What is the best way of assessing outcome after total knee replacement?

Quality of life after infection in total joint replacement

PURPOSE

To compare the health-related quality of life and functional outcomes of patients with and without periprosthetic infection after total joint replacement (TJR).

METHODS

62 uncomplicated TJRs and 34 TJRs complicated with deep infection were compared using a visual analogue scale for satisfaction, the Western Ontario and McMaster Universities Osteoarthritis Index, Assessment of Quality of Life, and Short Form-36.

RESULTS

Patients with complicated TJR had significantly poorer satisfaction in outcome (p<0.0001) and disease-specific functional outcomes (p<0.0001). Six of the 8 health-related quality-of-life scores were also significantly poorer (p<0.05). These results persisted after controlling for age, sex, and follow-up period in a multiple regression analysis.

CONCLUSION

Infection following TJR reduces patient satisfaction and seriously impairs functional health status and health-related quality of life. When hospitals are balancing the costs of preventative measures with the costs of treating infection in TJR, the effect on patients' quality of life must be considered. Our findings argue strongly for allocation of health care resources to minimise the occurrence of infection after TJR.

Assessing recovery and establishing prognosis following total knee arthroplasty

BACKGROUND AND PURPOSE

Information about expected rate of change after arthroplasty is critical for making prognostic decisions related to rehabilitation. The goals of this study were: (1) to describe the pattern of change in lower-extremity functional status of patients over a 1-year period after total knee arthroplasty (TKA) and (2) to describe the effect of preoperative functional status on change over time.

SUBJECTS

Eighty-four patients (44 female, 40 male) with osteoarthritis, mean age of 66 years (SD=9), participated.

METHODS

Repeated measurements for the Lower Extremity Functional Scale (LEFS) and the Six-Minute Walk Test (6MWT) were taken over a 1-year period. Data were plotted to examine the pattern of change over time. Different models of recovery were explored using nonlinear mixed-effects modeling that accounted for preoperative status and gender.

RESULTS

Growth curves were generated that depict the rate and amount of change in LEFS scores and 6MWT distances up to 1 year following TKA. The curves account for preoperative status and gender differences across participants.

DISCUSSION AND CONCLUSION

The greatest improvement occurred in the first 12 weeks after TKA. Slower improvement continued to occur from 12 weeks to 26 weeks after TKA, and little improvement occurred beyond 26 weeks after TKA. The findings can be used by physical therapists to make prognostic judgments related to the expected rate of improvement following TKA and the total amount of improvement that may be expected.

Functional improvement after total knee arthroplasty revision: new observations on the dimensional nature of outcome

BACKGROUND

Despite the numerous outcomes measures described it remains unclear what aspects of patient outcome are important in determining actual improvement following total knee arthroplasty revisions (TKAR). We performed a prospective cohort study of TKAR to determine the components of clinical improvement and how they are related and best measured.

METHODS

An improvement scale was devised utilizing data from 186 consecutive TKAR patients on SF-36 physical (PCS) and mental (MCS) components, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index, Knee Society Score (KSS), a novel Activity Scale (AS) and a physician derived severity assessment scale performed both preoperatively and at 6 month post-operative follow-up. The change in each of these scores was analyzed using factor analysis, deriving a composite improvement scale.

RESULTS

All the instruments demonstrated statistically significantly better scores following TKAR (except the SF-36 MCS). Furthermore, all significant correlations between the scores were positive. Statistical factor analysis demonstrated that scores could be arranged into 4 related factor groupings with high internal consistency (Cronbach Alpha = 0.7). Factor 1 reflected patient perceived functional outcomes, Factor 2 activity levels, Factor 3 the MCS and Factor 4 the KSS.

CONCLUSION

This study demonstrates that improvement following TKAR has a multidimensional structure. The improvement scales represent a more coordinated method of the previously fragmented analysis of TKAR outcomes. This will improve assessment of the actual effectiveness of TKAR for patients and what aspects of improvement are most critical.

Functional improvement after unicompartmental knee replacement: a follow-up study with a performance based knee test

In literature no reports appear on functional recovery of unicompartmental knee replacement using both subjective and objective methods. Functional aspects are especially of importance, since prosthetic replacement is considered more often in younger patients, who require an optimal knee function for activities such as sports. In a prospective study on 38 patients with a mean age of 62.2 years functional improvement was measured. Using Knee Society Score (KSS) as a clinician based score and the Dynaport Knee Test as a functional test measurements were performed at preoperative, 3 and 6 months, 1 and 2 years, after surgery. The Dynaport Knee Test is an accelerometer-based system that objectively measures functional aspects of gait during various tasks of daily life. It consists of four sub scores. The KSS assesses pain and function. Both scores range from 0 to 100. The mean KSS preoperative was 44.0 and improved significantly to 81.7 at 3 months (P<0.001) and to 87.4 (P=0.025) at 6 months. No significant differences were noted after 6 months. The mean preoperative Dynaport Knee Test score was 35.8 and at 3 months 43.6 (P<0.001), 48.6 at 6 months (P<0.001). No significant differences were noted after 6 months follow-up. Of the Dynaport sub scores, the low demanding tasks Lift and Move and Locomotion, cease to improve beyond 6 months. The high demanding task Transfers only improved up to 3 months. However, the other high demanding tasks Rise and Descend showed improvement beyond 1 year after surgery, since the improvement from 6 months to 2 years was significant (P=0.023). This study has found that functional recovery continues beyond 6 months and even up to 2 years. It seems only more challenging tests can discriminate on improvement beyond a point where questionnaires cease to improve. The use of objective measurement methods is advocated next to the clinician based scores and self reported questionnaires.

A cross-sectional look at patient concerns in the first six weeks following primary total knee arthroplasty

BACKGROUND

To date, no researchers have investigated patient concerns in the first six weeks following primary total knee arthroplasty (TKA). An understanding of patient concerns at a time when physical therapists are involved in the treatment of these patients will aid clinicians in providing patient-centered care. Linking of items to the International Classification of Functioning, Disability and Health (ICF) allows for comparison and sharing of data amongst researchers, as the ICF is the accepted framework for evaluating disability in rehabilitation. The objective of this study was to identify patient concerns in the first six weeks following primary TKA and link these concerns to components of the ICF and map them to commonly used outcome measures.

METHODS

Individual interviews were conducted to identify patient concerns during their recovery following primary TKA. Concerns identified by patients were analysed for content and linked to the components of the ICF using the operational definitions of the ICF components. These concerns were mapped to the WOMAC, KOOS and Oxford Knee Scale.

RESULTS

Thirty patients (18 female) with an average age (SD) of 68.4 (11.1) years completed the study. Patients identified 32 concerns. Twenty-two percent (n = 7) of the concerns linked to Body Function and Structure, 47% (n = 15) to Activity, 13% (n = 4) to Participation, and 13% (n = 4) to the Environmental Factors component of the ICF. Six percent (n = 2) of the concerns did not link to the ICF. Of the 32 concerns identified by patients 14 mapped to the KOOS, 11 to the WOMAC and 4 to the Oxford Knee Scale.

CONCLUSION

Patient concerns linked to four different components of the ICF indicating that patients are involved in or are thinking of multiple aspects of life even in this early phase of recovery. The KOOS was found to be the most appropriate for use based on the patients' perspective. However, less than half of the concerns identified by patients were covered by the KOOS, WOMAC or Oxford Knee Scale indicating that other existing measures that evaluate the concepts identified as important to patients should be considered when evaluating outcomes during this acute phase of recovery following primary TKA.

Range of motion correlates with patient perception of TKA outcome

Despite the clinical success of total knee arthroplasty, little information can be found in the literature about the relationship between certain postoperative physical findings and the outcome. Specifically, is the range of motion related to patient perception of outcome? We performed a cohort prospective study on 48 patients assessed by patient-oriented evaluations (Short Form 36 Health Survey and Oxford Knee Questionnaire) and objective evaluations after total knee arthroplasty. Thirty-four patients were women and 14 were men. The mean age at followup was 71 years (range, 64-80 years) and the minimum followup was 20 months (mean, 28.5 months; range, 20-30 months). We found a positive correlation between range of motion and patient-oriented evaluations in some domains of the Short Form 36 and in the Oxford knee score.

Evaluation of the effect of Neptune Krill Oil on chronic inflammation and arthritic symptoms

OBJECTIVES

a) To evaluate the effect of Neptune Krill Oil (NKO) on C-reactive protein (CRP) on patients with chronic inflammation and b) to evaluate the effectiveness of NKO on arthritic symptoms.

METHODS

Randomized, double blind, placebo controlled study. Ninety patients were recruited with confirmed diagnosis of cardiovascular disease and/or rheumatoid arthritis and/or osteoarthritis and with increased levels of CRP (>1.0 mg/dl) upon three consecutive weekly blood analysis. Group A received NKO (300 mg daily) and Group B received a placebo. CRP and Western Ontario and McMaster Universities (WOMAC) osteoarthritis score were measured at baseline and days 7, 14 and 30.

RESULTS

After 7 days of treatment NKO reduced CRP by 19.3% compared to an increase by 15.7% observed in the placebo group (p = 0.049). After 14 and 30 days of treatment NKO further decreased CRP by 29.7% and 30.9% respectively (p < 0.001). The CRP levels of the placebo group increased to 32.1% after 14 days and then decreased to 25.1% at day 30. The between group difference was statistically significant; p = 0.004 at day 14 and p = 0.008 at day 30. NKO showed a significant reduction in all three WOMAC scores. After 7 days of treatment, NKO reduced pain scores by 28.9% (p = 0.050), reduced stiffness by 20.3% (p = 0.001) and reduced functional impairment by 22.8% (p = 0.008).

CONCLUSION

The results of the present study clearly indicate that NKO at a daily dose of 300 mg significantly inhibits inflammation and reduces arthritic symptoms within a short treatment period of 7 and 14 days.

Modeling early recovery of physical function following hip and knee arthroplasty

BACKGROUND

Information on early recovery after arthroplasty is needed to help benchmark progress and make appropriate decisions concerning patient rehabilitation needs. The purpose of this study was to model early recovery of physical function in patients undergoing total hip (THA) and knee (TKA) arthroplasty, using physical performance and self-report measures.

METHODS

A sample of convenience of 152 subjects completed testing, of which 69 (mean age: 66.77 +/- 8.23 years) underwent THA and 83 (mean age: 60.25 +/- 11.19 years) TKA. Postoperatively, patients were treated using standardized care pathways and rehabilitation protocols. Using a repeated measures design, patients were assessed at multiple time points over the first four postoperative months. Outcome measures included the Lower Extremity Function Scale (LEFS), the physical function subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC PF), the 6 minute walk test (6 MWT), timed up and go test (TUG) and a timed stair test (ST). Average recovery curves for each of the measures were characterized using hierarchical linear modeling. Predictors of recovery were sequentially modeled after validation of the basic developmental models.

RESULTS

Slopes of recovery were greater in the first 6 to 9 weeks with a second-degree polynomial growth term (weeks squared) providing a reasonable fit for the data over the study interval. Different patterns of recovery were observed between the self-report measures of physical function and the performance measures. In contrast to the models for the WOMAC PF and the LEFS, site of arthroplasty was a significant predictor (p = 0.001) in all of the physical performance measure models with the patients post TKA initially demonstrating higher function. Site of arthroplasty (p = 0.025) also predicted the rate of change for patients post THA and between 9 to 11 weeks after surgery, the THA group surpassed the function of the patients post TKA.

CONCLUSION

Knowledge about the predicted growth curves will assist clinicians in referencing patient progress, and determining the critical time points for measuring change. The study has contributed further evidence to highlight the benefit of using physical performance measures to learn about the patients' actual level of disability.

Total knee replacement in morbidly obese patients

The results of 41 consecutive total knee replacements performed on morbidly obese patients with a body mass index > 40 kg/m2, were compared with a matched group of 41 similar procedures carried out in non-obese patients (body mass index < 30 kg/m2). The groups were matched for age, gender, diagnosis, type of prosthesis, laterality and pre-operative Knee Society Score. We prospectively followed up the patients for a mean of 38.5 months (6 to 66). No patients were lost to follow-up. At less than four years after operation, the results were worse in the morbidly obese group compared with the non-obese, as demonstrated by inferior Knee Society Scores (mean knee score 85.7 and 90.5 respectively, p = 0.08; mean function score 75.6 and 83.4, p = 0.01), a higher incidence of radiolucent lines on post-operative radiographs (29% and 7%, respectively, p = 0.02), a higher rate of complications (32% and 0%, respectively, p = 0.001) and inferior survivorship using revision and pain as end-points (72.3% and 97.6%, respectively, p = 0.02).

Patients with a body mass index > 40 kg/m2 should be advised to lose weight prior to total knee replacement and to maintain weight reduction. They should also be counselled regarding the inferior results which may occur if they do not lose weight before surgery.

Unicompartmental or total knee arthroplasty?: Results from a matched study

There are few direct comparative studies evaluating results after unicompartmental knee arthroplasty and total knee arthroplasty. We determined the active range of motion, Knee Society score, and 5-year survivorship rate after 54 consecutive unilateral unicompartmental knee arthroplasties compared with a matched group of 54 unilateral total knee arthroplasties. The two groups of patients were matched for age, gender, body mass index, preoperative active range of movement, and preoperative Knee Society scores. All patients had osteoarthritis of the knee. Patients were assessed prospectively at 6, 18, 36, and 60 months postoperatively, and the mean followup was 59 months in both groups. The mean postoperative active range of motion was greater after unicompartmental knee arthroplasty, but there were no differences in the overall Knee Society knee and function scores. The 5-year survivorship rate based on revision for any reason was 88% for unicompartmental knee arthroplasty and 100% for total knee arthroplasty. The worst case 5-year survivorship rate, assuming all patients lost to followup had revision surgery, was 85% for unicompartmental knee arthroplasty and 98% for total knee arthroplasty. Total knee arthroplasty was a more reliable procedure. Midterm clinical outcomes were similar for both procedures, but the complication rate may be greater for unicompartmental knee arthroplasty.

Preoperative function and gender predict pattern of functional recovery after hip and knee arthroplasty

Gender, preoperative function, and other variables were explored as predictors of recovery after total hip and knee arthroplasty. One hundred fifty-two subjects (63.8 +/- 10.2 years) were repeatedly assessed in the first 4 postoperative months. Average recovery curves for the Western Ontario and McMaster Universities Osteoarthritis Index, 6-minute walk test, and timed up and go test were characterized using hierarchical linear modeling. Recovery predictors were sequentially modeled after validation of the basic developmental models. Gender was a significant predictor (P < or= .003) of physical performance measure scores 1 week after surgery. Thereafter, men and women had similar rates of improvement. Preoperative score was a significant predictor (P < or= .001) in all models. Patients' and surgeons' expectations of outcome need to take preoperative function into account.

Performance-based methods for measuring the physical function of patients with osteoarthritis of the hip or knee: a systematic review of measurement properties

OBJECTIVE

To systematically review the measurement properties (i.e. internal consistency, reproducibility, validity, responsiveness and interpretability) of all performance-based methods which have been used to measure the physical function of patients with osteoarthritis of the hip or knee.

METHODS

A systematic search was conducted in Medline, CINAHL, PsychINFO and Embase. Standardized criteria were applied to assess the quality of the clinimetric studies and the measurement properties.

RESULTS

Twenty-six performance-based methods were included: 13 walking tests, two stair-climb tests, one chair test and ten multi-item tests. Three out of seven multi-activity tests were tested for internal consistency and two were rated positively. Fourteen tests were tested for reliability and five were rated positively. The absolute measurement error (agreement) was assessed for 10 tests. Only one test received a positive rating. Fourteen tests were tested for construct validity. Only two tests received positive ratings. Responsiveness was assessed for 12 tests, but none of them received a positive rating. A lot of indeterminate ratings were given, mostly for small studies or non-optimal analyses.

CONCLUSION

Many more well-designed studies are needed to assess the measurement properties of performance-based methods. More importantly, however, before one can make a justified choice of a particular performance-based method, consensus is needed on what activities should be included in a performance-based test for patients with hip or knee osteoarthritis and which aspects of function should be measured.

Performance measures were necessary to obtain a complete picture of osteoarthritic patients

OBJECTIVES

Self-report questionnaires and performance measures represent two methods for assessing physical function. A recurring theme is that self-report measures are superior to performance measures. This study investigated the association between three performance test outcomes of four activities (pain, exertion, and time or distance; for self-paced walk, stair test, timed up-and-go, 6-minute walk) with self-reports of physical function (WOMAC Physical Function subscale and LEFS) and the association between the change scores of the performance tests and those of the self-report measures.

STUDY DESIGN AND SETTING

Performance and self-report measures were administered three times (presurgery and at approximately 1 week and approximately 8 weeks post arthroplasty) to 85 patients who underwent total hip or knee arthroplasty. Components of the performance tests were pooled within each domain across the four measures. Multiple regression analyses were applied. Independent variables were performance tests components; dependent variables were self-report measures. Standardized regression coefficients described the cross-sectional and longitudinal associations.

RESULTS

Pain was the principal determinant of WOMAC Physical Function subscale scores. Pain, exertion, and time or distance were strongly associated with the LEFS at the first, second, and third assessments, respectively. Change in pain was most strongly associated with change in self-reported physical function.

CONCLUSION

Our findings caution against the isolated use of self-report assessments of physical function.

Joint Recovery Programme Versus Usual Care

OBJECTIVE

The objective of the present study was to determine the incremental cost-effectiveness of a clinical pathway for patients undergoing joint replacement, the Joint Recovery Programme (JRP), as compared with usual care. The existing care process was revised to contain costs and shorten waiting lists by facilitating patient flows and improve healthcare efficiency.

METHODS

The study design was a before-after trial. In total, 160 patients undergoing total hip and total knee replacement, aged 28 to 87 years (mean age, 64.4 years), were treated either according to the Joint Recovery Programme (a standardized care process with patient education and rehabilitation in groups) or usual care. Both groups were followed for 1 year. Costs were studied from a societal perspective. Outcomes included functional level (Harris Hip score and American Knee Society score) and generic quality of life (EuroQol).

RESULTS

The results indicate that the Joint Recovery Programme resulted in a significant cost saving when compared with usual care mainly as a result of a considerable (>50%) reduction in length of hospital stay. The average cost saving per patient amounted to $1261 in the total hip replacement group and $3336 in the total knee replacement group. At the same time, both functional level and quality of life were higher in the JRP group.

CONCLUSIONS

Clinical pathway dominates usual care and is a highly cost-effective approach to contain costs related to joint replacement surgery without adverse consequences for patients.

Reproducibility and validity of the DynaPort KneeTest

OBJECTIVE

To determine the reproducibility and validity of the DynaPort KneeTest, a performance-based test that measures quality of movement of patients undergoing total knee replacement (TKR).

METHODS

A total of 92 patients with osteoarthritis (OA) of the knee performed the KneeTest twice on the same day; 94 healthy controls performed the KneeTest once. During the test, 29 activities were performed with accelerometers attached to the body. Relevant functional parameters were extracted from the accelerometers. A selection of parameters was used to calculate activity scores, based on the ability of parameters to discriminate between patients and controls (regression analyses). Based on internal consistency analyses (Cronbach's alpha), redundant activities were removed. Four cluster scores and a total KneeScore were calculated from the remaining activity scores. Reproducibility and validity of the cluster scores and the total KneeScore 2 were assessed.

RESULTS

Based on internal consistency analyses, the test was reduced to 23 activities. Inter- and intraobserver reliability using intraclass correlation coefficients were 0.90 (0.83-0.94) and 0.95 (0.83-0.98), respectively. Limits of inter- and intraobserver agreement were -8.3 to 11.3 and -4.2 to 9.0. Construct validity was confirmed by expected correlations with the Western Ontario and McMaster University Osteoarthritis Index physical functioning (0.55), Medical Outcomes Study Short Form-36 Health Survey physical functioning (0.62), and Knee Society Score function (0.64).

CONCLUSION

The KneeTest is a useful performance-based measure for research in patients with knee OA undergoing TKR, with good reliability and validity. Further research is required to improve its usefulness for clinical practice.

Construct validity of the DynaPort KneeTest: a comparison with observations of physical therapists

OBJECTIVE

To assess the construct validity of the DynaPort KneeTest (KneeTest), which is a performance-based test to assess functioning of patients with knee osteoarthritis (OA). Scores on the KneeTest (KneeScore) were compared with observations of physical therapists of the patients' functional disability. The reliability of these observations was also assessed.

METHOD

Twelve physical therapists received identical video tapes showing the performance of 33 patients on the KneeTest. Each physical therapist rated the functional disability of each patient, performing the 23 activities of the KneeTest, on 23 Visual Analogue Scales (VAS(activity)). The 23 VAS(activity) scores were averaged into a VAS(average) score. At the end of the test, an overall rating for the general performance of the patient was given on a VAS(overall). Inter-observer Reliability was assessed for the VAS(activity) scores, VAS(average), and the VAS(overall).

RESULTS

Inter-observer reliability of the VAS(average) was higher (ICC 0.85, 95% CI 0.74-0.92) than the VAS(overall) (ICC 0.65, 95% CI 0.51-0.77). The correlation between the KneeScore and the VAS(average), averaged over the 12 physiotherapists, was 0.86.

CONCLUSION

The construct validity of the KneeTest was supported by the strong correlation with the ratings of the patients' disability by physical therapists. Given these findings and the high test-retest reliability of the KneeTest that was found in our previous study, we conclude that the KneeTest is a valid measure for assessing functioning in orthopedic and physical therapy research in patients with knee-OA before and after total knee replacement. Longitudinal validity has to be evaluated yet.

Outcome instruments for patellofemoral arthroplasty

Although there are numerous patient outcome instruments available, the most reliable and valid instruments for evaluating patient outcomes after patellofemoral arthroplasty have not been identified. In this article, we review and evaluate the psychometric properties and practical considerations of administering general health instruments (Medical Outcomes Study (MOS) Short Form-36 and Short Form-12), knee scales (Knee Society Clinical Rating System, Knee Outcome Survey, International Knee Documentation Committee form, Knee Injury and Osteoarthritis Outcome Score) and a disease specific scale (Western Ontario and McMaster Universities Osteoarthritis Index) for patellofemoral arthroplasty outcome assessment. Based on our review of the literature, we recommend the Short Form-36 and Knee Injury and Osteoarthritis Outcome Score for evaluation of patellofemoral arthroplasty outcomes and provide recommendations for implementation of these instruments in a clinical setting.

Gait and clinical measurements in patients with knee osteoarthritis after surgery: a prospective 5-year follow-up study

The aim of this prospective follow-up study was to determine if gait measurements and/or clinical measurements could detect differences in treatment outcome between two surgical interventions in patients with knee osteoarthritis (OA). The patients were followed for 5 years after surgery. Forty patients, 55-70 years of age, with unilateral knee OA were included. The patients were treated either with a high tibial osteotomy (HTO) (n=18) or a unicompartmental knee arthroplasty (UKA) (n=22). Clinical outcome measures were the British Orthopaedic Association (BOA) score, pain during walking, passive range of knee motion (PROM) and patients' subjective opinion. The gait variables were free walking speed, step frequency, step length and single and double-stance phase for each leg. The patients were examined before surgery and 3 months, 1 year and 5 years after surgery. The time-distance variables of gait could detect differences in treatment outcome, 3 months after surgery, while the clinical outcome measures, as given here, could not detect any differences between the two groups of patients. Measurements of free walking speed could be recommended for clinical evaluation, after surgical interventions, in patients with knee OA.

A comparison of 2 continuous passive motion protocols after total knee arthroplasty: a controlled and randomized study

Effect of continuous passive motion (CPM) protocols on outcomes after total knee arthroplasty. In this prospective randomized controlled study, 147 patients were assigned to 1 of 3 treatment groups: CPM from 0 degrees to 40 degrees and increased by 10 degrees per day, CPM from 90 degrees to 50 degrees (early flexion) and gradually progressed into full extension over a 3-day period, and a no-CPM group. The CPM was administered twice a day for 3 hours over a 5-day period. All patients participated in the same postoperative physiotherapy program. Patients were assessed preoperatively, day 5, 3 months, and 1 year postoperatively. The early flexion group had significantly more range of flexion than both the standard and control groups at day 5. There was no significant difference between the groups for any other variable tested at any time frame. Key words: total knee arthroplasty, CPM, rehabilitation, outcomes.

Does total knee replacement restore normal knee function?

Despite the advanced age of many patients having total knee arthroplasty, previous attempts to quantify patient function postoperatively have not allowed for normal deterioration of musculoskeletal function that occurs with aging. We determined the effects of aging on knee function, thereby providing a realistic level of normal, healthy knee function for patients and surgeons after total knee arthroplasties. A self-administered, validated knee function questionnaire consisting of 55 scaled multiple choice questions was used in this study. Responses were collected from 243 patients at least 1 year after they had total knee arthroplasties, and from 257 individuals (age- and gender-matched) who had no previous history of knee disorders. Many of these latter subjects reported that they could do most of the activities cited in the questionnaire without symptoms attributable to their knees. However, knee symptoms were experienced more frequently during activities that placed greater loads on the extremity. There was no difference in the knee function of men and women, and both groups had continuous deterioration in knee function with increasing age. There were large differences in the functional capacity to do activities involving the knee between the group of patients who had total knee arthroplasties and the age- and gender-matched patients with no previous knee disorders. Overall, 52% of the patients who had total knee arthroplasties reported some degree of limitation in doing functional activities, versus 22% of subjects with no previous knee disorders. Two groups of activities were identified: activities in which the patients and control subjects had essentially similar knee function (swimming, golfing, and stationary biking), and activities in which the function scores of the control group exceeded the scores of the patients who had total knee arthroplasties (kneeling, squatting, moving laterally, turning and cutting, carrying loads, stretching, leg strengthening, tennis, dancing, gardening, and sexual activity). Our data show that many of the limitations reported by patients after total knee arthroplasties are shared by individuals with no previous knee disorders. However, only approximately 40% of the functional deficit present after a total knee arthroplasty seems to be attributable to the normal physiologic effects of aging. Patients who had total knee replacements still experienced substantial functional impairment compared with their age- and gender-matched peers, especially when doing biomechanically demanding activities. This suggests that significant improvements in the procedure and prosthetic designs are needed to restore normal knee function after a total knee arthroplasty.

Assessing stability and change of four performance measures: a longitudinal study evaluating outcome following total hip and knee arthroplasty

Background

Physical performance measures play an important role in the measurement of outcome in patients undergoing hip and knee arthroplasty. However, many of the commonly used measures lack information on their psychometric properties in this population. The purposes of this study were to examine the reliability and sensitivity to change of the six minute walk test (6MWT), timed up and go test (TUG), stair measure (ST), and a fast self-paced walk test (SPWT) in patients with hip or knee osteoarthritis (OA) who subsequently underwent total joint arthroplasty.

Methods

A sample of convenience of 150 eligible patients, part of an ongoing, larger observational study, was selected. This included 69 subjects who had a diagnosis of hip OA and 81 diagnosed with knee OA with an overall mean age of 63.7 ± 10.7 years. Test-retest reliability, using Shrout and Fleiss Type 2,1 intraclass correlations (ICCs), was assessed preoperatively in a sub-sample of 21 patients at 3 time points during the waiting period prior to surgery. Error associated with the measures' scores and the minimal detectable change at the 90% confidence level was determined. A construct validation process was applied to evaluate the measures' abilities to detect deterioration and improvement at two different time points post-operatively. The standardized response mean (SRM) was used to quantify change for all measures for the two change intervals. Bootstrapping was used to estimate the 95% confidence intervals (CI) for the SRMs.

Results

The ICCs (95% CI) were as follows: 6MWT 0.94 (0.88,0.98), TUG 0.75 (0.51, 0.89), ST 0.90 (0.79, 0.96), and the SPWT 0.91 (0.81, 0.97). Standardized response means varied from .79 to 1.98, being greatest for the ST and 6MWT over the studied time intervals.

Conclusions

The test-retest estimates of the 6MWT, ST, and the SPWT met the requisite standards for making decisions at the individual patient level. All measures were responsive to detecting deterioration and improvement in the early postoperative period.

Lessons learned from the hip and knee musculoskeletal outcomes data evaluation and management system

In 1994 the American Academy of Orthopaedic Surgeons established an outcomes initiative. The Musculoskeletal Outcomes Data Evaluation and Management System had two goals: (1) to create validated patient-based functional health questionnaires that would become the gold standard for musculoskeletal research, and (2) to collect data from practicing orthopaedists using these instruments. We assessed the adequacy of the hip and knee portion of the Musculoskeletal Outcomes Data Evaluation and Management System data collection process to learn how to improve these processes. Database elements included demographic and clinical information and health and well-being scales. Only 715 records or 578 patients of the initial 2419 records (30%) had complete baseline and followup information for either hip or knee replacement procedure. Only 17% of the patients who had a knee replacement and 20% of the patients who had a hip replacement returned for followup between 7 and 9 months. The Musculoskeletal Outcomes Data Evaluation and Management System achieved its goal regarding the development of validated questionnaires, but the data collection component did not. The project's implementation and management were flawed. This experience offers the field of orthopaedics valuable lessons that can be applied to future large-scale data collection efforts.

Medial unicompartmental knee arthroplasty with the Miller-Galante prosthesis

BACKGROUND

Unicompartmental knee arthroplasty has become a popular treatment alternative for osteoarthritis that is confined to the medial part of the knee. Excellent intermediate-term results recently have been reported in association with the Miller-Galante unicompartmental implant. The purpose of the present study was to report on our longer-term experience with the Miller-Galante medial unicompartmental knee implant.

METHODS

We evaluated the results of 113 medial unicompartmental knee arthroplasties that had been performed with use of the Miller-Galante implant in eighty-four patients between 1989 and 2000. The mean age of the patients at the time of surgery was sixty-eight years. Forty-five patients were men, and thirty-nine were women. Thirteen patients (sixteen knees) died at a mean of seven years after the index arthroplasty. No patient was lost to follow-up. The remaining seventy-one patients (ninety-seven knees) were followed for a mean of ten years and were evaluated with use of the Knee Society clinical and radiographic rating system.

RESULTS

Eleven knees were revised at a mean of four years after the index procedure. The mean Knee Society knee and function scores for the sixty-one patients (eighty-six knees) who were living and who had not had a revision improved from 48 and 53 points preoperatively to 93 and 80 points at the time of the most recent evaluation. The five and ten-year rates of survival were 94% and 90%, respectively, with revision to tricompartmental knee arthroplasty as the end point and 93% and 86%, respectively, with revision or radiographic loosening as the end point.

CONCLUSIONS

The Miller-Galante medial unicompartmental knee arthroplasty provided excellent pain relief and restoration of function in carefully selected patients and demonstrated durable implant survival at ten years.

Effectiveness of intensive rehabilitation on functional ability and quality of life after first total knee arthroplasty: a single-blind randomized controlled trial

OBJECTIVE

To evaluate the effectiveness of a new intensive functional rehabilitation (IFR) program on functional ability and quality of life (QOL) in persons who underwent a first total knee arthroplasty (TKA).

DESIGN

Randomized controlled trial.

SETTING

Ambulatory care.

PARTICIPANTS

Seventy-seven people with knee osteoarthritis.

INTERVENTION

Two months after TKA, subjects were randomly assigned to either a group with IFR (n=38), who received 12 supervised rehabilitation sessions combined with exercises at home between months 2 and 4 after TKA, or to a control group (n=39), who received standard care. All participants were evaluated by a blind evaluator at baseline (2mo after TKA), immediately after IFR (2mo later; POST1), and 2 and 8 months later (POST2 and POST3). Main outcome measures The primary outcome measure with respect to effectiveness was the 6-minute walk test (6MWT) at POST2. Secondary outcome measures were the 6MWT at the other evaluations and the Western Ontario and McMaster Universities Osteoarthritis Index and Medical Outcomes Study 36-Item Short-Form Health Survey.

RESULTS

Subjects in the IFR group walked longer distances (range, 23-26m) in 6 minutes at the 3 POST evaluations than subjects in the control group. At POST1 and POST2, they also had less pain, stiffness, and difficulty in performing daily activities. Positive changes in QOL in favor of the IFR were found only at POST2.

CONCLUSIONS

The IFR was effective in improving the short-term and mid-term functional ability after uncomplicated primary TKA. The magnitude of the IFR effect on the primary outcome was modest but consistent. More intensive rehabilitation should be promoted in the subacute recovery period after TKA, to optimize functional outcomes in the first year after surgery.

Evaluation of health-related quality of life of rheumatoid arthritis patients treated with celecoxib

OBJECTIVE

To study the functional status and health-related quality of life (HRQOL) of patients with rheumatoid arthritis (RA) after treatment with celecoxib, compared with placebo and naproxen.

METHODS

This was a prospective, randomized, double-blind, parallel group trial conducted at 79 sites in the United States and Canada over a 12-week treatment period. Patients were randomly assigned to 5 groups: placebo, 100 mg twice a day of celecoxib, 200 mg twice a day of celecoxib, 400 mg twice a day of celecoxib, and 500 mg twice a day of naproxen. The Health Assessment Questionnaire (HAQ) disability index was used to measure functional status. The Medical Outcomes Study Short Form 36 (SF-36) was used to measure general HRQOL.

RESULTS

Enrollees were 1,149 patients with diagnosed and active RA. At the end of the treatment period, patients in the 4 active treatment groups had significant improvement in both functional status and overall HRQOL in comparison with the placebo group. Patients in the twice-daily 100 mg celecoxib group significantly differed from placebo at weeks 2 and 6 on HAQ scores and at week 12 on 5 domains and both summary scores of the SF-36. Patients treated with twice-daily 200 mg celecoxib had significantly better functional status than placebo at all times of testing with the HAQ, and also had significantly better function than those treated with naproxen after 2 and 12 weeks of treatment. Patients in the twice-daily 200 mg and 400 mg celecoxib groups showed similar improvement in HRQOL as determined by the 8 domain scores and 2 summary scores of the SF-36.

CONCLUSION

Celecoxib was better than placebo and comparable with naproxen in improving functional status and overall HRQOL among RA patients.

Brake response time after total knee arthroplasty: when is it safe for patients to drive?

Total knee arthroplasty (TKA) dramatically decreases pain and improves mobility and quality of life. However, little has been reported on its effect on driving ability in the early postoperative period. This prospective study was conducted to compare preoperative and postoperative brake response times (BRTs) in patients undergoing TKA for osteoarthritis. The results showed that patients returned to preoperative BRT as early as 3 weeks after surgery, and at 9 weeks after surgery, BRTs were significantly improved over baseline. Based on BRT analysis patients undergoing TKA may be allowed to return to driving 6 weeks after surgery.

Categorization diminishes the reliability of hip scores

Scoring systems frequently are used to assess the outcome of total hip arthroplasty. The result may be presented as a numeric value, or in descriptive terms such as excellent, good, fair, and poor (category system). The current study was done to investigate the influence of descriptive and numeric outcomes for interobserver reliability and interscore correlation of five different hip scores. Sixty-four patients (83 hips) were included in the study. The average age of the patients at followup was 70 years (range, 48-88 years). The average followup was 6.2 years (range, 2-17 years). For the numeric outcome a higher interobserver reliability (correlation coefficient, 0.71-0.81) and interscore correlation (correlation coefficient, 0.81-0.92) were found compared with the category system (interobserver reliability[correlation coefficient, 0.57-0.72]; interscore correlation [correlation coefficient, 0.46-0.62]). Findings from the study suggest that categorization of the results of total hip arthroplasty reduces interobserver reliability and interscore correlation.

Preoperative predictors of locomotor ability two months after total knee arthroplasty for severe osteoarthritis

OBJECTIVE

To identify preoperative predictors of locomotor ability 2 months after total knee arthroplasty (TKA).

METHODS

Sixty-five participants scheduled for a first TKA were recruited. The dependent variable was the distance covered during the 6-minute gait test 2 months after TKA. The independent variables, measured before surgery, were grouped into 3 categories: 1). personal; 2). organic system, and 3). capability variables. Multiple regression analyses were conducted to determine the best predictors of the dependent variable. Modified cross-validation of the model combining predictors from the three categories was obtained with 10 random samples derived from the original cohort by resampling with replacement.

RESULTS

Predictors were identified in the 3 categories: 1). gender, number of comorbidities, body mass index, 2). knee pain, flexion and strength, lower limb mechanical power, and 3). preoperative 6-minute gait distance. When these variables were modeled together only the preoperative 6-minute gait distance and knee pain and flexion remained significant (adjusted R(2) = 0.66).

CONCLUSION

Using variables easily measured before surgery, it is possible to predict with good accuracy locomotor ability 2 months after TKA.

Functional rating for knee arthroplasty: comparison of three scoring systems

This study evaluated the reliability of three rating systems for total knee arthroplasty. Twenty-nine patients were assessed by six observers with the American Knee Society Score, the British Orthopaedic Association Score, and the Oxford 12-item questionnaire. The inter- and intraobserver variations were calculated for the American Knee Society Score and the British Orthopaedic Association Score, as was the reproducibility of the Oxford 12-item questionnaire. Components of the scores were evaluated for agreement using Kappa statistics. The British Orthopaedic Association Score had smaller interobserver variation compared to the American Knee Society Score, and the greatest reproducibility of the three systems. This was attributed to the equal weighting of its component variables. The Oxford 12-item questionnaire, a self-administered questionnaire that eliminates interobserver error, emerged as the most reliable system. Observer experience affected the reliability of the American Knee Society Score and the British Orthopaedic Association Score. Subjective variables were more reliable and reproducible than the objective components.

Comparison of commonly used orthopaedic outcome measures using palm-top computers and paper surveys

INTRODUCTION

Measuring patient-perceived outcomes following orthopaedic procedures have become an important component of clinical research and patient care. General and disease-specific outcomes measures have been developed and applied in orthopaedics to assess the patients' perceived health status. Unfortunately, paper-based, self-administered instruments remain inefficient for collecting data because of: (a) missing data (b) respondent error, and (c) the costs to administer and enter data.

OBJECTIVE

To study the comparability of palm-top computer devices and paper-pencil self-administered questionnaires in the collection of health-related quality of life (HRQL) information from patients.

METHODS

The comparability of administering HRQL questionnaires using palm-top computer and traditional paper-based forms was tested in a sample of 96 patients with complaints of hip and/or knee pain. Each patient completed mailed versions of the Medical Outcomes Study (MOS), 36-item Health Survey (SF-36), and Western Ontario and McMasters University Arthritis Index (WOMAC) three weeks prior to presenting to clinic. At the clinic they were asked to complete the same outcomes measures using the palm-top computer or a paper-and-pencil version.

ANALYSIS

In the analysis, scale distributions, floor and ceiling effects, internal consistency and retest reliability of scales were compared across the two data collection methods. Because the baseline characteristics of the groups were not strictly comparable according to age, the data were analyzed for the entire sample and stratified according to age.

RESULTS

Few statistically significant differences were found for the means, variances and intra-class correlation coefficients between the methods of administration. While the scale distribution between the two methods was comparable, the internal consistency of the scales was dissimilar.

CONCLUSIONS

Administration of HRQL questionnaires using portable palm-top computer devices has the potential advantage of decreased cost and convenience. These data lend some support for the comparability of palm-top computers and paper surveys for outcomes measures widely used in the field of orthopaedic surgery. The present study identified the lack of reliability across modes of administration that requires further study in a randomized comparability trial. These mode effects are important for orthopaedic surgeons to appreciate before implementing innovative data-capture technologies in their practices.

What functional activities are important to patients with knee replacements?

There is interest in quantifying the patient's function and mobility after joint replacement. The current study identified activities important to patients having total knee replacement and the prevalence of limitations to participation in these activities. A Total Knee Function Questionnaire consisting of 55 questions addressing the patient's participation in various activities was developed, validated, and mailed to 367 patients at least 1 year after knee replacement. Patients were asked the frequency with which they did each activity, the activity's importance to them, and the extent to which their participation was limited by their knee replacement. The questionnaire was returned by 176 patients, 40% men and 60% women, with an average age of 70.5 years. The most prevalent activities were stretching exercises (73%), leg strengthening exercises (70%), kneeling (58%), and gardening (57%). The activities most important to the patients were stretching exercises (56%), kneeling (52%), and gardening (50%); those most difficult were squatting (75%), kneeling (72%), and gardening (54%). The current study showed a high correlation between the importance of activities and frequency of patient participation confirming that knee replacement successfully restores a significant degree of function. However, after knee replacement, improvements in knee function still are needed to allow patients to do all activities that they consider important.

Older adults' recovery from surgery for osteoarthritis of the knee: psychosocial resources and constraints as predictors of outcomes

The authors investigated psychosocial resources (positive support, active coping) and psychosocial constraints (negative support, avoidant coping) as predictors of improvement in the health of 63 older adults undergoing surgery for osteoarthritis of the knee. Following surgery, patients and social partners are motivated both to strive for the appetitive goal of recovery (approach), and to protect themselves from pain and impairment (avoidance). The authors assessed resources and constraints 6 weeks after surgery as predictors of outcomes (improvement in knee pain, knee functioning, and psychological well-being) 6 months after surgery. The constraints patients encountered early in recovery were strong predictors of poor recovery. Although resources were associated with some improvement, these effects were largely accounted for by constraints.

Scoring systems in total knee arthroplasty

For assessment of total knee arthroplasty outcome, various scoring systems have been introduced. The current study assessed the interobserver correlation of four commonly used total knee arthroplasty outcome scores. One hundred eighteen total knee arthroplasties were investigated by two independent observers, using the Hungerford score, the Hospital for Special Surgery score, the Knee Society score, and the Bristol score. Each score consisted of three subscores: pain, knee, and function. For the highest interobserver correlation was computed for the Bristol score (interobserver correlation coefficient, 0.88). For knee range of motion, flexion contracture, and extension lag there was high interobserver correlation (interobserver correlation coefficient > 0.8 each). For walking distance and walking aids, there also was a high interobserver correlation (interobserver correlation coefficient > 0.7 each). For clinical assessment of total knee arthroplasty, pain should be measured on a four-step system, the knee should be assessed by measurement of range of motion, extension lag, and flexion contracture, and function should be measured on a separate score assessing walking distance and walking aids.

Validity and responsiveness of the euroqol as a measure of health-related quality of life in people enrolled in an AIDS clinical trial

OBJECTIVE

Brief utility measures are needed in clinical trials in addition to existing descriptive measures of health-related quality of life (HRQOL). We examined the reliability and validity of the EuroQol (EQ-SD) and MOS-HIV and their responsiveness to HIV-related clinical events.

METHODS

Subjects with advanced HIV disease (CD4 < 100) were enrolled in a randomized trial for CMV prophylaxis (n = 990). The EQ-5D includes a weighted sum of five domains (EQ-5D Index) and a visual analog scale (EQ-VAS). The MOS-HIV has 10 subscales and physical (PHS) and mental health summary scores (MHS). Construct validity of the EQ-5D was tested based on hypothesized relationships to subscales of the MOS-HIV. Relative precision and responsiveness to adverse experiences and opportunistic infections (Ols) were compared for the two instruments.

RESULTS

Mean age of the patients was 38, 94% were male, 80% white, and 7% had injected drugs. Mean baseline scores for EQ-5D Index and EQ-VAS were 0.80 and 76.0, respectively, 28 and 4% reported maximum scores. Mean MOS-HIV subscales score ranged from 55 (role) to 84 (cognitive); mean PHS and MHS were 47.4 and 49.5, respectively. Correlations between MOS-HIV subscales and EQ-5D Index ranged from 0.45 (role) to 0.63 (pain); correlations with EQ-VAS ranged from 0.33 (cognitive) to 0.66 (health perceptions). Correlations between MOS-HIV PHS and MHS with EQ-5D Index were 0.61 and 0.58; and with EQ-VAS, 0.57 and 0.60, respectively. Responsiveness to adverse experiences was highest for MOS-HIV pain and PHS (effect sizes = 0.9 and 0.4); pain had the highest relative precision (2.4) for adverse experiences: EQ-VAS had the greatest relative precision (1.6) for developing an OI.

CONCLUSION

In these patients with advanced HIV disease. EQ-5D showed good construct validity, but there may be a ceiling effect for its EQ-5D Index component. EQ-5D was less responsive to adverse events than the MOS-HIV. However, the EQ-VAS was most sensitive to developing an OI and is likely to be a useful measure of HRQOL for generating QALYs in cost-utility studies involving patients with advanced HIV disease.

Does body weight influence outcome after total knee arthroplasty? A 1-year analysis

Obesity has been considered an adverse influence on the outcome of total knee arthroplasty (TKA), and overweight patients often are advised against having a TKA. The role of body weight has not been shown conclusively using objective outcome measures. A group of 180 patients undergoing primary TKA performed by a single surgeon for osteoarthritis was studied prospectively. Their baseline health status and knee scores were recorded, and changes in these measures were studied at 3 and 12 months after surgery. The Nottingham Health Profile was used to assess health status, and the Knee Society score was used to assess clinical outcome. Body mass index was used as a measure of obesity. We found that body weight did not influence adversely the outcome of TKA in the short-term.

The impact of surgical-site infections following orthopedic surgery at a community hospital and a university hospital: adverse quality of life, excess length of stay, and extra cost

OBJECTIVE

To measure the impact of orthopedic surgical-site infections (SSIs) on quality of life, length of hospitalization, and cost.

DESIGN

A pairwise-matched (1:1) case-control study within a cohort.

SETTING

A tertiary-care university medical center and a community hospital.

PATIENTS

Cases of orthopedic SSIs were prospectively identified by infection control professionals. Matched controls were selected from the entire cohort of patients undergoing orthopedic surgery who did not have an SSI. Matching variables included type of surgical procedure, National Nosocomial Infections Surveillance risk index, age, date of surgery, and surgeon.

MAIN OUTCOME MEASURES

Quality of life, duration of postoperative hospital stay, frequency of hospital readmission, overall direct medical costs, and mortality rate.

RESULTS

Fifty-nine SSIs were identified. Each orthopedic SSI accounted for a median of 1 extra day of stay during the initial hospitalization (P = .001) and a median of 14 extra days of hospitalization during the follow-up period (P = .0001). Patients with SSI required more rehospitalizations (median, 2 vs 1; P = .0001) and more total surgical procedures (median, 2 vs 1; P = .0001). The median total direct cost of hospitalizations per infected patient was $24,344, compared with $6,636 per uninfected patient (P = .0001). Mortality rates were similar for cases and controls. Quality of life was adversely affected for patients with SSI. The largest decrements in scores on the Medical Outcome Study Short Form 36 questionnaire were seen in the physical functioning and role-physical domains.

CONCLUSIONS

Orthopedic SSIs prolong total hospital stays by a median of 2 weeks per patient, approximately double rehospitalization rates, and increase healthcare costs by more than 300%. Moreover, patients with orthopedic SSIs have substantially greater physical limitations and significant reductions in their health-related quality of life.

Comparative responsiveness of locomotor tests and questionnaires used to follow early recovery after total knee arthroplasty

OBJECTIVES

To compare the responsiveness of 3 locomotor tests and 2 questionnaires in the early stage after a total knee arthroplasty (TKA) and to determine if the 4 responsiveness statistics ranked the measures similarly.

DESIGN

Longitudinal study.

SETTING

Rehabilitation institute.

PARTICIPANTS

Twenty-five men and 40 women with knee osteoarthritis scheduled for a first TKA.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Six-minute gait distance, in-laboratory gait speed and stair ascent duration, Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index difficulty subscale, and Medical Outcomes Study Short-Form 36-Item Health Survey role-physical and physical functioning subscale scores. Effect size, standardized response mean, paired t test, and relative efficiency statistics were computed for 3 time intervals: (1) before TKA to 2 months after TKA, (2) 2 to 4 months after TKA, and (3) before TKA to 4 months after TKA.

RESULTS

Responsiveness varied according to tests and intervals considered. For all intervals, the WOMAC difficulty subscale was the most responsive questionnaire and the 6-minute gait test was the most responsive locomotor test. Stair ascent duration was the least responsive measure. Of the responsiveness indices used, only effect size ranked the tests differently.

CONCLUSIONS

The 6-minute gait test and the WOMAC difficulty subscale are recommended for outcome assessment during the early recovery period after TKA. Because interpretation guidelines are available and confidence intervals can be calculated for it, the standardized response mean is the most useful statistic.

Validity and responsiveness of the Knee Society Clinical Rating System in comparison with the SF-36 and WOMAC

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.

The development of a disease-specific quality of life measurement tool for osteoarthritis of the shoulder: The Western Ontario Osteoarthritis of the Shoulder (WOOS) index

OBJECTIVE

The purpose of this study was to develop and validate a disease-specific quality of life measurement tool for osteoarthritis (OA) of the shoulder.

METHODS

An instrument which could be used as the primary outcome measure in clinical trials involving patients with OA of the shoulder was developed using a specific methodological protocol: (1) identification of a specific patient population; (2) item generation; (3) item reduction; (4) pre-testing of the prototype questionnaire and (5) determining the validity, reliability and responsiveness of the final questionnaire.

RESULTS

The final instrument contains 19 items, each with a visual analog response option for the four domains (six questions for pain and physical symptoms, five questions for sport, recreation and work, five questions for lifestyle function and three questions for emotional function). Ten of the 19 questions had not been identified previously on other shoulder measurement tools. The instrument proved to be valid by demonstrating predicted correlations with previously published shoulder measures, global health status measure and range of motion. The new instrument was also more responsive than other shoulder measurement tools, a global health status measure and range of motion.

CONCLUSIONS

Since the patient's own perception of changes in health status is the most important indicator of the success of treatment we suggest that this measurement tool be used as the primary outcome in clinical evaluation of various treatments for OA of the shoulder and monitoring patients over time.

The Knee Society Index of Severity for failed total knee arthroplasty: development and validation

Compared with primary knee replacement, total knee arthroplasty revision surgery is a more complex procedure and accounts for greater expenditures of healthcare resources at each clinical stage. Overall, patients having revision procedures have poorer functional outcomes and higher complication rates than patients having primary arthroplasty. Despite the expanded scope of revision problems and the rapidly emerging technology in revision surgery, the long-term success of any method remains in question. Because there is little consensus on the timing of revision surgery, optimal surgical reconstruction, and the type of prosthesis to be implanted, the Knee Society began development of an Index of Severity for Failed Total Knee Arthroplasty. Fifty-four percent of Knee Society members completed an 82-item questionnaire that determined their clinical impression about potential risk factors for the outcomes of revision surgery for failed total knee replacements. Using these results, a consensus group developed the final version of the index. The result of the nominal group process was the Knee Society Index of Severity, which was based on eight distinct domains. Each domain was divided into attributes and weights based on the questionnaire responses and consensus meeting. Actual case scenarios from five institutions were used to test interrater reliability and validity. The interrater reliability of the average score of all ratings was 0.95; the correlation of the criterion rating with the mean rating was 0.77. When three outliers were not included, the Pearson product correlation increased to 0.92. These data support the application of the Knee Society Index of Severity as a critical component of risk factor studies, effectiveness research, and cost-effectiveness analysis involving revisions of total knee replacements.

Radiographic stage of osteoarthritis or sex of the patient does not predict one year outcome after total hip arthroplasty

OBJECTIVE

To investigate whether patients with severe radiographic osteoarthritis (OA) have a different outcome at one year after total hip replacement than patients with moderate radiographic OA. To investigate sex related differences in preoperative radiographic and self reported status and in postoperative outcome.

METHODS

184 patients (96 women) with a mean age at surgery of 71.4 years (50-92), with primary OA of the hip were investigated preoperatively and six and 12 months postoperatively with two self administered questionnaires, SF-36 and WOMAC. The radiographs were evaluated by two independent radiologists using an atlas. Minimal joint space narrowing, osteophytes, cysts, sclerosis, and deformity were assessed. A summary grade 0-3 was made, based on joint space, where 3 is severe OA. The reference population for SF-36 consisted of 2901 subjects matched for age and sex from the general Swedish population.

RESULTS

162 patients fulfilled the study criteria. 113 had grade 3, 47 grade 2, and two grade 1 radiographic OA. There was no difference in preoperative or postoperative pain and physical impairment between patients with moderate and severe radiographic OA. There were no sex related differences in preoperative radiographic status, or in postoperative outcome. Neither were any differences in preoperative radiographic status of OA found in patients with previous total hip replacement of the contralateral hip, compared with those who had not been operated on before. All patients, regardless of preoperative radiographic OA stage, showed significant postoperative improvement and at one year achieved a health related quality of life similar to that of the reference group.

CONCLUSION

The severity of radiographic changes indicating OA often weighs heavily in the surgeon's decision to perform a total hip replacement. Yet, the findings of this study emphasise that the preoperative radiographic stage of OA has no correlation with the postoperative outcome after one year. Furthermore, this study failed to detect any sex related differences in preoperative radiographic and self reported status or in postoperative outcome of hip replacement.

Functional status and health-related quality of life of elderly osteoarthritic patients treated with celecoxib

BACKGROUND

This study evaluates the impact of celecoxib on functional status, health-related quality of life (HRQOL), and safety of elderly patients (> or =70 years) with osteoarthritis (OA) of the knee and/or hip.

METHODS

Data were pooled from three prospective, randomized, multicenter, double-blind, parallel group trials, each having a 12-week treatment period. Multicenter studies were conducted in the United States and Canada. Data for patients diagnosed with active OA of the knee and/or hip in a flare state who were 70 years of age and older were included in the comparison of therapeutic doses of celecoxib or naproxen versus placebo (N = 768). Elderly patients from each of the three trials who were randomly assigned to groups treated with a placebo. 200 mg/day of celecoxib, 400 mg/ day of celecoxib, or 1000 mg/day of naproxen were included in this analysis. The Western Ontario and McMaster Universities Osteoarthritis Index was used to measure functional status. The Short Form-36 was used as a general measure of HRQOL. Safety was assessed according to the incidence and type of adverse reactions as reported by the patients and the rate of withdrawal due to adverse events.

RESULTS

At the end of the treatment period, patients in the celecoxib groups had significant improvement in both functional status and HRQOL in comparison with the placebo group. The effects of total daily doses of 200 mg of celecoxib, 400 mg of celecoxib, and 1000 mg of naproxen on functioning and HRQOL were not found to be significantly different from each other. The incidence of serious adverse events and withdrawal from the studies due to adverse events were similar in the celecoxib groups as they were in the placebo group. Overall, the naproxen group reported a significantly higher incidence of gastrointestinal adverse events than did the placebo and the 200-mg-daily celecoxib groups.

CONCLUSIONS

This study showed that celecoxib and naproxen significantly improved functional status and HRQOL in elderly patients compared with those treated with a placebo. Celecoxib-treated patients were also found to experience safety and tolerability similar to that of the placebo-treated patients.

The reliability of the American Knee Society Score

We have investigated the reliability of the American Knee Society Score (AKS), a widely used functional outcome score for knee arthroplasty. 29 subjects were assessed in random order by 6 observers, each patient seen twice by each observer. The interobserver reference intervals were 16 points for the Knee Score (0-100 points) and 21 points for the Function Score (0-100 points). The intraobserver reference intervals were smaller, 11 points and 13 points for the Knee Score and the Function Score, respectively. The presence of arthritis in other joints and general debility did not affect the reliability of the scores. The more experienced observers had greater intraobserver reproducibility. Notably, we found moderate agreement between observers in the subjective variables, while the objective variables produced lower levels of agreement. The high inter- and intraobserver variations of the AKS makes estimation of score change questionable. Reliable use of the AKS would necessitate repeated evaluation by an experienced observer.

Evaluation of the functional status aspects of health-related quality of life of patients with osteoarthritis treated with celecoxib

STUDY OBJECTIVE

To evaluate the functional status of patients with signs and symptoms of osteoarthritis of the knee after treatment with celecoxib compared with placebo and naproxen.

DESIGN

Prospective, randomized, double-blind, parallel-group, 12-week trial.

SETTING

Multicenter study conducted at 71 sites in the United States and Canada.

PATIENTS

One thousand four patients with active osteoarthritis of the knee in a flare state.

INTERVENTIONS

Patients were assigned randomly to one of five treatment groups: placebo; celecoxib 50 mg twice/day, 100 mg twice/day, and 200 mg twice/day; and naproxen 500 mg twice/day.

MEASUREMENTS AND MAIN RESULTS

The Western Ontario and McMaster Universities Osteoarthritis Index was used to measure functional status. At the end of the treatment period, patients in the four active treatment groups had significantly better functional status than those receiving placebo. Patients treated with celecoxib 100 mg twice/day had significantly better improvements in pain scores than those treated with placebo and naproxen.

CONCLUSION

Celecoxib was better than placebo and comparable with naproxen in improving aspects of functional status in patients with osteoarthritis.