Risk Of Total Hip Replacement Research Articles

Predicting the Risk of Total Hip Replacement by Using A Deep Learning Algorithm on Plain Pelvic Radiographs: Diagnostic Study.

Total hip replacement (THR) is considered the gold standard of treatment for refractory degenerative hip disorders. Identifying patients who should receive THR in the short term is important. Some conservative treatments, such as intra-articular injection administered a few months before THR, may result in higher odds of arthroplasty infection. Delayed THR after functional deterioration may result in poorer outcomes and longer waiting times for those who have been flagged as needing THR. Deep learning (DL) in medical imaging applications has recently obtained significant breakthroughs. However, the use of DL in practical wayfinding, such as short-term THR prediction, is still lacking. In this study, we will propose a DL-based assistant system for patients with pelvic radiographs to identify the need for THR within 3 months. We developed a convolutional neural network-based DL algorithm to analyze pelvic radiographs, predict the hip region of interest (ROI), and determine whether or not THR is required. The data set was collected from August 2008 to December 2017. The images included 3013 surgical hip ROIs that had undergone THR and 1630 nonsurgical hip ROIs. The images were split, using split-sample validation, into training (n=3903, 80%), validation (n=476, 10%), and testing (n=475, 10%) sets to evaluate the algorithm performance. The algorithm, called SurgHipNet, yielded an area under the receiver operating characteristic curve of 0.994 (95% CI 0.990-0.998). The accuracy, sensitivity, specificity, and F1-score of the model were 0.977, 0.920, 0932, and 0.944, respectively. The proposed approach has demonstrated that SurgHipNet shows the ability and potential to provide efficient support in clinical decision-making; it can assist physicians in promptly determining the optimal timing for THR.

Alcohol Consumption and Risk of Total Hip Replacement Due to Hip Osteoarthritis in Women.

This study was undertaken to examine the relationship between alcohol consumption and hip osteoarthritis in women. Alcohol has been associated with both adverse and beneficial health effects generally; however, the relationship between alcohol consumption and hip osteoarthritis has been minimally studied. Among women in the Nurses' Health Study cohort in the US, alcohol consumption was assessed every 4 years, starting in 1980. Intake was computed as cumulative averages and simple updates with latency periods of 0-4 through 20-24 years. We followed 83,383 women without diagnosed osteoarthritis in 1988 to June 2012. We identified 1,796 cases of total hip replacement due to hip osteoarthritis defined by self-report of osteoarthritis with hip replacement. Alcohol consumption was positively associated with hip osteoarthritis risk. Compared with nondrinkers, multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) were HR 1.04 (95% CI 0.90, 1.19) for drinkers of >0 to <5 grams/day, HR 1.12 (95% CI 0.94, 1.33) for 5 to <10 grams/day, HR 1.31 (95% CI 1.10, 1.56) for 10 to <20 grams/day, and HR 1.34 (95% CI 1.09, 1.64) for ≥20 grams/day (P for trend < 0.0001). This association held in latency analyses of up to 16-20 years, and for alcohol consumption between 35-40 years of age. Independent of other alcoholic beverages, the multivariable HRs (per 10 grams of alcohol) were similar for individual types of alcohol intake (wine, liquor, and beer; P=0.57 for heterogeneity among alcohol types). Higher alcohol consumption was associated with greater incidence of total hip replacement due to hip osteoarthritis in a dose-dependent manner in women.

Increased Risk of Common Orthopedic Surgeries for Patients with Rheumatic Diseases in Taiwan.

Background and Objectives: Rheumatic diseases, including rheumatoid arthritis, ankylosing spondylitis, psoriasis, and systemic lupus erythematosus (SLE), are characterized by chronic arthritis or spondyloarthritis, which can lead to joint and spine destruction. Our previous studies showed that the risk of common orthopedic surgeries, including total knee replacement (TKR), total hip replacement (THR), or spine surgery, was increased in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. The aim of this review was to summarize the risk of TKR, THR, cervical spine, and lumbar spine surgery on the basis of studies conducted using data from Taiwan's National Health Insurance Research Database (NHIRD). Materials and Methods: The risk of TKR, THR, cervical spine surgery, and lumbar spine surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE was summarized from the results of our previous studies and unpublished findings based on NHIRD data. Results: Patients with rheumatoid arthritis and psoriasis and men with ankylosing spondylitis showed an increased risk of TKR. Patients with rheumatoid arthritis, ankylosing spondylitis, and women with SLE showed an increased risk of receiving THR. Only patients with ankylosing spondylitis had an increased risk of cervical spine surgery, and patients with rheumatoid arthritis or ankylosing spondylitis showed an increased risk of lumbar spine surgery. Although the risk of THR, TKR, or spine surgery in these patients has declined in the era of biologics use, direct evidence for the effects of biologics agents is not yet available. Conclusions: There was an increased risk of common orthopedic surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. Clinicians should be vigilant to reduce the increased risk of TKR and THR in young and middle-aged patients with rheumatoid arthritis, THR in young patients with ankylosing spondylitis, and young female patients with SLE, as well as cervical spine surgery in young patients with ankylosing spondylitis.

OA20 Radiographic hip osteoarthritis classified semi-automatically on dual-energy x-ray absorptiometry scans is strongly predictive of total hip replacement: findings from UK Biobank

Abstract Background/Aims Radiographic hip osteoarthritis (rHOA) is traditionally defined on hip x-rays, using subjective methods such as Kellgren-Lawrence scoring. Associations between subjective rHOA measures and symptoms are inconsistent. Applying digital tools to high-resolution dual-energy X-ray absorptiometry (DXA) scans, we aimed to develop a novel semi-automated classifier for rHOA and evaluate the face validity of the classifier based on relationships with hip pain, hospital diagnosed OA (HES OA), and risk of total hip replacement (THR). Methods Using hip DXAs in UK Biobank, osteophyte grades 0-3 were assigned based on manually measured osteophyte area. Minimum joint space width (mJSW) was automatically measured using outline points placed by a machine learning-based algorithm and then used to categorise individuals into joint space narrowing (JSN) grades 0-3. Osteophyte and JSN grades were combined, using a novel system giving greater to weight to osteophytes, to categorise individuals into rHOA grades 0-4. Logistic regression giving odds ratios (OR) was used to examine associations between rHOA grade and hip pain, and HES OA. Cox proportional hazard models giving hazard ratios (HR) were used to examine associations between rHOA grade and subsequent THR. Our adjusted model included age, sex, height and weight as covariates. Results 40,340 individuals were included in the study (mean age 63.7 [range 44-82], 19294/21046 male/female). 32758 (81.2%) had rHOA grade 0, 4565 (11.3%) grade 1, 2317 (5.7%) grade 2, 543 (1.3%) grade 3, 157 (0.4%) grade 4, with all features of rHOA being more common in males than females. rHOA grades ≥2 were associated with all three clinical outcomes in both unadjusted and adjusted models, a clear dose-response relationship was seen with each increase in grade showing a large rise in OR/HRs (Table 1). Grade 4 rHOA was strongly predictive of THR (HR 57.70 [95%CI 38.08-87.44]). Conclusion We successfully applied a novel semi-automated classifier to over 40,000 individuals from UKB. The validity of our classifier was supported by the strong and progressive relationships observed between rHOA and hip pain, and HES OA and risk of THR. We conclude that hip DXAs provide a promising means of defining rHOA, with potential screening applications in the clinic. Disclosure B.G. Faber: None. R. Ebsim: None. F.R. Saunders: None. M. Frysz: None. C. Lindner: None. J.S. Gregory: None. R.M. Aspden: None. N.C. Harvey: None. G. Davey Smith: None. T. Cootes: None. J.H. Tobias: None.

Relation significative entre l’incidence pelvienne et la lordose lombaire debout, et la flexibilité lombaire chez les patients japonais atteints d’arthrose de la hanche : une étude radiographique descriptive

IntroductionSpine stiffness is known to increase the risk of total hip replacement (THR) instability. The sagittal posture and lumbo-pelvic kinematics have therefore become parameters of interest when planning THR. We conducted this study to investigate (1) the distribution and characteristics of the spino-pelvic standing alignment, (2) the relationship between pelvic incidence (PI) and standing lumbar lordosis (LL) and lumbar flexibility, in Japanese hip osteoarthritis patients. Hypothesis(1) Japanese hip osteoarthritis patients with different sagittal spino-pelvic alignments do not differ markedly in their demographics, PI, or lumbar flexibility; and (2) there is no significant relationship between PI, standing LL, and lumbar flexibility in a population of Japanese hip osteoarthritis patients. Material and methodsA retrospective study of radiographs from 945 Japanese patients who consecutively received THR for the treatment of hip osteoarthritis. All patients preoperatively underwent lateral standing and deep-seated lumbo-pelvic radiography on which the spino-pelvic parameters were measured. The difference between the standing and deep-seated LL angles defined the lumbar flexibility and was calculated as the delta (Δ) LL. Individual spino-pelvic standing alignment was stratified based on the difference between the PI and standing LL (‘PI-LL mismatch’). ‘PI-LL mismatch’ of<−10°, between −10° and 10°, and>10° was defined as hyperlordosis, normolordosis, and flatback, respectively. ResultsIn the present study, the spinal alignment of 115/945 (12.2%), 559/945 (59.2%), and 271/945 (28.6%) patients were classified as hyperlordosis, normolordosis, and flatback, respectively. Hyperlordotic patients had significantly lower PI (47.6°±7.8° vs. 52.7°±10.5°, p<0.001) and higher ΔLL (60.6°±12.6° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. Patients with flatback were significantly older (age, 69.1±9.1years vs. 62.7±9.8years, p<0.001) with higher PI (56.9°±11.7° vs. 52.7°±10.5°, p<0.001) and lower ΔLL (35.2°±17.4° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. A significant relationship between PI and the standing LL was found in the whole cohort (r=0.409, p=0.009), hyperlordotic (r=0.785, p<0.001), normolordotic (r=0.857, p<0.001), and flatback (r=0.664, p<0.001) patients. Significant relationships between the PI and ΔLL were also found in normolordotic (r=0.442, p=0.004) and flatback (r=0.449, p=0.003) patients but not hyperlordotic patients (r=0.154, p=0.367). DiscussionA large proportion of Japanese hip osteoarthritis patients have abnormal PI-LL mismatch (12% and 29% have hyperlordosis and flatback, respectively). The PI was a determinant of the standing LL, and the standing LL was a strong determinant of the lumbar flexibility, especially in the normolordotic and hyperlordotic individuals. Level of evidenceIII; retrospective diagnostic radiographic study.

The significant relationship among the factors of pelvic incidence, standing lumbar lordosis, and lumbar flexibility in Japanese patients with hip osteoarthritis: A descriptive radiographic study

IntroductionSpine stiffness is known to increase the risk of total hip replacement (THR) instability. The sagittal posture and lumbo-pelvic kinematics have therefore become parameters of interest when planning THR. We conducted this study to investigate (1) the distribution and characteristics of the spino-pelvic standing alignment, (2) the relationship between pelvic incidence (PI) and standing lumbar lordosis (LL) and lumbar flexibility, in Japanese hip osteoarthritis patients. Hypothesis(1) Japanese hip osteoarthritis patients with different sagittal spino-pelvic alignments do not differ markedly in their demographics, PI, or lumbar flexibility; and (2) there is no significant relationship between PI, standing LL, and lumbar flexibility in a population of Japanese hip osteoarthritis patients. Material and MethodsA retrospective study of radiographs from 945 Japanese patients who consecutively received THR for the treatment of hip osteoarthritis. All patients pre-operatively underwent lateral standing and deep-seated lumbo-pelvic radiography on which the spino-pelvic parameters were measured. The difference between the standing and deep-seated LL angles defined the lumbar flexibility and was calculated as the delta (Δ) LL. Individual spino-pelvic standing alignment was stratified based on the difference between the PI and standing LL (‘PI-LL mismatch’). ‘PI-LL mismatch’ of<−10°, between −10° and 10°, and>10° was defined as hyperlordosis, normolordosis, and flatback, respectively. ResultsIn the present study, the spinal alignment of 115/945 (12.2%), 559/945 (59.2%), and 271/945 (28.6%) patients were classified as hyperlordosis, normolordosis, and flatback, respectively. Hyperlordotic patients had significantly lower PI (47.6°±7.8° vs. 52.7°±10.5°, p<0.001) and higher ΔLL (60.6°±12.6° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. Patients with flatback were significantly older (age, 69.1±9.1 years vs. 62.7±9.8 years, p<0.001) with higher PI (56.9°±11.7° vs. 52.7°±10.5°, p<0.001) and lower ΔLL (35.2°±17.4° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. A significant relationship between PI and the standing LL was found in the whole cohort (r=0.409, p=0.009), hyperlordotic (r=0.785, p<0.001), normolordotic (r=0.857, p<0.001), and flatback (r=0.664, p<0.001) patients. Significant relationships between the PI and ΔLL were also found in normolordotic (r=0.442, p=0.004) and flatback (r=0.449, p=0.003) patients but not hyperlordotic patients (r=0.154, p=0.367). DiscussionA large proportion of Japanese hip osteoarthritis patients have abnormal PI-LL mismatch (12% and 29% have hyperlordosis and flatback, respectively). The PI was a determinant of the standing LL and the lumbar flexibility, especially in the normolordotic and flatback individuals. Level of EvidenceIII; retrospective diagnostic radiographic study.

Association between circulating 25-hydroxyvitamin D concentrations and hip replacement for osteoarthritis: a prospective cohort study

BackgroundTo examine the association between circulating 25(OH)D concentrations and incidence of total hip replacement for osteoarthritis in a prospective cohort study.MethodsThis study examined a random sample of 2651 participants in the Melbourne Collaborative Cohort Study who had 25(OH)D concentrations measured from dried blood spots collected in 1990-1994. Participants who underwent total hip replacement for osteoarthritis between January 2001 and December 2018 were identified by linking the cohort records to the Australian Orthopaedic Association National Joint Replacement Registry. Cox proportional hazard regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of total hip replacement for osteoarthritis in relation to 25(OH)D concentrations, adjusted for confounders.ResultsEighty-six men and eighty-seven women had a total hip replacement for osteoarthritis. Compared with men in the lowest (1st) quartile of 25(OH)D concentration, the HR for total hip replacement was 2.32 (95% CI 1.05, 5.13) for those in the 2nd quartile, 2.77 (95% CI 1.28, 6.00) for those in the 3rd quartile, and 1.73 (95% CI 0.75, 4.02) for those in the highest quartile of 25(OH)D concentrations (p for trend 0.02). There was little evidence of an association in women.ConclusionsHigher circulating 25(OH)D concentrations were associated with an increased risk of total hip replacement for osteoarthritis in men but not in women. Although the underlying mechanism warrants further investigation, our findings highlight the need to determine the optimal levels of circulating 25(OH)D to reduce the risk of hip osteoarthritis.

Residual Acetabular Dysplasia in the Reduced Hip.

Residual acetabular dysplasia occurs in up to a third of patients treated successfully for developmental dysplasia of the hip (DDH) and has been found to be a significant risk factor for early hip osteoarthritis (OA). Age at the time of initial reduction and the initial severity of DDH have been linked to residual acetabular dysplasia. An anteroposterior pelvic radiograph is the main diagnostic modality, but MRI also provides valuable information, particularly in equivocal cases. The literature supports intervening when significant residual acetabular dysplasia persists at 4-5 years of age, and common surgical indications include acetabular index (AI) > 25°-30°, lateral center-edge angle (LCEA) < 8°-10°, and a broken Shenton's line on radiographs; and a cartilaginous acetabular angle (CAI) > 18°, cartilaginous center-edge angle (CCE) < 13°, and/or the presence of high-signal intensity areas on MRI. Surgical options include redirectional pelvic osteotomies and reshaping acetabuloplasties, which provide comparable radiographic and clinical results. RAD is common after treatment of DDH and requires regular follow-up for diagnosis and appropriate management to decrease the long-term risk of OA. Long-term outcomes of patients treated with pelvic osteotomies are generally favorable, and the risk of OA can be decreased, although the risk of total hip replacement in the long-term remains.

Core Decompression with Bone Marrow Stem Cells for Osteonecrosis of Femoral Head

The authors conducted a systematic review and meta-analysis to determine if Core Decompression (CD) with Bone Marrow Stem Cells (BMSC) is more effective in treating Osteonecrosis of the Femoral Head (ONFH) compared to CD. Authors used Cochrane Library, EMBASE, PubMed, Web of Science, and hand-searched references through January 2020, identifying relevant randomized controlled trials (RCTs). Risk of bias was assessed with Cochrane's handbook. Fifty-four abstracts were screened, and eight RCTs (five at high and three at unclear risk of bias) with 432 patients were included. Meta-analyses found statistically significant improvement in Harris Hip Score (HHS) at 12 months (Difference in Means [DM]=10.065;95% Confidence Interval [CI]=4.509 to 15.622; p&lt;0.001) and pain intensity at 24 months (DM=-7.364;95% CI=-12.113 to -2.615;p=0.002) in CD+BMSC group compared to CD alone although these results may not be clinically significant. Risk of Total Hip Replacement (THR) in patients receiving CD+BMSC was 33.4% lower than in CD group though not significant (RR=0.666; 95% CI=0.355 to 1.250;p=0.206). Though meta-analyses found the addition of BMSC to CD significantly improves clinical outcomes (HHS and pain intensity) compared to CD only, evidence was of moderate/low quality due to high risk of bias, imprecision, and small sample sizes. Further research is needed to confirm the results.

Association of Traditional Chinese Medicine Therapy with Risk of Total Hip Replacement in Patients with Nontraumatic Osteonecrosis of the Femoral Head: A Population-Based Cohort Study.

Background Osteonecrosis of the femoral head (ONFH) contributes to 45% of total hip replacements (THRs) annually in Taiwan. Nontraumatic ONFH (NONFH) is multifactorial; no effective Western medicine is available to delay the disease process. This population-based cohort study investigated the association of traditional Chinese medicine (TCM) therapy with risk of THR in patients with NONFH. Methods This retrospective study was conducted using claims data from all insured residents covered by the National Health Insurance from 2000 to 2010. We enrolled 1,680 newly diagnosed ONFH patients who had not undergone THR, before or within 6 months after diagnosis of ONFH; these patients did not exhibit hip fracture or dislocation before the endpoint. In total, 595 propensity score-matched pairs were selected from among 1,028 TCM users and 652 non-TCM users. The association between TCM use and risk of THR was analyzed using a Cox proportional hazard model. Kaplan-Meier and log rank tests were performed to plot the cumulative incidence of THR. Results The mean follow-up periods were 5.00 years and 3.57 years for TCM and non-TCM cohorts, respectively. Compared to the non-TCM cohort, the TCM cohort had fewer patients undergoing THR surgery (25.4% vs. 18.2%, adjusted hazard ratio: 0.60, p<0.0001). The risk of reduction was noted in the group aged 30–59 years (adjusted hazard ratio: 0.56, p<0.0001), but there was no association with gender nor socioeconomic status. There was a significantly lower cumulative incidence of THR in TCM users (p<0.0001). Shu-Jing-Huo-Xue-Tang and Yan Hu Suo were the most frequently prescribed formula and single herb, respectively. Conclusions NONFH patients using TCM had a lower risk of THR; the risk of reduction was noted in the group aged 30–59 years but was not associated with gender nor socioeconomic status. TCM might be useful in conservative treatment for NONFH.

Lifetime Risk of Primary Total Hip Replacement Surgery for Osteoarthritis From 2003 to 2013: A Multinational Analysis Using National Registry Data.

To compare the lifetime risk of total hip replacement (THR) surgery for osteoarthritis (OA) between countries, and over time. Data on primary THR procedures performed for OA in 2003 and 2013 were extracted from national arthroplasty registries in Australia, Denmark, Finland, Norway, and Sweden. Life tables and population data were also obtained for each country. Lifetime risk of THR was calculated for 2003 and 2013 using registry, life table, and population data. In 2003, lifetime risk of THR ranged from 8.7% (Denmark) to 15.9% (Norway) for females, and from 6.3% (Denmark) to 8.6% (Finland) for males. With the exception of females in Norway (where lifetime risk started and remained high), lifetime risk of THR increased significantly for both sexes in all countries from 2003 to 2013. In 2013, lifetime risk of THR was as high as 1 in 7 women in Norway, and 1 in 10 men in Finland. Females consistently demonstrated the highest lifetime risk of THR at both time points. Notably, lifetime risk for females in Norway was approximately double the risk for males in 2003 (females 15.9% [95% confidence interval (95% CI) 15.6-16.1], males 6.9% [95% CI 6.7-7.1]), and 2013 (females 16.0% [95% CI 15.8-16.3], males 8.3% [95% CI 8.1-8.5]). Using representative, population-based data, this study found statistically significant increases in the lifetime risk of THR in 5 countries over a 10-year period, and substantial between-sex differences. These multinational risk estimates can inform resource planning for OA service delivery.

Age Related Macular Degeneration and Total Hip Replacement Due to Osteoarthritis or Fracture: Melbourne Collaborative Cohort Study.

Osteoarthritis is the leading cause of total hip replacement, accounting for more than 80% of all total hip replacements. Emerging evidence suggests that osteoarthritis has a chronic inflammatory component to its pathogenesis similar to age-related macular degeneration. We evaluated the association between age-related macular degeneration and total hip replacement as proxy for severe osteoarthritis or fractured neck of femur in the Melbourne Collaborative Cohort Study. 20,744 participants had complete data on both age-related macular degeneration assessed from colour fundus photographs taken during 2003–2007 and total hip replacement. Total hip replacements due to hip osteoarthritis and fractured neck of femur during 2001–2011 were identified by linking the cohort records to the Australian Orthopedic Association National Joint Replacement Registry. Logistic regression was used to examine the association between age-related macular degeneration and risk of total hip replacement due to osteoarthritis and fracture separately, adjusted for confounders. There were 791 cases of total hip replacement for osteoarthritis and 102 cases of total hip replacement due to fractured neck of femur. After adjustment for age, sex, body mass index, smoking, and grouped country of birth, intermediate age-related macular degeneration was directly associated with total hip replacement for osteoarthritis (odds ratio 1.22, 95% CI 1.00–1.49). Late age-related macular degeneration was directly associated with total hip replacement due to fractured neck of femur (odds ratio 5.21, 95% CI2.25–12.02). The association between intermediate age-related macular degeneration and an increased 10-year incidence of total hip replacement due to osteoarthritis suggests the possibility of similar inflammatory processes underlying both chronic diseases. The association of late age-related macular degeneration with an increased 10-year incidence of total hip replacement due to fractured neck of femur may be due to an increased prevalence of fractures in those with poor central vision associated with the late complications of age-related macular degeneration.

Total Hip Replacement due to Primary Osteoarthritis in Relation to Cumulative Occupational Exposures and Lifestyle Factors: A Nationwide Nested Case–Control Study

To investigate the risk of total hip replacement (THR) due to primary osteoarthritis in relation to cumulative occupational mechanical exposures and lifestyle factors. Using register information, we identified first-time THR cases within the Danish working population in 2005-2006. For each case, 2 age- and sex-matched controls were drawn. Persons within 2,500 randomly selected case-control sets received a questionnaire about job history, weight at age 25 years, present weight and height, smoking, and sports activities at age 25 years. The job history was combined with a job exposure matrix. Cumulative exposure estimates were expressed according to the pack-year concept of smoking (e.g., cumulative lifting was expressed as ton-years). We used conditional logistic regression for statistical analyses. In total, 1,776 case-control sets (71%) were available for analysis. The adjusted odds ratio (OR) for exposure to ≥20 ton-years was 1.35 (95% confidence interval [95% CI] 1.05-1.74) for men and 1.00 (95% CI 0.73-1.41) for women. Standing/walking and whole body vibration showed no associations. The adjusted OR for body mass index (BMI) ≥30 kg/m(2) at age 25 years was 2.44 (95% CI 1.38-4.32) for men and 5.12 (95% CI 2.30-11.39) for women. The corresponding adjusted ORs for an increase in BMI of ≥10 kg/m(2) since age 25 years were 2.16 (95% CI 1.25-3.70) and 2.46 (95% CI 1.47-4.13). Sports participation showed weak positive associations, while pack-years of smoking showed no associations. The results indicated a modest increase in risk of THR in relation to cumulative lifting among men and an increased risk in relation to a high BMI at age 25 years and to a gain in BMI in both sexes.

Lifetime Risk of Total Hip Replacement Surgery and Temporal Trends in Utilization: A Population‐Based Analysis

To investigate lifetime risk of total hip replacement (THR) surgery in the state of Victoria, Australia and to describe temporal trends in THR incidence. We analyzed a retrospective population-based longitudinal cohort of patients who received a primary THR in Victoria from 1998-2009. The factors potentially contributing to changes in lifetime risk were also examined, including temporal changes in THR incidence according to health care setting (public versus private), socioeconomic status, and geographic location (regional versus metropolitan). We identified 45,775 patients receiving THR over the time period. For a woman age 20-29 years, the mortality-adjusted lifetime risk rose significantly over time, from 8.49% (95% confidence interval [95% CI] 8.23-8.69%) in 1999-2000 to 10.30% (95% CI 10.07-10.49%) in 2007-2008. For a man age 20-29 years, the mortality-adjusted lifetime risk also increased significantly, from 9.29% (95% CI 8.97-9.58%) in 1999-2000 to 10.27% (95% CI 9.95-10.48%) in 2004-2005, but in contrast to the pattern observed for women, it decreased slightly in 2007-2008 (9.90% [95% CI 9.60-10.16%]). We also identified an increasing number of THRs in private hospitals, in people in middle and low socioeconomic groups, and in rural areas. The lifetime risk of THR for women was similar to men, despite a higher burden of hip osteoarthritis, and this warrants further investigation. However, increases in the number of THR procedures performed for patients in regional areas and in lower socioeconomic groups suggest some reductions over time in known disparities.

0140 Risk of total hip replacement in relationship to cumulative exposures in the work environment

ObjectivesTo investigate the risk of total hip replacement (THR) due to primary osteoarthritis (OA) in relation to cumulative occupational mechanical exposures and lifestyle factors.MethodIn a population of Danish employees, we...

Exercise reduces risk of total hip replacement

Exercise reduces risk of total hip replacement

Smoking and primary total hip or knee replacement due to osteoarthritis in 54,288 elderly men and women

BackgroundThe reported association of smoking with risk of undergoing a total joint replacement (TJR) due to osteoarthritis (OA) is not consistent. We evaluated the independent association between smoking and primary TJR in a large cohort.MethodsThe electronic records of 54,288 men and women, who were initially recruited for the Second Australian National Blood Pressure study, were linked to the Australian Orthopaedic Association National Joint Replacement Registry to detect total hip replacement (THR) or total knee replacement (TKR) due to osteoarthritis. Competing risk regressions that accounted for the competing risk of death estimated the subhazard ratios for TJR. One-way and probabilistic sensitivity analyses were undertaken to represent uncertainty in the classification of smoking exposure and socioeconomic disadvantage scores.ResultsAn independent inverse association was found between smoking and risk of THR and TKR observed in both men and women. Compared to non-smokers, male and female smokers were respectively 40% and 30% less likely to undergo a TJR. This significant association persisted after controlling for age, co-morbidities, body mass index (BMI), physical exercise, and socioeconomic disadvantage. The overweight and obese were significantly more likely to undergo TJR compared to those with normal weight. A dose–response relationship between BMI and TJR was observed (P < 0.001). Socioeconomic status was not independently associated with risk of either THR or TKR.ConclusionThe strengths of the inverse association between smoking and TJR, the temporal relationship of the association, together with the consistency in the findings warrant further investigation about the role of smoking in the pathogenesis of osteoarthritis causing TJR.

HFE C282Y Homozygosity Is Associated with an Increased Risk of Total Hip Replacement for Osteoarthritis

The evidence for an association between mutations in the HFE (hemochromatosis) gene and the risk of hip or knee osteoarthritis is inconsistent. Total joint replacement is considered a surrogate measure for symptomatic end-stage osteoarthritis. We examined the relationship between HFE gene mutations and risk of total hip and knee replacement using a prospective cohort study. The Melbourne Collaborative Cohort Study recruited participants between 1990 and 1994. Participants born in Australia, New Zealand, the United Kingdom, or Ireland (n = 27,848) were genotyped for the HFE C282Y mutation. Total hip and knee replacements for osteoarthritis during 2001 to 2009 were ascertained from the Australian Orthopaedic Association National Joint Replacement Registry. Hazard ratios (HR)/odds ratios (OR) and confidence intervals (CI) were obtained from Cox regression or logistic regression. Compared with those with no C282Y mutation, C282Y homozygotes had an increased risk of single total hip replacement (HR 1.94, 95% CI 1.04-3.62) and bilateral total hip replacement (OR 5.86, 95% CI 2.36-14.57) for osteoarthritis, adjusting for age, sex, body mass index, and educational level. Only 3 C282Y homozygotes had single total knee replacement; the HR was 0.51 (95% CI 0.16-1.57). C282Y/H63D compound heterozygosity was not related to the risk of total hip or knee replacement. HFE C282Y homozygosity was associated with an increased risk of both single and bilateral total hip replacement for osteoarthritis.

Weight gain and the risk of total hip replacement a population-based prospective cohort study of 265,725 individuals

To study the association between change in the body mass index (BMI) at different ages and the risk of a later total hip replacement (THR) due to primary osteoarthritis (OA). A total of 265,725 individuals who had two repeated measurements of weight and height were included from national health screenings. These individuals were followed prospectively. The data were matched with the Norwegian Arthroplasty Register and 4,442 of these individuals were identified as having received a THR for primary OA. Cox proportional hazard regression was used to calculate sex-specific relative risks for having a THR according to age at screening and BMI change. Men and women aged 20 years or younger at the first screening in the quartile with the greatest BMI change per year had more than twice the risk of later having a THR compared with those in the quartile with the smallest BMI change per year. For men older than 30 years at the first screening, there was no relationship between BMI gain, or weight gain, and later risk of THR. For older women, BMI gain was associated with risk of THR, but to a lesser degree than in younger women. There was a clear relationship between change in BMI and the risk of later THR in young men and women, whereas the association was absent in older men and weaker in older women. It is important to focus on weight control to prevent future OA, and the preventive strategy should be focused on the young population.

Neonatal hip instability and risk of total hip replacement in young adulthood: Follow-up of 2,218,596 newborns from the Medical Birth Registry of Norway in the Norwegian Arthroplasty Register

Neonatal hip instability and risk of total hip replacement in young adulthood: Follow-up of 2,218,596 newborns from the Medical Birth Registry of Norway in the Norwegian Arthroplasty Register