic morphology, pelvic incidence (PI), and the onset of degenerative lumbar, hip, and knee pathologies has not been studied in a large-scale setting. A total of 421 patients from the Cohort Hip and Cohort Knee (CHECK) database, a population-based observational cohort, with hip and knee complaints < 6 months, aged between 45 and 65 years old, and with lateral lumbar, hip, and knee radiographs available, were included. Sagittal spinopelvic parameters and pathologies (spondylolisthesis and degenerative disc disease (DDD)) were measured at eight-year follow-up and characteristics of hip and knee osteoarthritis (OA) at baseline and eight-year follow-up. Epidemiology of the degenerative disorders and clinical outcome scores (hip and knee pain and Western Ontario and McMaster Universities Osteoarthritis Index) were compared between low PI (< 50°), normal PI (50° to 60°), and high PI (> 60°) using generalized estimating equations. Demographic details were not different between the different PI groups. L4 to L5 and L5 to S1 spondylolisthesis were more frequently present in subjects with high PI compared to low PI (L4 to L5, OR 3.717; p = 0.024 vs L5 to S1 OR 7.751; p = 0.001). L5 to S1 DDD occurred more in patients with low PI compared to high PI (OR 1.889; p = 0.010), whereas there were no differences in L4 to L5 DDD among individuals with a different PI. The incidence of hip OA was higher in participants with low PI compared to normal (OR 1.262; p = 0.414) or high PI (OR 1.337; p = 0.274), but not statistically different. The incidence of knee OA was higher in individuals with a high PI compared to low PI (OR 1.620; p = 0.034). High PI is a risk factor for development of spondylolisthesis and knee OA. Low pelvic incidence is related to DDD, and may be linked to OA of the hip. Level of Evidence: 1b Cite this article: Bone Joint J 2020;102-B(9):1261-1267.

Incidence rate and risk factors for radiographic hip osteoarthritis in Japanese men and women: a 10-year follow-up of the ROAD study

To investigate the incidence and progression rate of radiographic hip osteoarthritis (OA) and its risk factors in Japanese men and women using a large-scale population of a nationwide cohort study, Research on Osteoarthritis/osteoporosis Against Disability (ROAD). From the baseline survey of the ROAD study, 2,975 participants (1,043 men and 1,932 women) aged 23-94 years (mean, 70.2 years) living in urban, mountainous, and coastal communities were followed up with hip radiography at 3, 7, and 10 years (mean follow-up, 7.1 years). Radiographs were scored using the Kellgren/Lawrence (K/L) grading system, and radiographic hip OA was defined as K/L≥2. The incidence and progression rate of hip OA were examined. Acetabular dysplasia was defined as a central-edge angle <20°. Cox's proportional hazard model was used to assess risk factors for incident and progressive radiographic hip OA. The incidence rate of radiographic hip OA was 5.6/1,000 person-years and 8.4/1,000 person-years in men and women, respectively. The progression rate of hip OA was 2.2/1,000 person-years and 6.0/1,000 person-years in men and women, respectively. The significant risk factors for incident hip OA were age, obesity, and acetabular dysplasia at baseline (hazard risk [HR] 1.05, 95% confidence interval [CI] 1.03-1.08; 1.78, 1.10-2.75; 2.06, 1.30-3.17, respectively). The significant risk factors for progressive hip OA were baseline hip pain and acetabular dysplasia (HR 5.68, 95%CI 1.07-22.61; 14.78, 3.66-56.06, respectively). Continued longitudinal surveys of the ROAD study will contribute to knowledge about and potential prevention of incident and progressive hip OA.

The two-year incidence of hip osteoarthritis after arthroscopic hip surgery for femoroacetabular impingement syndrome

BackgroundOne of the reported goals of hip preservation surgery is to prevent or delay the onset of osteoarthritis. This includes arthroscopic surgery to manage Femoroacetabular Impingement (FAI) Syndrome. The purpose of this study was to describe the prevalence of clinically-diagnosed hip OA within 2 years after hip arthroscopy for FAI syndrome, and 2) determine which variables predict a clinical diagnosis of OA after arthroscopy.MethodsObservational analysis of patients undergoing hip arthroscopy between 2004 and 2013, utilizing the Military Health System Data Repository. Individuals with prior cases of osteoarthritis were excluded. Presence of osteoarthritis was based on diagnostic codes rendered by a medical provider in patient medical records. Adjusted odds ratios (95% CI) for an osteoarthritis diagnosis were reported for relevant clinical and demographic variables.ResultsOf 1870 participants in this young cohort (mean age 32.2 years), 21.9% (N = 409) had a postoperative clinical diagnosis of hip osteoarthritis within 2 years. The 3 significant predictors in the final model were older age (OR = 1.04; 95%CI = 1.02, 1.05), male sex (OR = 1.31; 95%CI = 1.04, 1.65), and having undergone an additional hip surgery (OR = 2.33; 95% CI = 1.72, 3.16). Military status and post-surgical complications were not risk factors.ConclusionA clinical diagnosis of hip osteoarthritis was found in approximately 22% of young patients undergoing hip arthroscopy in as little as 2 years. These rates may differ when using alternate criteria to define OA, such as radiographs, and likely underestimate the prevalence. A more comprehensive approach, considering various criteria to detect OA will likely be necessary to accurately identify the true rates. Females were at lower risk, while increasing age and multiple surgeries increased the risk for an OA diagnosis. OA onset still occurs after “hip preservation” surgery in a substantial number of individuals within 2 years. This should be considered when estimating rates of disease prevention after surgery. Prospective trials with sound methodology are needed to determine accurate rates and robust predictors of osteoarthritis onset after hip preservation surgery.

Characteristics associated with incidence of hip osteoarthritis within 10 years in people with early hip complaints in the check study

Characteristics associated with incidence of hip osteoarthritis within 10 years in people with early hip complaints in the check study

Brief Report: Leg Length Inequality and Hip Osteoarthritis in the Multicenter Osteoarthritis Study and the Osteoarthritis Initiative.

Studies suggest that persons with a leg length inequality (LLI) of ≥2 cm have an increased risk of developing knee osteoarthritis (OA) in that limb. The present study was undertaken to examine whether LLI also confers an increased risk of hip OA. Using long limb radiographs from subjects in the Multicenter Arthritis Study (MOST) and the Osteoarthritis Initiative (OAI), we measured LLI and scored hip radiographs that were obtained at baseline and 3-5-year follow-up. The associations of LLI of ≥1 cm and LLI of ≥2 cm with radiographic hip OA were examined cross-sectionally and longitudinally, assessing risk in shorter limbs and longer limbs compared to limbs from subjects with no LLI. We carried out logistic regression analyses with generalized estimating equations and adjusted for age, sex, body mass index, height, and cohort of origin. There were 1,966 subjects from the MOST and 2,627 subjects from the OAI. Twelve percent had LLI of ≥1 cm and 1% had LLI of ≥2 cm. For LLI ≥1 cm, the adjusted odds ratio for prevalent hip OA in the shorter leg was 1.47 (95% confidence interval [95% CI] 1.07-2.02) and for LLI ≥2 cm, it was 2.15 (95% CI 0.87-5.34). For LLI ≥1 cm, the odds of incident hip OA in the shorter leg were 1.39 (95% CI 0.81-2.39) while for LLI ≥2 cm, they were 4.20 (95% CI 1.26-14.03). We found no increased risk of hip OA in longer limbs. Our findings suggest that, as with knee OA, legs that are at least 2 cm shorter than the contralateral leg are at increased risk of hip OA.

The ability of systemic biochemical markers to reflect presence, incidence, and progression of early-stage radiographic knee and hip osteoarthritis: data from CHECK

To relate systemic biochemical markers of joint metabolism to presence, incidence, and progression of early-stage radiographic knee and/or hip osteoarthritis (OA). The cartilage markers uCTX-II, sCOMP, sPIIANP, and sCS846, bone markers uCTX-I, uNTX-I, sPINP, and sOC, and synovial markers sHA and sPIIINP were assessed by enzyme-linked immunosorbent assay or radioactive immunoassay in baseline samples of CHECK (Cohort Hip and Cohort Knee), a cohort study of early-stage symptomatic knee and/or hip OA. Knee and hip radiographs were obtained at baseline and 5-year follow-up. Presence of OA at baseline was defined as Kellgren and Lawrence (K&L) = 1 (maximum observed). Incidence of OA was defined as K&L = 0 at baseline and K&L ≥ 1 at 5-year follow-up. Progression of OA was defined as K&L = 1 at baseline and K&L ≥ 2 at 5-year follow-up. Data were available for 801 subjects at baseline and for 723 subjects at both baseline and 5-year follow-up. Multiple cartilage and synovial markers showed positive associations with presence and progression of knee and hip OA and with incidence of hip OA, except for negative associations of uCTX-II and sCOMP with incidence of knee OA. uCTX-II and sCOMP showed multiple interactions with other biomarkers in their associations with knee and hip OA. Bone markers were positively associated with presence of radiographic knee OA, but negatively associated with progression of radiographic hip OA. Especially metabolism in cartilage and synovial matrix appear to be of relevance in knee and hip OA. The role of bone metabolism appears to differ between knee and hip OA.

The contribution of hip geometry to the prediction of hip osteoarthritis

To determine how well measures of hip geometry can predict radiological incident hip osteoarthritis (HOA) compared to well known clinical risk factors. The study population is part of the Rotterdam Study, a prospective population-based cohort. Baseline pelvic radiographs were used to measure hip geometry by two methods: Statistical Shape Models (SSM) and predefined geometry parameters (PGPs). Incident HOA (Kellgren and Lawrence (KL)≥2) was assessed in 688 participants after 6.5 years without radiographic HOA at baseline. The ability to predict HOA was quantified using the area under the Receiver Operating Characteristics (ROC) curve (AUC). Comparison of the two methods showed that both contain information that is not captured by the other method. At 6.5 years follow-up 132 hips had incident HOA. Five PGPs (Wiberg angle, Neck Width (NW), Pelvic Width (PW), Hip Axis Length (HAL) and Triangular Index (TI)) and two SSM (modes 5 and 9) were significant predictors of HOA (P=0.007). Hip geometry added 7% to the prediction obtained by clinical risk factors (AUC=0.67 (geometry), 0.66 (gender, age, Body Mass Index (BMI)) and combining both: AUC=0.73, respectively). Mode 12 (associated with position of the femoral head in acetabulum) and Wiberg angle were predictors of HOA in participants without radiological signs at baseline (KL=0). Although the strength of the prediction decreased for all variables at a longer follow-up, the contribution of hip geometry was still significant (P = 0.01). Hip geometry has a moderate ability to predict HOA in participants with and without initial signs of osteoarthritis (OA), similar to and largely independent of the predictive value of clinical risk factors.

SAT0327 Predicting hip osteoarthritis progression using active appearance modelling (AAM) applied to hip DXA images from the auckland calcium study

BackgroundDual energy Xray absorptiometry (DXA) scanners are used to assess osteoporosis but recently, DXA images have also been shown to adequately assess osteoarthritis (OA) and Active Shape modelling (ASM) to...

Occurrence of Radiographic Osteoarthritis of the Knee and Hip Among African Americans and Whites: A Population‐Based Prospective Cohort Study

To compare the incidence and progression of radiographic osteoarthritis (OA) in the knee and hip among African Americans and whites. Using the joint as the unit of analysis, we analyzed data from the Johnston County Osteoarthritis Project, a population-based prospective cohort study in rural North Carolina. Baseline and followup assessments were 3-13 years apart. Assessments included standard knee and hip radiographs read for Kellgren/Lawrence (K/L) radiographic grade. Weighted analyses controlled for age, sex, body mass index, level of education, and baseline K/L grade; bootstrap methods adjusted for lack of independence between left and right joints. Time-to-event analysis was used to analyze the data. For radiographic knee OA, being African American had no association with incidence (adjusted hazard ratio [HRadj ] 0.80, 95% confidence interval [95% CI] 0.53-1.22), but had a positive association with progression (HRadj 1.67, 95% CI 1.05-2.67). For radiographic hip OA, African Americans had a significantly lower incidence (HRadj 0.44, 95% CI 0.27-0.71), whereas the association with progression was positive but nonsignificant (HRadj 1.46, 95% CI 0.53-4.01). In sensitivity analyses, the association with hip OA incidence was robust to a wide range of assumptions. African Americans are protected against incident hip OA, but may be more susceptible to progressive knee OA.

Variant alleles of the Wnt antagonist FRZB are determinants of hip shape and modify the relationship between hip shape and osteoarthritis

To test whether single-nucleotide polymorphisms (SNPs) of the FRZB gene are associated with hip shape, and to determine whether FRZB variant alleles affect the relationship between hip shape and radiographic osteoarthritis (OA) of the hip. A nested case-control study of Caucasian women, age ≥65 years, from the Study of Osteoporotic Fractures cohort was performed. Cases (n = 451) were defined as subjects with radiographic evidence of incident hip OA during followup, while controls (n = 601) were subjects in whom no radiographic hip OA was identified at baseline or followup. Statistical shape modeling (SSM) of the digitized hip radiographs was performed to assess the shape of the proximal femur, using 10 independent modes of shape variation generated by principal components analysis. In addition, center-edge angle and acetabular depth were assessed as geometric measurements of acetabular shape. The association of the rs288326 and rs7775 FRZB variant alleles with hip shape was analyzed using linear regression. The effect of these alleles on the relationship between hip shape and radiographic hip OA was analyzed using a logistic regression model with or without inclusion of interaction terms. The rs288326 and rs7775 alleles were associated with the shape of the proximal femur (SSM mode 2). There was a significant interaction between the rs288326 SNP and proximal femur shape (SSM mode 2) in predicting radiographic hip OA (P for interaction = 0.022). Among subjects with the rs288326 variant allele, there was an increased likelihood of radiographic hip OA in association with increasing quartiles of proximal femur shape mode 2 (for the fourth quartile of mode 2, odds ratio 2.5, 95% confidence interval 1.15, 5.25; P for linear trend = 0.02). The rs288326 and rs7775 FRZB SNPs are associated with the shape of the proximal femur. The presence of the rs288326 SNP alters the relationship between proximal femur shape and incident radiographic hip OA. These findings suggest that FRZB may serve an important role in determining hip shape and may modify the relationship between hip shape and OA.

Time spent in primary care for hip osteoarthritis patients once the diagnosis is set: a prospective observational study

BackgroundPrevious research on time to referral to orthopaedic surgery has predominantly used hip complaints as starting point instead of the moment the diagnosis of osteoarthritis (OA) of the hip is established, therefore little is known about the length of time a patient diagnosed with hip OA stays under the care of a general practitioner (GP). No knowledge on factors of influence on this time period is available either. Aim of this study was thus to determine the time an incident hip OA patient stays in the care of a GP until referral to an orthopaedic department. Influencing factors were also analyzed.MethodsA prospective observational study was conducted based on data over a 10-year period from a general practice-based registration network (17 GPs, > 30,000 patients registered yearly). Patients with the diagnosis of hip OA were included. A survival analysis was used to determine time until referral to an orthopaedic department, and to determine factors of influence on this time.ResultsOf 391 patients diagnosed with hip OA, 121 (31%) were referred; average survival time until referral was 82.0 months (95% CI 76.6-87.5). Less contact with the GP for hip complaints before the diagnosis of hip OA was established resulted in a decreased time to referral.ConclusionsThe results of this study show that patients with hip OA were under the care of a general practitioner, and thus in primary care, for a considerable amount of time once the diagnosis of hip OA was established.

Seasonal Trends in the Incidence of Hip Osteoarthritis in Japanese Patients

Purpose: There is an association between winter birth and developmental dysplasia of the hip, formerly termed congenital dislocation of the hip. The purpose of this study was to clarify the relationship between the month and season of birth and hip osteoarthritis in Japanese patients who had undergone total hip arthroplasty or transpositional osteotomy of the acetabulum.Methods: One thousand eight hundred and 52 female patients that presented for the surgical treatment of hip osteoarthritis between 1999 and 2005 were included in this study. Female out-patients who were seen at the initial visit during same period were used as controls to correct the bias of the month of birth.Results: There was a significant deviation of the observed number of births from the expected values calculated on a monthly basis (p<0.001). A comparison by seasons (periods of 3 months) revealed more births than expected in winter (p<0.001). The risk of hip osteoarthritis was significantly associated with the month of birth. Namely, it was highest for births in January (p<0.001).Conclusions: These data clearly revealed that the prevalence of hip osteoarthritis was significantly higher in those patients born in winter. The seasonal trend in hip osteoarthritis might be due to the winter prevalence of congenital dislocation of the hip in childhood.

Increasing incidence of hip arthroplasty for primary osteoarthritis in 30- to 59-year-old patients

Background and purpose The use of hip arthroplasties is evidently increasing, but there are few published data on the incidence in young patients.Methods We used data on total and resurfacing hip arthroplasties (THAs and RHAs) from the Finnish Arthroplasty Register and population data from Statistics Finland to analyze the incidences of THA and RHA in patients aged 30–59 years in Finland, for the period 1980 through 2007.Results The combined incidences of THAs and RHAs among 30- to 59-year-old inhabitants increased from 9.5 per 105 inhabitants in 1980 to 61 per 105 inhabitants in 2007. Initially, the incidence of THA was higher in women than men, but since the mid-90s the incidences were similar. The incidence increased in all age groups studied (30–39, 40–49, and 50–59 years) but the increase was 6-fold and 36-fold higher in the latter two groups than in the first. The incidence of THA was constant; the increased incidence of overall hip arthroplasty was due to the increasing number of RHAs performed.Interpretation We have found a steady increase in the incidence of hip arthroplasty in patients with primary hip osteoarthritis in Finland, with an accelerating trend in the past decade, due to an increase in the incidence of RHA. As the incidence of hip osteoarthritis has not increased, the indications for hip arthroplasty appear to have become broader.