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

Predictors for the Knee Extension Strength at 2 Yrs After Total Knee Arthroplasty Using Regression Tree Analysis

OBJECTIVE

The aim of the study is to clarify the interactive combinations of clinical factors associated with knee extension strength 2 yrs after total knee arthroplasty.

DESIGN

A retrospective cohort study was conducted on 264 patients who underwent total knee arthroplasty. Knee extension strength was assessed preoperatively, 3 wks, and 2 yrs after total knee arthroplasty. Physical functions were measured with 10-m walking test, Timed Up and Go test, one-leg standing time, isometric knee flexion strength, knee joint stability, knee pain, femora-tibial angle, and passive knee extension and flexion angle before surgery as a baseline and 3 wks after total knee arthroplasty as acute phase. Regression tree analysis was conducted to clarify the interactive combinations that accurately predict the knee extension strength 2 yrs after total knee arthroplasty.

RESULTS

Operational side knee extension strength (>1.00 Nm/kg) at acute phase was the primal predictor for the highest knee extension strength at 2 yrs after total knee arthroplasty. Acute phase Timed Up and Go test (≤10.13 secs) and baseline 10-m walking test (≤11.72 secs) was the second predictor. Acute phase nonoperative side knee extension strength (>0.90 Nm/kg) was also selected as the predictor.

CONCLUSIONS

This study demonstrated that knee extension strength or Timed Up and Go test in the acute phase and 10-m walking test before total knee arthroplasty are useful for estimating the knee extension strength after total knee arthroplasty. The results will help determine specific postoperative rehabilitation goals and training options.

Characterizing patient factors, perioperative interventions, and outcomes associated with inpatients falls after total knee arthroplasty

INTRODUCTION

Mechanical falls represent a potential adverse event after total knee arthroplasty (TKA) and may introduce further injury and delay postoperative recovery. This study aimed to identify patient characteristics associated with inpatient falls, to determine the impact of inpatient falls on surgical outcomes following TKA, and to describe the relationship between tourniquet and/or adductor canal block (ACB) use and fall rates.

METHODS

Patients undergoing primary, elective TKA at a single institution between 2018 and 2022 were retrospectively analyzed. Patients were stratified into groups based on whether they sustained a postoperative inpatient fall or not. Perioperative characteristics, lengths of stay (LOS), rates of 90-day readmissions, and revisions were compared, and fall characteristics were described. Subanalysis was conducted comparing fall incidence based on tourniquet and/or ACB use.

RESULTS

In total 6472 patients were included with 39 (0.6%) sustaining falls. Falls most commonly occurred on postoperative days one (43.6%) and two (30.8%), and were most commonly due to loss of balance (41.9%) or buckling (35.5%). Six (15.4%) fall patients sustained minor injuries, and one (2.6%) sustained major injury (malleolar fracture requiring non-operative orthopaedic management). The LOS (3.0 ± 1.5 vs 2.3 ± 1.5 days, p = 0.002) and all-cause revision rates at latest follow-up (10.3% vs. 2.0%, p = 0.008) were significantly higher in the fall group. Falls were comparable across subgroups based on tourniquet and/or ACB use (p = 0.429).

CONCLUSION

Patients who fell had a longer LOS and higher revision rate postoperatively. Rates of inpatient falls were comparable regardless of tourniquet and/or ACB use. Concern for inpatient falls should not influence surgeons when considering the use of tourniquets and/or ACBs, though well-designed, large-volume, prospective randomized studies are warranted to better understand this relationship.

Effect of Postoperative Kinesio Taping on Knee Edema, Pain, and Range of Motion After Total Knee Arthroplasty and Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Randomized Clinical Trials

BACKGROUND

Kinesio taping (KT) has been shown to be clinically effective in a wide range of musculoskeletal disorders. Despite evidence supporting KT, there still needs to be more certainty regarding its clinical worthiness in managing postoperative conditions. This study aims to assess the effect of postoperative KT on knee edema, pain, and range of motion (ROM) when added to routine physiotherapy after knee surgery.

METHODS

In this systematic review and meta-analysis, MEDLINE, Embase, Scopus, Web of Science, and CENTRAL databases were searched from their inception to July 2023. Randomized controlled trials (RCTs) comparing routine physiotherapy with and without KT were included. Random-effect models were used to calculate the standardized mean difference (SMD), confidence interval, and heterogeneity (I2).

RESULTS

Sixteen RCTs on 842 operated knees were included. KT reduced knee edema in first week (SMD, -0.59, p < 0.001), 14th postoperative day (POD) (SMD, -0.78, p < 0.001), and 28 to 42 days postop (SMD, -0.66, p < 0.001). The KT demonstrated significant pain improvement in second week (SMD, -0.87, p < 0.001) and the fourth week (SMD, -0.53, p < 0.001). The KT groups demonstrated ROM improvement within second week (SMD, 0.69, p = 0.010) and in the 28th POD (SMD, 0.89, p = 0.009). Subgroup analysis demonstrated minimal heterogeneity in anterior cruciate ligament reconstruction (ACLR) cases. However, it did not show significant superiority regarding ankle, calf, or thigh edema and Lysholm scale.

CONCLUSION

This study suggests that adding KT to routine postoperative physiotherapy reduces pain and knee edema after total knee arthroplasty or ACLR. Low to very low certainty of evidence for all outcomes and the limited number of studies emphasize the need for more high-quality primary studies to explore the optimal method of KT application and its effectiveness in specific knee surgeries.

LEVEL OF EVIDENCE

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

High-Intensity Progressive Rehabilitation Versus Routine Rehabilitation After Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

This study aimed to compare the effectiveness of high-intensity progressive rehabilitation training with routine training in the early treatment of patients undergoing total knee arthroplasty.

METHODS

There were 78 patients who underwent total knee arthroplasty and were randomized into high-intensity progressive training and routine rehabilitation training groups (RRT). The primary outcome measures were the American Hospital for Special Surgery Knee Score (HSS), with secondary outcomes including patient satisfaction, visual analog pain score, first time of standing after surgery, 6-minute walk test, 36-Item Short Form Survey (SF-36), and length of hospital stay. The incidence of postoperative complications were recorded.

RESULTS

The HSS scores were higher in the intervention group at 2 weeks, 3 months, and 12 months postoperatively (P < .001). The RRT group had higher visual analog pain scores than the intervention group at 24 hours, 3 days, and 2 weeks after surgery (P < .001). The intervention group had an earlier the first time of standing after surgery and a longer 6-minute walk test distance (P < .001, P = .028, P < .001, P < .001). Patient satisfaction was higher in the intervention group, with a higher quality of life rating at 3 months postoperatively (P < .001). However, 1 year after surgery, the 2 groups had no significant differences in mental component summaries. The length of hospital stay was shorter in the intervention group than in the RRT group.

CONCLUSION

Compared to routine training, high-intensity progressive rehabilitation training is more effective. It reduces postoperative patient pain, accelerates recovery of joint function, increases patient satisfaction, improves quality of life, shortens hospital stays, and promotes rapid recovery.

Enhanced recovery after surgery combined with quantitative rehabilitation training in early rehabilitation after total knee replacement: a randomized controlled trial

BACKGROUND

The number of patients undergoing total knee replacement (TKR) is increasing yearly; however, there is still a relative lack of specific, individualized, and standardized protocols for functional exercise after TKR. Quantitative rehabilitation training was developed to improve the recovery of postoperative joint function, increase patient satisfaction, shorten the length of the hospital stay, improve the quality of life, and promote rapid patient recovery.

AIM

We aimed to compare the effectiveness of quantitative rehabilitation training based on the enhanced recovery after surgery (ERAS) concept with conventional rehabilitation training in the early rehabilitation of patients with TKR.

DESIGN

This was a single-centre, prospective, randomized controlled trial.

SETTING

Inpatient department.

POPULATION

Participants were patients who underwent unilateral total knee replacement.

METHODS

Based on the ERAS concept, a quantitative rehabilitation training program was developed for the quantitative group, and the control group underwent conventional rehabilitation training. Seventy-eight patients undergoing TKR were randomly divided into two blinded groups: the quantitative rehabilitation group and the conventional rehabilitation group. The analysis was performed according to per-protocol practice. The primary outcome metric was the Hospital for Special Surgery Knee Score (HSS Score), and secondary outcomes included patient satisfaction, Visual Analog Pain Score (VAS), time to get out of bed for the first time after surgery, 6-minute-walk test (6MWT), quality-of-life score (SF-36), and number of days in the hospital. The incidence of postoperative complications was also recorded.

RESULTS

There was no significant difference in HSS scores between the two groups before surgery (P=0.967), but the quantitative rehabilitation training group had significantly higher scores at two weeks (P=0.031), 3 months (P<0.01), and 12 months (P<0.01) after surgery than did the conventional rehabilitation training group, and both groups had higher HSS scores than before surgery. The quantitative training group had significantly higher VAS scores at 24 hours and three days postoperatively than the conventional training group (P<0.01), while there was no statistical significance at any other time points. The quantitative rehabilitation group had an earlier time to get out of bed for the first time after surgery (P<0.01), a longer 6MWT distance (P=0.028), and higher patient satisfaction and quality of life scores (SF-36) (P<0.01) that did the control group. The number of days in the hospital was lower in the quantitative training group than in the control group (P<0.001). There was no significant difference in the incidence of postoperative complications between the two groups.

CONCLUSIONS

Compared with conventional rehabilitation training, quantitative rehabilitation training based on the ERAS concept was found to be safe and effective and can accelerate the recovery of joint function after surgery, shorten hospitalization time, improve patient satisfaction, and promote rapid recovery.

CLINICAL REHABILITATION IMPACT

The quantitative rehabilitation training based on the ERAS concept provides a new program for rehabilitation exercises after total knee arthroplasty, which is safe and reliable, accelerates the recovery of joint function, and should be considered for clinical promotion.

Abnormal gait pattern in downhill hiking is related to muscular deficits of the knee flexors and extensors in active patients with total knee arthroplasty

BACKGROUND

To assess the in-field walking mechanics during downhill hiking of patients with total knee arthroplasty five to 14 months after surgery and an age-matched healthy control group and relate them to the knee flexor and extensor muscle strength.

METHODS

Participants walked on a predetermined hiking trail at a self-selected, comfortable pace wearing an inertial sensor system for recording the whole-body 3D kinematics. Sagittal plane hip, knee, and ankle joint angles were evaluated over the gait cycle at level walking and two different negative slopes. The concentric and eccentric lower extremity muscle strength of the knee flexors and extensors isokinetically at 50 and 120°/s were measured.

FINDINGS

Less knee flexion angles during stance have been measured in patients in the operated limb compared to healthy controls in all conditions (level walking, moderate downhill, steep downhill). The differences increased with steepness. Muscle strength was lower in patients for both muscle groups and all measured conditions. The functional hamstrings to quadriceps ratio at 120°/sec correlated with knee angle during level and downhill walking at the moderate slope in patients, showing higher ratios with lower peak knee flexion angles.

INTERPRETATION

The study shows that even if rehabilitation has been completed successfully and complication-free, five to 14 months after surgery, the muscular condition was still insufficient to display a normal gait pattern during downhill hiking. The muscle balance between quadriceps and hamstring muscles seems related to the persistence of a stiff knee gait pattern after knee arthroplasty. LoE: III.

Effectiveness of an online management platform (Joint Cloud) versus standard process for patients undergoing total knee arthroplasty: study protocol for a prospective randomised controlled trial

INTRODUCTION

Osteoarthritis (OA) is one of the main causes of mobility impairment in the elderly worldwide. Therefore, total knee arthroplasty (TKA) is often performed and is one of the most successful surgery and has resulted in substantial quality-of-life gains for people with end-stage arthritis. There is still room for improvement in the standard treatment process in the preoperative, intraoperative and postoperative period of TKA. Telerehabilitation has the potential to become a positive alternative to face-to-face rehabilitation nowadays. But it remains unclear how well telemedicine interventions cover the entire surgical pathway (preoperation, intraoperation, postoperation). This study aims to explore the effectiveness of Joint Cloud (JC, an online management platform) compared with existing standard process in regulating functional recovery, pain management, muscle strength changes and other health-related outcomes in patients undergoing total knee arthroplasty preoperation, intraoperation and postoperation.

METHODS AND ANALYSIS

A randomised controlled trial was designed to compare the online management platform (JC) with standard process (SP) in patients undergoing TKA. A total of 186 TKA patients will be randomly assigned to the intervention (n=93) or control (n=93) group. Patients in the intervention group will receive access to the 'JC' mini-program. This mini-program provides popular science information (eg, information about OA and TKA), functional exercise information and communication channels. Patients evaluate their condition and functional level through standardised digital questionnaires. The control group of patients will not accept any functions of this mini-program. The primary outcome is knee functional recovery, and the secondary outcomes are pain management, isometric knee extensor muscle strength, patient satisfaction and cost-benefit analysis. Assessments will be performed 1 month and 3 days before surgery (T0) and 1 month and 3 months after surgery. Data analysis will be performed according to the intent-to-treat (ITT) principle. Repeated measures of linear mixed models and parametric and non-parametric testing will be used for statistical analysis.

ETHICS AND DISSEMINATION

The study was reviewed and approved by the Tianjin Hospital Medical Ethics Review Committee on 10 February 2023 (2022YLS155). Test data are considered highly sensitive but are available upon request. The findings will be disseminated in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ChiCTR2300068486.

Do Interlimb Knee Joint Loading Asymmetries Persist throughout Stance during Uphill Walking Following Total Knee Arthroplasty?

The purpose of this study was to determine differences in total (TCF), medial compartment (MCF), and lateral compartment (LCF) tibiofemoral joint compressive forces and related muscle forces between replaced and non-replaced limbs during level and uphill walking at an incline of 10°. A musculoskeletal modeling and simulation approach using static optimization was used to determine the muscle forces and TCF, MCF, and LCF for 25 patients with primary TKA. A statistical parametric mapping repeated-measures ANOVA was conducted on knee compressive forces and muscle forces using statistical parametric mapping. Greater TCF, MCF, and LCF values were observed throughout the loading response, mid-stance, and late stance during uphill walking. During level walking, knee extensor muscle forces were greater throughout the first 50% of the stance during level walking, yet greater during uphill walking during the last 50% of the stance. Conversely, knee flexor muscle forces were greater through the loading response and push-off phases of the stance. No between-limb differences were observed for compressive or muscle forces, suggesting that uphill walking may promote a more balanced loading of replaced and non-replaced limbs. Additionally, patients with TKA appear to rely on the hamstrings muscle group during the late stance for knee joint control, thus supporting uphill walking as an effective exercise modality to improve posterior chain muscle strength.

Effects of strength training on functional ambulation following knee replacement: a systematic review, meta-analysis, and meta-regression

Strength training is recommended by the American Physical Therapy Association to improve muscle strength, mobility, and balance following knee replacement. Few studies have focused on the direct effects of strength training on functional ambulation, and potential dose-response relationships between strength training parameters and the effect remain unclear. The aim of this systematic review, meta-analysis, and meta-regression was to evaluate the effects of strength training on functional ambulation following knee replacement (KR). We also aimed to explore potential dose-response relationships between strength training parameters and performance in functional ambulation. A systematic literature search of eight online databases was performed on March 12, 2023, for randomized controlled trials evaluating the effects of strength training on functional ambulation by six-minute walk test (6MWT) or timed-up and go test (TUG) after KR. Data were pooled by random-effect meta-analyses and presented as weighted mean difference (WMD). A random-effect meta-regression was performed for four predetermined training parameters, namely, duration (weeks), frequency (sessions per week), volume (time per session), and initial time (after surgery) separately to explore dose-response relationships with WMD. Fourteen trials encompassing 956 participants were included in our study. Meta-analyses showed an improvement in 6MWT performance after strength training (WMD: 32.15, 95% CI 19.44-44.85) and a decrease in time to complete TUG (WMD: - 1.92, 95% CI - 3.43 to - 0.41). Meta-regression revealed a dose-response relationship only between volume and 6MWT, with a decreasing trend (P = 0.019, 95% CI - 1.63 to - 0.20). Increasing trends of improvement in 6MWT and TUG were observed with increasing training duration and frequency. A slight decreasing trend of improvement was observed in 6MWT with postponed initial time, while an opposite trend was observed in TUG. Based on existing studies, moderate-certainty evidence suggests that strength training could increase 6MWT distance, and low-certainty evidence shows that strength training could decrease the time to complete TUG after KR. Meta-regression results only suggested a dose-response relationship between volume and 6MWT with a decreasing trend.Registration: PROSPERO: CRD42022329006.

Comparison of physical function, proprioception, muscle strength, postural balance, and walking in older women with and without total knee arthroplasty

The benefit of total knee arthroplasty (TKA) is that it alleviates pain caused by osteoarthritis; however, other postoperative effects on physical function are unclear. This study aimed to investigate the differences in physical function, proprioception, muscle strength, postural balance, and walking in older women with and without TKA. A total of 36 participants were included in this study; the TKA group comprised older women who underwent TKA (n = 18) and the non TKA group comprised older women who did not undergo TKA (n = 18). All the participants were evaluated for physical function, proprioception, muscle strength, postural balance, and walking. The outcome measures were compared between the 2 groups using an independent t test. Correlations were assessed using Pearson correlation coefficients. Participants in the TKA group had significantly reduced physical function, postural balance, and walking ability compared with those in the non TKA group (P < .05). In the TKA group, physical function was statistically correlated with proprioception, postural balance, and walking (P < .05); in particular, it had a strong correlation with proprioception (R > .60). In the non TKA group, postural balance was significantly associated with muscle strength and walking (P < .05). In particular, it was strongly correlated with walking (R > .90). This study demonstrated that older women undergoing TKA need to actively perform interventions to improve physical function, postural balance, and walking compared with older women with osteoarthritis.

Clinical Interpretability of Quadriceps Strength and Gait Speed Performance in Total Knee Arthroplasty: A Longitudinal Study

OBJECTIVE

After a total knee arthroplasty, physical assessments of quadriceps strength and gait speed performance are often undertaken during rehabilitation. Our study aimed to improve their clinical interpretability by examining trajectory curves across levels of self-reported walking and stair climbing function.

DESIGN

A sample of 2624 patients with primary total knee arthroplasty participated in this retrospective longitudinal study. Monthly, for 4 mos after surgery, quadriceps strength and gait speed were quantified. At the month-6 time point, self-reported walking and stair climbing function was measured.

RESULTS

All physical measures improved nonlinearly over time. In mixed-effects models, greater quadriceps strength and gait speed over time were associated with higher month-6 self-reported walking and stair climbing function ( P < 0.001). Steeper gains in quadriceps strength and gait speed were associated with higher levels of walking and stair-climbing function (interaction P < 0.001). Among female patients who had great difficulty with stair ascent and ambulation, quadriceps strength trajectory curves plateaued after 8 wks after total knee arthroplasty.

CONCLUSIONS

By stratifying trajectory curves across clinically interpretable functional levels, our findings potentially provide patients and clinicians a means to better interpret the continuous-scaled quadriceps strength and gait speed values. This information may be valuable when engaging patients in shared decision making and expectation setting.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME.

CME OBJECTIVES

Upon completion of this article, the reader should be able to: (1) Understand how self-reported walking and stair climbing abilities improved from baseline before total knee arthroplasty (total knee arthroplasty) to 6 mos postoperatively; (2) Describe the time course of the 2 performance-based measures of quadriceps strength and walking speed after a total knee arthroplasty; and (3) Relate the trajectories of post-total knee arthroplasty quadriceps strength and walking speed measurements across distinct levels of self-reported walking and stair climbing function.

LEVEL

Advanced.

ACCREDITATION

The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s) ™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Hip muscle strength in male and female patients with femoroacetabular impingement syndrome: Comparison to healthy controls and athletes

OBJECTIVES

To examine hip muscle strength deficits in patients with femoroacetabular impingent syndrome (FAIS), with special emphasis on potential sex- and comparison-related (between-subject vs within-subject) differences.

DESIGN

Cross-sectional comparative study.

PARTICIPANTS

Forty FAIS patients (20 women), 40 healthy controls (20 women) and 40 athletes (20 women).

MAIN OUTCOME MEASURES

Hip abduction, adduction and flexion isometric strength was tested using a commercially-available dynamometer. Two between-subject comparisons (FAIS patients vs controls and FAIS patients vs athletes) and one within-subject comparison (inter-limb asymmetry) of strength deficits were conducted, based on the calculation of respective percent differences.

RESULTS

For all hip muscle groups, women were 14-18% weaker than men (p < 0.001), but no sex-related interactions were observed. For all hip muscle groups, FAIS patients were 16-19% weaker than controls (p = 0.001) and 24-30% weaker than athletes (p < 0.001). For FAIS patients, the involved hip abductors were 8.5% weaker than the uninvolved ones (p = 0.015), while no inter-limb asymmetry was observed for the other hip muscles.

CONCLUSION

Sex had no influence on hip muscle strength deficits in FAIS patients while a major impact of comparison method/group was observed. Hip abductors showed consistent deficits for all comparison methods, suggestive of a possible greater impairment compared to hip flexors and adductors.

Patella height influences patellofemoral contact and kinematics following cruciate-retaining total knee replacement

The role of patella height is discussed controversially in total knee arthroplasty (TKA). Therefore, this computational study aims to systematically analyze the biomechanical effect of different patella heights on patellofemoral (PF) forces and kinematics after cruciate-retaining (CR) TKA. We implemented a CR bicondylar TKA with a dome patellar button in a validated dynamic musculoskeletal multibody model of a male human knee joint. Retropatellar dynamics (contact force [N], shear force [N], patellar shift [mm], tilt [°], and rotation [°]) were evaluated during dual-limb squat motion (flexion from 0° to 90°) with simulated active muscle forces and the effects of different patella heights (Blackburne-Peel [BP] ratio of 0.39, 0.49, 0.65, 0.85, 1.01, and 1.1 were systematically examined). As active knee flexion increased, PF contact force also increased. Patella alta (BP = 1.1) resulted in higher PF contact forces compared to normal patella height (BP = 0.65) by up to 16%. Contrarily, patella baja was associated with decreased PF forces by 7%. Compared to patella baja (BP = 0.39), patella alta (BP = 1.1) considerably increased the contact force by up to 25%. Different patellar heights mainly affected PF shear forces during early knee flexion. Concerning PF kinematics, patella alta (BP = 1.1) yielded a greater lateral tilt of more than 4° and higher patellar rotation by up to 3° during deep knee flexion, compared to normal patella height (BP = 0.65). Our computational study indicates that patella alta is associated with the highest PF contact and shear force after the implantation of a CR bicondylar TKA. This should be considered in PF disorders following TKA.

Effectiveness and therapeutic validity of physiotherapeutic exercise starting within one year following total and unicompartmental knee arthroplasty for osteoarthritis: a systematic review

BACKGROUND

To determine the effectiveness and therapeutic validity of physiotherapeutic exercise after total and unicompartmental knee arthroplasty for osteoarthritis. It was hypothesized that interventions of high therapeutic validity result in superior functional recovery after total and unicompartmental knee arthroplasty versus interventions of low therapeutic validity.

METHODS

A systematic review incorporating a comprehensive database search of five major databases relevant to the topic was conducted. Randomized controlled trials were reviewed if they included studies that compared postoperative physiotherapeutic exercise with usual care or compared two types of postoperative physiotherapeutic interventions. All included studies were assessed for risk of bias (using the Cochrane Collaboration's tool) and therapeutic validity (using the Consensus on Therapeutic Exercise Training scale). The characteristics of the included articles and their results on joint and muscle function, functional performance, and participation were extracted.

RESULTS

Of the 4343 unique records retrieved, 37 articles were included. Six of them showed good therapeutic validity, suggesting low therapeutic validity in 31 studies. Three articles showed a low risk of bias, 15 studies scored some concerns for risk of bias and 19 studies scored high risk of bias. Only one article scored well on both methodological quality and therapeutic validity.

CONCLUSION

Due to heterogeneity of outcome measures and length of follow-up, as well as limited reporting of details of the physiotherapeutic exercises and control interventions, no clear evidence was found on effectiveness of physiotherapeutic exercises after total and unicompartmental knee arthroplasty. Homogeneity in intervention characteristics and outcome measures would enhance comparability of clinical outcomes between trials. Future studies should incorporate similar methodological approaches and outcome measures. Researchers are encouraged to use the Consensus on Therapeutic Exercise Training scale as a template to prevent insufficient reporting.

Patellar tendon elastic properties derived from in vivo loading and kinematics

Patellar complications frequently limit the success of total knee arthroplasty. In addition to the musculoskeletal forces themselves, patellar tendon elastic properties are essential for driving patellar loading. Elastic properties reported in the literature exhibit high variability and appear to differ according to the methodologies used. Specifically in total knee arthroplasty patients, only limited knowledge exists on in vivo elastic properties and their corresponding loads. For the first time, we report stiffness, Young's modulus, and forces of the patellar tendon, derived from four patients with telemetric total knee arthroplasties using a combined imaging and measurement approach. To achieve this, synchronous in vivo telemetric assessment of tibio-femoral contact forces and fluoroscopic assessment of knee kinematics, along with full body motion capture and ground reaction forces, fed musculoskeletal multi-body models to quantify patellar tendon loading and elongation. Mechanical patellar tendon properties were calculated during a squat and a sit-stand-sit activity, with resulting tendon stiffness and Young's modulus ranging from 511 to 1166 N/mm and 259 to 504 MPa, respectively. During these activities, the patellar tendon force reached peak values between 1.31 and 2.79 bodyweight, reaching levels of just ∼0.5 bodyweight below the tibio-femoral forces. The results of this study provide valuable input data for mechanical simulations of the patellar tendon and the whole resurfaced knee.

Posterior cruciate-retaining total knee arthroplasty exhibits small kinematic changes in the first postoperative year

PURPOSE

Fluoroscopic knee kinematics have historically been quantified at least 1 year after total knee arthroplasty (TKA). The purpose of this study was to longitudinally assess knee kinematics at 6-12 weeks, 6 months, and 1 year after TKA to determine if earlier evaluation may be justified.

METHODS

Twenty-one patients participated after undergoing TKA with a posterior cruciate ligament-retaining fixed-bearing prosthesis. Fluoroscopic examinations of lunge, kneel, and step-up activities were performed at 12 ± 4 weeks (V1), 7 ± 2 months (V2), and 13 ± 2 months (V3) postoperatively. Images were analyzed using a three-dimensional to two-dimensional image registration technique. Maximum flexion poses for lunging and kneeling were compared between visits with repeated-measures statistical tests. For the step-up activity, mixed-effects linear models were constructed for condylar anteroposterior (AP) contact points and tibial internal rotation throughout flexion. Estimated marginal means of fitted values were plotted with 95% confidence intervals and used to compare mean kinematics between visits.

RESULTS

There were no significant changes in maximum lunging flexion over time (p = 0.405), though significant increases in maximum kneeling flexion were observed between V1 (106 ± 8°) and V2 (110 ± 9°) (p = 0.006), and V1 and V3 (113 ± 9°) (p = 0.0003). While statistical differences were calculated for lunging medial condyle AP translation and kneeling tibial internal rotation, absolute differences in condylar AP contact locations were less than ~ 2 mm between all visits during both movements. For the step-up activity, tibial internal rotation increased with flexion, and there were pair-wise significant differences at all flexion angles between V1-V2 (p < 0.001) and V1-V3 (p < 0.001). Anterior medial condylar translation was observed with flexion, with pair-wise significant differences present for V1-V3 (p = 0.005) and V2-V3 (p < 0.001). The lateral condyle exhibited initial posterior translation followed by anterior translation with increasing flexion, with pair-wise differences between all visits (p < 0.005 for all comparisons).

CONCLUSION

Though statistical differences were observed between visits for all activities, variations in estimated mean condylar positions were within ~ 2 mm from ~ 12 weeks to 1 year. Considering measurement error averages approximately 1 mm for sagittal plane translations, these results indicate that knee kinematics during kneel, lunge, and step-up activities may be sustained from as early as 12 weeks after TKA.

Effect of Combined Kinematic Chain Exercise on Physical Function, Balance Ability, and Gait in Patients with Total Knee Arthroplasty: A Single-Blind Randomized Controlled Trial

Total knee arthroplasty (TKA) is an effective treatment for end-stage osteoarthritis. However, evidence of combined kinematic chain exercise (CCE) in early-phase rehabilitation after TKA remains lacking. This study investigated the effects of CCE training on physical function, balance ability, and gait in 40 patients who underwent TKA. Participants were randomly assigned to the CCE (n = 20) and open kinematic chain exercise (OKCE) groups (n = 20). The CCE and OKCE groups were trained five times a week (for 4 weeks) for 30 min per session. Physical function, range of motion (ROM), balance, and gait were assessed before and after the intervention. The time × group interaction effects and time effect as measured with the Western Ontario and McMaster Universities Osteoarthritis Index, ROM, Knee Outcome Survey-Activities of Daily Living, balancing ability (e.g., confidence ellipse area, path length, and average speed), and gait parameters (e.g., timed up-and-go test, gait speed, cadence, step length, and stride length) were statistically significant (p < 0.05). In the group comparison of pre- and postintervention measurements for all variables, the CCE group showed substantial improvements compared to the OKCE group (p < 0.05). Both groups showed significant within-group improvement from baseline to postintervention. Our results suggest that CCE training positively affects physical function, balance ability, and gait as an early intervention for patients undergoing TKA.

Periarticular muscle status affects in vivo tibio-femoral joint loads after total knee arthroplasty

Background: Total knee arthroplasty (TKA) is a highly effective treatment for severe knee osteoarthritis that is increasingly performed in younger, more active patients. As postoperative muscular impairments may negatively affect surgical outcomes and implant longevity, functional muscle recovery gains increasing importance in meeting future patient demands. This study aimed to assess the status of periarticular muscles in the long-term follow-up after TKA and to evaluate its impact on in vivo tibio-femoral joint loads. Methods: A case series was created, with eight patients with knee osteoarthritis. All subjects received an instrumented knee implant in unilateral TKA. Native computed tomography scans, acquired pre and postoperatively, were used to evaluate distal muscle volumes and fatty infiltration. In vivo tibio-femoral joint loads were measured telemetrically during standing, walking, stair climbing and chair rising and were correlated to muscle status. Results: Postoperatively a reduction in fatty infiltration across all periarticular muscles was pronounced. High average peak loads acted in the tibio-femoral joint ranging from 264% during stand-to-sit activities up to 341% body weight (BW) during stair descent. Fatty infiltration of the m. quadriceps femoris and hamstrings were associated with increased tibio-femoral joint contact forces during walking (r = 0.542; 0.412 and 0.766). Conclusion: The findings suggest that a fatty infiltration of periarticular muscles may lead to increased tibio-femoral joint contact forces. However, we only observed weak correlations between these parameters. Improvements in functional mobility and the restoration of a pain-free joint likely explain the observed postoperative reductions in fatty infiltration. Perioperative rehabilitation approaches targeting residual impairments in muscle quality could, contribute to reduced tibio-femoral joint loads and improved long-term outcomes of TKA. However, it has to be pointed out that the study included a small number of patients, which may limit its validity.

Effects of low-intensity resistance exercise with blood flow restriction after high tibial osteotomy in middle-aged women

BACKGROUND

High tibial osteotomy (HTO) is an effective surgical method for treating medial compartment osteoarthritis. However, in most cases after surgery, muscle strength is decreased, and rapid muscle atrophy is observed. Therefore, the purpose of this study is to verify the effects of low-intensity resistance exercise (LIE) with blood flow restriction (BFR) on the cross-sectional area (CSA) of thigh muscles, knee extensor strength, pain, and knee joint function and investigate proper arterial occlusion pressure (AOP) in middle-aged women who underwent HTO.

METHOD

This study was designed as a prospective randomized controlled trial. Forty-two middle-aged women who underwent HTO were randomly divided into three groups and participated in LIE with (40% or 80% AOP applied) or without BFR. The main outcome was the measurement of the CSA of thigh muscles (at 30% and 50% distal length of the femur) before and 12 weeks after treatment. Additionally, knee extension muscle strength, pain, and joint function were evaluated before and 6 and 12 weeks after treatment.

RESULTS

CSA of thigh muscles at 30% and 50% distal length of the femur decreased in the AOP 40% and control groups and was the largest in the AOP 80% group 12 weeks after treatment. Knee extension strength increased in all groups and was the highest in the AOP 80% group 6 and 12 weeks after treatment. Pain improved in all groups, with no intergroup differences. Knee joint function improved in all groups and was superior in the 80% AOP group 12 weeks after treatment.

CONCLUSION

LIE with BFR at 80% AOP was effective in preventing atrophy of the thigh muscle, increasing muscle strength, and improving function. BFR at 40% AOP had no difference in the results when compared with the group in which BFR was not applied. Therefore, LIE with an AOP of 80% is recommended for patients undergoing HTO.

Fall classification, incidence and circumstances in patients undergoing total knee replacement

To propose a fall-classification framework for patients undergoing total knee replacement (TKR). In addition, we reinforced the available evidence on fall incidence and circumstances and compared the characteristics of fallers versus. nonfallers. Retrospective and prospective data were collected from 253 subjects with severe knee osteoarthritis who were waiting for primary TKR. Falls were classified considering the location of the destabilizing force, source of destabilization and fall precipitating factor. Fall incidence and circumstances were described; the characteristics of fallers and nonfallers in terms of functional and balance performance were compared with F-tests (95% CI). The fall incidence before surgery was 40.3% (95% CI 34.2% to 46.6%). This figure decreased to 13.1% (95% CI 9.2% to 18.0%) and to 23.4% (95% CI 17.8% to 29.6%) at 6 and 12 months after surgery, respectively. Most falls were caused by destabilizations in the base of support (n = 102, 72%) and were due to extrinsic factors (n = 78, 76%) and trip patterns. Significant differences between fallers and nonfallers were found in knee extensor strength and monopodal stability in the surgical limb (p < 0.05). Falls are prevalent in patients with severe knee osteoarthritis. Symptoms and functional performance improve after surgery, and fall incidence is reduced. Most fall events originate from disruptions in the base of support and are precipitated by extrinsic factors, generally trips during walking activities.

Improved Muscle Regeneration into a Joint Prosthesis with Mechano-Growth Factor Loaded within Mesoporous Silica Combined with Carbon Nanotubes on a Porous Titanium Alloy

Total joint replacement (TJR) is widely applied as a promising treatment for the reconstruction of serious joint diseases but is usually characterized by critical loss of skeletal muscle attachment to metal joint prostheses, resulting in fibrous scar tissue formation and subsequent motor dysfunction. Tissue engineering technology may provide a potential strategy for skeletal muscle regeneration into metal joint prostheses. Here, a porous titanium (Ti) alloy scaffold coated with carbon nanotubes (CNTs) and mesoporous silica nanoparticles (MSNs) through electrophoretic deposition (EPD) was designed as a mechano-growth factor (MGF) carrier. This two-layered coating exhibits a nanostructured topology, excellent MGF loading, and prolonged release performance via covalent bonding to improve myoblast adhesion, proliferation and myogenic differentiation in porous Ti alloy scaffolds without cytotoxicity. The Akt/mTOR signaling pathway plays a key role in this process. Furthermore, in vivo studies show that the scaffold promotes the growth of muscle, rather than fibrotic tissue, into the porous Ti alloy structure and improves muscle-derived mechanical properties, the migration of satellite cells, and possibly immunomodulation. In summary, this nanomaterial-coated scaffold provides a practical biomaterial platform to regenerate periprosthetic muscle tissue and restore comparable motor function to that of the natural joint.

The validity and reliability of the OneStep smartphone application under various gait conditions in healthy adults with feasibility in clinical practice

Objective

Primary purpose of this study was to determine the validity and reliability of the OneStep smartphone application in healthy adults. Secondary purpose was to determine the feasibility of measuring gait dysfunction, limitation in spatiotemporal characteristics, longitudinally in patients following total hip or knee arthroplasty.

Methods

First objective, 20 healthy adults (mean age, 42.3 ± 19.7 years; 60% males; mean body mass index, 29.0 ± 5.2 kg/m²) underwent gait analysis under four gait conditions (self-selected gait speed, fixed gait speed at 0.8 m/s, fixed gait speed at 2.0 m/s and self-selected gait speed with dual task) for the validity and reliability of the smartphone to the motion laboratory. Reliability was determined by intraclass correlation coefficients. Validity was determined by Pearson correlations. Agreement was assessed by the Bland–Altman method. Second objective, 12 additional patients with total hip or knee arthroplasty (mean age, 58.7 ± 6.5 years; 58% males; mean body mass index, 28.9 ± 5.8 kg/m²) were measured at 2- and 10 weeks postoperatively. The smartphone application was used to evaluate change in gait dysfunction over time within the patients’ own environment using paired t test.

Results

The smartphone application demonstrated moderate-to-excellent intraclass correlation coefficients for reliability between-system (ICC range, 0.56–0.99), -limb (ICC range, 0.62–0.99) and -device (ICC range, 0.61–0.96) for gait analysis of healthy adults. Pearson correlations were low-to-very high between methods (r range, 0.45–0.99). Bland–Altman analysis revealed relative underestimation of spatiotemporal variables by the smartphone application compared to the motion system. For patients following total hip or knee arthroplasty, gait analysis using the OneStep application demonstrated significant improvement (p < 0.001, Cohen’s d > 0.95) in gait dysfunction between 2- and 10 weeks postoperatively.

Conclusion

The smartphone application can be a valid, reliable and feasible alternative to motion laboratories in evaluating deficits in gait dysfunction in various environments and clinical settings.

An Improvement in Knee Disability does not Mean an Improvement in Functional Status in Geriatric Patients after Total Knee Arthroplasty

Purpose: We aimed to investigate the relationship between the change in knee disability and change in functional status from before bilateral total knee arthroplasty (TKA) to discharge in geriatric patients. Methods: We retrospectively analyzed the data of 88 patients who underwent bilateral TKA. Before surgery and at discharge, the knee disability and functinal status of the patients were assessed using the Hospital for Special Surgery (HSS) knee score and the Iowa Level of Assistance Scale (ILAS), respectively. The Spearman correlation test was used to assess the correlation between the change in the HSS knee score and the change in the ILAS score. Results: A statistically significant difference was found in the HSS knee score between before surgery and at discharge (p0.05). A moderate relationship was found between the change in the HSS knee score and the change in the ILAS score (r = –0.48, p

Relaxation exercise therapy improves pain, muscle strength, and kinesiophobia following total knee arthroplasty in the short term: a randomized controlled trial

PURPOSE

This study aimed to compare progressive muscle relaxation (PMR) + standard physiotherapy (PT) to standard PT during inpatient rehabilitation of total knee arthroplasty (TKA) patients in terms of post-operative outcomes. The hypothesis was that PMR + standard PT would lead to better pain, function, and neuromuscular outcomes than standard PT.

METHODS

A total of 106 patients were randomly allocated into PMR or standard rehabilitation (SR) groups. Both groups received standard PT during their hospital stay. PMR group additionally performed PMR exercise on post-operative days 1, 2, and 3. Patients were evaluated regarding pain intensity, functional outcomes, muscle strength, active range of motion, knee edema, anxiety, depression, and kinesiophobia.

RESULTS

There were no differences between groups at baseline (n.s.). During the inpatient period and at discharge, the PMR group had better results in terms of pain relief (p < 0.05), quadriceps strength (p = 0.001), kinesiophobia level (p = 0.011) compared to the SR group. No difference was detected between groups regarding other evaluation parameters during the inpatient period, at discharge, and third post-operative month (n.s.). The within-group analysis showed statistically significant differences over time in both groups in each variable (p < 0.05).

CONCLUSION

Our findings support that PMR therapy offers beneficial results in subjective and objective measures of TKA patients during the inpatient period. Therefore, PMR therapy could be implemented into the rehabilitation program of TKA patients to enhance their early recovery from various symptoms following TKA.

LEVEL OF EVIDENCE

II.

The effects of elastic band exercise on the pain, kinesiophobia, functional, and psychological status after total knee arthroplasty: a randomized controlled trial

INTRODUCTION

Elastic band exercise not only improves muscle strength and elasticity, increases efficiency, balance, and quality of life but also decreases the injury risk. This study was conducted to determine the effect of elastic band exercise on pain, kinesiophobia, functional, and psychological status after total knee arthroplasty.

METHODS

This study was conducted out between October 2019 and April 2020 as a randomized controlled experimental study with a total of 60 patients. Data collection tools in this study included a descriptive information form, visual analog scale, Tampa Kinesiophobia, WOMAC Osteoarthritis Index, and Beck Depression Inventory.

RESULTS

Before intervention, the total score of VAS, WOMAC, Tampa Kinesiophobia, and Beck Depression showed no statistically significant difference between intervention group and control group. However, 4 weeks after intervention observed a statistically significant difference between the intervention and control groups in terms of VAS (U = 10,000; p < 0.001), WOMAC (U = 0.00; p < 0.001), Tampa Kinesiophobia (U = 221.5; p = 0.001), and Beck Depression means score (U = 112.5; p < 0.001). In addition, 4 weeks after the intervention, joint range and walking test assessments were statistically significant between the intervention and control groups (p < 0.001).

CONCLUSION

The results of the research showed that elastic band exercise had a positive effect on psychological and functional capacity.

TRIAL REGISTRATION

This study is registered in the Clinical Trial Registry (registration number NCT04981106) Key points • Patients with total knee arthroplasty require rehabilitation exercise to avoid physical function weakness. • Elastic band exercise significantly reduces patients' fear of movement and depression. • Elastic band exercise activities facilitate significant physical motion function. • Elastic band exercise inspires the will of patients to engage in home rehabilitation exercise patients after total knee arthroplasty.

Comparison of the Therapeutic Effects Between Isokinetic and Isotonic Strength Training in Patients After Total Knee Replacement: A Prospective, Randomized Controlled Trial

Background:

Rebuilding the strength of the quadriceps as soon as possible after total knee replacement (TKR) is important so as to restore gait stability. To date, there are no standard postoperative strength training programs during the early recovery stage after TKR.

Purpose:

To compare the therapeutic effects between isokinetic and isotonic strengthening in patients after TKR.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

From April 2018 to August 2020, 37 patients met the inclusion criteria and were randomly assigned to perform either 4-week isokinetic or isotonic strength training programs. Other components of the rehabilitation program were kept the same between the 2 groups. All cases were evaluated by the Timed Up and Go (TUG) test, peak torque of knee extension and flexion (60 and 120 deg/s), 36-item Short Form Health Survey (SF-36), and Western Ontario and McMaster Universities Arthritis Index (WOMAC).

Results:

After undergoing a 4-week strength training regimen, significant improvements in the TUG test were noted in both groups; however, the time improvement in the isotonic group did not reach the minimal detectable change. All peak torque measurements improved in the isokinetic group but not in the isotonic group for knee flexion at 60 deg/s. The pain subdomain, physical domain, mental domain, total SF-36 score, and WOMAC index all improved significantly in both groups after training. Both training groups improved significantly in peak torque of knee strength, TUG test, and functional scores, but the differences between isokinetic and isotonic training were not statistically significant.

Conclusion:

The study findings showed that a 4-week strengthening exercise program in the early postoperative stage, involving either isokinetic or isotonic training, resulted in significant improvements in patients undergoing TKR.

Registration:

NCT02938416 (ClinicalTrials.gov identifier).

Total Knee Arthroplasty Assessments Should Include Strength and Performance-Based Functional Tests to Complement Range-of-Motion and Patient-Reported Outcome Measures

Range of motion (ROM) and pain often define successful recovery after total knee arthroplasty (TKA), but these routine clinical outcomes correlate poorly or not at all to functional capacity after TKA. The purpose of this Perspective is to underscore the importance of muscle strength and performance-based functional tests in addition to knee ROM and patient-reported outcome (PRO) measures to evaluate outcomes after TKA. Specifically: (1) muscle strength is the rate-limiting step for recovery of function after TKA; (2) progressive rehabilitation targeting early quadriceps muscle strengthening improves outcomes and does not compromise ROM after TKA; (3) ROM and PROs fail to fully capture functional limitations after TKA; and (4) performance-based functional tests are critical to evaluate function objectively after TKA. This Perspective also addresses studies that question the need for or benefit of physical therapy after TKA because their conclusions focus only on ROM and PRO measures. Future research is needed to determine the optimal timing, delivery, intensity, and content of physical therapy.

Feasibility and initial efficacy of a multimodal swelling intervention after total knee arthroplasty: A prospective pilot study with historical controls

BACKGROUND

Swelling after total knee arthroplasty (TKA) is often profound and persistent, increasing risks of DVT, infection, and wound dehiscence, and impairing rehabilitation. We investigated the feasibility and initial efficacy of a multimodal swelling control intervention (MSI), comprised of an inelastic adjustable compression garment (CG), manual lymph drainage (MLD) massage, and home exercise program (HEP) after total knee arthroplasty (TKA) compared to a control group.

METHODS

Sixteen individuals (mean age 64.7 ± 7.1y) performed MSI for three weeks after TKA, through day 21 (D21). Outcome measures included patient satisfaction, safety, patient adherence, and swelling measured by Single Frequency Bioimpedance Assessment (SF-BIA). All outcomes were measured preoperatively and at postoperative D4, D7, D14, D21 and, three weeks after discontinuing MSI, on D42. Efficacy of MSI was calculated with Hedge's g effect size estimates using the SF-BIA ratios for MSI versus CONTROL (N = 56; mean age 64.3 ± 9.3y) at key post operative time points.

RESULTS

Patient satisfaction was 93% with no adverse events. Adherence to CG, MLD, and HEP were 85%, 99%, and 97% respectively. Peak swelling reduction with MSI was at D21 (Hedges' g = 1.60 at D21 (95% CI 0.99, 2.21)). Minimal change in swelling was observed three weeks after cessation of MSI on D42.

CONCLUSIONS

The self-administered MSI program is feasible and demonstrated strong initial efficacy to control swelling after TKA. Minimal rebound swelling was observed once MSI was withdrawn at D21. Future studies should examine the efficacy of inelastic adjustable compression in a randomized controlled trial.

Rehabilitation of Total Knee Arthroplasty by Integrating Conjoint Isometric Myodynamia and Real-Time Rotation Sensing System

As the world population structure has already exhibited an inevitable trend of aging, technical advances that can provide better eldercare are highly desired. Knee osteoarthritis, one of the most common age-associated diseases, can be effectively treated via total knee arthroplasty (TKA). However, patients are suffering from the recovery process due to inconvenience in post-hospital treatment. Here, a portable, modular, and wearable brace for self-assessment of TKA patients' rehabilitation is reported. This system mainly consists of a force transducer for isometric muscle strength measurement and an active angle sensor for knee bending detection. Clinical experiments on TKA patients demonstrate the feasibility and significance of the system. Specifically, via brace-based personalized healthcare, the TKA patients' rehabilitation process is quantified in terms of myodynamia, and a definite rehabilitation enhancement is obtained. Additionally, new indicators, that is, isometric muscle test score, for evaluating TKA rehabilitation are proposed. It is anticipated that, as the cloud database is employed and more rehabilitation data are collected in the near future, the brace system can not only facilitate rehabilitations of TKA patients, but also improve life quality for geriatric patients and open a new space for remote artificial intelligence medical engineering.

Intersegmental Coordination in Patients With Total Knee Arthroplasty During Walking

Precise identification of deficient intersegmental coordination patterns and functional limitations is conducive to the evaluation of surgical outcomes after total knee arthroplasty (TKA) and the design of optimal personalized rehabilitation protocols. However, it is still not clear how and when intersegmental coordination patterns change during walking, and what functional limitations are in patients with TKA. This study was designed to investigate lower limb intersegmental coordination patterns in patients with knee osteoarthritis before and after TKA and identify how intersegmental coordination of patients is altered during walking before and after TKA. It was hypothesized that 6-month after TKA, intersegmental coordination patterns of patients are improved compared with that before TKA, but still do not recover to the level of healthy subjects. Gait analysis was performed on 36 patients before and 6-month after TKA and on 34 healthy subjects. Continuous relative phase (CRP) derived from the angle-velocity phase portrait was used to measure the coordination between interacting segments throughout the gait cycle. Thigh-shank CRP and shank-foot CRP were calculated for each subject. Statistical parametric mapping (SPM), a one-dimensional analysis of the entire gait cycle curve, was performed directly to determine which periods of the gait cycle were different in patients and healthy subjects. Six-month after TKA, thigh-shank CRP was significantly higher during 5–12% of the gait cycle (p = 0.041) and lower during 44–95% of the gait cycle (p < 0.001) compared with healthy subjects, and was significantly higher during 62–91% of the gait cycle (p = 0.002) compared with pre-operation. Shank-foot CRP was significantly lower during 0–28% of the gait cycle (p < 0.001) and higher during 58–94% of the gait cycle (p < 0.001) compared with healthy subjects, and was significantly lower during 3–18% of the gait cycle (p = 0.005) compared with pre-operation. This study found that patients exhibited altered intersegmental coordination during the loading response and swing phase both before and after TKA. Six-month after TKA, the thigh-shank coordination was partially improved compared with pre-operation, but still did not recover to the level of healthy subjects, while there was no improvement in the shank-foot coordination pattern after TKA compared with pre-operation. CRP combined with SPM methods can provide insights into the evaluation of surgical outcomes and the design of rehabilitation strategy.

Effect of tourniquet use on blood loss, pain, functional recovery, and complications in robot-assisted total knee arthroplasty: a prospective, double-blinded, randomized controlled trial

Background

Robot-assisted total knee arthroplasty (TKA) has been largely studied to confirm its advantages in terms of accurate component positioning, microembolus formation, less blood loss, and so on, but is currently usually performed under tourniquet due to its longer operative time than conventional TKA. The aim of this study was to estimate the effects of tourniquet use in robot-assisted TKA on blood loss, pain, functional recovery, and complications.

Methods

Patients scheduled for robot-assisted TKA were prospectively randomized into a tourniquet or non-tourniquet group (each n = 14). The primary outcome measure was blood loss. The secondary outcome measures were operation time; visual analog scale (VAS) pain scores; time to achieve the first straight-leg raise; swelling of the thigh, knee, and calf; range of motion; Hospital for Special Surgery score; length of stay; and postoperative complications.

Results

There was no significant difference in total blood loss between the tourniquet and non-tourniquet groups (738.57 ± 276.158 vs. 866.85 ± 243.422 ml, P = 0.061). The tourniquet group showed significantly lower intraoperative blood loss (P < 0.001), but higher hidden blood loss (P = 0.002). The non-tourniquet group showed better knee range of motion on postoperative days (PODs) 1–3 (all P < 0.001), less thigh swelling on PODs 2 and 3 (P < 0.05), earlier straight-leg raising (P = 0.044), and shorter length of stay (P = 0.044). Thigh pain VAS score at 1 month after surgery was significantly greater in the tourniquet group (P < 0.001), as was knee pain during activity and at rest on PODs 2–3 (all P < 0.05). The tourniquet group also showed a significantly higher rate of tension blisters (28.8% vs. 7.1%, P = 0.038).

Conclusions

Tourniquet use during robot-assisted TKA does not reduce total blood loss, and it appears to increase postoperative pain, aggravate muscle injury, and prolong postoperative recovery.

Trial registration ChiCTR, ChiCTR2100041800. Registered 5 January 2021, http://www.chictr.org.cn/index.aspx.

Motor effects of movement representation techniques and cross-education: a systematic review and meta-analysis

INTRODUCTION

The objective was to assess the impact of movement representation techniques (MRT) through motor imagery (MI), action observation (AO) and visual mirror feedback (VMF) and cross-education training (CE) on strength, range of motion (ROM), speed, functional state and balance during experimental immobilization processes in healthy individuals, in patients with injuries that did not require surgery and in those with surgical processes that did or did not require immobilization.

EVIDENCE ACQUISITION

MEDLINE, EMBASE, CINAHL and Google Scholar were searched. Thirteen meta-analyses were conducted.

EVIDENCE SYNTHESIS

Regarding the immobilized participants, in the healthy individuals, MI showed significant results regarding maintenance of strength and ROM, with low-quality evidence. Regarding the process with no immobilization, VMF and MI techniques showed significant changes in maintaining ROM in patients with injury without surgery, with very low-quality evidence. Results had shown that MI demonstrated significantly higher maintenance of strength and speed in patients undergoing surgery, with low-quality evidence. No significant results were found in ROM. Low-quality evidence showed better results in AO plus usual care compared with usual treatment in isolation with respect to maintenance of functional state and balance. CE training demonstrated maintenance of strength in patients undergoing surgery, with moderate evidence; however, not in healthy experimentally immobilized individuals. VMF did not show significant results in maintaining ROM after surgery without immobilization, nor did MI in maintaining strength after surgery and immobilization.

CONCLUSIONS

MRT and CE training have been shown to have a significant impact on the improvement of various motor variables and on physical maintenance in general.

Effect of Neuromuscular Electrical Stimulation After Total Knee Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: This systematic review and meta-analysis aimed to evaluate the effect of neuromuscular electrical stimulation (NMES) on quadriceps muscle strength, pain, and function outcomes following total knee arthroplasty (TKA).

Methods: PubMed/Medline, Embase, Web of Science, CENTRAL, Scopus, PsycINFO, PEDro, CINAHL, CNKI, and Wanfang were systematically searched for randomized controlled trials (RCTs) from their inception to 18 June 2021.

Results: Nine RCTs that involving 691 patients were included in the meta-analysis. Our pooled analysis showed that NMES improved quadriceps muscle strength after TKA within 1 months [standardized mean difference (SMD): 0.81; 95% CI: 0.51–1.11], 1–2 months (SMD: 0.55; 95% CI: 0.13–0.97), 3–4 months (SMD: 0.42; 95% CI: 0.18–0.66), and 12–13 months (SMD: 0.46; 95% CI: 0.18–0.74), pain between 1 and 2 months [mean difference (MD): −0.62; 95% CI: −1.04 to −0.19], pain between 3 and 6 months (MD: −0.44; 95% CI: −0.74 to −0.14) Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) between 3 and 4 months (MD: −0.43; 95% CI: −0.82 to −0.05), timed up and go test (TUG) within 1 month (MD: −2.23; 95% CI: −3.40 to −1.07), 3 minutes walk test between 3 and 6 months (MD: 28.35; 95% CI: 14.55–42.15), and SF-36 MCS between 3 and 6 months after TKA (MD: 4.20, 95% CI: 2.41–5.98).

Conclusion: As a supplementary treatment after TKA, postoperative NMES could improve the short-term to long-term quadriceps muscle strength, mid-term pain, and mid-term function following TKA. However, many outcomes failed to achieve statistically meaningful changes and minimal clinically important difference (MCID), thus the clinical benefits remained to be confirmed.

Level of Evidence: Therapeutic level I.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021265609.

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 Effect of Intensive Close-Kinetic-Chain Exercises on Functionality and Balance Confidence After Total Knee Arthroplasty

Objectives

The aim of this study was to evaluate the effects of an additional close-kinetic-chain exercise program (CKC-PT), in conjunction with the standard physiotherapy intervention (TKA-PT), on the general health status, functionality, balance confidence, and postoperative falls of knee osteoarthritic patients who had undergone total knee arthroplasty (TKA).

Patients and methods

Thirty community-dwellers, aged >65 years, were randomized into equal groups. The Greek versions of the SF-36 version1.0 (SF-36v1.0-Gr), WOMAC^® (WOMAC^®-Gr), Activities-specific Balance Confidence scale (ABC-Greek), Timed Up and Go (TUG) test, and Berg Balance Scale were assessed preoperatively and twice postoperatively (7^th week and 12^th month). Non-parametric (Mann-Whitney test) and parametric (two-way analysis of variance (ANOVA) model and student t-test) analyses were used to compare the percentage changes in all variables.

Results

The CKC-PT group reported better (%) functional improvement (WOMAC^®-Gr Physical­ Function subscale) and higher (%) balance confidence (ABS-Greek) at the seventh week and twelfth month as compared to TKA-PT (p<0.05). No other statistically significant differences were observed.

Conclusions

The implementation of a close-kinetic-chain exercise program, in addition to standard physiotherapy, may significantly increase both the functionality and balance confidence of patients who have undergone TKA. Further studies are needed to verify these findings.

Total knee arthroplasty patients using the in-home X10 machine fully recovered. No additional therapy required

Following total knee arthroplasties patients using the X10 increased their quadriceps strength 120% at 30 days post-surgery compared to their pre-surgical baseline. This contrasts sharply with contrast studies outpatient physical therapy that show patients suffer a 50-60% quadriceps strength deficit at 30 days post-surgery. For X10 patients, the average range of motion at 30 days was 124° and at discharge it was 128° (mean 43 days). The trial involved a single surgeon and two groups. Group one (21 patients) used only the X10 for pre-habilitation and rehabilitation, while group two (20 patients) used X10 alone for pre-habilitation and then utilized the X10 plus home care plus outpatient physical therapy for rehabilitation. Adding home care and outpatient physical therapy did not improve outcomes compared to patients who utilized X10 alone. Our results show no significant difference between the two groups. Indicating that the X10 by itself is adequate to completely rehabilitation patients from total knee arthroplasties. Finally, we compared our results to those of Calatayud et al.¹ who monitored two groups of patients, one group had only physical therapy for rehabilitation while the other group used physical therapy for both prehabilitation and rehabilitation. Our results were superior to Calatayud et al.¹ for extension, flexion, and quadriceps strength; for each of these measures the X10 treatment groups improved over time, while the Calatayud et al.¹ groups showed losses.

Are Medial and Lateral Tibiofemoral Compressive Forces Different in Uphill Compared to Level Walking for Patients Following Total Knee Arthroplasty?

The purpose of this study was to determine how tibiofemoral joint compressive forces and knee joint-spanning muscle forces during uphill walking change compared to level walking in patients with total knee arthroplasty (TKA). A musculoskeletal model capable of resolving total (TCF), medial (MCF), and lateral (LCF) tibiofemoral compressive forces was used to determine compressive forces and muscle forces during level and uphill walking on a 10 deg incline for twenty-five post-TKA patients. A 2 × 2 (slope: level and 10 deg × limb: replaced and nonreplaced) repeated measures analysis of variance was used to detect differences in knee contact forces between slope and limb conditions and their interaction. Peak loading-response TCF, MCF, and LCF were greater during uphill walking than level walking for nonreplaced limbs. During uphill walking, peak loading-response TCF was smaller in replaced limbs compared to nonreplaced limbs with no change in MCF or LCF. Peak knee extension moment and knee extensor muscle force were smaller in replaced limbs compared to nonreplaced limbs during uphill walking. During level walking, replaced and nonreplaced limbs experienced rather equal joint loading; however, replaced limb experienced reduced joint loading during uphill walking. Differences in joint loading between replaced and nonreplaced limbs were not present during level walking, suggesting compensation from the replaced limb during the more difficult task. Uphill walking following TKA promotes more balanced loading of replaced limbs during stance; however, these benefits may come at the expense of increased loading on nonreplaced limbs.

Patient- and Physical Therapist-Level Predictors of Patient-Reported Therapeutic Alliance: An Observational, Exploratory Study of Cohorts With Knee and Low Back Pain

OBJECTIVE

To identify patient- and physical therapist-level predictors for therapeutic alliance at the end of an episode of physical therapy for knee or low back pain (LBP).

DESIGN

Secondary analysis of observational cohort.

SETTING

Outpatient physical therapy clinics.

PARTICIPANTS

Patients receiving physical therapy for knee (n=189) or LBP (n=252) and physical therapists (n=19). Candidate predictor variables included demographics, patient clinical characteristics, and physical therapist attitudes and beliefs (Pain Attitudes and Beliefs Scale for Physical Therapists) and confidence in providing patient-centered care (Self-Efficacy in Patient-Centeredness Questionnaire).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Patient-reported therapeutic alliance was measured using the 12-item Work Alliance Inventory-Short Revised (WAI-SR).

RESULTS

Final linear mixed models indicated different patient- and physical therapist-level factor contributions in predicting final WAI-SR scores across cohorts with knee and LBP. Female sex was a consistent patient-level predictor for both knee (estimated β=1.57, P<.05) and LBP (β=1.42, P<.05), with age (β=-0.07, P<.01) and baseline function (β=0.06, P<.01) contributing to cohorts with knee and LBP, respectively. Physical therapist-level predictors included female sex (β=6.04, P<.05), Pain Attitudes and Beliefs Scale for Physiotherapists behavioral (β=0.65, P<.01), and Self-Efficacy in Patient-Centeredness Questionnaire (SEPCQ) Exploring Patient Perspective (β=-0.75, P<.01) subscale scores for LBP, with SEPCQ Sharing Information and Power subscale scores (β=0.56, P<.05) contributing to both cohorts with knee (β=0.56, P<.05) and LBP (β=0.74, P<.01). Random effects for patients nested within physical therapists were observed for both cohorts.

CONCLUSIONS

These findings provide preliminary evidence for inconsistent relationships among patient- and physical therapist-level factors and therapeutic alliance across cohorts with knee and LBP.

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.

Reporting of post-operative rehabilitation interventions for Total knee arthroplasty: a scoping review

Objective

The aim of this study was to evaluate the completeness of reporting of exercise adherence and exercise interventions delivered as part of clinical trials of post-operative total knee replacement (TKA) rehabilitation.

Design: Scoping review

Literature search

A literature search was conducted in PubMed, EMBASE, AMED, CINAHL, SPORTDiscus and Cochrane Library.

Study selection criteria

All randomized controlled trials (RCT) that examined post-operative exercise-based interventions for total knee arthroplasty were eligible for inclusion. Studies that were multifactorial or contained exercise interventions for both hip and knee arthroplasty were also included.

Data synthesis

The definition, type of measurement used and outcome for exercise adherence were collected and analyzed descreptively. Quality of reporting of exercise interventions were assessed using the Consensus for Exercise Reporting Tool (CERT) and the Cochrane Risk of Bias Tool.

Results

There were a total of 112 RCTs included in this review. The majority of RCTs (63%, n = 71) did not report exercise adherence. Only 23% (n = 15) of studies provided a definition of adherence. RCTs were of poor quality, with 85% (n = 95) of studies having high or unclear risk of bias. Reporting of exercise interventions was poor, with only 4 items (of 19) (21%) of the CERT adequately reported (88–99%), with other items not fulfilled on at least 60% of the RCTs. There were no RCTs that had fulfilled all the criteria for the CERT.

Conclusion

The RCTs included in this study poorly reported exercise adherence, as well as description of the post-operative TKA rehabilitation intervention. Future RCTs should use valid and reliable measures of adherence and a proper tool for reporting of exercise interventions (e.g., CERT, TiDER).

Pre-registration

OSF:https://osf.io/9ku8a/

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04460-w.

Evaluation of the Efficacy and Safety of an Exercise Program for Persons with Total Hip or Total Knee Replacement: Study Protocol for a Randomized Controlled Trial

Total hip replacement (THR) and total knee replacement (TKR) are among the most common elective surgical procedures. There is a large consensus on the importance of physical activity promotion for an active lifestyle in persons who underwent THR or TKR to prevent or mitigate disability and improve the quality of life (QoL) in the long term. However, there is no best practice in exercise and physical activity specifically designed for these persons. The present protocol aims to evaluate the efficacy and safety of an exercise program (6 month duration) designed for improving quality of life in people who had undergone THR or TKR. This paper describes a randomized controlled trial protocol that involves persons with THR or TKR. The participant will be randomly assigned to an intervention group or a control group. The intervention group will perform post-rehabilitation supervised training; the control group will be requested to follow the usual care. The primary outcome is QoL, measured with the Short-Form Health Survey (SF-36); Secondary outcomes are clinical, functional and lifestyle measures that may influence QoL. The results of this study could provide evidence for clinicians, exercise trainers, and policymakers toward a strategy that ensures safe and effective exercise physical activity after surgery.

Low-Load Unilateral and Bilateral Resistance Training to Restore Lower Limb Function in the Early Rehabilitation After Total Knee Arthroplasty: A Randomized Active-Controlled Clinical Trial

Background: Continuous passive motion (CPM) is frequently used during rehabilitation following total knee arthroplasty (TKA). Low-load resistance training (LLRT) using continuous active motion (CAM) devices is a promising alternative. We investigated the effectiveness of CPM compared to LLRT using the affected leg (CAMuni) and both legs (CAMbi) in the early post-operative rehabilitation. Hypotheses: (I) LLRT (CAMuni and CAMbi) is superior to CPM, (II) additional training of the unaffected leg (CAMbi) is more effective than unilateral training (CAMuni).

Materials and Methods: Eighty-five TKA patients were randomly assigned to three groups, respectively: (i) unilateral CPM of the operated leg; (ii) unilateral CAM of the operated leg (CAMuni); (iii) bilateral alternating CAM (CAMbi). Patients were assessed 1 day before TKA (pre-test), 1 day before discharge (post-test), and 3 months post-operatively (follow-up). Primary outcome: active knee flexion range of motion (ROM_Flex). Secondary outcomes: active knee extension ROM (ROM_Ext), swelling, pain, C-reactive protein, quality of life (Qol), physical activity, timed-up-and-go performance, stair-climbing performance, quadriceps muscle strength. Analyses of covariances were performed (modified intention-to-treat and per-protocol).

Results: Hypothesis I: Primary outcome: CAMbi resulted in a higher ROM_Flex of 9.0° (95%CI −18.03–0.04°, d = 0.76) and 6.3° (95%CI −14.31–0.99°, d = 0.61) compared to CPM at post-test and follow-up, respectively. Secondary outcomes: At post-test, C-reactive protein was lower in both CAM groups compared with CPM. Knee pain was lower in CAMuni compared to CPM. Improved ROM_Ext, reduced swelling, better stair-climbing and timed-up-and-go performance were observed for CAMbi compared to CPM. At follow-up, both CAM groups reported higher Qol and CAMbi showed a better timed-up-and-go performance. Hypothesis II: Primary outcome: CAMbi resulted in a higher knee ROM_Flex of 6.5° (95%CI −2.16–15.21°, d = 0.56) compared to CAMuni at post-test. Secondary outcomes: At post-test, improved ROM_Ext, reduced swelling, and better timed-up-and-go performance were observed in CAMbi compared to CAMuni.

Conclusions: Additional LLRT of the unaffected leg (CAMbi) seems to be more effective for recovery of function than training of the affected leg only (CAMuni), which may be mediated by positive transfer effects from the unaffected to the affected limb (cross education) and/or preserved neuromuscular function of the trained, unaffected leg.

Trial Registration:ClinicalTrials.gov Identifier: NCT02062138.

Cycle Sprint Test for the Evaluation of Lower Limb Muscle Power After Total Knee Arthroplasty: A Proof-of-Concept Study

Background

Lower limb muscle power is emerging as an important determinant of patient function after knee injury or surgery. This study tested proof of concept of a cycle sprint test for the evaluation of lower limb muscle power, as an outcome measure for patients having total knee arthroplasty (TKA).

Methods

Thirty-two patients were enrolled, of which 16 completed all follow-ups (3, 6, and 12 months). All patients completed the Oxford Knee Score and Knee Injury and Osteoarthritis Outcome Score questionnaires, a 10-m walk test, and 30-second sit-stand test. A trainer-mounted road cycle fitted with an instrumented crank was used for the cycle sprint test. Maximum muscle power was measured from 3, 10-second maximal efforts.

Results

Significant improvements in Oxford Knee Score and Knee Injury and Osteoarthritis Outcome scores relative to baseline were achieved at each follow-up (P < .001), and functional test performance improved significantly at 6 and 12 months (P < .001). Compared with the baseline of 268W, muscle power was significantly lower at 3 months (239W, −13%, P < .05) and significantly higher at 12 months (308W, +12%, P < .05).

Conclusion

The concept of muscle power measurement using a cycle sprint test before and after TKA has been demonstrated in this study. Identification of individuals with lower limb muscle power deficits after TKA may inform rehabilitation programs and enhance long-term outcomes.

Aquatic Exercise and Land Exercise Treatments after Total Knee Replacement Arthroplasty in Elderly Women: A Comparative Study

Background and Objectives: Early intensive exercise after total knee replacement arthroplasty (TKRA) has become increasingly popular due to its ability to enhance knee physical function and reduce pain. When implemented exclusively, aquatic exercise (AE) appears to be more advantageous than land exercise (LE), particularly in the early phase after TKRA. Our study aimed to compare the clinical efficacy of AE and LE with respect to their effects on pain and physical function after TKRA. Materials and Methods: Between February 2008 and January 2020, 100 female patients who underwent TKRA were enrolled in this retrospective study. We measured the range of motion (ROM) of the knee, the isokinetic strength of the knee joint (function), and pain both initially and one month after TKRA. Two weeks after TKRA, the participants were enrolled in either the AE or the LE program for a total of two weeks. Two 30 min sessions of intensive ROM and knee strengthening exercises and balance training were provided to the AE and LE groups for 10 days. The home exercise group (HE) only received information on ROM and strengthening exercises. There were 33, 21, and 46 patients allocated to the AE, LE, and HE groups, respectively. Results: The ROM of the side on which surgery was performed improved significantly in all groups, as did the pain scores. In the AE group, the knee flexor strength showed a tendency toward improvement. Contrastingly, there was no significant improvement in the knee extensor strength in the AE group. Conclusions: Overall, the AE and LE groups showed superior outcomes compared with HE. In addition, the AE group demonstrated some improvement in knee muscle strength even with a short hospital stay. Further study with long-term follow-up should be performed to better define the outcomes.

Mitochondrial Bioenergetics and Turnover during Chronic Muscle Disuse

Periods of muscle disuse promote marked mitochondrial alterations that contribute to the impaired metabolic health and degree of atrophy in the muscle. Thus, understanding the molecular underpinnings of muscle mitochondrial decline with prolonged inactivity is of considerable interest. There are translational applications to patients subjected to limb immobilization following injury, illness-induced bed rest, neuropathies, and even microgravity. Studies in these patients, as well as on various pre-clinical rodent models have elucidated the pathways involved in mitochondrial quality control, such as mitochondrial biogenesis, mitophagy, fission and fusion, and the corresponding mitochondrial derangements that underlie the muscle atrophy that ensues from inactivity. Defective organelles display altered respiratory function concurrent with increased accumulation of reactive oxygen species, which exacerbate myofiber atrophy via degradative pathways. The preservation of muscle quality and function is critical for maintaining mobility throughout the lifespan, and for the prevention of inactivity-related diseases. Exercise training is effective in preserving muscle mass by promoting favourable mitochondrial adaptations that offset the mitochondrial dysfunction, which contributes to the declines in muscle and whole-body metabolic health. This highlights the need for further investigation of the mechanisms in which mitochondria contribute to disuse-induced atrophy, as well as the specific molecular targets that can be exploited therapeutically.

Sensorimotor training prior total knee arthroplasty and effects on functional outcome: A systematic review and meta-analysis

BACKGROUND

Altered muscle activation patterns and proprioception, loss of strength, and weight bearing asymmetries are common limitations after total knee arthroplasty, which can also affect balance. Therefore, preoperative sensorimotor training has been proposed to enhance surgical outcome.

RESEARCH QUESTION

Is preoperative sensorimotor training effective in improving functional outcome in patients undergoing total knee arthroplasty? Does preoperative sensorimotor training affect secondary outcomes such as balance, pain, and quality of life?

METHODS

A systematic review and meta-analysis were conducted by searching PEDro, MEDLINE, Embase, Cochrane Library, and Scopus databases from inception to May 2020. Studies were eligible if participants underwent total knee arthroplasty after two or more weeks of preoperative sensorimotor training. A meta-analysis compared the effects of such interventions with standard care before and after surgery using standardized mean differences (SMD) with 95 % confidence interval (CI). Functional outcome was the primary measure. Balance, pain, and quality of life were also outcomes of interest.

RESULTS

Of the 384 items identified, 7 met the inclusion criteria, and 332 participants were assessed. There was limited evidence suggesting that preoperative sensorimotor training enhanced self-reported function (SMD, 0.89; 95 % CI, 0.16-1.62), functional performance (SMD, 0.56; 95 % CI, 0.19 to 0.93), or knee function (SMD = 0.22-1.05) compared with conventional care. Moderate quality evidence suggested that benefits were only maintained in terms of functional performance up to 3 months after surgery (SMD = 0.37; 95 % CI, 0.13 to 0.62). The outcome was similar after one year.

SIGNIFICANCE

Compared with conventional care, preoperative sensorimotor training may enhance early postoperative functional recovery, with no additional benefits on balance, knee function, or pain. The outcome is the same one year after surgery, regardless of whether such training is implemented. Further investigation is needed to determine whether sensorimotor training may be a feasible conservative treatment for severe knee osteoarthritis.

Potential Instability and Malfunction of Knee Joints with Vastus Medialis Impairment after Total Knee Arthroplasty

Four pairs of fresh-frozen cadaver knees (eight knees, four male knees) with a mean age of 72 ± 7 years were used for tests involving a customized simulator capable of controlling quadriceps loading conditions. The muscle force distribution of the quadriceps for the normal loading condition was applied on the basis of muscle cross-sectional area data, as previously reported (VM: 31 N; RF/VI: 49 N; VL: 45 N). To simulate vastus medialis (VM) impairment, we set the muscle force for VM in the muscle force distribution of the quadriceps at zero (VM: 0 N; RF/VI: 49 N; VL: 45 N). The joint reaction forces and moments on knee joints that underwent total knee arthroplasty (TKA) did not differ significantly according to VM impairment status for all flexion angles (p > 0.05). Nevertheless, the vectors of internal–external moments mostly showed a tendency for alteration from external to internal due to VM impairment. This tendency was evident in 9 cases in 12 total test pairs (with and without VM impairment). Furthermore, the vectors of the anterior–posterior reaction forces mostly showed a tendency to increase anteriorly due to VM impairment. This tendency was also evident in 9 cases in 12 total test pairs (with and without VM impairment). These results indicate that posterior dislocation of the tibia may be induced if VM impairment occurs after TKA. In conclusion, VM impairment in knee joints undergoing TKA may contribute to posterior dislocation of the tibia by a paradoxical roll-back with enhancements of the anterior joint reaction force and external moment during knee-joint flexion. Our findings may be valuable for understanding the mechanism of potential instability and malfunction due to VM impairment in knee joints after TKA, and may help to optimize clinical/rehabilitation training plans to improve the prognosis (stability and function) of knee joints undergoing TKA.