A Judge

Incidence and risk factors for clinically diagnosed knee, hip and hand osteoarthritis: influences of age, gender and osteoarthritis affecting other joints

Objectives Data on the incidence of symptomatic osteoarthritis (OA) are scarce. We estimated incidence of clinical hip, knee and hand OA, and studied the effect of prevalent OA on joint-specific incident OA. Methods SIDIAP contains primary care records for>5 million people from Catalonia (Spain). Participants aged ≥40 years with an incident diagnosis of knee, hip or hand OA between 2006 and 2010 were identified using International Classification of Diseases (ICD)-10 codes. Incidence rates and female-to-male rate ratios (RRs) for each joint site were calculated. Age, gender and body mass index-adjusted HR for future joint-specific OA according to prevalent OA at other sites were estimated using Cox regression. Results 3 266 826 participants were studied for a median of 4.45 years. Knee and hip OA rates increased continuously with age, and female-to-male RRs were highest at age 70–75 years. In contrast, female hand OA risk peaked at age 60–64 years, and corresponding female-to-male RR was highest at age 50–55 years. Adjusted HR for prevalent knee OA on risk of hip OA was 1.35 (99% CI 1.28 to 1.43); prevalent hip OA on incident knee OA: HR 1.15 (1.08 to 1.23). Prevalent hand OA predicted incident knee and hip OA: HR 1.20 (1.14 to 1.26) and 1.23 (1.13 to 1.34), respectively. Conclusions The effect of age is greatest in the elderly for knee and hip OA, but around the menopause for hand OA. OA clusters within individuals, with higher risk of incident knee and hip disease from prevalent lower limb and hand OA.

Patient-reported outcomes one year after primary hip replacement in a European Collaborative Cohort.

To identify whether patients have symptomatic improvement 12 months following total hip replacement (THR) surgery.

Equity in access to total joint replacement of the hip and knee in England: cross sectional study.

Objective To explore geographical and sociodemographic factors associated with variation in equity in access to total hip and knee replacement surgery. Design Combining small area estimates of need and provision to explore equity in access to care. Setting English census wards. Subjects Patients throughout England who needed total hip or knee replacement and numbers who received surgery. Main outcome measures Predicted rates of need (derived from the Somerset and Avon Survey of Health and English Longitudinal Study of Ageing) and provision (derived from the hospital episode statistics database). Equity rate ratios comparing rates of provision relative to need by sociodemographic, hospital, and distance variables. Results For both operations there was an “n” shaped curve by age. Compared with people aged 50-59, those aged 60-84 got more provision relative to need, while those aged ≥85 received less total hip replacement (adjusted rate ratio 0.68, 95% confidence interval 0.65 to 0.72) and less total knee replacement (0.87, 0.82 to 0.93). Compared with women, men received more provision relative to need for total hip replacement (1.08, 1.05 to 1.10) and total knee replacement (1.31, 1.28 to 1.34). Compared with the least deprived, residents in the most deprived areas got less provision relative to need for total hip replacement (0.31, 0.30 to 0.33) and total knee replacement (0.33, 0.31 to 0.34). For total knee replacement, those in urban areas got higher provision relative to need, but for total hip replacement it was highest in villages/isolated areas. For total knee replacement, patients living in non-white areas received more provision relative to need (1.04, 1.00 to 1.07) than those in predominantly white areas, but for total hip replacement there was no effect. Adjustment for hospital characteristics did not attenuate the effects. Conclusions There is evidence of inequity in access to total hip and total knee replacement surgery by age, sex, deprivation, rurality, and ethnicity. Adjustment for hospital and distance did not attenuate these effects. Policy makers should examine factors at the level of patients or primary care to understand the determinants of inequitable provision.

Future projections of total hip and knee arthroplasty in the UK: results from the UK Clinical Practice Research Datalink

OBJECTIVE To estimate the future rate of primary total hip (THR) or knee (TKR) replacement in the UK to 2035 allowing for changes in population demographics and obesity. DESIGN Using age/gender/body mass index (BMI)-specific incidence rates from a population-based cohort study of 50,000 THR and 45,609 TKR patients from the UK Clinical Practice Research Datalink (CPRD) between 1991 and 2010, we projected future numbers of THR and TKR using two models: a static, estimated rate from 2010 applied to population growth forecasts to 2035, and a log-linear rate extrapolation over the same period. Both scenarios used population forecast data from the UK Office for National Statistics (ONS). RESULTS Assuming rates of THR and TKR for 2010, and given projected population changes in age, gender and BMI, the number of THRs and TKRs performed in the UK in 2035 is estimated to be, respectively: 95,877 and 118,666. By comparison, an exponential extrapolation of historical rates using a log-linear model produces much higher estimates of THR and TKR counts in 2035 at 439,097 and 1,219,362 respectively. Projected counts were higher for women than men. Assuming a changing (rather than fixed) future BMI distribution increases TKRs by 2035 but not THRs. CONCLUSIONS Using historical rates and population forecasts we have projected the number of THR/TKR operations in the UK up to 2035. This study will inform policymakers requiring estimates of future demand for surgery. Incorporating future forecasts for BMI into projections of joint replacement may be more relevant for TKR rather than THR.

What is a good patient reported outcome after total hip replacement

OBJECTIVES There is an increasing movement to collect and report patient reported outcome measures (PROMs) following total hip replacement (THR). In the UK, the procedure specific PROM of choice is the Oxford Hip Score (OHS). It is currently unclear how to use this information to determine outcome following surgery. The aim of this study was to define a threshold for the OHS that is correlated with patient satisfaction. DESIGN Prospective cohort study. SETTING A district general hospital (St. Helier Hospital, Carshalton, UK). PARTICIPANTS 799 patients receiving THR from 1995 to 2004. MAIN OUTCOME MEASURES At 12 and 24 months after surgery patients were asked if they were satisfied with surgery and completed the OHS. Receiver operating characteristic (ROC) analyses were used to identify thresholds of follow-up OHS, which best discriminated patient satisfaction. Analyses were stratified by age, sex, body mass index (BMI), baseline OHS and patient expectations. RESULTS 91.9% of patients were satisfied with THR at 12 months (92.8% at 24 months). Using the ROC technique, the OHS at 12 months associated with patient satisfaction was 38 and at 24 months 33. The OHS at 24 months associated with satisfaction was higher in those with highest tertile of baseline OHS (30, 33, 43 respectively), and lowest tertile of BMI. CONCLUSIONS We have identified a value of the OHS that predicts patient satisfaction 12-24 months following THR within a standard clinical setting. However, this threshold is markedly influenced by pre-operative OHS and should be stratified accordingly.

Temporal trends and geographical variation in the use of subacromial decompression and rotator cuff repair of the shoulder in England

We explored the trends over time and the geographical variation in the use of subacromial decompression and rotator cuff repair in 152 local health areas (Primary Care Trusts) across England. The diagnostic and procedure codes of patients undergoing certain elective shoulder operations between 2000/2001 and 2009/2010 were extracted from the Hospital Episode Statistics database. They were grouped as 1) subacromial decompression only, 2) subacromial decompression with rotator cuff repair, and 3) rotator cuff repair only. The number of patients undergoing subacromial decompression alone rose by 746.4% from 2523 in 2000/2001 (5.2/100 000 (95% confidence interval (CI) 5.0 to 5.4) to 21 355 in 2009/2010 (40.2/100 000 (95% CI 39.7 to 40.8)). Operations for rotator cuff repair alone peaked in 2008/2009 (4.7/100 000 (95% CI 4.5 to 4.8)) and declined considerably in 2009/2010 (2.6/100 000 (95% CI 2.5 to 2.7)). Given the lack of evidence for the effectiveness of these operations and the significant increase in the number of procedures being performed in England and elsewhere, there is an urgent need for well-designed clinical trials to determine evidence of clinical effectiveness.

Patient-reported outcomes after total and unicompartmental knee arthroplasty: a study of 14 076 matched patients from the National Joint Registry for England and Wales

Whether to use total or unicompartmental knee replacement (TKA/UKA) for end-stage knee osteoarthritis remains controversial. Although UKA results in a faster recovery, lower rates of morbidity and mortality and fewer complications, the long-term revision rate is substantially higher than that for TKA. The effect of each intervention on patient-reported outcome remains unclear. The aim of this study was to determine whether six-month patient-reported outcome measures (PROMs) are better in patients after TKA or UKA, using data from a large national joint registry (NJR). We carried out a propensity score-matched cohort study which compared six-month PROMs after TKA and UKA in patients enrolled in the NJR for England and Wales, and the English national PROM collection programme. A total of 3519 UKA patients were matched to 10 557 TKAs. The mean six-month PROMs favoured UKA: the Oxford Knee Score was 37.7 (95% confidence interval (CI) 37.4 to 38.0) for UKA and 36.1 (95% CI 35.9 to 36.3) for TKA; the mean EuroQol EQ-5D index was 0.772 (95% CI 0.764 to 0.780) for UKA and 0.751 (95% CI 0.747 to 0.756) for TKA. UKA patients were more likely to achieve excellent results (odds ratio (OR) 1.59, 95% CI 1.47 to 1.72, p < 0.001) and to be highly satisfied (OR 1.27, 95% CI 1.17 to 1.39, p < 0.001), and were less likely to report complications than those who had undergone TKA. UKA gives better early patient-reported outcomes than TKA; these differences are most marked for the very best outcomes. Complications and readmission are more likely after TKA. Although the data presented reflect the short-term outcome, they suggest that the high revision rate for UKA may not be because of poorer clinical outcomes. These factors should inform decision-making in patients eligible for either procedure.

Knee arthroscopy in England and Ontario: patterns of use, changes over time, and relationship to total knee replacement.

BACKGROUND The role of knee arthroscopy in the management of osteoarthritis is unclear. The purpose of this study was to examine patterns of use of knee arthroscopy, overall and by diagnostic and sociodemographic subgroups, in countries with comparable health-care systems. METHODS Administrative databases were used to construct cohorts of adults, twenty years of age or older, who had undergone their first knee arthroscopy in 1993, 1997, 2002, or 2004 either in Ontario, Canada, or in England. For each year, age and sex-standardized rates of knee arthroscopy per 100,000 population were determined overall and by diagnosis, sex, age, and income quintile. Regression analysis, with control for confounders, was used to examine predictors of readmission for primary total knee replacement up to five years after an index knee arthroscopy performed in 1993 or 1997. We also analyzed the records of patients who had undergone primary knee replacement in 2002 to determine the rates of knee arthroscopy in the two years prior to that replacement. RESULTS In both countries, the proportion of arthroscopic procedures performed to treat internal derangement or dislocation of the knee increased over time; the rates were highest in the highest income quintiles. The study revealed that 4.8% of the patients in England and 8.5% of those in Ontario who had an arthroscopy to treat osteoarthritis in 1997 received a knee replacement within one year after that procedure. The risk of readmission for knee replacement was greater in association with a diagnosis of osteoarthritis, female sex, and an older age at the time of the arthroscopy. Of the patients who had a primary knee replacement in 2002, 2.7% in England and 5.7% in Ontario had undergone a knee arthroscopy in the previous year; the likelihood of the patient having had a prior arthroscopy increased with higher income and increasing age. CONCLUSIONS Variations in knee arthroscopy rates according to age, sex, income, and diagnosis were identified in both countries. Research to determine if these differences are consistent with need is warranted.

Association of vitamin D status with knee pain and radiographic knee osteoarthritis

OBJECTIVE The objective of the present study was to explore the association of serum vitamin D concentration and polymorphism in the vitamin D receptor (VDR), with knee pain and radiographic knee osteoarthritis (OA) among men and women in a large population-based UK cohort study. METHODS Seven hundred and eighty-seven participants in the Hertfordshire Cohort Study (399 men, 388 women; mean age 65.6±2.7 years) underwent a questionnaire on knee pain and radiographic knee examination. This study examined the association of Fok1, Cdx2 and Apa1 polymorphism in the gene for the VDR and serum 25(OH)D concentration with knee pain and radiographic knee OA by a generalized estimating equations population averaged logistic regression analysis in the Hertfordshire Cohort Study. RESULTS There were no associations of Fok1, Cdx2 and Apa1 polymorphisms of the VDR with knee OA except for Aa for Apa1 compared with AA [Odds ratio (OR) 0.59, 95% confidence interval (CI) 0.36-0.95, P=0.031]. While, ff for Fok1 (OR 1.60, 95% CI 1.07-2.39, P=0.022) and AA for Cdx2 polymorphism (OR 2.21, 95% CI 1.07-4.56, P=0.032) was significantly associated with higher prevalence of knee pain compared with FF for Fok1 and GG for Cdx2, respectively. None of these are statistically significant after adjusting for the three polymorphisms tested. 25(OH)D level was not significantly associated with radiographic knee OA, while, low tertile of 25(OH)D level tended to be associated with knee pain compared with high tertile of 25(OH)D level. CONCLUSION The present cross-sectional study using a large-scale population from the Hertfordshire Cohort study indicated that vitamin D may be associated with pain rather than radiographic change, but the evidence for an association between vitamin D genetic variation and pain in knee OA is very weak in the present study. Further replication of our results will be required to elucidate the association of vitamin D and knee OA.

The natural history of radiographic knee osteoarthritis: a fourteen-year population-based cohort study.

OBJECTIVE To establish the natural history of radiographic knee osteoarthritis (OA) over 14 years in a community-based cohort. METHODS We examined women from the Chingford Womens Study, a community-based cohort followed up for more than 14 years. We selected women for whom bilateral radiographs of the knees (with the legs in full extension) were obtained at approximately 5-year intervals. Radiographs were scored for OA in a blinded manner, using Kellgren/Lawrence (K/L) grades. Descriptive statistics and odds ratios (ORs) were used to compare the incidence, worsening, and progression of radiographic knee OA. RESULTS A complete radiography series was available for 561 of the original 1,003 subjects enrolled in the study. The median age of these subjects at baseline was 53 years (interquartile range 48-58 years). At baseline, 13.7% of the subjects had radiographic knee OA (K/L grade≥2) in at least one knee, and the prevalence increased to 47.8% by year 15. The annual cumulative incidence of radiographic knee OA was 2.3% between baseline and year 15. The annual rates of disease progression and worsening between baseline and year 15 were 2.8% and 3.0%, respectively. Subjects with a K/L grade of 1 at baseline were more likely to experience worsening by year 15 compared with subjects with a baseline grade of 0 (OR 4.5, 95% confidence interval 2.7-7.4). CONCLUSION This is the longest natural history study of radiographic knee OA to date. The results showed relatively low rates for the incidence and progression of radiographic knee OA; more than half of all subjects had no radiographic evidence of knee OA over a 15-year period of time. Subjects with a baseline K/L grade of 1 were more likely than subjects with other baseline K/L grades to experience worsening of knee OA.