Cemented, cementless or hybrid fixation options in total knee arthroplasty for osteoarthritis and other non-traumatic diseases.

BACKGROUND: It is not clear which fixation of total knee arthroplasty obtains the best clinical, functional and radiographic results in people with osteoarthritis and other non-traumatic diseases, such as rheumatoid arthritis. OBJECTIVES: To assess the benefits and harms of cemented, cementless and hybrid knee prostheses fixation techniques in participants with primary osteoarthritis (osteoarthritis following trauma was not included) and other non-traumatic diseases, such as rheumatoid arthritis. SEARCH METHODS: We searched CENTRAL (2011, issue 10), MEDLINE via PubMed, EMBASE, Current Controlled Trials, LILACS, The Cumulative Index to Nursing and Allied Health Literature, SPORTDiscus, Health Technology Assessment Database and the Database of Abstracts of Reviews of Effectiveness, all from implementation to October 2011, along with handsearches of high-yield journals and reference lists of articles. No language restrictions were applied. SELECTION CRITERIA: Randomized controlled trials (RCTs) evaluating cemented, cementless and hybrid fixation. Participants included patients that were 18 years or older with osteoarthritis and other non-traumatic diseases who were undergoing primary total knee arthroplasty. DATA COLLECTION AND ANALYSIS: Three authors independently selected the eligible trials, assessed the trial quality, risk of bias and extracted data. Researchers were contacted to obtain missing information. MAIN RESULTS: Five RCTs and 297 participants were included in this review. Using meta-analysis on roentgen stereophotogrammetric analysis (RSA) we observed that cemented fixation of the tibial components demonstrated smaller displacement in relation to cementless fixation (with and without hydroxyapatite) after a follow-up of two years (maximum total point-motion, N = 167, two RCTs, mean difference (MD) = 0.52 mm, 95% confidence interval (CI) 0.31 to 0.74). However, the risk of future aseptic loosening with uncemented fixation was approximately half that of cemented fixation according to the arthroplasty instability classification (moderate quality as assessed by GRADE) inferred from RSA (N = 216, three RCTs, risk ratio (RR) = 0.47, 95% CI 0.24 to 0.92) with a 16% absolute risk difference between groups. The number needed to treat for an additional beneficial outcome (NNTB) to prevent future aseptic loosening was 7 (95% CI 5 to 44). There was a low risk of bias for RSA among the studies included. It was not possible to perform meta-analysis on patient-important outcomes, such as the survival rate of the implant (any change of a component), patient global assessments, functional measures, pain, health-related quality of life measures and adverse events. Almost all included studies recorded functional measures of Knee Society and Hospital for Special Surgery knee scores, but the authors of each study found no significant difference between the groups. AUTHORS' CONCLUSIONS: There was a smaller displacement of the cemented tibial component in relation to the cementless fixation in studies with osteoarthritis and rheumatoid arthritis participants who underwent primary total knee prosthesis with a follow-up of two years; however, the cemented fixation presented a greater risk of future aseptic loosening than cementless fixation.

Multi-label classification for the analysis of human motion quality.

Knowing how well an activity is performed is important for home rehabilitation. We would like to not only know if a motion is being performed correctly, but also in what way the motion is incorrect so that we may provide feedback to the user. This paper describes methods for assessing human motion quality using body-worn tri-axial accelerometers and gyroscopes. We use multi-label classifiers to detect subtle errors in exercise performances of eight individuals with knee osteoarthritis, a degenerative disease of the cartilage. We present results obtained using various machine learning methods with decision tree base classifiers. The classifier can detect classes in multi-label data with 75% sensitivity, 90% specificity and 80% accuracy. The methods presented here form the basis for an at-home rehabilitation device that will recognize errors in patient exercise performance, provide appropriate feedback on the performance, and motivate the patient to continue the prescribed regimen.

Physical activity measured by the SenseWear Armband in women with rheumatoid arthritis.

BACKGROUND: Individuals with rheumatoid arthritis (RA) often are sedentary and have an increased risk of developing comorbid conditions. Women with RA are more likely to experience challenges in maintaining an active lifestyle over their life span than men with RA or people who are healthy. As the benefits of physical activity (PA) are well known, measuring PA accurately in this population is important. OBJECTIVES: The purposes of this study were: (1) to characterize PA as measured with the SenseWear Armband (SWA) in women with RA and (2) to determine the measurement time frame to obtain consistent estimates of PA and daily energy expenditure (EE) in women with RA. DESIGN: This was a cross-sectional study. METHODS: Participants wore the SWA for 7 days. Measurements of daily total energy expenditure (TEE), physical activity energy expenditure (PAEE) during activities at or above 1 metabolic equivalent (MET) level (PAEE≥1MET), PAEE during activities at or above 2 METs (PAEE≥2METs), PAEE during activities at or above 3 METs (PAEE≥3METs), and number of steps were obtained. RESULTS: Fifty-three women participated. Complete data were obtained for 47 participants (89%). Daily usage of the SWA was 98% of the time (23:31 hours/24 hours). Means (SD) were 2,099 (340) kcal/d for TEE, 1,050 (331) kcal/d for PAEE≥1MET, 642 (309) kcal/d for PAEE≥2METs, 239 (178) kcal/d for PAEE≥3METs, and 7,260 (2,710) for number of steps. Results of intraclass correlation coefficient analyses and multiple linear regressions indicated that 2 days were needed to reliably estimate TEE; 3 days for PAEE≥1MET, PAEE≥2METs, and number of steps; and 4 days for PAEE≥3METs. LIMITATIONS: The sample was composed of well-educated women with RA who had mild to moderate difficulty performing daily activities. CONCLUSION: The SWA may be useful to quantify PA in women with RA and to monitor effectiveness of interventions aiming to increase PA levels. Minimizing the number of days necessary for data collection will reduce the individual's burden and may improve adherence in studies of PA behaviors.

Contribution of hip abductor strength to physical function in patients with total knee arthroplasty.

BACKGROUND: Investigating modifiable factors that contribute to functional limitations in patients with total knee arthroplasty (TKA) may guide changes in rehabilitation protocols and improve functional outcomes. Whereas quadriceps muscle weakness has been demonstrated to contribute to functional limitations in TKA, the role of hip abductor weakness has not received attention. OBJECTIVE: The purpose of this study was to determine whether hip abductor strength (force-generating capacity) contributes to physical function beyond what can be explained by quadriceps muscle strength in patients after a TKA. DESIGN: A cross-sectional design was used in the study. SETTING: The study was conducted in a clinical laboratory at an academic center. PATIENTS: Thirty-one people with TKA (74% female; mean age=68 years, SD=8; mean body mass index=31 kg/m(2), SD=5) participated in the study. MEASUREMENTS: Strength of quadriceps muscles and hip abductors was measured using an isokinetic dynamometer. Performance-based physical function was assessed with 4 measures: self-selected walking speed, the Figure-of-8 Walk Test, the Stair Ascend/Descend Test, and the 5-Chair Rise Test. Self-reported physical function was assessed with the Western Ontario and McMaster Universities Osteoarthritis Index Physical Function Subscale. RESULTS: In hierarchical regression models, after accounting for demographic and anthropometric factors, quadriceps muscle strength was associated with performance on the Stair Ascend/Descend Test. After accounting for demographic, anthropometric, and quadriceps strength, hip abductor strength was associated with performance on the Stair Ascend/Descend Test, the Figure-of-8 Walk Test, and the 5-Chair Rise Test. LIMITATIONS: The study design precluded ascertainment of causal relationships. CONCLUSIONS: After TKA, hip abductor strength influenced physical function in participants more than did demographic or anthropometric measures or quadriceps strength. Longitudinal studies with larger samples are warranted. If findings are replicated, they will justify targeting the hip abductors during rehabilitation after TKA.

Classifying human motion quality for knee osteoarthritis using accelerometers.

In this paper, we describe methods for assessment of exercise quality using body-worn tri-axial accelerometers. We assess exercise quality by building a classifier that labels incorrect exercises. The incorrect performances are divided into a number of classes of errors as defined by a physical therapist. We focus on exercises commonly prescribed for knee osteoarthritis: standing hamstring curl, reverse hip abduction, and lying straight leg raise. The methods presented here will form the basis for an at-home rehabilitation device that will recognize errors in patient exercise performance, provide appropriate feedback on the performance, and motivate the patient to continue the prescribed regimen.

A balance exercise program appears to improve function for patients with total knee arthroplasty: a randomized clinical trial.

BACKGROUND: Patients with total knee arthroplasty (TKA) have impaired balance and movement control. Exercise interventions have not targeted these impairments in this population. OBJECTIVES: The purposes of this study were: (1) to determine the feasibility of applying a balance exercise program in patients with TKA, (2) to investigate whether a functional training (FT) program supplemented with a balance exercise program (FT+B program) could improve physical function compared with an FT program alone in a small group of individuals with TKA, and (3) to test the methods and calculate sample size for a future randomized trial with a larger study sample. DESIGN: This study was a double-blind, pilot randomized clinical trial. SETTING: The study was conducted in the clinical laboratory of an academic center. PARTICIPANTS: The participants were 43 individuals (30 female, 13 male; mean age=68 years, SD=8) who underwent TKA 2 to 6 months prior to the study. INTERVENTIONS: The interventions were 6 weeks (12 sessions) of a supervised FT or FT+B program, followed by a 4-month home exercise program. MEASUREMENTS: Feasibility measures included pain, stiffness, adherence, and attrition. The primary outcome measure was a battery of physical performance tests: self-selected gait speed, chair rise test, and single-leg stance time. Secondary outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index and the Lower Extremity Functional Scale. RESULTS: Feasibility of the balance training in people with TKA was supported by high exercise adherence, a relatively low dropout rate, and no adverse events. Both groups demonstrated clinically important improvements in lower-extremity functional status. The degree of improvement seemed higher for gait speed, single-leg stance time, and stiffness in the FT+B group compared with the FT group. LIMITATIONS: Due to the pilot nature of the study, differences between groups did not have adequate power to show statistical significance. CONCLUSIONS: There is a need for conducting a larger randomized controlled trial to test the effectiveness of an FT+B program after TKA.

Association of physical function and physical activity in women with rheumatoid arthritis.

OBJECTIVE: To explore the associations between measures of physical activity (PA) and measures of physical function (PF) in women with rheumatoid arthritis (RA). We hypothesized that the strength of the associations between PA and PF would be moderate, and that after controlling for social and biomedical characteristics, the associations would decrease. METHODS: Women with RA (n = 47, mean +/- SD age 56.5 +/- 7.0 years) participated in the cross-sectional analysis of this study. Social and biomedical characteristics explored included age, ethnicity, disease duration, marital and educational status, height, weight, comorbidity, and disease activity. PF was measured by the self-reported Health Assessment Questionnaire (HAQ) and by a battery of performance-based measures that included self-selected gait speed, the 5 chair rise test, and the single leg stance test. PA was measured by a portable activity monitor worn for 10 days, and was characterized in 2 ways: daily average number of steps and daily energy expenditure during moderate levels of PA. RESULTS: Correlations between measures of PA and PF were small to moderate (zero-order correlations = 0.189-0.479). After controlling for social and biomedical characteristics, the correlations became smaller (semi-partial correlations = 0.095-0.277) and only HAQ score remained significantly associated with PA. CONCLUSION: Associations between measures of PA and measures of PF were explained, in part, by social and biomedical characteristics in women with RA. The results indicate that measures of PF and PA may represent different constructs and support the need to measure PA in rehabilitation research in RA.

Patella fracture during rehabilitation after bone-patellar tendon-bone anterior cruciate ligament reconstruction: 2 case reports.

STUDY DESIGN: Case report. BACKGROUND: Patellar fracture is a rare but significant complication following anterior cruciate ligament (ACL) reconstruction when using a bone-patellar tendon-bone (BPTB) autograft. The purpose of these case reports is to describe 2 cases in which patellar fracture occurred during rehabilitation after ACL reconstruction using a BPTB. CASE DESCRIPTION: Both patients were 23-year-old males referred for rehabilitation after ACL reconstruction using a BPTB autograft. They were both progressing satisfactorily in rehabilitation until sustaining a fracture of the patella. One fracture occurred during the performance of the eccentric phase of a knee extension exercise during the sixth week of rehabilitation (7 weeks postsurgery), whereas the other fracture occurred during testing of the patient is quadriceps maximum voluntary isometric contraction in the ninth week of rehabilitation (10 weeks postsurgery). Both patients were subsequently treated with open reduction and internal fixation of the patella. DISCUSSION: During rehabilitation following ACL reconstruction using BPTB autograft, clinicians should consider the need to balance the sometimes-competing goals of improving quadriceps strength while providing protection to the healing graft, minimization of patellofemoral pain, and protection of the patellar donor site.