Factors associated with gait speed recovery after total knee arthroplasty: A longitudinal study

Overhead support systems differentially affect gait analysis of overground and treadmill walking

BACKGROUND

Overhead support or catch systems are frequently used in gait studies involving clinical populations to ensure participant safety. These systems remain slack when the participant is upright and therefore are assumed to not interfere with gait biomechanics. However, these systems follow participant's transverse motion during walking via rail systems, which could produce additional inertial and frictional forces that affect gait biomechanics.

OBJECTIVE

Quantify the influence of overhead support systems on gait biomechanics during treadmill and overground walking.

METHODS

We recruited fifteen uninjured adults to perform treadmill and overground walking. In each of these walking conditions, we varied each participant's walking speed (80, 100, and 120 % of preferred speed) and attachment to an overhead support system. We measured the participants' joint angles, moments and ground reaction forces using a three-dimensional motion capture system and an instrumented treadmill built into an overground walkway. For overground and treadmill walking, we examined changes in each biomechanical variable across speed and harness conditions using one-dimensional statistical parametric mapping (spm1d).

RESULTS

During overground walking, the overhead support system altered ground reaction forces, joint kinematics, and moments, and these effects became more pronounced with increased speed. During treadmill walking, we found very few changes in gait biomechanics resulting from the harness.

CONCLUSIONS

These results caution the use of experimental paradigms involving overground walking when an overhead support is required, although these results may be less pronounced in clinical populations with slower walking speeds. Overhead support systems can be used during treadmill walking without affecting biomechanical measurements.

Wearable health technology finds improvements in daily physical activity levels following total knee arthroplasty: A prospective study

PURPOSE

Wearable technologies, like the Apple Watch, offer new possibilities for collecting objective data on physical activity post-operatively following total knee arthroplasty (TKA). This study aims to describe changes in daily physical activity levels using objective metrics over different time points following TKA.

METHODS

This study analyzed data from a prospective cohort of 152 patients undergoing a unilateral TKA. Patients wore an Apple Watch and used a digital care management application for data collection. Step count, steadiness, standing duration, gait speed and performance on a 6-min walk test were collected from Apple HealthKit at multiple time points: pre-operative, 6 weeks post-operatively, 6 months post-operatively and 12 months post-operatively. Statistical analyses were performed using R software, including descriptive statistics and paired t tests to compare outcomes at different time points post-operatively.

RESULTS

Participants demonstrated significant improvements in daily physical activity levels over the course of 12 months post-operative. At 6 months post-operative, participants showed the highest average daily step count (mean ± SD: 5293 ± 236 steps; p < 0.001), with improvements persisting at 12 months post-operative (5180 ± 260 steps; p < 0.001) compared to preoperative values. Gait speed increased from 0.88 ± 0.01 m/s preoperatively to 1.01 ± 0.01 m/s (p = 0.006) at 12 months post-operative. Standing hours increased from 9.99 ± 0.30 to 11.47 ± 0.31 h at 6 months post-operative and persisted. Steadiness and the estimated 6-minute walk test showed recovery trends, though variability remained at 12 months post-operative, suggesting the need for additional longitudinal assessment CONCLUSION: This study provides one of the first longitudinal analyses of post-operative functional recovery using Apple HealthKit, offering continuous real-world gait and activity tracking beyond traditional patient-reported measures. These findings highlight the value of wearable technology in monitoring post-operative activity and offering insights into TKA recovery patterns. The study suggests a critical recovery window at 6 months post-operative and emphasizes the need for ongoing support to maintain improvements. The integration of wearable technology in post-operative monitoring offers a promising approach to tracking patient progress and optimizing functional outcomes following TKA.

LEVEL OF EVIDENCE

Level II.

Comparison of pain, functional and psychological trajectories between total and unicompartmental knee arthroplasties: secondary analysis of a 6-month prospective observational study

INTRODUCTION

Unicompartmental knee arthroplasty (UKA) treats osteoarthritis in one knee compartment, while total knee arthroplasty (TKA) addresses all compartments. The debate focuses on UKA's advantages of quicker recovery and fewer complications versus TKA's lower long-term revision rates, emphasizing the need for thorough outcome evaluations. The aim of the present study is to describe and compare the pain, functional and psychological trajectories during a 6-month postoperative rehabilitation period between total and unicompartmental knee arthroplasties.

MATERIALS AND METHODS

115 participants who had undergone either TKA or UKA were recruited. Outcome measurements were performed at 1, 4, 12 and 24 weeks post-surgery. Measurements included pain intensity (Visual Analog Scale), range of motion, walking speed (4 m walking test), physical performance (30-s chair stand test), health functioning (Western Ontario and McMaster Universities Osteoarthritis Index), pain catastrophizing (pain catastrophizing scale), fear of movement (Tampa Scale of Kinesiophobia), anxiety and depression (Hospital Anxiety and Depression Scale). A mixed-effects model was used to estimate the influence of type of surgery (either unicompartmental or total knee arthroplasty) to pain, function, and psychological trajectories.

RESULTS

Both TKA and UKA groups showed significant improvements across the six-month rehabilitation period except for anxiety symptoms in the TKA group, and fear of movement and depression in the UKA group. Between group analysis revealed that in the acute phase UKA patients showed improved range of motion and TKA patients displayed faster walking speed but higher fear of movement. Overall, the type of surgery does not significantly influence the overall rehabilitation pain, functional and psychological trajectories.

CONCLUSIONS

Despite differences in the acute phase, there are no differences in pain, functional and psychological trajectories throughout the six-month rehabilitation period. These results should be acknowledged to better inform patients and to improve patient education during the perioperative period.

TRIAL REGISTRATION NUMBER

NCT03378440 (2017-12-18), retrospectively registered.

LEVEL OF EVIDENCE

Level II.

Development of a clinical prediction rule for mobility status at discharge in patients with total knee arthroplasty: Using a decision tree model

BACKGROUND

Total knee arthroplasty (TKA) is an effective treatment to improve mobility in patients with severe knee osteoarthritis. However, some patients continue to have poor mobility after surgery. The preoperative identification of patients with poor mobility after TKA allows for better treatment selection and appropriate goal setting. The purpose of this study was to develop a clinical prediction rule (CPR) to predict mobility after TKA.

METHODS

This study included patients undergoing primary TKA. Predictors of outcome included patient characteristics, physical function, and psychological factors, which were measured preoperatively. The outcome measure was the Timed Up and Go test, which was measured at discharge. Patients with a score of ≥11 s were considered having a low-level of mobility. The classification and regression tree methodology of decision tree analysis was used for developing a CPR.

RESULTS

Of the 101 cases (mean age, 72.2 years; 71.3 % female), 26 (25.7 %) were classified as low-mobility. Predictors were the modified Gait Efficacy Scale, age, knee pain on the operated side, knee extension range of motion on the non-operated side, and Somatic Focus, a subscale of the Tampa Scale for Kinesiophobia (short version). The model had a sensitivity of 50.0 %, a specificity of 98.7 %, a positive predictive value of 92.9 %, a positive likelihood ratio of 37.5, and an area under the receiver operating characteristic curve of 0.853.

CONCLUSION

We have developed a CPR that, with some accuracy, predicts the mobility outcomes of patients after TKA. This CPR may be useful for predicting postoperative mobility and clinical goal setting.

Prediction of postoperative gait speed change after bilateral primary total knee arthroplasty in female patients using a machine learning algorithm

BACKGROUND

An important aim of total knee arthroplasty is to achieve functional recovery, which includes post-operative increase in walking speed. Therefore, predicting whether a patient will walk faster or slower after surgery is important in TKA, which has not been studied in previous literatures. Who walks faster and who walks slower after TKA? Can we predict these kinds of patients before surgery?

HYPOTHESIS

Whether or not a patient walk faster after total knee arthroplasty can be predicted with preoperative characteristics.

PATIENTS AND METHODS

In this retrospective cohort study, 128 female patients who underwent staged bilateral total knee arthroplasty were analyzed with gait analysis preoperatively and at postoperative two years. These patients were divided into three different groups according to the percentage of gait speed change after total knee arthroplasty: 1) V(+), more than 10% gait speed increase; 2) V(-), more than 10% gait speed decrease; and 3) V(0), those in-between. Gait parameters, mechanical axis angles, WOMAC pain score and Knee Society scores of the two groups (V(+) and V(-)) were compared. Furthermore, a classification model predicting whether a patient walks faster after total knee arthroplasty was designed using a machine learning algorithm.

RESULTS

After total knee arthroplasty, average gait speed increased by 0.07m/s from 0.87m/s to 0.94m/s (p<0.001) and gait speed increased in 43.8% of the patients (n=56). However, gait speed decreased in a significant number of patients (n=17, 13.3%). When V(+) and V(-) groups were compared, gait speed, cadence, sagittal/coronal knee range of motion, and Knee Society Function score were lower in the V(+) group before surgery, but became higher after surgery. Gait speed change could be predicted using three variables (preoperative gait speed, age, and the magnitude of mechanical axis angle). The area under the receiver operating characteristic curve of the machine learning model was 0.86.

DISCUSSION

After total knee arthroplasty, gait speed was maintained or increased in most patients. However, gait speed decreased in a significant number of patients. The machine learning classification model showed a good predictive performance, which could aid in the decision-making and the timing of total knee arthroplasty.

LEVEL OF EVIDENCE

III; retrospective cohort study.

Feasibility, reliability and validity of self-measurement of knee range-of-motion using an accelerometer-based smartphone application by patients with total knee arthroplasty

AIMS

Limited knee range-of-motion (ROM) is common following total knee arthroplasty (TKA). It is associated with functional limitations and patient dissatisfaction. Regular knee ROM assessment is important but accurate testing traditionally requires timely access to trained healthcare professionals. Although accelerometer-based smartphone goniometry has shown to provide reliable and valid joint angles, current evidence of its use still positions healthcare providers as end users instead of patients themselves. Therefore, to maximize the impact of smartphone goniometry on post-TKA care, our study aimed to examine the feasibility, reliability, and validity of patients' self-measurement of knee ROM using an accelerometer-based smartphone goniometry application.

METHODS

Patients were given standard instructions with a practice trial before the actual measurements. Passive knee flexion and extension ROM was measured on 2 sessions in 30 patients with TKA using 4 block-randomized methods: (i) smartphone self-assessment, (ii) long-arm goniometry by physiotherapist, (iii) smartphone assessment by physiotherapist, and (iv) extendable-arm goniometry by physiotherapist with placement adjudication. Feasibility was assessed by the number of participants who could independently perform the self-measurement. To assess intra- and inter-session reliability, we computed intraclass correlation coefficients (ICCs) from random-effects models. To assess intra- and inter-session agreement, we computed mean absolute differences (MADs) and minimum detectable change (MDC). To assess concurrent validity, we designated extendable-arm goniometry as the "gold standard" and compared other methods against it using ICCs and MADs.

RESULTS

All patients were able to comprehend and execute the assessment. 87% (n = 26) found the application easy to administer. Smartphone goniometry by patients showed excellent intra- and inter-session reliability (ICCs>0.97) and minimum variability (MAD = 0.9°-3.9°; MDC95 = 3.1°-9.0°). Smartphone or long-arm goniometry by physiotherapists did not outperform patients' self-assessment (ICC = 0.96-0.99, MAD = 0.7°-3.1°; MDC95 = 2.2°-8.0°). Compared against extendable-arm goniometry, smartphone goniometry by patients measured knee flexion and extension ROM with a MAD of 4.5° (ICC, 0.97) and 2.2° (ICC = 0.98), respectively.

CONCLUSION

Our study demonstrates that smartphone goniometry is feasible, reliable and accurate, and can be used with confidence in the self-assessment of knee ROM post-TKA. Future studies should further explore its utility in telemonitored rehabilitation, and its possible integration into mobile health applications to enhance accessibility to care following TKA.

Machine learning model identifies patient gait speed throughout the episode of care, generating notifications for clinician evaluation

INTRODUCTION

The advent of digital and mobile health innovations, especially use of wearables for passive data collection, allows remote monitoring and creates an abundance of data. For this information to be interpretable, machine learning (ML) processes are necessary.

RESEARCH QUESTION

Can a machine learning model successfully identify patients expected to have low gait speed in the early recovery period following joint replacement surgery?

METHODS

A commercial database from a smartphone-based care management platform passively collecting mobility data pre- and post-lower limb arthroplasty was used. We sought to create a ML model to predict gait speed recovery curves and identify patients at risk of poor gait speed outcome, a measure associated with range of motion and patient-reported outcomes. Model performance including sensitivity, specificity, precision, and accuracy were determined. Receiver operator curve (ROC) analysis was used to compare true and false positive rates. To benchmark our model, we compared threshold-based notifications based on the patient's current gait speed.

RESULTS

The performance of the predictive model was significantly improved compared to baseline of threshold-based exceptions using current gait speed. The ML model currently provides 53 % precision, 88 % accuracy, 36 % sensitivity, and 95 % specificity on the held-out test set. The ROC analysis suggests good clinical performance (AUC=0.81).

SIGNIFICANCE

Utilization of ML to predict gait recovery following total joint replacement is feasible and provides results with excellent specificity. This model will allow inclusion of additional data for retraining as patient populations evolve. Clinician feedback regarding notifications, including resulting actions and outcomes, can be used to further inform the model and improve clinical utility.

Long-term gait analysis in patients after total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Gait abnormalities have been described in patients after total knee arthroplasty (TKA), leading to the development of inter-joint coordination abnormalities and increased risk of falling. Such impairments have been reported to persist in the long-term, although the majority of studies assessed gait pattern especially in the first months after TKA.

RESEARCH QUESTION

What are the long-term gait impairments in patients after TKA compared to healthy age-matched subjects?

METHODS

A systematic search was conducted on MEDLINE/PubMed, EMBASE, CENTRAL and Scopus databases. Observational studies or randomized controlled trials investigating gait spatial-temporal, kinematic and kinetics parameters in a time-window longer than 6 months in patients with TKA compared to healthy age-matched subjects were included. Methodological quality was assessed using the modified Downs and Black (D&B) checklist and participants' characteristics, surgical procedures details and outcome measures were extracted. Pooled or un-pooled findings were categorized into "6 months - 1 year" and "more than 1 year" timepoint categories.

RESULTS

Twenty-eight studies (976 patients) were included. Overall quality was fair with a mean modified D&B score of 63.5 %. Reduced speed, stride length, cadence and longer stance phase were found in patients when compared to healthy individuals at "6 months - 1 year" follow-up. Spatial-temporal parameters deficits were also found at more than 1 year after TKA, where lower single-limb support and longer double-limb support durations were detected. These impairments occurred in concomitance with decreased knee range of motion along the sagittal and frontal planes and altered kinetic parameters. Hip kinematic and kinetic long-term impairments were also detected after TKA.

SIGNIFICANCE

These findings highlighted long-term gait pattern alterations in patients with TKA compared to age-matched healthy subjects. Future studies should identify interventions able to reduce long-term gait pattern alterations and improve function in patients after TKA.

Efficacy of Protein and Essential Amino Acid Supplementation in Lower Limb Surgeries: A Systematic Review and Meta-Analysis

This study aimed to examine the efficacy and safety of protein and/or essential amino acid (EAA) supplementation in all lower limb surgeries using systematic reviews and meta-analysis of randomized controlled trials (RCTs). We included RCTs that assessed the efficacy of protein and/or EAA supplementation in lower limb surgeries. On June 2, 2023, we searched EMBASE, MEDLINE, the Cochrane Central Register of Controlled Trials, the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. The primary outcomes were mobility, patient-reported outcomes (PRO), and acute kidney injury (AKI). The secondary outcomes were exercise capacity, muscle strength, muscle mass, and all adverse events. We performed meta-analyses using the random-effects model. We assessed the risk of bias using the Cochrane risk-of-bias tool and the certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation approach. We included 12 RCTs (622 patients). These studies included four on hip fracture surgery, three on total hip arthroplasty, and five on total knee arthroplasty. Protein and/or EAA supplementation may slightly improve PRO (standard mean difference 0.51, 95% confidence interval (CI): 0.22 to 0.80, low certainty of evidence). Nevertheless, it may not improve mobility (mean difference 0.07 m/s, 95% CI: -0.01 to 0.16, low certainty of evidence). No adverse events including AKI were reported. Muscle strength may have increased (standard mean difference 0.31, 95% CI: 0.02 to 0.61, very low certainty of evidence). However, exercise capacity (mean difference 5.43 m, 95% CI: -35.59 to 46.45, very low certainty of evidence) and muscle mass (standard mean difference -0.08, 95% CI: -0.49 to 0.33, very low certainty of evidence) were not improved. While protein and/or EAA supplementation in lower limb surgeries may improve PRO, it is unlikely to affect mobility. Despite this, the medical team and patients might still consider protein and/or EAA supplementation a useful option.

Quadriceps Strength Loss Following Total Knee Arthroplasty as a Predictor of Three-Month Strength Recovery: A Secondary Analysis of a Randomized Controlled Trial

Background and objectives Patients often experience significant quadriceps muscle weakness immediately after total knee arthroplasty (TKA), which can persist and lead to reduced physical function, increased risk of falls, and reduced patient satisfaction. Immediate postoperative quadriceps weakness is commonly caused by several factors, such as preoperative quadriceps weakness related to knee osteoarthritis (OA) and TKA-induced quadriceps weakness. Although many interventions have focused on addressing knee OA-related quadriceps weakness, there may be fewer studies specifically investigating TKA-induced quadriceps weakness. This study aimed to clarify whether TKA-induced quadriceps weakness is a significant predictor of quadriceps strength at three months postoperatively, highlighting the clinical importance of preoperative interventions targeting this specific weakness. Methods This secondary analysis of a randomized controlled trial included patients aged 60-79 years with advanced knee OA who underwent unilateral TKA. The study used pooled data from two groups of 11 participants each: those receiving preoperative low-intensity resistance training with blood flow restriction and those performing low-intensity resistance training with slow movement and tonic force generation. Quadriceps strength was assessed using a pull-type handheld dynamometer preoperatively at six weeks and one week as well as postoperatively at four days, one month, and three months. TKA-induced quadriceps weakness was defined as a change in strength from one week preoperatively to four days postoperatively. Postoperative quadriceps strength gain, reflecting postoperative recovery, was defined as the strength change from four days to three months postoperatively. Correlation and multiple regression analyses were used to identify the predictors of postoperative quadriceps strength at three months. Statistical significance was set at p < 0.05. Results The analysis included 22 participants. The median preoperative quadriceps strength was 1.1 Nm/kg (IQR: 0.9-1.4) at six weeks and 1.3 Nm/kg (IQR: 1.1-1.4) at one week. Quadriceps strength significantly decreased immediately after TKA (median quadriceps strength dropped to 0.4 Nm/kg (IQR: 0.3-0.4) at four days postoperatively) and gradually improved over three months (median three-month postoperative quadriceps strength was 0.9 Nm/kg (IQR: 0.8-1.0)). TKA-induced quadriceps weakness was -72% (SD: 11%), and postoperative quadriceps strength gain was 210% (IQR: 98-324%). TKA-induced quadriceps weakness was strongly correlated with quadriceps strength at four days (r = 0.84, p < 0.01). The postoperative quadriceps strength at four days was significantly correlated with the quadriceps strength at three months (r = 0.51, p = 0.02). Regression analysis showed that one-week preoperative quadriceps strength, TKA-induced quadriceps weakness, and postoperative quadriceps strength gain significantly predicted quadriceps strength at three months (R² = 0.77, p < 0.001). Conclusions This study highlights TKA-induced quadriceps weakness as a key predictor of postoperative quadriceps strength at three months. Preoperative interventions targeting TKA-induced weakness may improve postoperative recovery of quadriceps strength and functional outcomes.

Safety and Effects of a Four-Week Preoperative Low-Load Resistance Training With Blood Flow Restriction on Pre- and Postoperative Quadriceps Strength in Patients Undergoing Total Knee Arthroplasty: A Single-Blind Randomized Controlled Trial

Background/Objectives Enhancing preoperative quadriceps strength and mitigating quadriceps strength loss due to total knee arthroplasty (TKA) is crucial for post-TKA recovery. This study compared the safety and effect of a four-week preoperative regimen of low-load resistance training with blood flow restriction (LLRT-BFR) with those of low-intensity resistance training with slow movement and tonic force generation (LST) on the pre- and postoperative quadriceps strength in patients undergoing TKA. Methods In this randomized controlled trial, 22 patients were assigned to either the LLRT-BFR (n=11) or LST (n=11) group. Primary outcomes included changes in quadriceps strength before and after the intervention and surgery. To assess safety, we monitored D-dimer and high-sensitivity C-reactive protein levels pre- and post-intervention. Statistical analysis involved independent samples t-tests and Mann-Whitney U tests for group comparisons of quadriceps strength changes. Additionally, a two-way repeated-measures analysis of variance was used to assess safety parameters. Results No significant differences were observed between the BFR and LST groups in terms of the rate of increase in quadriceps strength pre- and post-intervention (BFR: median 12.1%, interquartile range -0.8% to 19.5%; LST: median 6.2%, interquartile range 2.7% to 14.7%; p>0.99) or in the rate of reduction in quadriceps strength pre- and post-surgery (BFR: mean -72.4%, standard deviation ±11.2%; LST: mean -75.3%, standard deviation ±12.2%; p=0.57). Safety assessments showed no significant main effects of time, group, or interaction on the safety parameters (all p>0.05). Conclusions LLRT-BFR and LST demonstrated comparable effects on quadriceps strength before and after intervention and surgery in patients undergoing TKA. The lack of significant changes in the safety parameters supports the safety profile of both interventions, indicating their suitability for preoperative conditioning in patients scheduled for TKA.

Cost and outcomes of Hospital-based Usual cAre versus Tele-monitor self-directed Rehabilitation (HUATR) in patients with total knee arthroplasty: A randomized, controlled, non-inferiority trial

OBJECTIVE

To evaluate the clinical efficacy and cost-effectiveness of telemonitored self-directed rehabilitation (TR) compared with hospital-based rehabilitation (HBR) for patients with total knee arthroplasty (TKA).

DESIGN

In this randomized, non-inferiority clinical trial, 114 patients with primary TKA who were able to walk independently preoperatively were randomized to receive HBR (n = 58) or TR (n = 56). HBR comprised at least five physical therapy sessions over 10 weeks. TR comprised a therapist-led onboarding session, followed by a 10-week unsupervised home-based exercise program, with asynchronous monitoring of rehabilitation outcomes using a telemonitoring system. The primary outcome was fast-paced gait speed at 12 weeks, with a non-inferiority margin of 0.10 m/s. For economic analysis, quality-adjusted-life-years (QALY) was the primary economic outcome (non-inferiority margin, 0.027 points).

RESULTS

In Bayesian analyses, TR had >95% posterior probability of being non-inferior to HBR in gait speed (week-12 adjusted TR-HBR difference, 0.02 m/s; 95%CrI, -0.05 to 0.10 m/s; week-24 difference, 0.01 m/s; 95%CrI, -0.07 to 0.10 m/s) and QALY (0.006 points; 95%CrI, -0.006 to 0.018 points). When evaluated from a societal perspective, TR was associated with lower mean intervention cost (adjusted TR-HBR difference, -S$227; 95%CrI, -112 to -330) after 24 weeks, with 82% probability of being cost-effective compared with HBR at a willingness to pay of S$0/unit of effect for the QALYs.

CONCLUSIONS

In patients with uncomplicated TKAs and relatively good preoperative physical function, home-based, self-directed TR was non-inferior to and more cost-effective than HBR over a 24-week follow-up period. TR should be considered for this patient subgroup.

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.

A Retrospective Study on the Feasibility of Using Low-burden Patient-reported Pain Scores to Track Recovery and Outcomes After Total Joint Replacement

Background

Patients undergo total joint arthroplasty to improve function and resolve pain. Patient-reported outcome measures (PROMs) are often sought to determine the success of total joint arthroplasty but are time-consuming and patient response rates are often low. This study sought to determine whether pain numeric rating scores (NRSs) were associated with PROMs and objective mobility outcomes.

Methods

This is a retrospective review of data in patients who utilized a smartphone-based care management application prior to and following total joint arthroplasty. NRS, Hip Disability and Osteoarthritis Outcome Score, Joint Replacement and Knee Injury and Osteoarthritis Outcome Score, Joint Replacement, and objective mobility data (step counts, gait speed, and gait asymmetry) were collected preoperatively and at 30 and 90 days postoperatively. Quantile regression was performed to evaluate the correlations between NRS and PROMs.

Results

Total knee arthroplasty patients reported higher NRS than total hip arthroplasty patients postoperatively. NRS was significantly correlated with gait speed preoperatively and at 30 and 90 days postoperatively on quantile regression. Gait asymmetry was significantly associated with NRS at 30 days postoperatively. Regression results suggested significant correlations between NRS and PROMs scores; Hip Disability and Osteoarthritis Outcome Score, Joint Replacement, -0.46 (95% confidence interval: -0.48 to -0.44, P < .001) and Knee Injury and Osteoarthritis Outcome Score, Joint Replacement, -0.38 (95% confidence interval: -0.40 to -0.36, P < .001).

Conclusions

NRS is correlated with both objective and subjective measures of function in patients undergoing arthroplasty. Simple pain ratings may be a valid measurement to help predict functional outcomes when collection of traditional PROMs is not feasible.

Factors associated with physical activity following total knee arthroplasty for knee osteoarthritis: a longitudinal study

BACKGROUND

After total knee arthroplasty (TKA), patients' physical activity (PA) levels at 6 months are lower than those of healthy subjects. Few studies have investigated the factors associated with PA at 6 months after TKA by objectively measuring preoperative and postoperative PA intensity using an accelerometer and knee function using a goniometer and dynamometer. The purpose of this study was to determine the factors associated with PA levels at 6 months after TKA based on objective data.

METHODS

Eighty-two patients (mean [SD] age 74.5 [6.4] years) with moderate-to-severe knee osteoarthritis (OA) who were scheduled for TKA at the Nagoya Orthopaedic and Joint Replacement Clinic from July 2018 to July 2019 were enrolled in this longitudinal study. All patients underwent evaluations of knee function, including range-of-motion and knee-extension muscle strength; knee pain; performance in the timed up-and-go test; and accelerometer-measured PA both preoperatively and 6 months postoperatively. Factors associated with PA at 6 months after TKA were assessed using a hierarchical multiple linear regression analysis adjusted for age, sex, body mass index, and presence of diabetes mellitus.

RESULTS

A higher average daily step count at 6 months after TKA was significantly associated with greater preoperative knee-extension muscle strength on the operated side (β = 0.155, p = 0.028) as well as a higher preoperative average daily step count (β = 0.834, p < 0.001). Furthermore, average daily time spent in moderate-to-vigorous-intensity PA postoperatively was significantly associated only with time spent in moderate-to-vigorous-intensity PA preoperatively (β = 0.723, p < 0.001).

CONCLUSION

These findings indicate that a higher preoperative daily step count and greater preoperative knee-extension muscle strength on the operated side may be associated with a higher daily step count at 6 months after TKA. Factors associated with PA differed by the PA intensity level. Rehabilitation and interventions for psychosocial factors before TKA beginning when mild knee OA first occurs are expected to lead to increased PA in TKA patients.

Association between Obesity and Short-Term Patient-Reported Outcomes following Total Knee Arthroplasty: A Retrospective Cohort Study in Japan

Background: This study investigated the association between obesity and short-term patient-reported outcomes after total knee arthroplasty (TKA). Methods: The primary outcomes were the Western Ontario and McMaster Universities Osteoarthritis Index's (WOMAC) pain and function scores. Data were collected preoperatively and 2 and 4 weeks after surgery. Patients were stratified into three groups based on body mass index (BMI): normal weight (BMI < 24.99 kg/m2), overweight (25 ≤ BMI < 29.99 kg/m2), and obese (BMI ≥ 30 kg/m2). The associations between BMI and the WOMAC pain and function scores were assessed using generalized linear mixed models. Results: Among the 102 patients (median age: 75.0, women [85.3%]), 29.4%, 48.0%, and 22.5% were normal weight, overweight, and obese, respectively. The mean pain and function scores at baseline were similar across the BMI-stratified groups (p = 0.727 and 0.277, respectively). The pain score significantly improved 2 weeks post-surgery (p = 0.001). The function score improved significantly 4 weeks post-surgery (p < 0.001). The group and group-by-time interaction effects lacked statistical significance. Conclusions: All patients statistically and clinically showed relevant pain reduction and functional improvement shortly after TKA, irrespective of their obesity status. These data may help healthcare professionals discuss the expectations of pain amelioration and functional improvement with TKA candidates.

Comparison of time courses in postoperative functional outcomes between simultaneous bilateral and unilateral total knee arthroplasty with propensity score matching

INTRODUCTION/OBJECTIVES

No consensus has been reached on which is better in terms of functional outcomes between simultaneous bilateral and unilateral total knee arthroplasty (TKA). As patient characteristics, such as age, sex, and body mass index, have significant effects on functional outcomes after TKA, these factors should be matched before comparisons are made. This study aimed to compare time courses in functional outcomes between simultaneous bilateral TKA and unilateral TKA after matching the patient characteristics.

MATERIALS AND METHODS

In this retrospective study, the clinical records of patients admitted to a hospital were reviewed. Of 425 patients, 43 underwent simultaneous bilateral TKA, whereas 382 underwent unilateral TKA. Propensity score matching was performed for age, sex, and body mass index between simultaneous bilateral and unilateral TKA patients. Therapists measured pain intensity, knee extensor strength, and knee-specific functional outcomes by using the new knee society score, including total score, symptoms, patient satisfaction, patient expectations, and functional activities preoperatively and 3 and 12 months postoperatively. Two-way repeated analysis of variance was performed to compare the time courses in functional outcomes between simultaneous bilateral and unilateral TKA.

RESULTS

After propensity score matching, 40 patients each for underwent bilateral TKA and unilateral TKA were selected. Knee extensor strength in simultaneous bilateral TKA patients was significantly lower than that in unilateral TKA patients at 3 months postoperatively (p = 0.04). A significant interaction was observed between the effects of time and group on knee extensor strength (F [1, 78] = 3.338; interaction: p = 0.042; η2 = 0.052). No significant interactions were found among the other variables measured.

CONCLUSIONS

Patients who underwent simultaneous bilateral TKA should undergo postoperative rehabilitation focused on alleviating delayed recovery in knee extensor strength during the acute phase.

Patient-reported outcomes measurement information system physical function and knee injury and osteoarthritis outcome score relationship on performance measures in people undergoing total knee arthroplasty

PURPOSE

Primary purpose was to identify relationships between performance-based measures onto both computerized adaptive testing [Physical Function-Computer Adaptive Testing (PF-CAT)] and joint-specific legacy [Knee injury and Osteoarthritis Outcome Score-Activities of Daily Living (KOOS-ADL)] instruments pre- and 12-month post-TKA.

METHODS

The PF-CAT and KOOS-ADL were identified as outcomes and performance on the 40-m fast-paced walking test, stair climb test and chair stand test were identified as predictors. Linear regression was used for all comparisons after adjusting for confounders.

RESULTS

Sixty-eight people with TKA (56.7% male) were tested. Better scores on the 40-m fast-paced walking (KOOS-ADL, p = 0.02), stair climb (KOOS-ADL, p = 0.05) and chair stand (KOOS-ADL, p < 0.01) associated with better self-reported scores pre-TKA. Better scores on the 40-m fast-paced walking (PF-CAT, p = 0.05; KOOS-ADL, p = 0.01), stair climb (KOOS-ADL, p < 0.01), chair stand (PF-CAT, p < 0.01) and range of motion (KOOS-ADL, p = 0.02) were associated with better self-reported scores 12-month post-TKA. Decrease knee range of motion related to poorer 40-m fast-paced walking (p = 0.01) and stair climb (p = 0.03) scores pre-TKA. Quadriceps weakness related to poorer 40-m fast-paced walking (p = 0.04) score pre-TKA.

CONCLUSION

Self-reported instruments are a moderate, but inconsistent surrogate to performance-based measures pre- and post-TKA. Our findings indicate that both self-reported and performance-based measures are necessary to fully characterize physical function and should be used jointly to aid in the recovery analysis of people undergoing TKA.Implications for RehabilitationMonitoring the trajectory of pre- to post-total knee arthroplasty (TKA) physical function is important as it directly relates to mortality, morbidity and poorer quality of life in older adults.Both self-reported and performance-based measures of physical function are used to determine progress in recovery for patients pre- and post- TKA.This study provides evidence that perceived physical function measures are a moderate, but an inconsistent, surrogate to objective physical function measures pre- and post-TKA.Joint specific deficits in knee range of motion and quadriceps strength were weakly associated with deficits in function measures pre-TKA, but no association was observed 12-month post-TKA.Our findings indicate that both self-reported and performance-based measures are necessary to fully characterize physical function and should be used jointly to aid in the complete recovery analysis of people undergoing TKA.

The impact of preoperative muscle strength on postoperative walking ability in patients undergoing total knee arthroplasty

Although knee extensor muscle strength is strongly associated with postoperative walking ability (PWA) in patients undergoing total knee arthroplasty (TKA), few studies have considered the impact of both knee extensor and flexor muscle strength. This study aimed to determine whether operative side knee flexor and extensor muscle strength before surgery affects the PWA of patients who undergo TKA while accounting for potential covariates. This multicenter retrospective cohort study involved four university hospitals, and patients who underwent unilateral primary TKA were included. The outcome measure was the 5-m maximum walking speed test (MWS), which was completed 12 weeks postoperatively. Muscle strength was measured as the maximum isometric muscle strength required for knee flexor and extensor. Three multiple regression models with a progressively larger number of variables were developed to determine the predictors of 5-m MWS at 12 weeks post-TKA surgery. One hundred thirty-one patients who underwent TKA were enrolled in the study (men, 23.7%; mean age, 73.4 ± 6.9 years). Age, sex, operative side knee flexor muscle strength before surgery, Japanese Orthopaedic Association knee score, and preoperative walking ability were significantly associated with PWA in the final model of the multiple regression analysis ( R2  = 0.35). The current findings suggest that the operative side knee flexor muscle strength before surgery is a robust modifiable predictor of improved PWA. We believe that further validation is needed to determine the causal relationship between preoperative muscle strength and PWA.

Comparison of Functional Recovery Between Unicompartmental and Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Comparisons of functional recovery between unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) using performance-based tests are lacking. Therefore, this study aimed to compare 2-minute walk test (2MWT) and Timed Up-and-Go test (TUG) results between UKA and TKA for isolated medial knee osteoarthritis (OA). We hypothesized that UKA yields faster functional recovery than TKA as measured with the 2MWT and TUG.

METHODS

We conducted a randomized controlled trial comparing medial UKA and TKA in patients with isolated medial knee OA. A total of 110 patients were enrolled; after 11 exclusions, 99 patients (50 UKA, 49 TKA) were included in the final analysis. The patients were tested using the 2MWT and TUG preoperatively and at 6 weeks, 3 and 6 months, and 1 and 2 years postoperatively. Patient-reported outcome measures (PROMs) were also evaluated. The mean 2MWT, TUG, and PROM results were compared between groups at each time point.

RESULTS

The mean 2MWT distance after UKA was significantly longer than that after TKA at 6 weeks (96.5 ± 22.6 m for UKA compared with 81.1 ± 19.1 m for TKA; difference, 18 m [95% confidence interval (CI),10.4 to 25.6 m]; p < 0.001), 3 months (102.1± 24.4 compared with 87.5 ± 22.3 m; difference, 14.7 m [95% CI, 5.4 to 24.0 m]; p = 0.002), and 6 months (102.8 ± 16.2 compared with 89.6 ± 15.3 m; difference, 13.2 m [95% CI, 6.9 to 19.5 m]; p < 0.001). The values at 1 and 2 years were similar after UKA and TKA. The mean TUG after UKA was also significantly shorter than that after TKA at 6 weeks and 3 months. The mean PROMs were similar after both treatments, with the exception of the Oxford Knee Score and subscales of the Knee injury and Osteoarthritis Outcome Score at 6 weeks and 3 months postoperatively.

CONCLUSIONS

The 2MWT indicated that UKA for isolated medial knee OA enabled faster recovery than TKA did at 6 weeks to 6 months, and earlier recovery was also seen with the TUG at 6 weeks to 3 months. The 2MWT and TUG results after UKA and TKA were similar to one another at 1 and 2 years.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Effects of 24 Weeks of a Supervised Walk Training on Knee Muscle Strength and Quality of Life in Older Female Total Knee Arthroplasty: A Retrospective Cohort Study

Poor supervision, impaired exercise adherence, and low compliance with exercise regimens result in inconsistent effects regarding exercise interventions. A supervised-walk training regimen (9 km/week) may have a positive effect on functional recovery in female total knee arthroplasty (TKA). This study aimed to evaluate the effect of a supervised walking regimen on lower limb muscle strength, functional fitness, and patient-reported outcomes in female TKA. Twenty-eight female TKA were allocated into a control (CON) (n = 14) or walk training (WT) (n = 14) group. WT on treadmills was initiated 12 weeks after TKA. All patients were examined for lower muscle strength (including extension and flexion of hip and knee), physical function (including a 6-min walk test, 8-foot up-and-go test, and 30-s chair stand test), and Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. Knee flexor (WT: CON; 64.4 ± 4.1 nm/kg: 43.7±3.3 nm/kg; p = 0.001; effect size: 5.62) and extensor strengths (WT: CON; 73.1 ± 7.5 nm/kg: 48.2 ± 2.4 nm/kg; p = 0.001; effect size: 4.47) statistically increased in the WT group compared to the CON group. The 6-min walk test (from 341.3 ± 20.5 m to 405.5 ± 30.7 m; p = 0.001; effect size: 2.46) and 8-foot up-and-go test (from 9.5 ± 0.7 s to 8.3 ± 0.7 s; p = 0.002; effect size: 1.71) tests also showed significant improvements in the WT group in the follow-up compared to the baseline. An increase in quality of life score according to the KOOS questionnaire (WT: CON; 91.0 ± 2.8: 68.1 ± 5.8; p = 0.001; effect size: 5.02) was noted in the WT group compared to the CON group in the follow-up. WT facilitated improvements in knee muscle strength and functional outcomes in TKA patients.

Interactive Combinations Between Gait Speed and Physical Function at Acute Phase Can Predict the Physical Activity at 2 Years After Total Knee Arthroplasty Using Classification and Regression Tree Analysis

OBJECTIVE

To clarify the interactive combinations of various clinical factors associated with physical activity (PA) at 2 years after total knee arthroplasty (TKA) using classification and regression tree (CART) analysis.

DESIGN

A retrospective cohort study.

SETTING

A single university hospital.

PARTICIPANTS

286 patients who underwent TKA (N=286).

MAIN OUTCOME MEASURES

PA was assessed preoperatively, 3 weeks, and 2 years after TKA. Physical functions, namely, 10 m walking test (10MWT), timed Up and Go test, 1-leg standing time, isometric knee extension and flexion strength, knee joint stability, knee pain, femora-tibial angle, and the passive knee extension and flexion angle, were measured before surgery as a baseline and 3 weeks after TKA as acute phase. CART analysis was conducted to clarify the interactive combinations that accurately predict the PA at 2 years after TKA.

RESULTS

The results of CART analysis indicated that gait speed (≥1.05 m/s) at the acute phase after TKA was the primal predictor for the postoperative PA at 2 years. The highest postoperative PA at 2 years was determined by gait speed (≥1.05 m/s) and PA (>74.5) at the acute phase. The PA at baseline and at acute phase, as well as the body mass index were also selected as predictors of postoperative PA at 2 years.

CONCLUSION

The present study suggested that acquiring gait speed (≥1.05 m/s) and PA (>74.5) in the postoperative acute phase is the predictive of a high PA at 2 years after TKA.

Development of reference charts for monitoring quadriceps strength with handheld dynamometry after total knee arthroplasty

Purpose: To develop reference charts that describe normative quadriceps strength recovery after total knee arthroplasty (TKA) as measured by handheld dynamometry (HHD).Materials and Methods: We conducted a retrospective analysis of post-TKA quadriceps strength recovery in a longitudinal dataset consisting of both clinical and research HHD data. We created sex-specific models for recovery using Generalized Additive Models for Location, Scale, and Shape. We created reference charts from the models to display the recovery of population centiles over the first six postoperative months.Results: A total of 588 patient records with 1176 observations were analyzed. Reference charts for both sexes demonstrated a rapid increase in quadriceps strength over the first 60 postoperative days followed by a more gradual increase over the next 120 days. Males appeared to demonstrate faster recovery and greater strength on average compared to females. The quadriceps strength recovery of three female patient records was plotted on the reference chart to illustrate the charts' potential clinical utility.Conclusions: These reference charts provide normative data for quadriceps strength recovery after TKA as assessed by HHD. The reference charts may augment clinicians' ability to monitor and intervene upon quadriceps weakness-a pronounced and debilitating post-TKA impairment-throughout rehabilitation.Implications for RehabilitationHandheld dynamometry (HHD) is an objective and clinically feasible method for assessing muscle strength, but normative HHD values are lacking for quadriceps strength recovery after total knee arthroplasty (TKA).We created sex-specific reference charts which provide normative quadriceps strength HHD values for the first 180 days after TKA.These reference charts may improve clinicians' ability to monitor and intervene upon post-TKA quadriceps strength deficits.

The Value of a Standardized Knee Functional Assessment in Predicting the Outcomes of Total Knee Arthroplasty

Questionnaires and physical tests are tools to determine the ability of an individual to perform tasks of the daily living. In our institution, a standardized knee performance evaluation including patient-reported outcome measures (PROMs) and physical performance tests has been applied to all patients undergoing total knee arthroplasty (TKA). Our goal was to identify which preoperative tools influence the outcomes of a TKA and if physical performance tests can be of value if used along with PROMs in predicting functional outcomes. Classification and regression tree was used to analyze which preoperative factors influence function after TKA. Western Ontario and McMaster Universities Arthritis Index (WOMAC) function (WOMAC-F), 6-minute walk test (6MWT), and timed up and go (TUG) test at the 12th postoperative month were the dependent variables. Age, body mass index, preoperative WOMAC function and pain score, muscle strength, 6MWT, and TUG test score were used as preoperative predictors of dependent variables. TUG ≤19.3 seconds and age <62 years were preoperative predictors of better scores in the WOMAC-F (5.5). Strength of extensor muscles of the nonoperated knee ≥99.43 N·m/kg and 6MWT> 328 m were preoperative predictors of a better postoperative 6MWT (499 m). TUG <12.3 seconds and 6MWT ≥421 m were preoperative predictors of better postoperative TUG (7.3 seconds). Preoperative performance in physical tests had an influence on postoperative outcome scores than PROMs after TKA. Less age, good muscular strength, greater capacity of walking, and smaller TUG times were associated with better outcomes.

Sit-to-Stand Weight-Bearing Symmetry Performance in Total Knee Arthroplasty: Recovery Curves, Correlates, and Predictive Validity With Gait Speed

OBJECTIVE

After total knee arthroplasty, the ability to weight bear symmetrically during the sit-to-stand task provides important information regarding altered movement patterns. Despite this, comprehensive recovery curves and validity data for sit-to-stand weight-bearing symmetry are lacking in the total knee arthroplasty population. Our study aimed to (1) develop recovery curves with reference ranges, (2) identify the correlates of standard and constrained sit-to-stand weight-bearing symmetry, and (3) evaluate their predictive validity with gait speed.

DESIGN

We performed a retrospective longitudinal study of 706 patients with primary unilateral total knee arthroplasty. Monthly, for 4 mos after surgery, sit-to-stand weight-bearing symmetry, knee pain, knee range of motion, quadriceps strength, and gait speed were quantified.

RESULTS

Standard and constrained sit-to-stand weight-bearing symmetry measures improved nonlinearly over time. Standard sit-to-stand weight-bearing symmetry was most strongly associated with bilateral quadriceps strength, whereas constrained sit-to-stand weight-bearing symmetry was most strongly associated with ipsilateral quadriceps strength. Knee range of motion and contralateral knee pain were additional correlates. Both standard sit-to-stand and constrained sit-to-stand weight-bearing symmetry were independently and nonlinearly associated with gait speed in multivariable models.

CONCLUSIONS

Our study provided recovery curves and validity data to support routine clinical measurement of sit-to-stand weight-bearing symmetry in total knee arthroplasty. Our results also indicate that constrained sit-to-stand may promote greater use of the operated limb than standard sit-to-stand.

The functional outcome after tumor resection and endoprosthesis around the knee: a systematic review

The evidence for the functional outcome of endo- prosthetic replacement (EPR) after tumour resection has been from few cohort studies. A scoping search revealed no systematic review on patient reported outcome measures after EPR around the knee. The purpose of this study was to evaluate the functional outcome of distal femoral and proximal tibial EPR after tumour resection. A systematic review was conducted using the PRISMA guidelines. The search identified 2560 articles from MEDLINE, EMBASE, CINAHL, and Web of Science. 36 studies satisfying the selection criteria were included for data synthesis. Pooled analysis was performed for homogenous studies. Narrative synthesis was performed for all the studies due to heterogeneity in methodological and statistical analysis. Amongst the overall patient population of 2930, mean ages ranged from 18-66 years and the mean follow up periods in the studies ranged from 12 - 180 months. The weighted mean functional outcome was similar for patients who had DFEPR and PTEPR. The functional outcome scores of Rotating Hinge Knee implants (RHK) were significantly greater than that for Fixed Hinge Knee implants (FHK). The weighted mean functional outcome scores were higher after cemented fixation and after primary EPR procedures. The current evidence suggests that functional out- come after EPR in the knee is good, and RHK implants are better than FHK implants. Functional outcome after primary EPR was significantly better than following revision EPR, and this underscores the importance of minimising complications at the primary surgery.

Changes in 6DOF knee kinematics during gait with decreasing gait speed

BACKGROUND

Gait speed is recognized to correlate to knee kinematic alterations. Clinically, patients with knee diseases tend to walk slowly compared to healthy controls. Hence, gait speed may serve as a confounding factor in the kinematic characteristics of patients during gait compared to healthy controls.

RESEARCH QUESTION

Whether and how gait speed affects six degrees of freedom (6DOF) knee kinematics remains unclear. The current study was designed to explore whether and how decreased gait speeds affect 6DOF knee kinematics.

METHODS

Thirty subjects (15 males and 15 females) were recruited for this study. A three-dimensional gait analysis system was used to assess the 6DOF knee kinematics of subjects at gait speeds of 4.0 km/h, 3.5 km/h, 3.0 km/h, 2.5 km/h, 2.0 km/h, 1.5 km/h, and 1.0 km/h. Kinematics of gait cycle (GC) were assessed at all gait speed levels.

RESULTS

Decreased adduction angle (0.5-3.2 °, p < 0.05), increased external rotation (0.6-3.3 °, p < 0.05) and decreased flexion angle (1.5-17.4 °, p < 0.05) were found during most GC as gait speed level decreased. Greater anterior tibial translation (0.9-2.6 mm, p < 0.05), greater proximal translation (0.4-2.4 mm, p < 0.05) and decreased lateral tibial translation (0.5-3.0 mm, p < 0.05) were found during most GC as gait speed level decreased. Gender was also found to have great effects on 6DOF knee kinematics (p < 0.05). Interactions between gender and gait speed were also found (p < 0.05).

SIGNIFICANCE

Our findings suggest that additional attention should be paid when dealing with kinematic comparisons of GC between controls and patients with significantly different gait speeds or genders than controls. Kinematic alterations induced by gait speed may raise concern for patients with knee diseases who struggle to walk faster than their normal speed. This may enhance our knowledge of the relationship between gait speed and 6DOF knee kinematics.

Influence of the Amount of Change in Quadriceps Tendon Young’s Modulus on Amount of Change in Walking Speed before and after Total Knee Arthroplasty

Background and Objectives: Walking speed after total knee arthroplasty (TKA) is an important outcome. However, the effect of quadriceps tendon stiffness on walking speed remains unclear. This study aimed to clarify the influence of the amount of change in quadriceps tendon stiffness on the degree of change in walking speed before and after TKA. Materials and Methods: Sixteen patients who underwent TKA for knee osteoarthritis participated in this study (median age: 74.0 years (interquartile range: 64.5–75.8)). Shear-wave elastography was deployed to measure quadriceps tendon stiffness using Young’s modulus. A motion analysis system was used to assess kinematic parameters and walking speed. Participants’ knee circumference, range of motion, extension strength, one-leg standing time, walking pain level, and activity level were measured preoperatively and one year after TKA, and changes in values were calculated. We used path analysis to clarify the influence of the amount of change in the quadriceps tendon Young’s modulus on the change in walking speed. Results: The quadriceps tendon Young’s modulus negatively affected the knee flexion angle during swing (standardized partial regression coefficients (β) = −0.513, p = 0.042). The knee flexion angle during swing positively affected step length (β = 0.586, p = 0.017). Step length positively affected cadence (β = 0.733, p = 0.001). Step length and cadence positively affected walking speed (β = 0.563, p < 0.001, β = 0.502, p < 0.001, respectively). Conclusions: The amount of change in the quadriceps tendon Young’s modulus may affect the degree of change in walking speed after TKA through the amount of change in the knee flexion angle during swing, step length, and cadence. Clinically, reducing quadriceps tendon stiffness can be addressed in rehabilitation programs to increase walking speed after TKA.

Functional characteristics of female patients based on ambulatory ability 1 year after total knee arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) is commonly performed to reduce knee pain and improve physical function. Compared with the values for healthy, age-matched women, previous studies have reported large deficits in functional ability, such as muscle strength and ambulatory ability, in women 1 year post-TKA. Ambulatory ability is to move around, particularly by walking and is clinically assessed by the timed up and go test (TUG).

AIM

This study aimed to clarify the characteristics of knee functions in female patients whose ambulatory ability recovered to a normal level at 1 year after TKA.

METHODS

This cross-sectional study included 151 female patients who underwent TKA. The muscle strength of the lower extremity was measured, and the 2011 Knee Society Scoring (2011 KSS) system was used postoperatively. The TUG was conducted to assess ambulatory ability after TKA; then the patients were classified into the fast and slow ambulation groups based on previously reported gait-speed values of healthy female individuals. Then, we identified significant indicators of ambulatory ability at 1 year after TKA.

RESULTS

Forty-nine percent of patients after TKA achieved the level of ambulatory ability of a healthy female. Logistic regression analysis identified that the non-operative side knee extensor strength and the functional activity score, as assessed by the 2011 KSS, were variables significantly associated with the mid-term ambulatory ability after TKA.

CONCLUSION

Female patients with high non-operative knee extensor strength and a functional activity score at 1 year postoperatively can achieve better ambulatory ability than those of healthy, age-matched females.

The Cut-off Value of Physical Activity for Undergoing Total Knee Arthroplasty in Patients with Knee Osteoarthritis

BACKGROUND

We aimed to determine a cut-off value for physical activity (PA), measured using an accelerometer, between patients with knee osteoarthritis (OA) who decided to undergo total knee arthroplasty (TKA) and those who continued conservative treatment.

METHODS

Forty-two participants were assigned to either a TKA group or a non-TKA group (21 per group). They were instructed to wear an accelerometer throughout the day. Average daily steps (steps/day), average daily time of light PA (LPA) (min/day), and average daily time of moderate-to-vigorous PA (MVPA) (min/day) were measured for seven days. Variables between the two groups were compared using univariate analyses, and then a stepwise logistic regression was conducted to determine which variables best correlated with undergoing TKA. The PA cut-offs were analysed using the receiver operating characteristic curve.

RESULTS

Pain severity (p = 0.002), KL grade (p = 0.001), and MVPA (p = 0.012) differed significantly between the groups. The most useful cut-off value was 5.84 (min/day) for MVPA (AUC = 0.773), although only pain severity and KL grade were found to be significant contributors to undergoing TKA.

CONCLUSIONS

Our results revealed there was a significant decrease in PA levels (MVPA cut-off, 5-6 min/day) in the TKA group compared with the non-TKA group.

Gait mechanics are influenced by quadriceps strength, age, and sex after total knee arthroplasty

Although most patients are satisfied with outcomes after total knee arthroplasty (TKA), many retain preoperative altered gait mechanics. Identifying patient characteristics associated with gait mechanics will improve rehabilitation strategies and enhance our understanding of movement disorders. Therefore, the purpose of this study was to identify which patient characteristics are related to gait mechanics in the surgical limb during walking post-TKA. Patient characteristics included age, body mass, sex, quadriceps strength, self-reported function, and knee pain. General linear regression was used to compare patient characteristics associated with gait mechanics, after controlling for gait speed, functional capacity and time from surgery. We tested 191 patients cross-sectionally at 6-24 months after primary, unilateral TKA. Quadriceps weakness in the surgical limb was associated with less peak vertical ground reaction force (PvGRF) (β = .245, p = .044), knee extension moment (β = .283, p = .049), and knee extension excursion (β = .298, p = .038). Older age (β = .168, p = .050) was associated with less PvGRF. Quadriceps strength in the nonsurgical limb (β = -.357, p = .021) was associated with greater knee extension excursion in the surgical limb. Females with TKA (β = -.276, p = .007) had less knee flexion excursion compared to males. Faster gait speed was also associated with greater PvGRF (β = .585, p < .001), knee extensor moment (β = .481, p < .001), and knee flexion excursion (β = .318, p < .001). Statement of Clinical Significance: This study showed quadriceps weakness, slower gait speed, older age and being female were related to altered gait mechanics post-TKA. These findings will help clinicians better educate patients and develop targeted interventions for improving care in patients post-TKA.

Early Recovery of Walking Ability in Patients After Total Knee Arthroplasty Using a Hip-Wearable Exoskeleton Robot: A Case-Controlled Clinical Trial

Introduction:

The Honda Walking Assist (HWA) is a hip-wearable exoskeleton robot for gait training that assists in hip flexion and extension movements to guide hip joint movements during gait. This study aimed to evaluate the effects of walking exercises with HWA in patients who underwent total knee arthroplasty (TKA).

Materials and Methods:

This study involved 10 patients (11 knees) in the HWA group and 11 patients (11 knees) in the control group who underwent conventional physical therapy. The patients assigned to the HWA group underwent a total of 17-20 gait training sessions, each lasting approximately 20 min from week 1 to 5 following TKA. Self-selected walking speed (SWS), maximum walking speed (MWS), range of motion (ROM), knee extension and flexion torque, and Western Ontario and McMaster Universities Osteoarthritis Index subscales of pain (WOMAC-p) and physical function (WOMAC-f) scores were measured preoperatively, at 2, 4, and 8 weeks following TKA.

Results:

Interventions were successfully completed in all patients, with no severe adverse events. A significant difference was noted in the time × group interaction effect between preoperative and week 2 SWS and MWS. Regarding knee function, there was a significant difference in the time × group interaction between preoperative and week 2 active ROM extension; however, no significant difference in knee torque, WOMAC-p, and WOMAC-f scores were observed. In the between-group post hoc analysis, WOMAC-f in the HWA group was higher than that in the control group at week 8.

Discussion:

Although the control group showed a temporary reduction in SWS and MWS 2 weeks after TKA, the HWA group did not. These results suggest that HWA intervention promotes early improvement in walking ability after TKA.

Conclusions:

The gait training using HWA was safe and feasible and could be effective for the early improvement of walking ability in TKA patients.

Association between Preoperative Long-Chain Polyunsaturated Fatty Acids and Oxidative Stress Immediately after Total Knee Arthroplasty: A Pilot Study

Quadriceps muscle atrophy following total knee arthroplasty (TKA) can be caused by tourniquet-induced ischemia–reperfusion (IR) injury, which is often accompanied by oxidative stress and inflammatory responses. n-3 long-chain polyunsaturated fatty acids (LCPUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), exert antioxidant and anti-inflammatory effects against IR injury, whereas n-6 LCPUFAs, particularly arachidonic acid (AA), exhibit pro-inflammatory effects and promote IR injury. This study aimed to examine whether preoperative serum EPA + DHA levels and the (EPA + DHA)/AA ratio are associated with oxidative stress immediately after TKA. Fourteen eligible patients with knee osteoarthritis scheduled for unilateral TKA participated in this study. The levels of serum EPA, DHA, and AA were measured immediately before surgery. Derivatives of reactive oxygen metabolites (d-ROMs) were used as biomarkers for oxidative stress. The preoperative serum EPA + DHA levels and the (EPA + DHA)/AA ratio were found to be significantly negatively correlated with the serum d-ROM levels at 96 h after surgery, and the rate of increase in serum d-ROM levels between baseline and 96 h postoperatively. This study suggested the preoperative serum EPA + DHA levels and the (EPA + DHA)/AA ratio can be negatively associated with oxidative stress immediately after TKA.

Paretic and Nonparetic Step Tests Are Noninterchangeable in Stroke: A Prospective Cohort Study

OBJECTIVE

The step test (ST) is a common clinical assessment of dynamic balance among survivors of stroke. The ST assesses a person's ability to place their paretic (paretic ST) or nonparetic (nonparetic ST) foot rapidly and repeatedly on and off a standardized block while standing. No study has formally explored if the 2 tests are interchangeable. Our study aimed to: (1) differentiate the correlates of paretic and nonparetic ST, and (2) compare their associations with physical function and falls.

METHODS

Eighty-one survivors of stroke were consecutively recruited from inpatient rehabilitation units (n = 4) and were assessed within 1 week prior to discharge. In addition to the ST, a handheld dynamometer and computerized posturography were used to measure lower limb muscle strength and standing balance, respectively. Self-selected gait speed and Timed Up and Go test were also assessed as measures of physical function. Falls data were monitored for 12 months post discharge using monthly calendars. Multivariable regression analyses were used to differentiate (1) the correlates of paretic and nonparetic STs, and (2) their associations with physical function and falls.

RESULTS

The median score for the paretic and nonparetic STs were 8 and 9 steps, respectively. Paretic ankle plantar-flexor and dorsiflexor strength were the strongest correlates of nonparetic ST, whereas both paretic ankle and knee extensor strength were the strongest correlates of paretic ST. In multivariable analyses adjusting for each other, both STs were independently associated with gait speed and Timed Up and Go scores. Paretic ST (odds ratio = 0.37; 95% CI = 0.22 to 0.62) was a stronger predictor than nonparetic ST (odds ratio = 0.51; 95% CI = 0.34 to 0.78) in predicting future falls.

CONCLUSION

This study confirmed that the paretic and nonparetic STs are noninterchangeable. ST scores should be assessed separately to achieve a more complete interpretation.

IMPACT

To our knowledge, this study is the first to objectively evaluate the similarities and differences between paretic and nonparetic STs. This information may refine the use and interpretation of the 2 STs for survivors of stroke.

Effects of preoperative low-intensity training with slow movement on early quadriceps weakness after total knee arthroplasty in patients with knee osteoarthritis: a retrospective propensity score-matched study

Background

Severe and early quadriceps weakness (QW) after total knee arthroplasty (TKA), which is caused by acute inflammation resulting from surgical trauma and tourniquet-induced ischemia-reperfusion (IR) injury, can be especially problematic. We focused on tourniquet-induced IR injury, because it has been shown to be preventable through ischemic and exercise preconditioning. Low-intensity resistance exercise with slow movement and tonic force generation (LST) share some similarities with ischemic and exercise preconditioning. The present study primarily aimed to clarify the efficacy of preoperative LST program as prehabilitation for early QW among patients with TKA using propensity score matching analysis.

Methods

This single-center retrospective observational study used data from patients with knee osteoarthritis (n = 277) who were scheduled to undergo unilateral TKA between August 2015 and January 2017. Those with missing outcome data due to their inability to perform tests were excluded. The LST group included participants who performed LST and aerobic exercise (LST session) more than seven times for three months prior to surgery. The control group included participants who performed less than eight LST sessions, a general and light exercise or had no exercise for three months prior to surgery. Knee circumference, thigh volume, knee pain during quadriceps strength test (QST) and timed up and go test (TUG), quadriceps strength, and TUG were measured before and 4 days after surgery. Knee swelling, thigh swelling, Δknee pain, QW, and ΔTUG were determined by comparing pre- and postoperative measurements.

Results

Propensity score matching generated 41 matched pairs who had nearly balanced characteristics. The LST group had a significantly lower knee and thigh swelling, QW, and ΔTUG compared to the control group (all, p < 0.05). No significant differences in Δknee pain during the QST and TUG were observed between both groups (both, p > 0.05).

Conclusions

The present study demonstrated the beneficial effects of preoperative LST program on knee swelling, thigh swelling, QW, and walking disability immediately after TKA.

Effect of Nonelastic Compression With an Adjustable Wrap After Total Knee Arthroplasty

Swelling is a common phenomenon after total knee arthroplasty, with potential for negative impact on the rehabilitation process and final outcome. The aim of this study was to investigate the effectiveness of a new compression protocol with a self-adjustable, nonelastic compression wrap for the knee region. This study was conducted as a prospective comparative study. Total leg volume and the circumference of the knee at three levels were compared between groups. The results of our study suggest that the application of the new compression protocol has no effect on swelling in the acute postoperative phase (0-2 days) but reduces swelling at Day 14 within the subacute phase. The observed positive effect of the compression protocol could be of clinical importance in the subacute phase as well as for a subgroup of patients suffering from aberrant quadriceps weakness concomitant with knee swelling.

Gait Training Using a Hip-Wearable Robotic Exoskeleton After Total Knee Arthroplasty: A Case Report

The Honda Walking Assist® (HWA) is a light and easy wearable robot device for gait training, which assists patients’ hip flexion and extension movements to guide hip joint movements during gait. However, the safety and feasibility of gait training with HWA after total knee arthroplasty (TKA) remains unclear. Thus, we aimed to evaluate the safety and feasibility of this gait training intervention using HWA for a patient who underwent TKA. The patient was a 76-year-old female who underwent a left TKA. Gait training using HWA was conducted for 18 sessions in total, from 1 to 5 weeks after TKA. To verify the recovery process after TKA surgery, knee function parameters and walking ability were measured at pre-TKA and 1, 2, 4, and 8 weeks after TKA. The gait patterns at self-selected walking speed (SWS) without HWA at pre- and 5 weeks after TKA were measured by using 3-dimensional (3D) gait analysis. The patient completed a total of 18 gait training interventions with HWA without any adverse complications such as knee pain and skin injury. The postoperative knee extension range of motion (ROM), knee extension torque, SWS, and maximum walking speed were remarkably improved. Regarding gait kinematic parameters, though this patient had a characteristic gait pattern with decreased knee ROM (called stiff knee gait) preoperatively, the knee flexion angle at 5 weeks after TKA showed knee flexion movement at loading response phase (LR; called double knee action), increased knee ROM during gait, and increased knee flexion angle at swing phase. In this case, the gait training using HWA was safe and feasible, and could be effective for the early improvement of gait ability, hip function, and gait pattern after TKA.

Physical Performance Correlates with Self-Reported Physical Function and Quality of Life in Patients at 3 Months after Total Knee Arthroplasty

Background

Although total knee arthroplasty (TKA) is an effective treatment for knee osteoarthritis, assessment of postoperative outcomes remains unclear. This study aimed to identify postoperative physical performance factors that are correlated with self-reported physical function and quality of life (QoL) at 3 months after unilateral TKA.

Methods

In total, 158 patients who underwent unilateral primary TKA completed performance-based physical function tests at 3 months after surgery, including Stair Climbing Tests (SCT), 6-Minute Walk Tests (6MWT), Timed Up and Go tests (TUG), and instrumental gait analysis. We also measured the isometric knee flexor and extensor strengths of the operated and non-operated knees. Self-reported physical function and QoL were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Euro-QoL Five Dimensions (EQ-5D) questionnaire, respectively.

Results

Bivariate analyses showed that WOMAC function and EQ-5D were correlated with age, other self-reported measures, and performance-based measures. The WOMAC pain (r=0.71, p<0.001) showed a high positive correlation. While the EQ-5D (r=-0.7, p<0.001) showed a highly negative correlation with WOMAC function, WOMAC pain (r=-0.67, p<0.001) showed a moderately negative correlation with EQ-5D. In multivariate linear regression analyses, WOMAC pain, peak torque of the flexor of the non-operated knee, and reductions in extensor and stride length were associated with self-reported physical function, whereas WOMAC pain, SCT ascent, and cadence were associated with postoperative QoL.

Conclusions

Physical performance factors were significantly associated with self-reported physical function and QoL in patients at 3 months after unilateral TKA. These findings suggest that performance-based physical function could be used to assess outcomes after TKA.

Comparison of posterior-stabilized, cruciate-retaining, and medial-stabilized knee implant motion during gait

Accurate knowledge of knee joint motion is needed to evaluate the effects of implant design on functional performance and component wear. We conducted a randomized controlled trial to measure and compare 6-degree-of-freedom (6-DOF) kinematics and femoral condylar motion of posterior-stabilized (PS), cruciate-retaining (CR), and medial-stabilized (MS) knee implant designs for one cycle of walking. A mobile biplane X-ray imaging system was used to accurately measure 6-DOF tibiofemoral motion as patients implanted with PS (n = 23), CR (n = 25), or MS (n = 26) knees walked over ground at their self-selected speeds. Knee flexion angle did not differ significantly between the three designs. Relative movements of the femoral and tibial components were generally similar for PS and CR with significant differences observed only for anterior tibial drawer. Knee kinematic profiles measured for MS were appreciably different: external rotation and abduction of the tibia were increased while peak-to-peak anterior drawer was significantly reduced for MS compared with PS and CR. Anterior-posterior drawer and medial-lateral shift of the tibia were strongly coupled to internal-external rotation for MS, as was anterior-posterior translation of the contact center in the lateral compartment. MS exhibited the least amount of paradoxical anterior translation of the femur relative to the tibia during knee flexion. The joint center of rotation in the transverse plane was located in the lateral compartment for PS and CR and in the medial compartment for MS. Substantial differences were evident in 6-DOF knee kinematics between the healthy knee and all three prosthetic designs. Overall, knee kinematic profiles observed for MS resemble those of the healthy joint more closely than PS and CR.

The Effectiveness and Safety of General and Spinal Anesthesia on Systemic Inflammatory Response in Patients with Tumor-Type Total Knee Arthroplasty

BACKGROUND

The anesthesia procedure in tumor-type total knee arthroplasty (TKA) may contribute to systemic inflammatory response. Therefore, we aim to investigate the effectiveness and safety of general and spinal anesthesia in patients with tumor-type TKA.

PATIENTS AND METHODS

Twenty-five patients with tumors around the knee undergoing primary unilateral TKA were randomly divided into the general anesthesia group (n = 13) and spinal anesthesia group (n = 12). Knee joint HSS scores and Western Ontario and McMaster University osteoarthritis index (WOMAC osteoarthritis) were recorded before surgery and 12 months after surgery. Visual analogue scale, C-reactive protein (CPR), tumor necrosis factor-α (TNF-α), and interleukin-8 (IL-8) concentration were measured preoperatively (T0), on the day of the operation (T1), and on the first day (T2) after the operation. Complications in the two groups were recorded.

RESULTS

The operative time, intraoperative blood loss, postoperative drainage, tourniquet time, and complication rate were not significantly different between the general anesthesia and spinal anesthesia groups (all p > 0.05). There were no significant differences in CPR (7.6 ± 3.1, 8.1 ± 4.1, 91.3 ± 24.2 vs. 7.1 ± 2.9, 7.6 ± 3.8, 85.1 ± 19.3 pg/mL, respectively), IL-8 (12.2 ± 6.6, 13.4 ± 7.3, 19.2 ± 10.5 vs. 11.9 ± 5.7, 12.9 ± 8.6, 22.2 ± 12.4 pg/mL, respectively), and TNF-α (2.5 ± 1.7, 2.2 ± 1.9, 2.8 ± 2.1 vs. 2.4 ± 1.3, 2.7 ± 2.1, 2.9 ± 1.6 pg/mL, respectively) between the two groups at T0, T1, and T2 (all p > 0.05). There were no statistical differences in pre- and postoperative HSS knee scores (39.78 ± 11.3, 90.24 ± 15.3 vs. 42.68 ± 12.5, 91.21 ± 16.3) and WOMAC indexes (49.89 ± 7.9, 25.12 ± 6.2 vs. 51.3 ± 8.3, 23.15 ± 5.3) between the two groups (p > 0.05).

CONCLUSION

General anesthesia and spinal anesthesia in patients with tumor-type TKA had the same effectiveness and safety.

Association between serum n-3 polyunsaturated fatty acids and quadriceps weakness immediately after total knee arthroplasty

Objectives

Quadriceps weakness (QW) following total knee arthroplasty (TKA) can be elicited by tourniquet-induced ischaemia reperfusion (IR), which causes a vigorous acute inflammatory response. Dietary n-3 polyunsaturated fatty acids (PUFA) are important determinants of organ and tissue protection from IR. This study aimed to examine the association between serum n-3 PUFA levels and QW, knee pain, and knee swelling immediately after TKA.

Methods

A total of 32 patients who underwent unilateral TKA participated in this prospective study. On Postoperative Day 1, serum n-3 PUFA (eicosapentaenoic acid and docosahexaenoic acid) levels were measured. Preoperatively and on Postoperative Day 4, quadriceps strength, knee pain during quadriceps testing, and knee circumference were measured. QW, knee pain, and knee swelling were defined as changes in quadriceps strength, knee pain during quadriceps testing, and knee circumference, respectively, between the preoperative to the postoperative measurement.

Results

Mean serum n-3 PUFA levels were 192 μg/mL (standard deviation, 58 μg/mL) on Postoperative Day 1. All measured variables changed significantly between the preoperative and the postoperative measurement time-points (P <0.01). Quadriceps strength decreased from 1.2 to 0.4 Nm/kg (QW = −65%). Knee pain during quadriceps testing increased from 1.1 to 6.0 (knee pain = 4.0). Knee circumference increased from 40 to 44 cm (knee swelling = 10%). Multivariate analysis showed that lower serum n-3 PUFA levels were independently associated with an increased QW after adjusting for the Kellgren-Lawrence grade and the tourniquet time (P = 0.04). No significant relationship was observed between serum n-3 PUFA levels and knee pain or knee swelling.

Conclusion

Higher serum n-3 PUFA are independently associated with a lower increase in the QW immediately after TKA.

Twenty-four-week hospital-based progressive resistance training on functional recovery in female patients post total knee arthroplasty

BACKGROUND

After total knee arthroplasty (TKA) surgery, a decline in muscle strength is associated with a decrease in function. The aim of this study was to demonstrate the effect of a further 24 weeks of hospital-based resistance training under supervision, and precise dose on knee functional recovery and daily activities for female TKA patients.

METHODS

Twenty-nine patients who underwent unilateral primary TKA were allocated into either resistance training (RT) (n = 14) or control (CON) (n = 15) groups. All patients were assessed, with an isokinetic dynamometer, for hip and knee flexor and extensor muscle strength, physical function test, and Knee Injury and Osteoarthritis Outcome Score (KOOS). Resistance training was initiated three months after index surgery. The assessments were performed before exercise (Baseline), in the middle of the resistance training at 12 weeks (Mid-exercise), completion of the resistance training (Post-exercise), and 12 weeks after resistance training completion (Follow-up). A statistical test was performed by using generalized estimating equations.

RESULTS

Patients in RT had more of an increase in both knee extensor and flexor muscle strength than those in CON at the Post-exercise assessment. The six-minute walk test distance was more in RT compared with CON at the same Post-exercise assessment. Furthermore, the RT group had increases in Activities of daily living and Sports subscales compared to the CON group.

CONCLUSIONS

A further 24 weeks of hospital-based progressive resistance training facilitated improvement in knee muscle strength and functional outcome in TKA patients. Active hospital-based progressive resistance training is recommended for rehabilitation following TKA surgery.

Different improvement trends in gait function and quadriceps strength early after total knee arthroplasty

[Purpose] Improved quadriceps strength is a primary target of rehabilitation early after total knee arthroplasty. However, patients demonstrate varying improvement trends in gait function and quadriceps strength. This study evaluated the relationship between improvements in quadriceps strength and gait function. [Participants and Methods] The study included 49 patients who were scheduled to undergo unilateral total knee arthroplasty. Gait function, bilateral quadriceps strength, and pain were assessed in all patients. All assessments were performed preoperatively and at 2 and 3 weeks postoperatively. [Results] A significant correlation between gait function and the quadriceps strength on the operated side was observed preoperatively and 3 weeks postoperatively. The quadriceps strength on the non-operated side was significantly correlated with gait function at all time points. Multiple regression analysis showed that the quadriceps strength on the non-operated side was significantly associated with gait function, except the gait speed at 2 weeks. However, the quadriceps strength on the operated side was not observed to be an independent variable at all time points. [Conclusion] The quadriceps strength on the operated side is not an important determinant of gait function. It may be necessary to reconsider typical rehabilitation programs by focusing on the quadriceps strength on the operated side in patients undergoing total knee arthroplasty.

The effect of intensive exercise program and kinesiotaping following total knee arthroplasty on functional recovery of patients

Background

Total knee arthroplasty (TKA) is a gold standard for terminal term gonarthrosis patients in order to diminish pain, correct deformities, and regain stability. Postoperative functional recovery of patients depends on the current postoperative rehabilitation program to an important extent. The purpose of our study is to compare midterm functional level of gonarthrosis patients who were included in physiotherapy rehabilitation program following TKA with people in similar ages without any surgical indication nor intervention. We have aimed also to compare functionality of people who had additional kinesiotaping (KT) treatment with people who had conservative treatment only after knee arthroplasty.

Methods

Functional level and knee functionality of people in study were evaluated at the end of postoperative first month by 6-min walk test and Lysholm knee score respectively.

Results

There was no statistical difference between groups with and without TKA in terms of height, weight, body mass index, Lysholm score, and 6-min walk test score (p > 0.05). In patient group with TKA, people with postoperative KT treatment had greater 6-min walk test score for postoperative first month (p = 0.005).

Conclusion

TKA is considered a gold standard procedure in order to increase the quality of life and improve functionality of terminal term gonarthrosis patients. It is necessary to immediately control pain and edema of knee and apply intensive rehabilitation program aimed at muscle strengthening around hip and knee in order to increase the success of operation.

Lower limb angular velocity during walking at various speeds

BACKGROUND

Although it is well established that lower limb joint angles adapt to walking at various speeds, limited research has examined the modifications in joint angular velocity. There is currently no normative dataset for joint angular velocity during walking, which would be useful to allow comparisons for patient cohorts. Additionally, understanding normal joint angular velocity may assist clinical assessment and treatment procedures to incorporate methods that replicate the movement speed of the lower limb joints during walking.

RESEARCH QUESTION

This study aimed to examine lower limb joint angles and angular velocities in a healthy population walking at various gait speeds.

METHODS

Thirty-six healthy adult participants underwent three-dimensional gait analysis while walking at various speeds during habitual and slowed walking. The peak joint angles and angular velocities during important phases of the gait cycle were examined for the hip, knee and ankle in the sagittal plane. Data were grouped in 0.2 m/s increments from a walking speed of 0.4 m/s to 1.6 m/s to represent the range of walking speeds reported in studies of people with gait impairments.

RESULTS

For joint angles and angular velocities, the shape of the gait traces were consistent regardless of the walking speed. However as walking speed increased, so did the peak joint angles and angular velocities for the hip, knee and ankle. The largest angular velocity occurred when the knee joint extended at the terminal swing phase of gait. For the ankle and hip joints, the largest angular velocity occurred during the push-off phase.

SIGNIFICANCE

This study examined how lower limb joint angular velocities change with various walking speeds. These data can be used as a comparator for data from clinical cohorts, and has the potential to be used to match clinical assessment and treatment methods to joint angular velocity during walking.

Functions, disabilities and perceived health in the first year after total knee arthroplasty; a prospective cohort study

Background

In end-stage knee osteoarthritis total knee arthroplasty (TKA) is an effective intervention to reduce pain and improve functioning in the majority of patients. However, after TKA some patients still experience pain, loss of function, deficient muscle strength or reduced walking speed. This study systematically assesses patients’ functions, disabilities and health before TKA and at short- (3 months) and long-term (12 months) on all International Classification of Functioning, Disability and Health domains.

Methods

In this prospective cohort study 150 patients underwent the following tests before and at 3 and 12 months after surgery: Western Ontario and McMaster Universities Arthritis Index, Short Form 12, Knee Society Score, Patient Specific Functioning Scale, knee range of motion, quadriceps and hamstring strength, gait parameters, global perceived effect (only after surgery). All data was analyzed with repeated measures ANOVA for all measurement time points.

Results

Despite increased gait speed, quadriceps strength and scores on questionnaires being above pre surgical levels, patients do not reach levels of healthy persons. Walking speeds approach normal values and are higher in our study compared with the literature. Quadriceps strength stays at around 70 till 80% of norm values. However, dissatisfaction rates are below 10%, which is low compared to the literature.

Conclusions

Quality of life, activities, muscle strength and gait parameters improve significantly after TKA. However, some complaints regarding activities and walking speed remain. Most striking outcome is the remaining deficit in quadriceps strength.

Validity of a low-cost laser with freely available software for improving measurement of walking and running speed

OBJECTIVES

Accurately measuring speed and acceleration during walking, running and sprinting has important implications for rehabilitation, planning training and talent identification in sporting and clinical populations. Light detection and ranging laser technology provides a continuous stream of distance data. It has the potential to allow rapid and precise measurement and may be advantageous compared with discrete methods of assessment, such as stopwatches and timing gates, which may be inaccurate over short distances. Therefore, the aim of this study was to assess the validity of a novel, low-cost and easy to implement laser-based system during walking and running trials.

DESIGN

Cross-sectional study.

METHODS

Thirty-two healthy adults performed walking and running trials from flying and static starts while monitored concurrently with reference standard three-dimensional motion analysis and laser systems. Velocity was calculated over short (0.5m) and longer (3m) intervals using both systems. Validity was assessed using absolute agreement intraclass correlation coefficients (ICC_2,1), mean absolute errors, Pearson's correlations and regressions and Bland-Altman plots.

RESULTS

All intraclass correlation coefficients and correlations were excellent (ICC>0.88, R>0.89). For the longer interval, all mean absolute errors were <0.03m/s (0.24-1.31%). Slightly higher mean absolute error values were reported for the shorter interval (3.16-5.10%), with the highest error of 0.184m/s evident for the flying start running trial.

CONCLUSIONS

These results indicate that a low-cost and accessible laser system can be used to accurately assess walking and running speed. To aid implementation and further research, freely available hardware design descriptions and downloadable software can be accessed at www.rehabtools.org/LIDAR.