Quadriceps strength impairment in the mid- to long-term follow-up period after total knee arthroplasty

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.

Cut-off values of preoperative knee extensor strength and hip abductor strength for predicting good walking ability after total knee arthroplasty

INTRODUCTION

Total knee arthroplasty (TKA) reduces pain and improves physical function; however, not all patients have successful outcomes after surgery. To identify these patients would be critical information for improving rehabilitation programs. The purpose of this study was to clarify the cut-off values of lower extremity muscle strength for predicting postoperative good walking ability.

MATERIALS AND METHODS

Timed Up and Go test of 105 patients was measured at 6 months postoperatively, and participants were divided into good (< 9.1 s) and poor (≥ 9.1 s) walking ability. Both sides of knee extensor strength (KES) and hip abductor strength (HAS) were measured using hand-held dynamometer preoperatively. Receiver operating characteristic (ROC) curve analysis was used to identify cut-off values for classifying the participants into the two groups.

RESULTS

Of the 105 patients, 54 were allocated in the poor walking ability group, whereas 51 were allocated in the good walking ability group. KES and HAS were significantly greater in the good walking ability group than in the poor walking ability group. ROC curve analysis revealed that the cut-off value for KES was 0.79 Nm/kg (area under the curve (AUC) 0.68; sensitivity 64.7%; specificity 68.5%) on the involved side and 0.86 Nm/kg (AUC 0.73; sensitivity 84.6%; specificity 55.6%) on the uninvolved side, and for HAS was 0.57 Nm/kg (AUC 0.71; sensitivity 60.8%; specificity 71.7%) on the involved side and 0.61 Nm/kg (AUC 0.76; sensitivity 66.7%; specificity 77.4%) on the uninvolved side.

CONCLUSION

The cut-off values of preoperative KES and HAS for predicting good walking ability after TKA are 0.79 Nm/kg on the involved side and 0.86 Nm/kg on the uninvolved side, and 0.57 Nm/kg on the involved side and 0.61 Nm/kg on the uninvolved side, respectively. We should provide enhanced pre- and post-operative rehabilitation programs for patients with muscle strength lower than these values.

Arterial Stiffness, Assessed Using the Cardio-Ankle Vascular Index, before and 2 Years after Total Knee Arthroplasty in Patients with Knee Osteoarthritis

Purpose: Cardiovascular disease (CVD) is a major risk factor for mortality in patients with osteoarthritis, and such comorbidities increase the risk of postoperative complications following total knee arthroplasty (TKA). Arteriosclerosis plays a major role in hemodynamic dysfunction and CVD; however, the postoperative changes in arteriosclerosis following TKA have not been evaluated. Therefore, we assessed the postoperative changes in arteriosclerosis using the cardio-ankle vascular index (CAVI) in patients undergoing TKA, and its relationships with preoperative patient characteristics. Methods: Arteriosclerosis was prospectively evaluated in 119 consecutive patients (140 knees) (15 males (17), 104 females (123); median age 73 years) with knee osteoarthritis who underwent TKA. CAVI was measured before and 2 years after TKA, and the relationships between CAVI and preoperative age, sex, BMI, physical activity status, comorbidities, clinical score, triglyceride concentration, cholesterol concentration, and smoking history were analyzed. Results: CAVI remained stable or improved in 54 joints (39%) and worsened in 86 joints (61%) 2 years post-operation. The median difference between pre- and postoperative CAVI was 0.2 (-0.3, 0.8), and the only preoperative factor associated with this change was preoperative CAVI (r = -0.469, p < 0.001). No other preoperative factor had a significant effect on postoperative arteriosclerosis. Conclusions: The results suggest that patients who undergo TKA subsequently show less severe arteriosclerosis, and the protective effect of TKA on arterial stiffness is greater in those with a higher preoperative CAVI. TKA may be an effective means of reducing the deterioration of arteriosclerosis associated with knee osteoarthritis, at least in the relatively short term.

Anterior knee pain and sit-up tests predicts patients' satisfaction and improvement in quality of life after anterior stabilized total knee replacement without patellar resurfacing

PURPOSE

The purpose of this study was to assess patient satisfaction and identify risk factors for dissatisfaction after anterior stabilised conventional total knee arthroplasty (TKA) without patellar resurfacing, using the Goodman score.

METHODS

We conducted a cross-sectional study using data from our institutional database from 1 January 2018 to 1 March 2021. Patients who underwent TKA with the Vanguard® Cruciate Retaining Anterior Stabilized Knee System (Zimmer Biomet, Warsaw, Indiana, USA) without patellar replacement were included. Patients with other bearing surfaces (posterior stabilised or medial congruent) or diagnosed with infection or instability were excluded. Patients' reported outcomes, body mass index (BMI), passive range of motion, the timed up-and-go test, sit-up test, and algometry were assessed. Patients were also asked if they had anterior knee pain. Satisfaction was assessed using the Goodman scale, and logistic multivariate regression was used to identify variables associated with dissatisfaction and perceived improvement in quality of life.

RESULTS

A total of 131 TKA patients were included in the study. The median satisfaction score was 100 (interquartile range [IQR], 87.5 to 100), with the 75-point threshold at the 90th percentile according to Section A of Goodman. Section B of Goodman showed that 113 TKA patients (86.26%) reported "great improvement" or "more than I ever dreamed." Multivariate logistic regression revealed that anterior knee pain (OR 5.16, 95% CI 1.24 to 21.39), the sit-up test (OR 0.63, 95% CI 0.49 to 0.81), and BMI (OR 0.84, 95% CI 0.70 to 0.99) were significantly associated with patient dissatisfaction and a worse perceived improvement in quality of life. The receiver operating characteristics curve for the models had areas under the curve of 0.83 (95% CI 0.69 to 0.97) and 0.82 (95% CI 0.70 to 0.94), respectively.

CONCLUSION

Anterior stabilised TKA without patellar resurfacing can achieve 90% satisfaction and 86% improvement in quality of life. To improve these results, it is essential to prevent and treat anterior knee pain and enhance quadriceps strength.

LEVEL OF EVIDENCE

Level III (retrospective cohort study).

Positive effect of total knee arthroplasty on progression of arteriosclerosis evaluated by cardio-ankle vascular index

INTRODUCTION

Physical function is expected to improve with an increase in physical activity owing to improvement in knee joint pain after total knee arthroplasty (TKA). This study was performed to evaluate the impact of TKA on arteriosclerosis by measuring the cardio-ankle vascular index (CAVI) before and after surgery.

MATERIALS AND METHODS

In total, 206 consecutive patients undergoing unilateral TKA were investigated. The CAVI, an index of the overall stiffness of the artery from the origin of the aorta to the ankle, was used to evaluate the degree of arteriosclerosis. The CAVI of the TKA side and non-TKA side was compared before and 1 year after TKA.

RESULTS

There were no differences in the CAVI before and after TKA on the TKA side and non-TKA side, although these values should have worsened at 1 year compared with preoperative values. The CAVI, which did not differ between the two sides preoperatively, differed significantly between the two sides postoperatively (p = 0.013). A generalized linear model showed no interaction between each time point and the measured sides in terms of the CAVI. The relationship between the preoperative CAVI and the difference between the preoperative and postoperative CAVI were examined, showing that R =  - 0.428 (p < 0.001) for the TKA side and R =  - 0.416 (p < 0.001) for the non-TKA side (significant negative correlation).

CONCLUSIONS

The lack of significant age-related deterioration over time on both sides suggests that TKA may slow the progression of arteriosclerosis, especially on the operated side. The effect of TKA was found to be greater with a higher CAVI (i.e., more advanced arteriosclerosis).

Principal Component Analysis of Knee Joint Differences Between Bilateral and Unilateral Total Knee Replacement Patients During Level Walking

Many unilateral total knee replacement (TKR) patients will need a contralateral TKR. Differences in knee joint biomechanics between bilateral patients and unilateral patients are not well established. The purpose of this study was to examine knee joint differences in level walking between bilateral and unilateral patients, and asymptomatic controls, using principal component analysis. Knee joints of 1st replaced limbs of 15 bilateral patients (69.40 ± 5.04 years), 15 replaced limbs of unilateral patients (66.47 ± 6.15 years), and 15 asymptomatic controls (63.53 ± 9.50 years) were analyzed during level walking. Principal component analysis examined knee joint sagittal- and frontal-plane kinematics and moments, and vertical ground reaction force (GRF). A one-way analysis of variance analyzed differences between principal component scores of each group. TKR patients exhibited more flexed and abducted knees throughout stance, decreased sagittal knee range of motion (ROM), increased early-stance adduction ROM, decreased loading-response knee extension and push-off knee flexion moments, decreased loading-response and push-off peak knee abduction moment (KAbM), increased KAbM at midstance, increased midstance vertical GRF, and decreased loading-response and push-off vertical GRF. Additionally, bilateral patients exhibited reduced sagittal knee ROM, increased adduction ROM, decreased sagittal knee moments throughout stance, decreased KAbM throughout stance, an earlier loading-response peak vertical GRF, and a decreased push-off vertical GRF, compared to unilateral patients. TKR patients, especially bilateral patients had stiff knee motion in the sagittal-plane, increased frontal-plane joint laxity, and a quadriceps avoidance gait.

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.

Biomechanical Parameters that May Influence Lower Limb Injury during Landing in Taekwondo

Background and Objectives: The jumping kick of Taekwondo was a unilateral exercise that repeatedly moves in one direction. The exercise was exposed to the risk of injury due to the heavy ground reaction force and load in the landing. The first purpose of this study was to compare the impact force (IF), peak vertical ground reaction force (PVGRF), vertical loading rate (VLR), vertical stiffness (VS), and landing foot angle (LFA) during the landing of the jumping kick according to the experience of lower injury. The second purpose of this study was to investigate the lower extremities’ strength and the bilateral/ipsilateral asymmetry between the groups; Material and Methods: Ten injury-experience athletes (IG, age: 21.0 ± 0.8 years; height: 170.5 ± 4.1 cm; body weight: 66.7 ± 6.0 kg; career: 8.1 ± 5.0 years) and seven non-injury experience athletes (NG, age: 22.9 ± 4.0 years; height: 173.4 ± 3.1 cm; body weight: 67.9 ± 7.9 kg; career: 8.3 ± 5.0 years) participated; Results: There was no statistical difference between the two groups in the landing and lower extremity muscle strength impact variables. However, in the bilateral asymmetry of the ankle plantar flexor and the ipsilateral asymmetry of the hip abductor/adductor, IG was statistically larger than NG (p < 0.05). The landing foot angle also showed negative correlation to all impact variables (IF, PVGRF, VLR, and VS) (p < 0.05); Conclusions: It is desirable to place the landing foot down at a wide angle to prevent injury in performing Taekwondo jumping kicks. Although NGs have been shown to have better muscle strength symmetry and balance in some areas compared to IG, further research is needed to determine whether they are effective in preventing injury.

Improvements in Isokinetic Quadriceps and Hamstring Strength Testing After Focused Therapy in Patients With Flexion Instability

BACKGROUND

There is a paucity of literature to guide non-operative treatment for patients with problems after total knee arthroplasty (TKA). We sought to quantify how quadriceps and hamstring strength could improve with focused physical therapy (PT) and whether improving leg strength may prevent revision surgery for patients with flexion instability (FI) after TKA.

METHODS

This retrospective study included patients diagnosed with FI by one of the 4 fellowship-trained arthroplasty surgeons at a single academic institution. Patients with FI were referred for strength measurements and a focused PT program. In total, 166 patients completed isokinetic testing to quantify their relative quadriceps and hamstring power, torque, and work measures compared to their contralateral leg. Fifty-five (33.5%) patients subsequently completed post-PT isokinetic testing. Statistical analysis was conducted to evaluate strength deficits in the knee with FI.

RESULTS

Patients with FI were found to be 20.5%-38.4% weaker in all strength domains compared to the contralateral leg (P < .001). Patients who completed PT and pre-isokinetic and post-isokinetic testing demonstrated statistically significant gains in all extension metrics by a net range of 24.7%-34.2% (P = .011-.029) and their flexion strength metrics improved by 32.5%-40.2% (P = .002-.005). About 81.9% of patients in this subgroup did not undergo revision TKA. Those subjects who went on to revision did not statistically improve in any strength domain (P = .063-.121).

CONCLUSION

Patients with FI after TKA have significantly weaker quadriceps and hamstrings in the operative compared to contralateral leg. Patients who did not undergo revision knee arthroplasty and completed a formal PT program improved quadriceps and hamstring strength by 30%.

LEVEL OF EVIDENCE

IV (Case series).

Retrieval Analysis of Cruciate-Retaining and Posterior-Stabilized Total Knee Arthroplasty and Correlations to Laxity and Wear

BACKGROUND

Total knee arthroplasty (TKA) with posterior-stabilized (PS) or posterior cruciate-retaining (CR) implants has high success rates and survivorship. However, it is uncertain how laxity and constraint are associated with long-term polyethylene wear under physiological conditions.

METHODS

To answer this question, we measured the laxity patterns of 47 harvested cadaver specimens with primary TKAs in a custom knee-testing machine at full extension and at 30°, 60°, and 90° of flexion. The wear patterns of the tibial inserts were assessed using a semiquantitative method which is a modified approach of that proposed by Hood et al in 1983.

RESULTS

Statistical analysis found that the PS TKA cohort had a statistically significant increase in varus laxity at 60° and 90° of flexion, as well as total coronal laxity at 60° of flexion when compared to the CR cohort. Furthermore, analysis demonstrated a significant correlation between increased PS coronal laxity and increased tibial wear, a trend that was not seen in the CR specimens.

CONCLUSION

Our findings suggest that greater laxity in flexion after primary TKA may increase the wear realized over time and that PS TKAs may be more susceptible due to the loss of support the PCL affords to the flexion space. Whether a CR or PS TKA is used, surgeons need to avoid the pitfalls that may create greater flexion laxity during the procedure to optimize long-term polyethylene wear.

Outcome reporting patterns in total knee arthroplasty: A systematic review

BACKGROUND

Total knee arthroplasty (TKA) is one of the most effective ways to treat end-stage painful conditions of the knee. However, non-standardized reporting patterns can make quantitative analysis of patient outcomes difficult.

METHODS

A systematic review of the literature was performed using keywords "total knee arthroplasty" and "total knee replacement." Randomized controlled trials (RCTs) meeting the inclusion criteria were sorted and reviewed. Type of study, outcome measures used to report their results, and the actual results were recorded. Quantitative analysis was performed.

RESULTS

A total of 233 RCTs were included. There was significant variability in the reporting of short term and long term outcomes in total knee arthroplasty. The most common treatment domains in order of decreasing frequency were objective knee function, subjective knee function, perioperative complications, and pain. Range of motion was the most common outcome metric reported in all the RCTs and also was the most common metric used to assess objective knee function. The most common patient reported outcome measure used to assess postoperative function was the Knee Society Score followed by Knee Injury and Osteoarthritis Outcome Score. The Visual Analog Scale was the most common measurement tool used to assess postoperative pain. Most studies assessed patient outcomes in three treatment domains. None reported outcomes in all seven domains.

CONCLUSION

There is significant variability in outcome reporting patterns in TKA literature. Most studies do not track outcomes comprehensively, with a significant minority of the RCTs tracking outcomes in only one treatment domain.

Association of knee osteoarthritis grade with one-leg standing balance and quadriceps strength in male independent ambulators aged ≥80 years

Background

One-leg standing (OLS) balance is an important predictor of falls in people of advanced age. In this population, muscle weakness and knee osteoarthritis also contribute to falls and resultant fractures and thereby affect mortality rates. The Kellgren-Lawrence (KL) classification is widely used in the radiographic evaluation of knee osteoarthritis. This study was performed to evaluate OLS balance and the quadriceps strength (QS) for each KL grade and to clarify the impact of the knee osteoarthritis grade on OLS balance and QS.

Hypothesis

OLS balance shows results compatible with those of previous reports when independent walking is possible because of maintenance of QS regardless of the OA grade.

Methods

This single-center prospective cross-sectional study included data on 106 male orthopedic patients (106 knees) aged ≥80 years who could walk independently. OLS balance with eyes open was assessed using the patient's preferred leg. A handheld dynamometer was used to measure QS. The ratio of muscle strength to body weight (QS/BW ratio) was used to evaluate outcomes. Weight-bearing standing knee radiographs were evaluated using the KL classification. OLS balance and the QS/BW ratio were evaluated for each KL grade, and the correlations of the KL grade with OLS balance and the QS/BW ratio were assessed simultaneously.

Results

For each KL grade, the number of participants (n), median OLS balance (seconds), and QS/BW ratio (N/kg) were as follows: grade I: 24, 12, and 4.9; grade II: 51, 14, and 5.2; grade III: 22, 14, and 4.9; and grade IV: 9, 26, and 5.7, respectively. There were no significant differences in either OLS balance or the QS/BW ratio among the four grades.

Conclusions

Participants exhibited good OLS balance and QS/BW ratio regardless of their KL grade. This study demonstrated an absence of correlations of the KL grade with OLS balance and the QS/BW ratio, as was previously reported for the KL grade and pain.

Level of evidence

Level II prospective study.

Reference Values and Correlations for Multiple Physical Performance Measures: A Cross-Sectional Study among Independently Mobile Older Men in Japan

Purpose: Japan is one of few countries with a male life expectancy over 80 years. The gap between the healthy life span and the total life expectancy is large, highlighting the importance of maintaining physical performance. The present study aims to establish reference values for multiple physical performance measures among high-functioning oldest-old Japanese men and to investigate the correlations among these measurements to understand how these variables are related. Methods: This study was conducted with 120 Japanese males aged 80 years or older who were able to walk independently. Seven measures of physical performance were assessed: handgrip strength, quadriceps strength, static balance ability (one-legged stance), dynamic balance ability (Functional Reach Test; FRT), walking ability (5-m walking time test), combined movement ability (Timed Up & Go test), and bone quality. Cognitive function was also measured (Mini-Mental State Examination; MMSE). Results: Specific reference values are reported for each physical performance measurement explored in this study. Only six participants were classified as cognitively impaired, and 16 had mild cognitive impairment. There were significant correlations of varying levels among all of the measures of physical performance. Age was significantly correlated with all performance measures except FRT, and there was no correlation between age and MMSE. MMSE was weakly correlated with FRT and unrelated to the other performance measures. Conclusions: The reference ranges can be used by older men who have not yet reached 80 years and their health care providers as physical performance targets to facilitate the maintenance of independent mobility in later life.

Knee Osteoarthritis Grade does not Correlate with Quadriceps Muscle Strength or Bone Properties of the Calcaneus in Men Aged 80 Years or More who Can Walk independently

Purpose: Muscle weakness and bone deterioration in the elderly are related to falls and fractures, resulting in decreased mobility. Knee osteoarthritis also may contribute to falls and fractures and thereby affect mortality rates. The Kellgren–Lawrence (KL) classification is widely used in the radiographic evaluation of knee osteoarthritis. Aims: This study aimed to evaluate the quadriceps strength and bone properties of the calcaneus for each KL grade, and to clarify the impact of knee osteoarthritis grade on quadriceps strength and bone properties. Methods: This prospective cross-sectional study included data on 108 male patients (213 knees), aged ≥80 years, who could walk independently. A handheld dynamometer was used to measure quadriceps strength. Bone properties were evaluated using broadband ultrasound attenuation with a portable bone densitometer. Weight-bearing standing knee radiographs were evaluated using KL classification. Quadriceps strength and bone properties were evaluated for each KL grade and the correlations between the grade and quadriceps strength and bone properties were assessed simultaneously. Results: The numbers of participants in KL grades I–IV were 46, 102, 45, and 20, respectively. There were no differences among grades for either quadriceps strength or bone properties. Conclusions: Participants exhibited good quadriceps strength and bone properties regardless of their KL grade. Relatively high mechanical loading of muscle and bone incurred while walking independently, likely explaining this result. Clinically, this study demonstrated the absence of correlations between KL grade and quadriceps strength and bone properties, as was previously reported in studies showing the absence of a correlation between KL grade and pain.

Short-term outcomes for total knee arthroplasty patients with active extension lag

Background

Despite the success of total knee arthroplasty (TKA), quadriceps strength can fail to recover. Active extension lag [quadriceps lag (Q-lag)] is a function of quadriceps weakness. Q-lag presents itself in patients who maintain a full passive range of motion (ROM), but are limited in active extension ROM. Few studies have evaluated the outcomes of post-TKA patients in the presence of post-operative Q-lag. Thus, this study aims to compare: (I) pain scores; and (II) rates of readmission to physical therapy (PT) in TKA patients with Q-lag of ≥15 degrees to patients without Q-lag.

Methods

A retrospective review of primary TKA patients between 2013 and 2015 was performed. A total of 150 patients (mean age 63.0 years) with a mean follow-up of 30.7 months were analyzed. All patients received an evidence-based protocol for PT at our institution. Patient readmission to PT was recorded if the orthopedic surgeon wrote an additional prescription for PT intervention following the standard of care following TKA. An independent samples t-test and chi-square analysis was conducted to assess the continuous and categorical variables, respectively.

Results

Fifty-one patients had Q-lag ≥15 degrees and 97 patients had Q-lag <15 degrees. Analysis of mean pain scores between the groups demonstrated a significant difference in mean pain scores (1.9 vs. 3.9; P=0.043). Chi-square analysis demonstrated no significant difference in rates of PT readmission between patients who presented with Q-lag, and patients without Q-lag (23.5% vs. 13.4%; P=0.118).

Conclusions

There was no significant difference in readmission rates; however, patients with Q-lag experienced a clinically significant higher pain level. Since this is the first study of its kind, we suggest further investigations on the effect of Q-lag on patient outcomes following primary TKA.

Circuit training enhances function in patients undergoing total knee arthroplasty: a retrospective cohort study

Background

The number of patients receiving total knee arthroplasty (TKA) has been rising every year due to the aging population and the obesity epidemic. Post-operative rehabilitation is important for the outcome of TKA.

Methods

A series of 34 patients who underwent primary unilateral TKA was retrospectively collected and divided into either exercise group (n = 16) and control group (n = 18). The exercise group underwent a 24-week course of circuit training beginning 3 months after total knee arthroplasty (TKA). The effect of circuit training on TKA patients in terms of motion analysis, muscle strength testing, Knee injury and Osteoarthritis Outcomes Score (KOOS) questionnaire and patient-reported outcome measurement Short-Form Health Survey (SF-36) at the pre-operation, pre-exercise, mid-exercise, and post-exercise.

Results

Motion analysis revealed the stride length, step velocity, and excursion of active knee range of motion significantly improved in the exercise group when compared to those in the control group. KOOS questionnaire showed a greater improvement in pain, ADL, and total scores in the exercise group. The SF-36 questionnaire revealed a significant improvement in general health, bodily pain, social function, and physical components score in the exercise group.

Conclusions

The post-operative circuit training intervention can facilitate recovery of knee function and decrease the degree of pain in the TKA and might be considered a useful adjunct rehabilitative modality. The ultimate influence of circuit training on TKA needs further a prospective randomized clinical trial study and long-term investigation.

Trial registration

NCT02928562