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Background: Several studies have described equivalent performance on radiostereometric analysis at two years for metal-backed compared with all-polyethylene stemmed tibial implants. The purpose of this study was to determine the ten-year survivorship results of these two designs from a large randomized controlled trial.Methods: Patients who were fifty years old or more, with no history of infection, and were undergoing primary total knee arthroplasty were randomized at the time of surgery to receive either an all-polyethylene or a metal-backed tibial component. Patients were assessed preoperatively and at one, three, five, eight, and ten years postoperatively. All assessments included a clinical history, a physical examination, and a radiographic evaluation. A total of 510 consecutive patients (566 knees) were recruited from August 1993 to January 1997. The mean age of the patients at the time of the index arthroplasty was 69.3 years, and 299 (59%) were women. The primary diagnosis was osteoarthritis for 458 knees (80.9%) and rheumatoid arthritis for 108 knees (19.1%).Results: Two hundred and ninety-three patients returned for the ten-year follow-up evaluation. A total of twenty-eight knees had been revised. Ten-year survivorship, with revision for any reason (or the time at which patients were documented as requiring revision but were unfit for surgery) as the end point, was 94.5% (95% confidence interval, 90.4% to 96.8%) for the all-polyethylene design and 96% (95% confidence interval, 92.6% to 97.8%) for the metal-backed design. Ten-year survivorship, with aseptic failure as the end point, was 97% (95% confidence interval, 93.3% to 98.7%) for the all-polyethylene design and 96.8% (95% confidence interval, 93.6% to 98.4%) for the metal-backed design. On the basis of the numbers available at ten years, there was no significant difference in survivorship between the two designs (p > 0.05).Conclusions: The long-term results demonstrate excellent survivorship, with revision as the end point, for both the metal-backed and the all-polyethylene tibial component designs with no differences noted between the two. [ABSTRACT FROM AUTHOR]

We have attempted to quantify the influence of clinical, radiological and prosthetic design factors upon flexion following knee replacement. Our study examined the outcome following 101 knee replacements performed in two prospective randomized trials using similar cruciate retaining implants. Multivariate analyses, after adjusting for age, sex, diagnosis and the type of prosthesis revealed that the only significant correlates for range of movement at 12 months were the difference in posterior condylar offset ratio (p < 0.001), tibial slope (p < 0.001) and preoperative range of movement (p = 0.025). We found a moderate correlation between 12-month range of movement and posterior tibial slope (R = 0.58) and the difference of post femoral condylar offset (i.e, post-operative minus preoperative posterior condylar offset, R = 0.65). Posterior condylar offset had the greatest impact upon final range of movement highlighting this as an important consideration for the operating surgeon at pre-operative templating when choosing both the design and size of the femoral component. [ABSTRACT FROM AUTHOR]

Objective: To identify whether patients in lower socioeconomic groups had worse pain and functional levels prior to total knee arthroplasty and then establish whether these patients had poorer post-operative outcomes following total knee arthroplasty.Method: Data was obtained from a prospective observational study of 974 patients undergoing primary total knee arthroplasty for osteoarthritis. The study was undertaken in 13 centers in 4 countries. Pre-operative data was collected and patients were followed for 2 years post-operatively. Pre-operative details of the patients' demographics; socioeconomic status (SES) (education and income); height; weight and co-morbid conditions were obtained. The WOMAC scores were obtained preoperatively and during follow-up.Results: Using multivariate linear regression analysis, patients with a lower income had a significantly worse pre-operative WOMAC Pain (P = 0.021) and function score (P = 0.039) than those with higher incomes. However, income did not have a significant impact on outcome at final follow-up after adjusting for other significant covariates. Level of education did not correlate with pre-operative scores or with outcome at any time during follow-up.Conclusion: Across all four countries, patients with lower incomes appeared to have a greater need for total knee arthroplasty. However, level of income and educational status did not appear to affect the final outcome following total knee arthroplasty. Patients with lower incomes appeared able to compensate for their worse pre-operative score and obtain similar outcomes post-operatively. These findings are in contrast to studies on other medical conditions and surgical interventions, in which a lower SES has been found to have a negative impact on patient outcomes. [ABSTRACT FROM AUTHOR]

Background: Venous thromboembolism has been independently associated with both malignant disease and orthopaedic surgery. Patients with bone or soft-tissue tumors who undergo orthopaedic surgery may therefore be at high risk for thromboembolic events. The purpose of the present retrospective study was to determine the rate of clinically detected deep venous thrombosis and pulmonary embolism in patients with trunk or extremity bone or soft-tissue sarcomas.Methods: The medical records of patients with a confirmed diagnosis of primary bone or soft-tissue sarcoma who had presented to our unit between 1998 and 2003 were reviewed with use of a standardized chart abstraction tool. The data that were retrieved included patient-related data (demographic characteristics, diagnoses, and surgical interventions), the use of adjuvant chemotherapy or radiation therapy, additional risk factors for thromboembolism, the use of thromboembolic prophylaxis, and confirmed thromboembolic events.Results: Of the 252 patients who were identified, ninety-four had a diagnosis of primary bone sarcoma and 158 had a diagnosis of primary soft-tissue sarcoma. Approximately 70% of the cohort received thromboprophylaxis, with 57% receiving low-molecular-weight heparin. Thirty-seven patients were clinically suspected of having a deep venous thrombosis. Nine patients had a deep venous thrombosis that was confirmed radiographically, and in one case the diagnosis was made at another center, resulting in a rate of clinically evident deep venous thrombosis of 4%. Nine patients had a clinically suspected pulmonary embolism. One patient had confirmation of the pulmonary embolism with use of a ventilation-perfusion scan, one patient died of pulmonary embolism, and one patient had diagnosis of the pulmonary embolism at another center, resulting in an overall rate of pulmonary embolism of 1.2% and a rate of fatal pulmonary embolism of 0.4%. All patients with thromboembolic events had a tumor involving the hip or thigh, with the majority of the events occurring prior to definitive surgery.Conclusions: The risk of a clinically apparent thromboembolic event in patients with bone or soft-tissue sarcomas is comparable with that in other orthopaedic patients. However, tumors in the hip or thigh may be associated with a particularly high risk of thromboembolism. A prospective study is needed to investigate factors that are predictive of thromboembolism and the role of chemical thromboprophylaxis. [ABSTRACT FROM AUTHOR]

Background: Preoperative psychological distress has been reported to be an important risk factor for poor outcome following lower-extremity arthroplasty. We determined the independent impact of preoperative psychological distress on three, twelve, and twenty-four-month WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) pain and function scores and on change scores over those time periods.Methods: Data were obtained from an international group of 952 patients in thirteen centers participating in the Kinemax Outcomes Study. Patients completed the WOMAC and Short Form-36 (SF-36) questionnaires. The mental health (MH) scale of the SF-36 was used to quantify the impact of psychological distress on WOMAC pain and function scores. We also dichotomized patients into groups with and without psychological distress on the basis of evidence-based cut-points. Repeated-measures models were used to derive mean preoperative and three, twelve, and twenty-four-month WOMAC pain and function scores and general linear models were used to derive change scores for patients with and without psychological distress after adjustment for covariates.Results: Psychological distress, when examined on a continuous scale, was found to predict pain and function at all time-points. WOMAC pain scores for psychologically distressed patients were 3 to 5 points lower, depending on the time-frame, than the scores for the non-distressed patients, after adjustment for covariates. WOMAC function scores did not differ significantly between the two groups following surgery. The changes in the WOMAC pain and function scores for the psychologically distressed patients were not significantly different from those for the non-distressed patients.Conclusions: Many patients with psychological distress demonstrate a substantial decrease in that distress following surgery. Patients who are distressed have slightly worse pain preoperatively and for up to two years following knee arthroplasty as compared with patients with no psychological distress. With the exception of preoperative scores, these differences are not likely to be measurable at the individual patient level. WOMAC pain and function change scores do not differ between patients with and without distress after adjustment for covariates.Level Of Evidence: Prognostic Level I. [ABSTRACT FROM AUTHOR]

Background: Total knee arthroplasty is an effective treatment for severe osteoarthritis of the knee. Our aim was to determine whether patients from the United Kingdom, United States, and Australia have different preoperative expectations regarding total knee arthroplasty and whether these expectations have an impact on outcomes and patient satisfaction.Methods: Patients from the United Kingdom, the United States, and Australia were recruited into a prospective observational study of primary total knee arthroplasty for the treatment of osteoarthritis. Preoperative expectations, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Short Form-36 (SF-36) scores, and demographic, socioeconomic, and follow-up data, including satisfaction with outcome, were obtained from self-administered patient questionnaires.Results: A total of 598 patients with a mean age of sixty-nine years at the time of the index arthroplasty were recruited; 58% were women. The majority of patients expected to have no pain at twelve months after the surgery, and with the numbers available there was no significant difference among the countries with regard to pain expectations. Australian patients were more likely than patients in the United Kingdom or the United States to expect better function at twelve months after the surgery. With the numbers available, satisfaction scores at twelve months did not differ significantly among the countries and were not influenced by preoperative expectations. Australian patients were more likely than patients in the United Kingdom or the United States to be unwilling to undergo total knee arthroplasty again at twelve months under similar circumstances.Conclusions: Patients from different countries have different expectations regarding total knee arthroplasty, which are not fully explained by differences in sociodemographic factors, clinical characteristics, and pain and functional status. Australian patients had the highest expectations but, despite reporting similar outcomes and satisfaction following total knee arthroplasty, they were more likely not to want to have the surgery again under similar circumstances. [ABSTRACT FROM AUTHOR]

Background: The lengths of acute hospital stays following total hip replacement have diminished substantially in recent years. As a result, a greater proportion of complications occurs following discharge. Data on the incidence trends of major complications of total hip replacement would facilitate recognition and management of these adverse events.Methods: We used Medicare claims data on beneficiaries sixty-five years and older who had had elective, primary total hip replacement for a reason other than a fracture (58,521 patients) or had had revision total hip replacement (12,956 patients) between July 1, 1995, and June 30, 1996. We calculated incidence rates of dislocation, pulmonary embolism, and deep hip infection per 10,000 person-weeks for four time-periods following the admission for the surgery (during the index hospitalization, from discharge to four weeks postoperatively, from five to thirteen weeks postoperatively, and from fourteen to twenty-six weeks postoperatively). We then used life-table methods to estimate the cumulative incidence of each complication over the first six postoperative months.Results: Of the patients who had had a primary total hip replacement, 3.9% had a dislocation, 0.9% had a pulmonary embolism, and 0.2% had a deep infection in the first twenty-six postoperative weeks. In the revision total hip replacement cohort, the proportions with dislocation, pulmonary embolism, and deep infection were 14.4%, 0.8%, and 1.1%, respectively. The rates of these adverse outcomes were highest during the index hospitalization, diminished considerably in the period from discharge to four weeks postoperatively, and continued to drop in the periods from five to thirteen and fourteen to twenty-six weeks postoperatively.Conclusions: The incidence rates of dislocation, pulmonary embolism, and deep infection are highest immediately after total hip replacement, but they continue to be elevated throughout the first three postoperative months. With the lengths of hospital stays continuing to diminish, an increasing proportion of complications will occur in outpatients. These findings provide a basis for developing strategies to prevent these complications in the postdischarge management of patients who have had elective total hip replacement.Level Of Evidence: Prognostic study, Level II-1 (retrospective study). See p. 2 for complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to validate the Knee Society Clinical Rating System (knee and function scores) and to compare its responsiveness with that of the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and the Medical Outcomes Study Short Form-36 (SF-36).Methods: Patients were recruited as part of a prospective observational study of the outcomes of primary total knee arthroplasty for the treatment of osteoarthritis in four centers in the United States, six centers in the United Kingdom, and two centers in Australia. Independent research assistants at each site collected the Knee Society clinical data. The WOMAC, SF-36, patient satisfaction, and demographic data were obtained with self-administered questionnaires.Results: A total of 862 eligible patients were recruited, and complete preoperative and twelve-month data were available for 697 (80.9%) of them. The mean age was seventy years (range, thirty-eight to ninety years), and the majority of the patients (58.9%) were women. Low correlations were found among the items of both the knee and the function score at both assessment times. The Knee Society pain and function scores had moderate-to-strong correlations with the corresponding pain and function domains of the WOMAC and SF-36 (r = 0.31 to 0.72). Measurement of the standardized response mean showed the Knee Society knee score to be more responsive (standardized response mean, 2.2) than the WOMAC (standardized response means, 2.0 for pain and 1.4 for function) and the SF-36 (standardized response means, 1.0 for bodily pain and 1.1 for physical functioning). The Knee Society function score was the least responsive measure (standardized response mean, 0.8). Correlation of changes in scores at twelve months with patient reports of satisfaction and improvement in health status showed the WOMAC and SF-36 to be more responsive than the Knee Society scores.Conclusions: There is a poor correlation among the items of the Knee Society Clinical Rating System, but the rating system has adequate convergent construct validity. The WOMAC and SF-36 are more responsive measures of outcome of total knee arthroplasty. As they are less labor-intensive for researchers to use and as use of these instruments removes observer bias from the study design, they are preferable for knee arthroplasty outcome studies. [ABSTRACT FROM AUTHOR]

Background: It is essential to adjust for the level of preoperative pain and functional status when measuring the outcome of total knee arthroplasty. Some study designs rely on postoperative patient recall to derive preoperative status. In this study, we compared prospectively collected preoperative data with data derived from patient recall of preoperative status three months after total knee arthroplasty.Methods: Patients were recruited as part of a prospective observational study of the outcome of primary total knee arthroplasty for osteoarthritis at four centers in the United States, six centers in the United Kingdom, and two centers in Australia. Independent research assistants recruited patients and collected data with use of a uniform documentation system preoperatively and three months postoperatively. Preoperative data included the findings of a clinical history and physical examination, demographic information, socioeconomic status, and scores from two health-status instruments: the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and the Medical Outcomes Study Short Form-36 Health Survey (SF-36). Postoperative data included the WOMAC and SF-36 scores and patient recall of preoperative status on selected items from these health-status measures.Results: A total of 862 patients were recruited, and recall data were available for 770 patients (89%). The mean age was seventy years (range, thirty-eight to ninety years), and 59% of the patients were women. Comparisons of prospective and recall data on individual pain and function items showed poor-to-fair agreement (weighted kappa, 0.20 to 0.41). Patients recalled significantly more pain than they had reported preoperatively (p < 0.001), but there were random recollection errors for the function items. There was only moderate correlation between the prospective and recalled summary scores for pain (Spearman r = 0.53) and function (Spearman r = 0.48). In addition, 61% of the recalled pain scores and 50% of the recalled function scores differed from the prospective scores by more than 10 points (10% of the total range).Conclusions: Patients' recall of preoperative pain and functional status three months after total knee arthroplasty demonstrated only moderate agreement with what the patients had reported prospectively. Researchers who use recall data to derive preoperative status must recognize these limitations when drawing conclusions about the effectiveness of total knee arthroplasty. [ABSTRACT FROM AUTHOR]

There is a paucity of information detailing functional outcome following total knee arthroplasty for this length of follow-up. We collected data from 187 knees in 150 surviving patients, beyond 15 years from implantation. Survival of the implant was confirmed and a patient administered questionnaire including WOMAC, SF-36 and patient satisfaction was used, data was scrutinised for differences between primary and revision knee surgery. Seventy knees were revised at a mean of 10.8 years. The mean WOMAC Pain score was 72 indicating predominantly mild pain. The mean WOMAC Function scores were lower at 55 indicating moderate limitation of most activities. No significant differences were found between revised and un-revised patients. Long-term pain and satisfaction scores in this population were good illustrating the benefits of TKA in the long term even in patients who have undergone revision surgery. [ABSTRACT FROM AUTHOR]

Background: Osteoarthritis is associated with a strong biomechanical component. Persistent pain in the index knee after total knee arthroplasty could lead to pain in the contralateral knee. The purpose of the present study was to examine whether a change in the natural history of pain in the contralateral knee was related to postoperative pain in the index knee., Methods: Seven hundred and seventy-two patients undergoing primary unilateral total knee arthroplasty with use of the Kinemax prosthesis for the treatment of osteoarthritis comprised the cohort (Kinemax Outcomes Study cohort). Patients were assessed preoperatively and were followed for twenty-four months after surgery with use of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). We collected separate WOMAC pain scores for the index knee and the contralateral knee. Our primary outcome measure was the WOMAC pain score (rescaled to 100, with 100 being the best score) for the contralateral knee at three, twelve, and twenty-four months. We examined whether within-subject changes in the WOMAC pain score for the contralateral knee were predicted by the WOMAC pain score for the index knee at three months with use of linear regression and multilevel models after adjustment for sex, age, country, body mass index, income, and mental well-being., Results: Improvement in terms of pain was observed in both the index and contralateral knees between baseline and three months. Subsequently, there was a modest deterioration of 3.5 units per year (standard deviation, 9.8 units per year) in the contralateral knee (p < 0.001), which was not predicted by pain in the index knee shortly after surgery (p > 0.6)., Conclusions: Pain in the index knee at three months after total knee arthroplasty did not appear to predict a symptomatic increase in pain in the contralateral knee over two years of follow-up in our cohort. The contralateral knee did not require any additional clinical surveillance over and above the patients' reports on their symptoms.

The effects of elevated levels of metal ions in patients who have undergone metal-on-metal total hip arthroplasty are not fully understood. The effects of femoral head size on serum metal-ion levels have been the subject of conflicting reports, and further investigation is needed to evaluate the impact of acetabular and femoral component alignment. The conduct of clinical trials of metal-on-metal total hip arthroplasties has been inadequate as few investigators have used a randomized controlled design to compare metal-on-metal bearings with other bearing surfaces. Additional clinical research needs to include appropriate validated patient-reported outcome measures, activity monitoring, and health economics.

We aimed to investigate the factors affecting range of flexion after hip resurfacing. A total of 82 cases, operated by a single surgeon, were assessed at a mean of 43 months. The Einzel-Bild-Roentgen-Analysis for the acetabular cup software was used to measure socket orientation. Range of flexion had a moderate positive correlation with cup anteversion (R = 0.26, P = .017), weak but significant negative correlation with neck diameter (R = -0.23, P = .042), and none with anterior femoral head-neck offset. Using multivariate analysis that adjusted for age, sex, cup anteversion and inclination, head-neck offset ratio, head-neck ratio, and neck diameter, the only significant correlate of flexion was cup anteversion (P = .017). Care should be taken during cup placement to allow adequate anteversion to be maintained in Birmingham hip resurfacing because this can affect flexion range of motion., ((c) 2010 Elsevier Inc. All rights reserved.)

Background: the presence of osteoporosis in patients with hip and knee osteoarthritis (OA) has important implications for understanding disease progression and providing optimal surgical and medical management., Objective: to determine the prevalence of osteoporosis among patients with osteoarthritis awaiting total knee arthroplasty or total hip arthroplasty aged between 65 and 80 years., Design: cross-sectional observational study., Setting: tertiary referral centre in Newcastle upon Tyne, UK., Subjects: patients with osteoarthritis awaiting total knee hip arthroplasty aged between 65 and 80 years., Methods: lumbar spine, bilateral femoral and forearm bone mineral density (BMD) measurements were obtained using dual-energy X-ray absorptiometry., Results: the cohort consisted of 199 patients with a mean age of 72 years (SD 4), and 113 (57%) were women. The overall rate of osteoporosis at any site was 23% (46/199) and a further 43% (85/199) of patients would have been classified as osteopaenic according to World Health Organization criteria. Osteoporosis was more commonly detected in the forearm (14%) than the lumbar spine (8.5%) and proximal femur of the index side (8.2%)., Conclusions: in summary, a significant proportion of patients with end-stage OA have osteoporosis but this diagnosis may be missed unless BMD measurements are performed at sites distant from joints affected by OA.

Background and Purpose: Our institution began using the Kinemax total knee arthroplasty system in 1988, both with and without cement fixation. We report 10-year survival figures., Methods: Theater records showed that 284 Kinemax total knee arthroplasties had been performed 1988 through 1993. Life-table survival estimates were used to determine the probability of survivorship 10 years after surgery for the total group and by age, sex, diagnosis, and mode of fixation. Median follow-up was 11 (0.8-15) years for unrevised knees in patients who were still alive., Results: The 10-year cumulative survivorship was higher (93%, 95% CI: 81-97) when both components had been cemented than if either, or both, were uncemented (77%, CI: 67-83; p < 0.001). There was an increased incidence of failure in patients who were less than 60 years of age at the time of surgery (p = 0.004)., Interpretation: The smooth-backed Kinemax knee without cement was found to be associated with a high failure rate at 10 years. The 10-year cumulative survival results of the cemented prosthesis are acceptable.

Background: We examined the long-term survivorship and patient-reported outcomes at a minimum of ten years following primary total knee arthroplasty. We hypothesized (1) that the survival rate would be at least 90% at ten years; (2) that age, gender, body-mass index, and primary diagnosis would not affect the survival rate; and (3) that the functional status of patients would be comparable with that of an age and gender-matched normal population., Methods: A total of 407 patients (523 knees) who had had primary total knee arthroplasty between January 1988 and April 1991 were identified. The mean age of the patients at the time of surgery was sixty-nine years, and 68% of the patients were women. At ten years, 165 patients (211 knees) had died; seven of these 211 knees had been revised before the time of death. Of the remaining 242 patients, 208 (86%) completed a questionnaire, which included the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), the Short Form-36 (SF-36), and questions regarding patient satisfaction and revision surgery. In the group of patients who participated in the study, ten patients (eleven knees) had had a revision before the review., Results: A total of eighteen knees were revised. Twelve knees were revised because of aseptic failure and, of these, nine were revised because of polyethylene wear. The probability of survival at ten years was 96.1% with revision for any reason as the end point (and 97.2% when only aseptic failures were considered). Because of the small number of failures, we were unable to draw conclusions about associations between failure and age, gender, diagnosis, and body-mass index. The mean WOMAC scores (and standard deviation) at the time of the evaluation were 88 +/- 17 for pain and 79 +/- 20 for function. The SF-36 scores were similar to those for an age and gender-matched normal population, with only the physical functioning score being significantly lower (p < 0.001) and with the general health score being significantly higher (p < 0.001). Patients generally were very satisfied with all aspects of the outcome., Conclusions: At ten years, the survival of the prosthesis was excellent and the majority of patients were functionally independent, had very little knee pain, and were very satisfied with the result. The health benefits of this total knee arthroplasty were maintained after a minimum duration of follow-up of ten years.

Background: The relief of pain and the restoration of functional activities are the main outcomes of primary total knee arthroplasty for the treatment of osteoarthritis. This paper examines the preoperative predictors of pain and functional outcome at one and two years following total knee arthroplasty., Methods: Patients were recruited for a prospective observational study of primary total knee arthroplasty for the treatment of osteoarthritis from centers in the United States, the United Kingdom, and Australia. Research assistants recruited the patients and collected the clinical history and physical examination data preoperatively and at three, twelve, and twenty-four months postoperatively. The Western Ontario and McMaster University Osteoarthritis Index (WOMAC), Short Form-36 (SF-36), and demographic data were obtained by self-administered patient questionnaires., Results: We recruited 860 patients and obtained one-year WOMAC data on 759 patients (88%) and two-year data on 701 (82%). The mean age was seventy years, and 59% of the patients were female. Using hierarchical regression models, we found that the most significant preoperative predictors of worse scores on the pain and function domains of the WOMAC scale and on the physical functioning domain of the SF-36 at one and two years postoperatively were low preoperative scores, a higher number of comorbid conditions, and a low SF-36 mental health score. After adjusting for these predictors, we found that the functional status of the patients from the United Kingdom was significantly worse than that of the patients from the other countries and the difference was clinically important at both the one-year and two-year follow-up examination (p < 0.0005). The mean WOMAC pain scores for the three countries were not significantly different at one year, and, although they were significantly different at two years (p = 0.025), the difference was not clinically important., Conclusions: Patients who have marked functional limitation, severe pain, low mental health score, and other comorbid conditions before total knee arthroplasty are more likely to have a worse outcome at one year and two years postoperatively. After adjusting for these predictors, it was found that patients from the United Kingdom had significantly worse functional outcomes but similar pain relief compared with those from the United States and Australia.

We used prospective data from 862 total knee and 716 total hip replacements three years after surgery in order to derive and validate a reduced Western Ontario and McMasters University Osteoarthritis Index (WOMAC) function scale. The reduced scale was derived using the advice of clinical experts as well as analysis of data. The scale was tested for validity, reliability and responsiveness. Items which were retained included: ascending stairs, rising from sitting, walking on the flat, getting in or out of a car, putting on socks, rising from bed, and sitting. The reduced and full scales had comparable, moderate correlations with other measures of function, confirming convergent validity. Cronbach's alpha was high (alpha > 0.85) with the reduced scale confirming reliability. Responsiveness was greater for the reduced scale (full = 1.4, reduced = 1.6). This reduced version of the WOMAC function scale provides a practical, valid, reliable and responsive alternative to the full function scale for use after total joint replacement. Further work is needed to demonstrate its wider applicability.

We investigated the relationship of knee range of motion (ROM) and function in a prospective, observational study of primary total knee arthroplasty (TKA). Preoperative and 12-month data were collected on 684 patients, including knee ROM, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function questionnaire scores, patient satisfaction, and perceived improvement in quality of life (QOL). Only modest correlations were found between knee ROM and WOMAC function (r<0.34). At 12 months we found significantly worse WOMAC function scores for patients with <95 degrees flexion compared with patients with > or =95 degrees (mean, 61.9 vs 75.0; P<.0001). In linear regression models, WOMAC pain and function scores at 12 months were both correlates of patient satisfaction and perceived improvement in QOL (standardized beta>3.5; P<.0001), but knee flexion was not. For assessment of these outcomes, WOMAC function appears to be more important than knee flexion., (Copyright 2003 Elsevier Inc. All rights reserved.)

Objective: To evaluate whether hospital volume and surgeon volume of total hip replacements (THRs) are associated with patient-reported functional status and satisfaction with surgery 3 years postoperatively., Methods: We performed a population-based cohort study of a stratified random sample of Medicare beneficiaries who underwent elective primary or revision THR in Ohio, Pennsylvania, or Colorado in 1995. The primary outcomes were the self-reported Harris hip score and a validated scale measuring satisfaction with the results of surgery. Both outcomes were assessed 3 years postoperatively. Hospital volume was defined as the aggregate number of elective primary and revision THRs performed on Medicare beneficiaries in the hospital in 1995. High-volume hospitals were defined as those in which >100 such procedures are performed annually, and low-volume centers were defined as those in which 12 procedures per year., Conclusion: Hospital volume and surgeon volume have little effect on 3-year functional outcome following THR, after adjusting for patient sociodemographic and select clinical characteristics. However, satisfaction with primary THR is greater among patients who underwent surgery in high-volume centers, and satisfaction with revisions is greater among patients whose operations were performed by higher-volume surgeons. Referring clinicians should incorporate these findings into their discussion of referral choices with patients considering THR. Conclusions regarding the effect of volume on longevity of the implants must await longer-term followup studies. Finally, further research is warranted to better understand the association between hospital and surgeon procedure volume and patient satisfaction with surgery.

We have developed a Japanese self-administered questionnaire based on an English version of the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) to measure subjective function and pain status of patients who undergo a total knee arthroplasty procedure. Using multiple international cohorts, the performance of the developed Japanese scale was compared to the results of the WOMAC in the United Kingdom, United States, Canada, and Australia. The developed scale showed a comparable level of internal consistency and construct/criterion validity. The responsiveness of the scale was superior to the concurrently measured MOS Short Form 36 Physical Function scale. These results suggest that the developed scale is reliable, valid, and responsive for assessing the effectiveness of total knee arthroplasty in the Japanese context despite the cultural life style differences from Western countries.

Objective: Mortality and complication rates after total hip replacement (THR) are inversely associated with the volume of THRs performed at hospitals and by individual surgeons. It is not clear, however, why a higher volume of such procedures is associated with better outcomes. We evaluated the contribution of hospital structural characteristics to the volume-outcome relationship in THR by examining the rates and predictors of postoperative complications., Methods: We analyzed data pertaining to 5,211 Medicare patients who underwent primary THR in 1995 or 1996 at 167 hospitals in Colorado, Pennsylvania, and Ohio. Data were derived from several sources, including Medicare Part A and Part B claims, the American Board of Medical Specialties, a hospital survey regarding institution-specific characteristics and structural aspects of the care setting, and the American Hospital Association 1995 Annual Survey. Multivariate models were constructed to determine whether hospital structure or surgeon-associated factors may underlie the relationship between volume of THRs and the occurrence of perioperative orthopedic adverse events, defined as deep wound infection or hip dislocation within 90 days of surgery., Results: Of the patients studied, 2.6% experienced an orthopedic adverse event after THR. Sixty-nine percent fewer events occurred in hospitals where >100 THRs in Medicare patients were performed annually, compared with hospitals where

Objectives: To examine variation in the process of care for total knee arthroplasty (TKA) and to highlight the need for rigorous research into the ideal management of TKA. We hypothesize that variation in the process of care for TKA across and within health care systems is associated with identifiable financial and historical factors., Methods: We compared access to TKA and typical postoperative rehabilitation management in 12 orthopedic centers in the United States (4 centers), United Kingdom (6 centers), and Australia (2 centers). We collected data from two sources: 1) Empirical data on length of stay and discharge management were collected as part of a prospective study of the outcomes of primary TKA for patients with a diagnosis of osteoarthritis; 2) Structured qualitative interviews were conducted at each of the participating centers to collect data on academic status and reimbursement structure, as well as waiting times for orthopedic consultation and TKA surgery once it had been scheduled., Results: We demonstrated differences in length of acute hospital stay, use of extended care facilities, home physical therapy, and outpatient physical therapy within our cohort of hospitals. The publicly funded hospitals had a significantly longer acute hospital length of stay (mean 11.8 days, SD 7.1) than the private hospitals (mean 6.6 days, SD 4.1; P < 0.0001). Variation in waiting times was associated with the method of surgeon reimbursement and whether the hospital is publicly funded or private. Patients attending private hospitals waited 1-8 weeks for the first consultation and 2-12 weeks for a surgical date after scheduling. In contrast, patients attending publicly funded hospitals waited 4-12 months for a first consultation and 12-18 months for a surgical date after scheduling., Conclusions: Our observations are consistent with the hypothesis that financial reimbursement schemes influence the management of TKA. Further research needs to be done to quantify effects of varying processes of care on the outcome of TKA surgery across different health care settings. This data would elucidate the optimal management of TKA using objective evidence rather than relying on financial incentives or the preservation of historical practices.