Measured ambulation and self-reported health status following total joint replacement for the osteoarthritic knee

Device-Measured Physical Activity in 3506 Individuals with Knee or Hip Arthroplasty

PURPOSE

Hip and knee arthroplasty aims to reduce joint pain and increase functional mobility in patients with osteoarthritis; however, the degree to which arthroplasty is associated with higher physical activity is unclear. The current study sought to assess the association of hip and knee arthroplasty with objectively measured physical activity.

METHODS

This cross-sectional study analyzed wrist-worn accelerometer data collected in 2013-2016 from UK Biobank participants (aged 43-78 yr). Multivariable linear regression was performed to assess step count, cadence, overall acceleration, and activity behaviors between nonarthritic controls, end-stage arthritic, and postoperative cohorts, controlling for demographic and behavioral confounders. From a cohort of 94,707 participants with valid accelerometer wear time and complete self-reported data, electronic health records were used to identify 3506 participants having undergone primary or revision hip or knee arthroplasty and 68,389 nonarthritic controls.

RESULTS

End-stage hip or knee arthritis was associated with taking 1129 fewer steps per day (95% confidence interval (CI), 811-1447; P < 0.001) and having 5.8 fewer minutes per day (95% CI, 3.0-8.7; P < 0.001) of moderate-to-vigorous activity compared with nonarthritic controls. Unilateral primary hip and knee arthroplasties were associated with 877 (95% CI, 284-1471; P = 0.004) and 893 (95% CI, 232-1554; P = 0.008) more steps than end-stage osteoarthritic participants, respectively. Postoperative unilateral hip arthroplasty participants demonstrated levels of moderate-to-vigorous physical activity and daily step count equivalent to nonarthritic controls. No difference in physical activity was observed between any cohorts in terms of overall acceleration, or time spent in daily light activity, sedentary behavior, or sleep.

CONCLUSIONS

Hip and knee arthroplasties are associated with higher levels of physical activity compared with participants with end-stage arthritis. Unilateral hip arthroplasty patients, in particular, demonstrate equivalence to nonarthritic peers at more than 1 yr after surgery.

Different modalities of patellar management in primary total knee arthroplasty: a Bayesian network meta-analysis of randomized controlled trials

BACKGROUND

The primary management modalities for the patella in TKA include patellar resurfacing, patellar non-resurfacing, patellar resurfacing with denervation, and patellar non-resurfacing with denervation. Traditionally, meta-analyses have predominantly focused on examining comparisons between two management modalities. However, this study performed a network meta-analysis to compare all four patellar management interventions to identify the most optimal approach for patellar management in TKA.

METHODS

A computer-based search of PubMed, China National Knowledge Infrastructure (CNKI), The Cochrane Library, Web of science, Embase, and MEDLINE databases was performed to identify randomized controlled trials focusing on the four management interventions for the patella in TKA. Comparisons included two-by-two comparisons as well as those involving more than two concurrent comparisons. The search timeframe spanned from inception to June 30, 2023. Two independent authors extracted the data and evaluated the quality of the literature. The Cochrane Collaboration Risk of Bias (ROB) tool was used to evaluate the overall quality of the literature. Subsequently, a network meta-analysis was conducted using the "gemtc" package of the R-4.2.3 software. Outcome measures such as anterior knee pain (AKP), reoperation rate, and patient satisfaction rate were evaluated using odd ratio (OR) and 95% confidence intervals (CI). Additionally, the knee society score (KSS), function score (FS), and range of motion (ROM) were evaluated using mean differences (MD) with associated 95% CI. The different treatment measures were ranked using the surfaces under the cumulative ranking curves (SUCRA).

RESULTS

A total of 50 randomized controlled trials involving 9,283 patients were included in the analysis. The findings from this network meta-analysis revealed that patellar resurfacing exhibited significantly lower postoperative reoperation rate (OR 0.44, 95% CI 0.24-0.63) and AKP (OR 0.58, 95% CI 0.32-1) compared to non-resurfacing. Additionally, patellar resurfacing exhibited higher postoperative KSS clinical scores in comparison with non-resurfacing (MD: 1.13, 95% CI 0.18-2.11). However, for postoperative FS, ROM, and patient satisfaction, no significant differences were observed among the four management interventions.

CONCLUSION

Patellar resurfacing emerges as the optimal management modality in primary TKA. However, future studies should aim to reduce sources of heterogeneity and minimize the influence of confounding factors on outcomes.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023434418 identifier: CRD42023434418.

Outcomes Vary by Pre-Operative Physical Activity Levels in Total Knee Arthroplasty Patients

Physical activity (PA) is suggested to reduce osteoarthritis pain; however, it may be avoided by patients requiring arthroplasty. Our goal was to investigate objective and patient-reported outcomes as a function of pre-operative PA levels in patients undergoing total knee arthroplasty (TKA). A total of 1941 patients enrolled in a multicenter prospective cohort study investigating a smartphone-based care management platform for self-directed rehabilitation underwent TKA and were included in the analysis. Activity was categorized based on the cohort's step count quartiles into low, moderate, and high pre-operative PA. Pre-operative and post-operative pain, EQ5D5L, KOOS JR, and step counts were compared by ANOVA according to activity group. Pre-operative pain scores increased with the decreasing activity level (all, p < 0.05) and were most improved post-operatively in the low PA group. High PA patients demonstrated the smallest improvements in EQ-5D-5L and KOOS JR. Low and moderate PA patients increased physical activity by three months, reaching 176% and 104% of pre-operative steps; high PA patients did not return to full step counts by one year post-operatively. Patients undergoing TKA who present with higher levels of physical activity report lower levels of pain and higher function pre-operatively but appreciate less improvement up to one year post-operatively. These results may be helpful in appropriate counseling of patient expectations before TKA.

Recovery Curve for Patient Reported Outcomes and Objective Physical Activity After Primary Total Knee Arthroplasty - A Multicenter Study Using Wearable Technology

BACKGROUND

This study aimed to describe the trajectory of recovery based on patient reported outcomes (PROs) and objective metrics of physical activity measures over the first 12 months post-total knee arthroplasty (TKA).

METHODS

In total, 1,005 participants who underwent a primary unilateral TKA surgery between November 2018 and September 2021 from a multi-site prospective study were analyzed. Generalized estimating equations were used to evaluate PROs and objective physical activity measures over time.

RESULTS

All Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), EuroQol-5D (EQ-5D) and steps per day scores were greater than pre-operative scores (P<0.05). The flights of stairs per day, gait speed and walking asymmetry all declined at 1-month (all, P<0.001). However, all subsequent scores improved by 6 months (all, P<0.01). The greatest clinically important differences from previous visit in KOOS JR (β=18.1; 95% Confidence Interval (CI)=17.2, 19.0), EQ-5D (β=0.11; 95% CI=0.10, 0.12), steps per day (β=1169.3; 95% CI=1012.7, 1325.9), gait speed (β=-0.05; 95% CI=-0.06, -0.03), and walking asymmetry (β=0.00; 95% CI=-0.03, 0.03) were observed at 3 months.

CONCLUSION

The KOOS JR, EQ-5D, and steps per day measures showed earlier improvements than other physical activity metrics, with the greatest magnitude of improvement within the first 3 months post-TKA. The greatest magnitude of improvement in walking asymmetry was not observed until 6 months, while gait speed and flights of stairs per day were not observed until 12 months. This data may further help provide expectation setting information to patients prior to surgery, and may aid in identifying outliers to the normal recovery curve who may benefit from targeted interventions.

Clinical Outcomes of Culture-Negative and Culture-Positive Periprosthetic Joint Infection: Similar Success Rate, Different Incidence of Complications

OBJECTIVE

To compare the clinical outcomes of culture-negative periprosthetic joint infection (CN PJI) with those of culture-positive periprosthetic joint infection (CP PJI).

METHODS

This study retrospectively examined data from 77 patients who underwent revision surgery due to periprosthetic joint infection (PJI) after hip and knee arthroplasty at our center from January 2012 to June 2017. There were 37 males and 40 females, with an average age of 63.6 year. All patients were classified by Tsukayama type, according to the bacterial culture results of synovial fluid and pre- and intraoperative tissues, 24 cases were included in the CN PJI group, and 53 cases were included in the CP PJI group. All patients underwent routine blood tests, liver, renal function tests, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) measurements. The remission rates of CN PJI and CP PJI were compared. The effects of the culture results on the curative effect were further compared by survival analysis.

RESULTS

The patients were followed regularly with an average of 29.2 months (range, 12-76 months). In total, there were 24 cases of CN PJI, with an incidence of 29.63%. The overall success rate of CN PJI group was 86.4% (19/22), and overall success rate of CP PJI group was 87.5% (42/48). The relative efficacy of various surgical options was: one-stage revision 100% (7/7), two-stage revision 96.3% (26/27), debridement and implant retention 64.3% (9/14), respectively. There was no significant difference in the success rate between the CN PJI group and the CP PJI group. The incidence of antibiotic-related complications for the CN PJI group was significantly higher than that of the CP PJI group, with 58.3% for CN PJI and 11.3% for CP PJI, respectively.

CONCLUSION

When CN PJI was treated according to the strict standards for the diagnosis and treatment, the success rate of treatment for the CN PJI group was similar to that for the CP PJI group. The incidence of antibiotic-related complications from the CN PJI group was higher than that from the CP PJI group.

Review and synthesis of the experience of patients following total hip or knee arthroplasty in the era of rapidly decreasing hospital length of stay

AIM

The hospital length of stay for orthopedic surgery has been decreasing during the last couple of decades. Therefore, this study was performed to explore the postoperative experiences of adult/older patients (age ≥20 years) with osteoarthritis who underwent total hip or knee arthroplasty, focusing on the first 6 weeks following discharge.

METHODS

A systematic literature search on qualitative studies was conducted using six databases, such as Medline, CINAHL and Mednar. Verbatim interview data and themes or subthemes related to the patients' experience after discharge were extracted. Content analysis was used to code interview data. Codes similar in meaning were grouped, and subcategories were formed. These subcategories were then grouped into categories.

RESULTS

Sixteen qualitative studies with 253 participants were analyzed. In total, 136 codes were generated and formed 29 subcategories. Six categories were generated: (a) postoperative pain and medication; (b) difficulty in performing activities of daily living; (c) appreciation for support and difficulties associated with receiving support; (d) variability in recovery process and information-seeking; (e) lack of patient-centered care; and (f) transportation problems and social isolation.

CONCLUSION

Our review suggests that prospective patients and their caregivers need individually tailored presurgical education and advanced planning for postsurgical reduced mobility.

Changes in actual daily physical activity and patient-reported outcomes up to 2 years after total knee arthroplasty with arthritis

The current study aimed 1) to describe changes in patient-reported outcomes and physical activity measured with an accelerometer preoperatively, 6 months and 2 years postoperatively in older patients undergoing total knee arthroplasty (TKA) for arthritis, and 2) to examine the predictors of the changes in physical activity (PA). This study included 58 patients (mean age 72.6 years, 84.5% women) who completed the Oxford Knee Score (OKS) and the 8-item Short Form Health Survey. Physical activity measured mean steps per day, duration of light physical activity and moderate-to-vigorous physical activity (MVPA) per week. All PA indicators and patient-reported outcomes improved 6 months postoperatively. After 6 months, knee-related pain and function gradually improved, and MVPA increased. The OKS was a sole predictor of improvement in PA during the 2-year study period, suggesting the importance of disease-specific quality of life.

Does Activity-Based Rehabilitation With Goal Attainment Scaling Increase Physical Activity Among Younger Knee Arthroplasty Patients? Results From the Randomized Controlled ACTION Trial

BACKGROUND

Especially in younger knee osteoarthritis patients, the ability to perform physical activity (PA) after knee arthroplasty (KA) is of paramount importance, given many patients' wish to return to work and perform demanding leisure time activities. Goal Attainment Scaling (GAS) rehabilitation after KA may improve PA because it uses individualized activity goals. Therefore, our aim was to objectively quantify PA changes after KA and to compare GAS-based rehabilitation to standard rehabilitation.

METHODS

Data were obtained from the randomized controlled ACTION trial, which compares standard rehabilitation with GAS-based rehabilitation after total and unicompartmental KA in patients <65 years of age. At 2 time points, preoperatively and 6 months postoperatively, 120 KA patients wore a validated 3-dimensional accelerometer for 1 consecutive week. Data were classified as sedentary (lying, sitting), standing, and active (walking, cycling, running). Repeated measures analysis of variance was used to compare PA changes over time.

RESULTS

Complete data were obtained for 97 patients (58% female), with a mean age of 58 years (±4.8). For the total group, we observed a significant increase in PA of 9 minutes (±37) per day (P = .01) and significant decrease in sedentary time of 20 minutes (±79) per day (P = .02). There was no difference in standing time (P = .11). There was no difference between the control group and the intervention group regarding changes in PA, nor between the total KA group and the unicompartmental KA group.

CONCLUSION

We found a small but significant increase in overall PA after KA, but no difference between GAS-based rehabilitation and standard rehabilitation. Likely, enhanced multidisciplinary perioperative strategies are needed to further improve PA after KA.

Light intensity physical activity increases and sedentary behavior decreases following total knee arthroplasty in patients with osteoarthritis

PURPOSE

To describe objectively measured changes in the volume and pattern of physical activity and sedentary behavior in patients undergoing total knee arthroplasty for osteoarthritis.

METHODS

Physical activity and sedentary behavior were measured in patients (13 males, 76 females) with a mean age of 64 years (range 55-80) and end-stage osteoarthritis of the knee, using an accelerometer (ActiGraph GT3X+) for seven consecutive days (24 h/day) prior to, 6 weeks and 6 months after total knee arthroplasty. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), University of California Los Angeles (UCLA) Activity index and range of motion (ROM) were also assessed.

RESULTS

Proportion of time spent in sedentary behavior decreased from baseline to 6 months (mean 70.1 vs. 64.0%; p = 0.009) and the interruptions to sedentary behavior improved between baseline and 6 months after total knee arthroplasty (mean 85.0-93.0 breaks/day, p = 0.014). Proportion of time spent in light physical activity increased from baseline to 6 months after total knee arthroplasty (29.0 vs. 34.8%; p = 0.008). There was no change in time spent in moderate to vigorous physical activity after total knee arthroplasty. WOMAC (median 71.0 vs. 4.0, p < 0.001), UCLA (median 2.0 vs. 5.0, p < 0.001) as well as ROM [median (0.0°-90.0°) vs. (0.0°-110°), p < 0.05] scores improved between baseline and 6 months after total knee arthroplasty.

CONCLUSION

Clinically, functional improvements in patients following total knee arthroplasty may be assessed by objectively measuring changes in low intensity activity behaviors. The use of accelerometers in this study gives new insights into activity accumulation patterns in a clinical population and highlights their use in determining a behavioral response to an intervention.

LEVEL OF EVIDENCE

II.

Historical and projected fractures associated with mobility scooters presenting to U.S. emergency departments: 2004-2025

Introduction

The proportion of mobility scooter users in the United States continues to rise. However, these devices impart a substantial yet underappreciated risk of serious injury - namely, fractures - on users.

Methods

The purpose of this cross-sectional, retrospective study was to use the National Electronic Injury Surveillance System (NEISS) to quantify the national burden of these device-associated fractures between 2004 and 2017, analyzing in two-year intervals. We also projected estimates to 2025, and described the demographic characteristics of those injured.

Results

We found that national estimates of device-associated fractures increased significantly between the 2004-2005 (N = 2583; C.I. 1851 - 3316) and 2016-2017 (N = 6553; C.I. 5026 - 8081) periods (p < 0.001). A linear regression model (R² = 0.89; P = 0.002) was applied to project 9824 such fractures (C.I. 8273-11,328) in the 2024-2025 period. Injured patients were commonly over age 65 (63.5%; C.I. 57.7%-69.4%) and white (61.4%; C.I. 50.7% - 72.1). Fractures often occurred at home (28.6%; C.I. 22.0%-35.3%) or in public (26.0%; C.I. 21.1%-30.9%).

Conclusion

Our study suggests that osteoarthritic patients relying on mobility scooters to manage pain during ambulation should be considered candidates for total joint replacement procedures. This may help minimize the growing economic and health burden of mobility scooter fractures.

The Effect of Total Knee Arthroplasty on Physical Activity and Body Mass Index: An Analysis of the Osteoarthritis Initiative Cohort

Introduction:

Preliminary analysis of accelerometry measurements has shown physical activity may not increase significantly after total knee arthroplasty (TKA). This study evaluates the effect of TKA on physical activity accelerometry measurements and body mass index (BMI).

Methods:

Using the multicenter Osteoarthritis Initiative (OAI) database, a cohort of patients with physical activity level accelerometry measurements and BMI before and after TKA was identified. Physical activity levels and BMI were acquired at pre-TKA and post-TKA accelerometry visits 2 years apart. Survey scores pertaining to knee functionality and quality of life were also analyzed before and after knee surgery. Each patient included in the study had a unilateral TKA completed between these 2 accelerometry visits. Accelerometry measurements, BMI of the patients, and survey scores relating to knee functionality and pain relief from before and after TKA were compared using paired samples t tests.

Results:

Twenty-three patients from the OAI database were identified for the paired analysis. They were evaluated at a mean postoperative follow-up of 15 months. There were no statistically significant differences between the post-TKA group and pre-TKA group for the accelerometry variables and BMI, though patients experienced a significant improvement in knee function and pain relief measures included in this analysis.

Discussion:

Although TKA can successfully restore function and relieve pain, there remains no good evidence that neither physical activity nor BMI improve postoperatively.

Conclusion:

No significant differences in physical activity and BMI were observed after TKA in this study.

Changes in Physical Activity After Total Hip or Knee Arthroplasty: A Systematic Review and Meta-Analysis of Six- and Twelve-Month Outcomes

OBJECTIVE

Little is known about the extent to which physical activity (PA) levels change following total knee or hip joint replacement relative to pain, physical function, and quality of life. Our objective was to conduct a systematic review and meta-analysis on changes in PA relative to pain, quality of life, and physical function after total knee or hip joint replacement.

METHODS

We searched the PubMed (Medline), Embase, and CINAHL databases for peer-reviewed, English-language cohort studies measuring PA with an accelerometer from presurgery to postsurgery. Random-effects models were used to produce standardized mean differences (SMDs) for PA, quality of life, pain, and physical function outcomes. Heterogeneity was assessed using I² .

RESULTS

Seven studies (336 participants) met the eligibility criteria. No significant increase in PA was found at 6 months (SMD 0.14 [95% confidence interval (95% CI) -0.05, 0.34]; I² = 0%) and a small to moderately significant effect was found for increasing PA at 12 months (SMD 0.43 [95% CI 0.22, 0.64]; I² = 0%). Large improvements were found at 6 months in physical function (SMD 0.97 [95% CI 0.12, 1.82]; I² = 92.3%), pain (SMD -1.47 [95% CI -2.28, -0.65]; I² = 91.6%), and quality of life (SMD 1.02 [95% CI 0.30, 1.74]; I² = 83.2%).

CONCLUSION

Physical activity did not change at 6 months, and a small to moderate improvement was found at 12 months postsurgery, despite large improvements in quality of life, pain, and physical function. Reasons for the lack of increased PA are unknown but may be behavioral in nature, as a sedentary lifestyle is difficult to change. Changing sedentary behavior should be a future focus of research in this subgroup.

Physical activity after total joint arthroplasty: a narrative review

Background

Total joint arthroplasty (TJA) is a common procedure to treat individuals with hip and knee osteoarthritis. While TJAs are successful in decreasing pain and improving quality of life, it is unclear whether individuals who undergo TJA become more physically active after surgery. It is possible that TJA, by itself, is not sufficient to affect the behavior of patients toward physical activity (PA) participation. To increase PA participation, individuals with TJA may need to be exposed to exercise/behavioral interventions specifically aimed to promote PA (ie, in addition to the surgery).

Objectives

This narrative review aimed to assess the evidence on 1) whether TJAs change PA participation from pre- to postsurgery and 2) whether exercise/behavioral interventions delivered before or after TJA help to promote PA in these patients.

Results

For aim 1, the studies that assessed PA from pre- to post-TJA reported that PA does not change in the first 3 months postsurgery. The results of follow-ups longer than 3 months but shorter than 12 months are contradictory, and the results of follow-ups longer than 12 months provide weak evidence of increased PA. Assessment of changes in PA due to TJA is challenged by the wide variability in demographics, methods used to assess PA, and different pathways of care used across studies. The results for aim 2 were limited by a scarcity of studies that used exercise/behavioral interventions to promote PA.

Conclusion

TJA relieves joint pain and offers a unique opportunity for patients to become more physically active. However, the current evidence is limited and unable to offer definitive results of whether TJA is effective to change PA from pre- to postsurgery. Future large studies in representative samples of patients with TJA are needed to adequately answer this question.

Measurement of physical activity in the pre- and early post-operative period after total knee arthroplasty for Osteoarthritis using a Fitbit Flex device

Total knee arthroplasty (TKA) is a standard treatment for patients with end stage knee Osteoarthritis (OA) to reduce pain and restore function. The aim of this study was to assess pre- and early post-operative physical activity (PA) with Fitbit Flex devices for patients with OA undergoing TKA and determine any benchmarks for expected post-operative activity. Significant correlations of pre-operative step count, post-operative step count, Body Mass Index (BMI) and Short Form 12 Physical Component Summaries (SF-12 PCS) were found. Mean step counts varied by 3,203 steps per day between obese and healthy weight patients, and 3,786 steps per day between those with higher and lower SF-12 PCS scores, suggesting the need for benchmarks for recovery that vary by patient pre-operative factors. A backwards stepwise regression model developed to provide patient specific step count predictions at 6 weeks had an R² of 0.754, providing a robust patient specific benchmark for post-operative recovery, while population means from BMI and SF-12 subgroups provide a clinically practical alternative.

The monitoring of activity at home after total hip arthroplasty

AIMS

Total hip arthroplasty (THA) has well known subjective benefits, but little is known objectively about the recovery of mobility in the early post-operative period.

PATIENTS AND METHODS

A total of 33 patients aged > 60 years who underwent elective primary THA had their activity monitored for 30 days post-operatively using an at-home (Fitbit) ankle accelerometer. Their mean age was 70.7 years (61 to 86); 15 (45.5%) were female. The rate of compliance and the mean level of activity were determined. Comparisons between subgroups based on age, body mass index (BMI), surgical approach, and the destination of the patients when discharged were also performed.

RESULTS

The mean compliance over the 30 days was 26.7 days (16 to 30; 89%) of use. The mean number of steps increased from 235 (5 to 1152) to 2563 (87 to 7280) (p < 0.001) between the first and the 30th post-operative day. Age < 70 years and an anterior surgical approach were significantly associated with higher levels of activity (1600 to 2400 (p = 0.016 to 0.031) and 1000 to 1800 (p = 0.017 to 0.037) more steps per day, respectively) between the second and the fourth week post-operatively. There was also a trend towards higher levels of activity in those who were discharged to their home rather than to a nursing facility (a mean of 1500 more steps per day, p = 0.02). BMI greater or less than 30 kg/m² was not predictive of activity (p = 0.45 to 0.98).

CONCLUSION

At-home remote mobility monitoring using existing commercially available technology is feasible in patients who have undergone THA. It showed a clear trend towards increased activity with the passage of time. Additionally, the remote device was able to detect differences in levels of activity clearly between patients in relation to variables of interest including age, BMI, surgical approach, and the destination of the patient at the time of discharge from hospital. Such monitoring may allow for the early identification and targeted intervention in patients who recover slowly. Cite this article: Bone Joint J 2016;98-B:1450-4.

Moderate-intensity resistance exercise alters skeletal muscle molecular and cellular structure and function in inactive older adults with knee osteoarthritis

High-intensity resistance exercise (REX) training increases physical capacity, in part, by improving muscle cell size and function. Moderate-intensity REX, which is more feasible for many older adults with disease and/or disability, also increases physical function, but the mechanisms underlying such improvements are not understood. Therefore, we measured skeletal muscle structure and function from the molecular to the tissue level in response to 14 wk of moderate-intensity REX in physically inactive older adults with knee osteoarthritis (n = 17; 70 ± 1 yr). Although REX training increased quadriceps muscle cross-sectional area (CSA), average single-fiber CSA was unchanged because of reciprocal changes in myosin heavy chain (MHC) I and IIA fibers. Intermyofibrillar mitochondrial content increased with training because of increases in mitochondrial size in men, but not women, with no changes in subsarcolemmal mitochondria in either sex. REX increased whole muscle contractile performance similarly in men and women. In contrast, adaptations in single-muscle fiber force production per CSA (i.e., tension) and contractile velocity varied between men and women in a fiber type-dependent manner, with adaptations being explained at the molecular level by differential changes in myosin-actin cross-bridge kinetics and mechanics and single-fiber MHC protein expression. Our results are notable compared with studies of high-intensity REX because they show that the effects of moderate-intensity REX in older adults on muscle fiber size/structure and myofilament function are absent or modest. Moreover, our data highlight unique sex-specific adaptations due to differential cellular and subcellular structural and functional changes.NEW & NOTEWORTHY Moderate-intensity resistance training causes sex-specific adaptations in skeletal muscle structure and function at the cellular and molecular levels in inactive older adult men and women with knee osteoarthritis. However, these responses were minimal compared with high-intensity resistance training. Thus adjuncts to moderate-intensity training need to be developed to correct underlying cellular and molecular structural and functional deficits that are at the root of impaired physical function in this mobility-limited population.

Rationale, design and protocol of a longitudinal study assessing the effect of total knee arthroplasty on habitual physical activity and sedentary behavior in adults with osteoarthritis

Background

Physical activity levels are decreased and sedentary behaviour levels are increased in patients with knee osteoarthritis (OA). However, previous studies have shown that following total knee arthroplasty (TKA), objectively measured physical activity levels do not change compared to before the surgery. Very few studies have objectively assessed sedentary behaviour following TKA. This study aims to assess patterns of objective habitual physical activity and sedentary behaviour in patients with knee OA and to determine whether these change following TKA.

Methods

Patients diagnosed with knee osteoarthritis and scheduled for unilateral primary total knee arthroplasty will be recruited from the Orthopaedic Division at the Charlotte Maxeke Johannesburg Academic Hospital. Eligible participants will have assessments completed one week before the scheduled arthroplasty, six weeks, and six months post-operatively. The primary outcomes are habitual physical activity and sedentary behaviour which will be measured using accelerometry (Actigraph GTX3+ and activPal monitors) at the specific time points. The secondary outcomes will be improvements in osteoarthritis-specific quality of life measures using the following questionnaires: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS), Knee Society Clinical Rating System (KSS), UCLA activity index; subjective pain scores, and self reported sleep quality.

Discussion

The present study will contribute to the field of musculoskeletal health by providing a rich detailed description of the patterns of accumulation of physical activity and sedentary behaviour in patients with knee OA. These data will contribute to existing knowledge using an objective measurement for the assessment of functional ability after total knee arthroplasty. Although studies have used accelerometry to measure physical activity in knee OA patients, the data provided thus far have not delved into the detailed patterns of how and when physical activity is accumulated before and after TKA. Accurate assessment of physical activity is important for physical activity interventions that target special populations.

Trial registration

NCT02675062 (4 February 2016).

Do Total Knee Arthroplasty Patients Have a Higher Activity Level Compared to Patients With Osteoarthritis?

Background:

Despite the alleviation of osteoarthritis (OA) symptoms that total knee arthroplasty (TKA) provides for patients with end-stage knee OA, recent studies have suggested that TKA may not increase physical activity levels. In this study, we compare the physical activity levels of patients with OA treated nonoperatively (non-TKA) with both patients who had received TKA (post-TKA) and patients who received TKA within 3 years of data collection (pre-TKA).

Methods:

Utilizing the Osteoarthritis Initiative database, accelerometry data were collected from non-TKA, pre-TKA, and post-TKA patients. Accelerometry data were subdivided by physical activity intensity levels, yielding daily minutes of each level of activity. Physical activity levels were then compared between non-TKA and pre-TKA/post-TKA patients. Physical activity levels for each patient were also compared to the Department of Health and Human Services (DHHS) guidelines for physical activity.

Results:

There was no difference in physical activity between non-TKA and pre-TKA patients, with the exception of non-TKA patients achieving more daily minutes of vigorous activity (P < .001). There was no difference in physical activity between non-TKA and post-TKA patients. Although 11.6% of non-TKA patients met DHHS guidelines, only 4.8% of pre-TKA and 5.3% of post-TKA patients met guidelines.

Conclusion:

Despite the improvements in patient-reported outcome measures following TKA, we found that TKA alone does not improve physical activity levels beyond those seen in the average patient with OA. In our study, the vast majority of patients with OA, treated nonoperatively or operatively, did not meet current DHHS guidelines for physical activity.

Does Physical Activity Increase After Total Hip or Knee Arthroplasty for Osteoarthritis? A Systematic Review

Study Design Systematic review. Background Despite improvements in self-reported symptoms and perceived functional ability after total hip arthroplasty (THA) and total knee arthroplasty (TKA), it is unclear whether changes in objectively measured physical activity (PA) occur after surgery. Objective To determine if objectively measured PA increases after THA and TKA in adults with osteoarthritis. Methods Five electronic databases were searched from inception to March 3, 2015. All study designs objectively measuring PA before and after THA or TKA were eligible, including randomized controlled trials, cohort studies, and case-control studies. Two reviewers independently screened abstracts and full texts and extracted study demographic, PA, and clinical outcome data. Standardized mean differences (SMDs) and 95% confidence intervals were calculated for accelerometer- and pedometer-derived estimates of PA. Risk of methodological bias was assessed with Critical Appraisal Skills Programme checklists. Results Eight studies with a total of 373 participants (238 TKA, 135 THA) were included. Findings were mixed regarding improvement in objectively measured PA at 6 months after THA (SMDs, -0.20 to 1.80) and TKA (SMDs, -0.36 to 0.63). Larger improvements from 2 studies at 1 year postsurgery were generally observed after THA (SMDs, 0.39 to 0.79) and TKA (SMDs, 0.10 to 0.85). However, at 1 year, PA levels were still considerably lower than those of healthy controls (THA SMDs, -0.25 to -0.77; TKA SMDs, -1.46 to -1.80). Risk-of-bias scores ranged from 3 to 9 out of 11 (27%-82%) for cohort studies, and from 3 to 8 out of 10 (30%-80%) for case-control studies. Conclusion The best available evidence indicates negligible changes in PA at 6 months after THA or TKA, with limited evidence for larger changes at 1 year after surgery. In the 4 studies that reported control-group data, postoperative PA levels were still considerably less than those of healthy controls. Improved perioperative strategies to instill behavioral change are required to narrow the gap between patient-perceived functional improvement and the actual amount of PA undertaken after THA and TKA. Registered with PROSPERO (registration number CRD42014010155). Level of Evidence Therapy, level 2a. J Orthop Sports Phys Ther 2016;46(6):431-442. Epub 26 Apr 2016. doi:10.2519/jospt.2016.6449.

How Much Improvement in Patient Activity Can Be Expected After TKA?

Most patients expect an improvement of physical activity after total knee arthroplasty (TKA). The aim of this study was to evaluate improvement in physical activity after TKA. An accelerometer was used to measure activity in 221 patients before and 1 year after TKA. The measurements included the total number of steps and time spent lying, sitting/standing, or walking. Threshold for achievement of health-enhancing physical activity (HEPA) guidelines and step-defined lifestyle were applied to the data. Measured steps per day improved from 5371 to 6587. Only 50 patients (22.6%) met the HEPA guidelines, whereas 31% achieved an active lifestyle. Improvement in daily step number was influenced by age (P<.001), body mass index (P<.001) and preoperative activity (P<.001). After TKA, patients improved in physical activity and one-third achieved an active lifestyle. Patient-specific characteristics and preoperative levels of physical activity had a relevant influence on activity after TKA. [Orthopedics. 2016; 39(3):S18-S23.].

Does Total Knee Arthroplasty Affect Physical Activity Levels? Data from the Osteoarthritis Initiative

Total knee arthroplasty (TKA) is associated with improved patient-reported pain levels, function, and quality of life; however, it is poorly understood whether there is increased physical activity following TKA. Using data from the Osteoarthritis Initiative (OAI), we compare physical activity, as measured using an accelerometer, and patient-reported outcome measures of 60 patients who had already received a TKA with 63 patients who eventually received a TKA during the OAI study. There was no significant difference in activity levels between the two groups as measured by the accelerometer. Total WOMAC, KOOS Quality of Life, KOOS Knee Pain, and KOOS Function scores improved in the post-TKA compared to the pre-TKA group. In both pre-TKA and post-TKA groups, physical activity guidelines were met in only 5% or less.

Patient activity after TKA depends on patient-specific parameters

BACKGROUND

Most patients expect an improvement of walking ability and an increase in activity levels after TKA. Unfortunately, few studies report qualitative and quantitative activity improvements after TKA.

QUESTIONS/PURPOSES

The aims of this study were (1) to evaluate quantity and quality of physical activity before and after TKA with an accelerometer, and to compare activity level with that of an age-matched control group without lower-extremity disorders. (2) Improvement in measured steps per day after TKA and the ability to meet physical activity guidelines were evaluated. (3) The influence of patient-specific and implant parameters were assessed.

PATIENTS AND METHODS

An accelerometer was used to measure activity in 97 patients who were assessed before TKA and 1 year after TKA. The measurements included the total number of steps, moderate to vigorous activity defined as at least 100 steps per minute, and time spent lying, sitting/standing, or walking. We then calculated the proportion of patients who met the 10,000 steps per day guideline recommendation and determined factors that predicted failure to meet that goal. Thirty-nine age-matched control subjects without lower-extremity disorders were selected and underwent the same assessments using the accelerometer for comparison with patients 1 year after TKA.

RESULTS

Measured steps per day improved from a mean of 5278 (SD, 2999) preoperatively to 6473 (SD, 3654) postoperatively (effect size, 1.23; 95% CI, 1.10-1.35; p < 0.001). Moderate to vigorous steps per day improved from a mean of 1150 (SD, 982) to 1935 (SD, 1728; p < 0.001). Times spent in lying, sitting, or standing position or during walking did not change after TKA. For all measured parameters, activity of the patients after TKA was considerably less than that of the age-matched control subjects, who walked a mean of 13,375 (SD, 4614) steps per day (p < 0.001), performed a mean of 6562 (SD, 3401) vigorous steps per day (p < 0.001), and spent a mean of 2.9 hours (SD, 1.1) per day walking (p < 0.001). Only 16 patients (16.5%) met physical activity guidelines after TKA. BMI (p = 0.017), sex (p = 0.027), and comorbidities (American Society of Anesthesiologists Grade, p = 0.042) were independent factors associated with steps per day after TKA.

CONCLUSIONS

One year after TKA, patients had increased walking and moderate to vigorous steps. However, only 16.5% achieved the guideline recommendations for walking activity. BMI, sex, and comorbidities are patient factors that are associated with activity after TKA. Even with improvements in walking, activity level after TKA remains less than that seen for age-matched control subjects. Surgeons should be aware of this when counseling patients undergoing TKA.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Associations between socioeconomic status and primary total knee joint replacements performed for osteoarthritis across Australia 2003-10: data from the Australian Orthopaedic Association National Joint Replacement Registry

Background

Relatively little is known about the social distribution of total knee joint replacement (TKR) uptake in Australia. We examine associations between socioeconomic status (SES) and TKR performed for diagnosed osteoarthritis 2003–10 for all Australian males and females aged ≥30 yr.

Methods

Data of primary TKR (n = 213,018, 57.4% female) were ascertained from a comprehensive national joint replacement registry. Residential addresses were matched to Australian Census data to identify area-level social disadvantage, and categorised into deciles. Estimated TKR rates were calculated. Poisson regression was used to model the relative risk (RR) of age-adjusted TKR per 1,000py, stratified by sex and SES.

Results

A negative relationship was observed between TKR rates and SES deciles. Females had a greater rate of TKR than males. Surgery utilisation was greatest for all adults aged 70-79 yr. In that age group differences in estimated TKR per 1,000py between deciles were greater for 2010 than 2003 (females: 2010 RR 4.32 and 2003 RR 3.67; males: 2010 RR 2.04 and 2003 RR 1.78).

Conclusions

Identifying factors associated with TKR utilisation and SES may enhance resource planning and promote surgery utilisation for end-stage osteoarthritis.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-356) contains supplementary material, which is available to authorized users.

Do activity levels increase after total hip and knee arthroplasty?

BACKGROUND

People with osteoarthritis (OA) often are physically inactive. Surgical treatment including total hip arthroplasty or total knee arthroplasty can substantially improve pain, physical function, and quality of life. However, their impact on physical activity levels is less clear.

QUESTIONS/PURPOSES

We used accelerometers to measure levels of physical activity pre- and (6 months) postarthroplasty and to examine the proportion of people meeting the American Physical Activity Guidelines.

METHODS

Sixty-three people with hip or knee OA awaiting arthroplasty were recruited from a major metropolitan hospital. Physical activity was measured using accelerometry before, and 6 months after, surgery. The ActiGraph GT1M (ActiGraph LLC, Fort Walton Beach, FL, USA) was used in this study and is a uniaxial accelerometer contained within a small activity monitor designed to measure human movement through changes in acceleration, which can then be used to estimate physical activity over time. Questionnaires were used to assess patient-reported changes in pain, function, quality of life, and physical activity. Complete data sets (including valid physical activity data) for both time points were obtained for 44 participants (70%). At baseline before arthroplasty, the activity level of patients was, on average, sedentary for 82% of the time over a 24-hour period (based on accelerometry) and self-rated as "sometimes participates in mild activities such as walking, limited shopping, and housework" according to the UCLA activity scale.

RESULTS

There was no change in objectively measured physical activity after arthroplasty. The majority of participants were sedentary, both before and after arthroplasty, and did not meet the American Physical Activity Guidelines recommended to promote health. This was despite significant improvements in self-reported measures of pain, function, quality of life, and physical activity after arthroplasty.

CONCLUSIONS

Despite patient-reported improvements in pain, function, and physical activity after arthroplasty, objectively measured improvements in physical activity may not occur. Clinicians should incorporate strategies for improving physical activity into their management of patients after hip and knee arthroplasty to maximize health status. Future research is needed to explore the factors that impact physical activity levels in people after arthroplasty.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

What proportion of people with hip and knee osteoarthritis meet physical activity guidelines? A systematic review and meta-analysis

OBJECTIVE

To determine the proportion of people with hip and knee osteoarthritis that meet physical activity guidelines recommended for adults and older adults.

METHOD

Systematic review with meta-analysis of studies measuring physical activity of participants with hip and knee osteoarthritis using an activity monitor. Physical activity levels were calculated using the mean average [95% confidence interval (CI)] weighted according to sample size. Meta-analyses determined the proportion of people meeting physical activity guidelines and recommendations of (1) ≥150 min per week of moderate to vigorous physical activity (MVPA) in bouts of ≥10 min; (2) ≥150 min per week of MVPA in absence of bouts; (3) ≥10,000 steps per day and ≥7000 steps per day. The Grades of Research, Assessment, Development and Evaluation (GRADE) approach was used to determine the quality of the evidence.

RESULTS

For knee osteoarthritis, 21 studies involving 3266 participants averaged 50 min per week (95% CI = 46, 55) of MVPA when measured in bouts of ≥10 min, 131 min per week (95% CI = 125, 137) of MVPA, and 7753 daily steps (95% CI = 7582, 7924). Proportion meta-analyses provided high quality evidence that 13% (95% CI = 7, 20) completed ≥150 min per week of MVPA in bouts of ≥10 min, low quality evidence that 41% (95% CI = 23, 61) completed ≥150 min per week of MVPA in absence of bouts, moderate quality evidence that 19% (95% CI = 8, 33) completed ≥10,000 steps per day, and low quality evidence that 48% (95% CI = 31, 65) completed ≥7000 steps per day. For hip osteoarthritis, 11 studies involving 325 participants averaged 160 min per week (95% CI = 114, 216) of MVPA when measured in bouts of ≥10 min, 189 min per week (95% CI = 166, 212) of MVPA, and 8174 daily steps (95% CI = 7670, 8678). Proportion meta-analyses provided low quality evidence that 58% (95% CI = 18, 92) completed ≥150 min per week of MVPA in absence of bouts, low quality evidence that 30% (95% CI = 13, 50) completed ≥10,000 steps per day, and low quality evidence that 60% (95% CI = 47, 73) completed ≥7000 steps per day.

CONCLUSION

A small to moderate proportion of people with knee and hip osteoarthritis met physical activity guidelines and recommended daily steps. Future research should establish the effects of increasing physical activity in this population to meet the current physical activity guidelines.

Utilisation of primary total knee joint replacements across socioeconomic status in the Barwon Statistical Division, Australia, 2006-2007: a cross-sectional study

OBJECTIVES

There are few Australian data that examine the association between total knee joint replacement (TKR) utilisation and socioeconomic status (SES). This study examined TKR surgeries with a diagnosis of osteoarthritis (OA) performed for residents of Barwon Statistical Division (BSD) for 2006-2007.

DESIGN

Cross-sectional.

SETTING

BSD, South-eastern Victoria, Australia

PARTICIPANTS

All patients who underwent a TKR for OA, 2006-2007, and whose residential postcode was identified as within the BSD of Australia, and for whom SES data were available, were eligible for inclusion.

PRIMARY OUTCOME MEASURE

Primary TKR data ascertained from the Australian Orthopaedic Association National Joint Replacement Registry. Residential addresses were matched with the Australian Bureau of Statistics census data, and the Index of Relative Socioeconomic Disadvantage was used to determine SES, categorised into quintiles whereby quintile 1 indicated the most disadvantaged and quintile 5 the least disadvantaged. Age-specific and sex-specific rates of TKR utilisation per 1000 person-years were reported for 10-year age bands.

RESULTS

Females accounted for 62.7% of the 691 primary TKR surgeries performed during 2006-2007. The greatest utilisation rates of TKR in males was 7.6 observed in those aged >79 years, and in 10.2 in females observed in those aged 70-79 years. An increase in TKR was observed for males in SES quintile four compared to quintile 1 in which the lowest utilisation which was observed (p=0.04). No differences were observed in females across SES quintiles.

CONCLUSIONS

Further investigation is warranted on a larger scale to examine the role that SES may play in TKR utilisation, and to determine whether any social disparities in TKR utilisation reflect health system biases or geographic differences.

Differences between actual and expected leisure activities after total knee arthroplasty for osteoarthritis

This prospective cohort study determined the type, frequency, intensity, and duration of actual vs expected leisure activity among a cohort undergoing total knee arthroplasty. Data on actual and expected participation in 36 leisure activities were collected preoperatively and at 12 months in 90 patients with knee osteoarthritis. Despite high expectations, there were statistically and clinically significant differences between actual and expected activity at 12 months suggesting that expectations may not have been fulfilled. The differences were equivalent to walking 14 less miles per week than expected, which is more than the amount of activity recommended in national physical activity guidelines. Perhaps an educational intervention could be implemented to help patients establish appropriate and realistic leisure activity expectations before surgery.

Cross-sectional analysis of association between socioeconomic status and utilization of primary total hip joint replacements 2006-7: Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

The utilization of total hip replacement (THR) surgery is rapidly increasing, however few data examine whether these procedures are associated with socioeconomic status (SES) within Australia. This study examined primary THR across SES for both genders for the Barwon Statistical Division (BSD) of Victoria, Australia.

METHODS

Using the Australian Orthopaedic Association National Joint Replacement Registry data for 2006-7, primary THR with a diagnosis of osteoarthritis (OA) among residents of the BSD was ascertained. The Index of Relative Socioeconomic Disadvantage was used to measure SES; determined by matching residential addresses with Australian Bureau of Statistics census data. The data were categorised into quintiles; quintile 1 indicating the most disadvantaged. Age- and sex-specific rates of primary THR per 1,000 person years were reported for 10-year age bands using the total population at risk.

RESULTS

Females accounted for 46.9% of the 642 primary THR performed during 2006-7. THR utilization per 1,000 person years was 1.9 for males and 1.5 for females. The highest utilization of primary THR was observed in those aged 70-79 years (males 6.1, and females 5.4 per 1,000 person years). Overall, the U-shaped pattern of THR across SES gave the appearance of bimodality for both males and females, whereby rates were greater for both the most disadvantaged and least disadvantaged groups.

CONCLUSIONS

Further work on a larger scale is required to determine whether relationships between SES and THR utilization for the diagnosis of OA is attributable to lifestyle factors related to SES, or alternatively reflects geographic and health system biases. Identifying contributing factors associated with SES may enhance resource planning and enable more effective and focussed preventive strategies for hip OA.

Knee arthroplasty: a cross-sectional study assessing energy expenditure and activity

BACKGROUND

What has been missing from current assessment tools post knee arthroplasty is a means by which a patient's mobility and activity levels can be objectively measured over time in a real world setting. The Intelligent Device for Energy Expenditure and Activity (Minisun, Fresno, USA) (IDEEA) is one such device that meets these criteria. It quantifies activity by measuring energy expenditure and records the type of activity performed. The purposes of this study were to (i) determine if there were differences in energy expenditure in different groups of patients at various time points pre- and post-surgery and (ii) determine the correlations between energy expenditure and each of the subjective International Knee Documentation Committee (IKDC), Oxford and Tegner scoring systems.

METHODS

Sixty-five total knee arthroplasty (TKA) patients were recruited into a cross-sectional study to collect energy expenditure and activity data using the IDEEA. Data were collected preoperatively and post-operatively at 6-week, 3-month, 6-month and 12-month time intervals.

RESULTS

Energy expenditure and type of activity did not significantly change over the five recording periods. The patients spent <5% of the recording time walking, stepping or in transitions between movements. Energy expenditure showed a low to moderate correlation with the subjective IKDC, Oxford and Tegner questionnaires.

CONCLUSIONS

Current evaluation questionnaires may not accurately record activity levels and TKA patients spend less time walking than the normal population. We believe the IDEEA is an effective tool for objectively measuring activity and energy expenditure following knee arthroplasty.

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

OBJECTIVE

To explore geographical and sociodemographic factors associated with variation in equity in access to total hip and knee replacement surgery.

DESIGN

Combining small area estimates of need and provision to explore equity in access to care.

SETTING

English census wards.

SUBJECTS

Patients throughout England who needed total hip or knee replacement and numbers who received surgery.

MAIN OUTCOME MEASURES

Predicted rates of need (derived from the Somerset and Avon Survey of Health and English Longitudinal Study of Ageing) and provision (derived from the hospital episode statistics database). Equity rate ratios comparing rates of provision relative to need by sociodemographic, hospital, and distance variables.

RESULTS

For both operations there was an "n" shaped curve by age. Compared with people aged 50-59, those aged 60-84 got more provision relative to need, while those aged >or=85 received less total hip replacement (adjusted rate ratio 0.68, 95% confidence interval 0.65 to 0.72) and less total knee replacement (0.87, 0.82 to 0.93). Compared with women, men received more provision relative to need for total hip replacement (1.08, 1.05 to 1.10) and total knee replacement (1.31, 1.28 to 1.34). Compared with the least deprived, residents in the most deprived areas got less provision relative to need for total hip replacement (0.31, 0.30 to 0.33) and total knee replacement (0.33, 0.31 to 0.34). For total knee replacement, those in urban areas got higher provision relative to need, but for total hip replacement it was highest in villages/isolated areas. For total knee replacement, patients living in non-white areas received more provision relative to need (1.04, 1.00 to 1.07) than those in predominantly white areas, but for total hip replacement there was no effect. Adjustment for hospital characteristics did not attenuate the effects.

CONCLUSIONS

There is evidence of inequity in access to total hip and total knee replacement surgery by age, sex, deprivation, rurality, and ethnicity. Adjustment for hospital and distance did not attenuate these effects. Policy makers should examine factors at the level of patients or primary care to understand the determinants of inequitable provision.

How active are patients undergoing total joint arthroplasty?: A systematic review

BACKGROUND

Qualitative research studies regarding physical activity in patients undergoing total joint arthroplasty (TJA) unfortunately are sparse in the current literature.

QUESTIONS/PURPOSES

To provide a foundation for future investigations, we performed a systematic review to identify the different instruments used to quantify physical activity in patients undergoing TJA and to determine how active these patients really are.

METHODS

We systematically reviewed the literature on the bibliographic databases Medline, Cochrane Library, and EMBASE published until September 2008, focusing on studies assessing total physical activity in patients after or undergoing TJA. Results of those studies quantifying physical activity using accelerometers and pedometers were combined using meta-analytic methods.

RESULTS

In the 26 studies included (n = 2460 patients), motion sensors and recall questionnaires were most commonly used. The research aims and goals varied widely among the studies and the results mainly were descriptive. Studies quantifying physical activity using pedometers and accelerometers suggested a weighted mean of 6721 steps/day (95% confidence interval [CI], 5744-7698). Steps per day determined by accelerometers were 2.2 times the steps measured by pedometers. Metaregression showed that walking activity decreased by 90 steps/day (95% CI, -156 to -23) every year of patient age.

CONCLUSIONS

These results suggest patients undergoing TJA are less active than recommended to achieve health-enhancing activity levels (greater than 10,000 steps/day), but they appear more active than normally assumed in typical wear simulations. Future investigations have to evolve more standardization in the assessment and reporting of physical activity in TJA patients.

The synergistic effects of lysophosphatidic acid receptor agonists and calcitriol on MG63 osteoblast maturation at titanium and hydroxyapatite surfaces

Successful osseointegration stems from the provision of a mechanically competent mineralised matrix at the implant site. Mature osteoblasts are the cells responsible for achieving this and a key factor for ensuring healthy bone tissue is associated with prosthetic materials will be 1 alpha,25 dihydroxy vitamin D3 (calcitriol). However it is known that calcitriol per se does not promote osteoblast maturation, rather the osteoblasts need to be in receipt of calcitriol in combination with selected growth factors in order to undergo a robust maturation response. Herein we report how agonists of the lysophosphatidic acid (LPA) receptor, LPA and (2S)-OMPT, synergistically co-operate with calcitriol to secure osteoblast maturation for cells grown upon two widely used bone biomaterials, titanium and hydroxyapatite. Efforts could now be focussed on functionalizing these materials with LPA receptor agonists to support in vivo calcitriol-induced osseointegration via heightened osteoblast maturation responses.

Reduced rates of primary joint replacement for osteoarthritis in Italian and Greek migrants to Australia: the Melbourne Collaborative Cohort Study

Introduction

Racial and ethnic disparities in rates of total joint replacement have been described, but little work has been done in well-established migrant groups. The aim of this study was to compare the rates of primary joint replacement for osteoarthritis for Italian and Greek migrants to Australia and Australian-born individuals.

Methods

Eligible participants (n = 39,023) aged 27 to 75 years, born in Italy, Greece, Australia and the United Kingdom, were recruited for the Melbourne Collaborative Cohort Study between 1990 and 1994. Primary hip and knee replacement for osteoarthritis between 2001 and 2005 was determined by data linkage to the Australian Orthopaedic Association National Joint Replacement Registry.

Results

Participants born in Italy and Greece had a lower rate of primary joint replacement compared with those born in Australia (hazard ratio [HR] 0.32, 95% confidence interval [CI] 0.26 to 0.39, P < 0.001), independent of age, gender, body mass index, education level, and physical functioning. This lower rate was observed for joint replacements performed in private hospitals (HR 0.17, 95% CI 0.13 to 0.23), but not for joint replacements performed in public hospitals (HR 0.96, 95% CI 0.72 to 1.29).

Conclusions

People born in Italy and Greece had a lower rate of primary joint replacement for osteoarthritis in this cohort study compared with Australian-born people, which could not simply be explained by factors such as education level, physical functioning, and weight. Although differential access to health care found in the population may explain the different rates of joint replacement, it may be that social factors and preferences regarding treatment or different rates of progression to end-stage osteoarthritis in this population are important to ethnic disparity.

Knee arthroplasty: disabilities in comparison to the general population and to hip arthroplasty using a French national longitudinal survey

Background

Knee arthroplasty is increasing exponentially due to the aging of the population and to the broadening of indications. We aimed to compare physical disability and its evolution over two years in people with knee arthroplasty to that in the general population. A secondary objective was to compare the level of disabilities of people with knee to people with hip arthroplasty.

Methodology/Principal Findings

16,945 people representative of the French population were selected in 1999 from the French census and interviewed about their level of disability. This sample included 815 people with lower limb arthroplasty. In 2001, 608 of them were re-interviewed, among whom 134 had knee arthroplasty. Among the other participants re-interviewed, we identified 68 who had undergone knee arthroplasty and 145 hip arthroplasty within the last two years (recent arthroplasty). People with knee arthroplasty reported significantly greater difficulties than the general population with bending forward (odds ratio [OR] = 4.7; 95% confidence interval [CI]: 1.7, 12.6), walking more than 500 meters (OR = 6.0; 95% CI: 1.5, 24.7) and carrying 5 kg kilograms for 10 meters (OR = 4.6; 95% CI: 1.3, 16.4). However, the two years evolution in disability was similar to that in the general population for most activities. The level of mobility was similar between people with recent knee arthroplasty and those with recent hip arthroplasty. Nevertheless, people with recent knee arthroplasty reported a lower level of disability than the other group for washing and bending forward (OR = 0.3; 95% CI: 0.1, 0.6 and OR = 0.4; 95% CI: 0.1, 0.9, respectively).

Conclusions/Significance

People with knee arthroplasty reported a higher risk of disability than the general population for common activities of daily living but a similar evolution. There was no relevant difference between recent knee and hip arthroplasties for mobility.

Total knee arthroplasty: muscle impairments, functional limitations, and recommended rehabilitation approaches

The number of total knee arthroplasty (TKA) surgeries performed each year is predicted to steadily increase. Following TKA surgery, self-reported pain and function improve, though individuals are often plagued with quadriceps muscle impairments and functional limitations. Postoperative rehabilitation approaches either are not incorporated or incompletely address the muscular and functional deficits that persist following surgery. While the reason for quadriceps weakness is not well understood in this patient population, it has been suggested that a combination of muscle atrophy and neuromuscular activation deficits contribute to residual strength impairments. Failure to adequately address the chronic muscle impairments has the potential to limit the long-term functional gains that may be possible following TKA. Postoperative rehabilitation addressing quadriceps strength should mitigate these impairments and ultimately result in improved functional outcomes. The purpose of this paper is to describe these quadriceps muscle impairments and discuss how these impairments can contribute to the related functional limitations following TKA. We will also describe the current concepts in TKA rehabilitation and provide recommendations and clinical guidelines based on the current available evidence.

LEVEL OF EVIDENCE

Therapy, level 5.

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.

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.

Trends in hip and knee joint replacement: socioeconomic inequalities and projections of need

OBJECTIVES

To examine trends in primary and revision joint (hip and knee) replacement in England between 1991 and 2000.

METHODS

Analysis of hospital episodes statistics between 1 April 1991 and 30 March 2001 for total hip replacement (THR) and total knee replacement (TKR). Descriptive statistics and regression modelling were used to summarise patients' demographic and clinical characteristics and to explore variations in joint surgery rates by age, sex, and deprivation.

RESULTS

Between 1991 and 2000, the incidence of primary THR increased by 18%, while the incidence of revision THR more than doubled. The incidence of primary TKR doubled, with revision TKR increasing by 300%. Over the 10 year period, the proportion of THR episodes that involved revision operations rose from 8% to 20%. Substantial variations in operation rates by socioeconomic status were seen, with the most deprived fifth of the population experiencing significantly lower rates. Projections estimate that primary THR numbers could rise by up to 22% by the year 2010, with primary TKR numbers rising by up to 63%.

CONCLUSIONS

Provision of joint replacement surgery in English NHS hospitals has increased substantially over the past decade. Revision operations in particular have increased markedly. The growth in primary operations has mostly occurred among those aged 60 years and over; rates among young people have changed very little. There is a significant deprivation based gradient in rates. If current trends continue there would be almost 47 000 primary hip and 54 000 primary knee operations annually by 2010.