Preoperative Quadriceps Muscle Strength and Functional Ability Predict Performance-Based Outcomes 6 Months After Total Knee Arthroplasty: A Systematic Review

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.

Comparison of Pre- and Postoperative Motor-proprioceptive Abilities in Patients with Gonarthrosis

Both surgeons and patients want to achieve a high level of satisfaction and the best possible functional results within a short time after knee TEP surgery. By using a tool that digitally records various measurement parameters of balance and motor function preoperatively and postoperatively on a mobile basis and with little time expenditure, progressive results can be compared. Individual factors can thus be determined and these can influence the progress in regeneration and training progress perioperatively.In a prospective study, 100 patients before and 66 patients after installation of a cement-retained knee TEP were evaluated for the following parameters: balance, maximum strength, and power. All measurements were performed with the KMP measurement platform from MotoSana. The second measurements were performed in each case after a standardised follow-up treatment.It was shown that there are significant relationships between personal factors such as age, height, body weight and with baseline values and performance measures: maximum strength and power. Furthermore, it was shown that postoperative improvement could be achieved for the most part around balance support. All patients who previously had to hold on with one hand or both hands no longer needed support after surgery to maintain the single-leg stance for the specified time of 15 s. For a more detailed analysis of the balance parameters, the samples were adjusted and only the patients who did not hold on for support pre- and postoperatively were counted. In patients with low and medium initial stance, the sway area increased at the second measurement session, and in patients with large sway areas, it decreased, and the stance became more stable. In the area of maximum strength and power, patients with high baseline values still had higher values after AHB compared with the other patients, but lower values compared with their own baseline values.Patients who already had very good motor skills before surgery were able to achieve a greater increase in motor skills compared to the weaker group. However, all patients failed to reach their preoperative baseline values after completion of the AHB. Deficits in balance were still detectable in all groups. By using the presented force plate, measurement-based coordinated rehabilitation procedures are possible during and after completion of the AHB. Rehabilitation with individualised improvement of balance and motor function could be expected to prevent dissatisfaction after knee arthroplasty, e.g. due to muscular imbalance in femoropatellar pain syndromes.

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

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

Anterior Knee Pain Following Primary Unilateral Total Knee Arthroplasty With Posterior-Stabilized Prosthesis and Patellar Resurfacing: Prevalence and Clinical Implications

BACKGROUND

Anterior knee pain following total knee arthroplasty (TKA) is associated with patient dissatisfaction. Factors related to postoperative anterior knee pain and its impact on patient outcomes are poorly understood. The following are the aims of this study: (1) to report the prevalence of anterior knee pain before and after TKA using a posterior-stabilized prosthesis with routine patellar resurfacing; (2) to investigate the association of preoperative clinical factors with the presence of anterior knee pain after TKA; and (3) to explore the association of postoperative anterior knee pain with postoperative self-reported function and quality of life.

METHODS

This retrospective study included 506 patients who had undergone elective primary unilateral TKA with a posterior-stabilized prosthesis and patellar resurfacing. Outcome measures prior to and 12 months after TKA included self-reported anterior knee pain, knee function, and quality of life.

RESULTS

Prevalence of anterior knee pain was 72% prior to and 15% following TKA. Patients who had preoperative anterior knee pain had twice the risk of experiencing anterior knee pain after TKA than patients who did not have preoperative anterior knee pain (risk ratio: 2.37, 95% CI 1.73-2.96). Greater severity of preoperative anterior knee pain and worse self-reported function were associated with the presence of postoperative anterior knee pain (rho = 0.15, P < .01; rho = 0.13, P < .01, respectively). Preoperative age, gender, and quality of life were not associated with postoperative anterior knee pain. Greater severity of postoperative anterior knee pain was associated with worse knee function at 12 months postoperative (rho = 0.49, P < .01).

CONCLUSION

One in 7 patients reported anterior knee pain 12 months following posterior-stabilized and patella-resurfaced TKA. The presence of preoperative anterior knee pain and worse self-reported function are associated with postoperative anterior knee pain.

The course of knee extensor strength after total knee arthroplasty: a systematic review with meta-analysis and -regression

PURPOSE

Muscular strength loss and atrophy are postoperative complications. This systematic review with meta-analysis investigated the course of on knee extensor mass and strength from pre-surgery over total knee arthroplasty to rehabilitation and recovery.

METHODS

A systematic literature search was conducted in PubMed (Medline), Cochrane Library (CINAHL, Embase) and Web of Science (until 29th of June 2022). Main inclusion criteria were  ≥ 1 preoperative and  ≥ 1 measurement  ≥ 3-months post-operation and ≥ 1 objective assessment of quadriceps strength, muscle mass or neuromuscular activity, measured at both legs. Studies were excluded if they met the following criteria: further impairment of treated extremity or of the contralateral extremity; further muscle affecting disease, or muscle- or rehabilitation-specific intervention. The Robins-I tool for non-randomized studies, and the Cochrane Rob 2 tool for randomized controlled studies were used for risk of bias rating. Pre-surgery, 3 months, 6 months and 1 year after surgery data were pooled using random effects meta-analyses (standardized mean differences, SMD, Hedge's g) in contrast to the pre-injury values.

RESULTS

1417 studies were screened, 21 studies on 647 participants were included. Thereof, 13 were non-randomized controlled trails (moderate overall risk of bias in most studies) and 7 were randomized controlled trials (high risk of bias in at least one domain in most studies). Three (k = 12 studies; SMD = - 0.21 [95% confidence interval = - 0.36 to - 0.05], I² = 4.75%) and six (k = 9; SMD = - 0.10 [- 0.28 to - 0.08]; I² = 0%) months after total knee arthroplasty, a deterioration in the strength of the operated leg compared with the strength of the non-operated leg was observed. One year after surgery, the operated leg was stronger in all studies compared to the preoperative values. However, this increase in strength was not significant compared to the non-operated leg (k = 6, SMD = 0.18 [- 0.18 to 0.54], I² = 77.56%).

CONCLUSION

We found moderate certainty evidence that deficits in muscle strength of the knee extensors persist and progress until 3 months post-total knee arthroplasty in patients with end-stage knee osteoarthritis. Very low certainty evidence exists that preoperatively existing imbalance of muscle strength and mass in favor of the leg not undergoing surgery is not recovered within 1 year after surgery.

Pre- and Post-Operative Rehabilitation Interventions in Patients at Risk of Poor Outcomes Following Knee or Hip Arthroplasty: Protocol for Two Systematic Reviews

Objective

Total knee (TKA) and hip arthroplasty (THA) are successful procedures in treating end-stage osteoarthritis when nonoperative treatments fail. However, a growing body of literature has been reporting suboptimal outcomes following TKA and THA. While pre- and post-operative rehabilitation is imperative to recovery, little is known about their effectiveness for patients at risk of poor outcomes. In the 2 systematic reviews with identical methodology, we aim to evaluate the effectiveness of (a) pre-operative and (b) post-operative rehabilitation interventions for patients at risk of poor outcomes following TKA and THA.

Methods

The 2 systematic reviews will follow the principles and recommendations outlined in the Cochrane Handbook. Only randomized controlled trials (RCTs) and pilot RCTs will be searched in 6 databases: CINAHL, MEDLINE, Embase, Web of Science, Pedro, and OTseeker. Eligible studies including patients at risk of poor outcomes and evaluating rehabilitation interventions following and preceding arthroplasty will be considered for inclusion. Primary outcomes will include performance-based tests and functional patient-reported outcome measures, and secondary outcomes will include health-related quality of life and pain. The quality of eligible RCTs will be evaluated using the Cochrane's risk of bias tool, and the strength of evidence will be assessed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE).

Discussion

These reviews will synthesize the evidence regarding the effectiveness of pre-and post-operative rehabilitation interventions for patients at risk of poor outcomes, which in turn may inform practitioners and patients in planning and implementing the most optimal rehabilitation programs to achieve the best outcomes after arthroplasty.

Systematic Review Registration

PROSPERO CRD42022355574.

Association of preoperative muscle composition of the lower extremity with gait function after total knee arthroplasty

BACKGROUND

Limitations of gait function persist in some patients with knee osteoarthritis after total knee arthroplasty. This study aimed to identify preoperative muscle composition variables of the operated limb associated with postoperative gait function.

METHODS

Longitudinal data from 45 patients who underwent unilateral primary total knee arthroplasty were retrospectively analyzed. Timed Up-and-Go test and gait speed were measured preoperatively and at 3 and 6 months postoperatively. Preoperative muscle composition in the glutei medius and minimus, the quadriceps, the hamstrings, and combination of the hamstrings and quadriceps were evaluated by computed tomography. The area ratio of the individual muscle composition to the total muscle was calculated. The factors associated with Timed Up-and-Go test and gait speed were identified using stepwise regression analysis.

RESULTS

Shorter Timed Up-and-Go test and faster gait speed at each time point correlated with higher lean muscle mass area of the total hamstrings, higher area ratio of lean muscle mass to the total hamstrings or to combination of the hamstrings and quadriceps, and lower area ratio of low density lean tissue or intramuscular adipose tissue to the total hamstrings. Shorter Timed Up-and-Go test at each time point also correlated with higher combined area of lean muscle mass of the hamstrings and quadriceps. Faster gait speed at each time point additionally correlated with lower area ratio of intramuscular fat to the total hamstrings and lower area ratio of lean tissue mass or intramuscular adipose tissue to combination of the hamstrings and quadriceps. Regression analysis using the significant muscle composition variables revealed that the area ratio of lean muscle mass to the total hamstrings was the only predictor of Timed Up-and-Go test and gait speed after operation.

CONCLUSIONS

Preoperative area ratio of ipsilateral lean muscle mass to the total hamstrings could predict gait function after total knee arthroplasty.

Current applications of gait analysis after total knee arthroplasty: A scoping review

Introduction

The biomechanics of the knee do not return to normal after knee replacement. The purpose of this scoping review is to summarize the current use of gait analysis in total knee arthroplasty and to identify the preoperative motion analysis parameters for which a systematic review aimed at determining the reliability and validity may be warranted.

Materials and methods

This IRB-exempt scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. The 279 articles from the five search engines underwent a title/abstract and full-text screening. Included articles were categorized as either: the role of gait analysis as a research tool for operative decisions, other research applications for motion analysis in total knee arthroplasty, gait analysis as a tool in predicting radiologic outcomes, or gait analysis as a tool in predicting clinical outcomes.

Results

Eleven articles studied gait analysis as a research tool in studying operative decisions. Five articles studied other research applications for motion analysis in total knee arthroplasty. Other research applications for motion analysis currently include studying the role of the unicompartmental knee arthroplasty and novel physical therapy protocols aimed at optimizing post-operative care. Two articles studied motion analysis as a tool for predicting radiographic outcomes. 15 articles studied motion analysis in conjunction with clinical scores.

Conclusions

There is a broad range of research applications for motion analysis in knee reconstruction. Current limitations include vague definitions of 'gait analysis' or 'motion analysis' and a limited number of articles with preoperative and postoperative outcomes. Knee adduction moment, knee adduction impulse, total knee range of motion, varus angle, cadence, stride length, and velocity have the potential for integration into composite clinical scores. A systematic review to determine the psychometric properties of these variables is warranted.

Content and delivery of pre-operative interventions for patients undergoing total knee replacement: a rapid review

BACKGROUND

Total knee replacement (TKR) is a common operation typically performed for end-stage knee osteoarthritis. Patients awaiting TKR often have poor health-related quality of life. Approximately 20% of patients experience persistent pain post-TKR. Pre-operative TKR interventions could improve pre- and post-operative outcomes, but future research is required to inform their design. This review aimed to identify and synthesize recent literature on the content and delivery of pre-operative TKR interventions to help guide future research and clinical practice.

METHODS

This rapid review included randomized trials of pre-operative TKR interventions ("outcomes studies") and primary studies exploring patients' and/or health professionals' views of pre-operative TKR interventions ("views studies"). Medline, Embase, PsycINFO, CINAHL and the Cochrane Central Register of Controlled Trials were searched for English language studies published between January 2009 and December 2020. Eligible studies' reference lists were screened. Studies were appraised using the Mixed Methods Appraisal Tool. The findings were narratively synthesized using a convergent segregated approach.

RESULTS

From 3263 records identified, 52 studies were included (29 outcomes studies, 21 views studies, two outcomes/views studies). The studies' methodological quality varied but was generally highest in qualitative studies. The outcomes studies investigated education (n=5), exercise (n=20), psychological (n=2), lifestyle (n=1), and/or other interventions (n=5). The views studies addressed education (n=20), exercise (n=3), psychological (n=1), lifestyle (n=4), and/or other interventions (n=1). Only three outcomes studies (two randomized controlled trials (RCTs) and a pilot study) compared the effectiveness of intervention components/delivery approaches. The two RCTs' results suggest that pre-operative TKR exercise interventions are equally effective regardless of whether they include strength or strength plus balance training and whether they are hospital- or home-based. Personal tailoring and using more than one delivery format were associated with improved outcomes and/or perceived as beneficial for multiple intervention types.

CONCLUSIONS

Definitive evidence on the optimal design of pre-operative TKR interventions is lacking. Personal tailoring and employing multiple delivery formats appear to be valuable design elements. Preliminary evidence suggests that including balance training and hospital versus home delivery may not be critical design elements for pre-operative TKR exercise interventions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019143248 FUNDER: National Institute for Health and Care Research (ICA-CDRF-2018-04-ST2-006).

Impact of a Six-Week Prehabilitation With Blood-Flow Restriction Training on Pre- and Postoperative Skeletal Muscle Mass and Strength in Patients Receiving Primary Total Knee Arthroplasty

Introduction: Total Knee Arthroplasty (TKA) is one of the most successful interventions in gonarthrosis, however the operation is leading to muscle atrophy and long-term muscular deficits. To enhance rehabilitation after TKA, exercise programs try to improve muscle function preoperatively, called prehabilitation. Blood-Flow-Restriction Exercises (BFRE) is a training method which is characterized by using tourniquets to reduce arterial and occlude venous blood flow simultaneously during the exercise to increase metabolic stress. The present study aimed to evaluate the effects of a 6-week prehabilitation with BFR on pre- and postoperative muscle mass, strength, and quality of life (QoL).

Methods: 30 patients with end-stage gonarthrosis participated in this study. Patients were randomized into one of three groups: 1) Control-Group (CON): Standard clinical approach without prehabilitation. 2) Active-Control-Group (AC): Participation in a prehabilitation with sham-BFR. 3) BFR-Group (BFR): Participation in a prehabilitation with BFR. The prehabilitation protocol consist of a cycling-ergometer-based training performed twice per week over 6 weeks. During exercise, BFR was applied periodically three times per leg with a pressure of 40% of the individual-limb-occlusion-pressure. Measurement time points were six- (baseline), 3-weeks and 5-days before the surgery (Pre-OP), as well as three- and 6-months postoperatively. Outcome measures were muscular strength of the thigh muscles, thigh circumference as well as QoL and functional activity, examined by 6-min walking- and chair rising test.

Results: Both training groups indicated significantly improved leg muscle strength following the prehabilitation period with a superior effect for the BFR-group (BFR: ∼170% vs. AC: ∼91%, p < 0.05). No significant changes in leg strength occurred in the CON (∼3%, p = 0.100). Further, patients in BFR-group indicated significantly improved skeletal muscle mass assessed by femoral circumference following prehabilitation period (∼7%, p < 0.05), while no significant changes occurred in the CON (−1.14%, p = 0.131) and AC-group (∼3%, p = 0.078). At 3-months Post-OP, the CON and BFR-group revealed a significant decrease in femoral circumference compared to the Pre-OP (CON: ∼3%, BFR: ∼4%; p < 0.05), but BFR-group remained above the baseline level (∼3%, p < 0.05). No significant change in femoral circumference was found for AC-group (∼2%, p = 0.078). In addition, the prehabilitation with BFR provided notably improved Knee Injury and Osteoarthritis Outcome Scores (KOOS) especially in pain perception with significant higher effect compared to other groups (CON: −2%, AC: 13%, BFR: 41%; p < 0.05). In long-term rehabilitation after 6-months, all groups showed significantly improved KOOS scores in all dimensions (CON: ∼110%, AC: ∼132%, BFR: ∼225%; p < 0.01), and functional examinations (CON: ∼26%, AC: ∼16%, BFR: ∼53%; p < 0.01).

Conclusion: The present findings show that BFR-prehabilitation induce significant improvements in muscle function and QoL before TKA surgery. In addition, the supporting effect of prehabilitation on postoperative regeneration and QoL should be highlighted, illustrating prolonged beneficial effects of BFR on muscular and functional performance in a “better in, better out”-manner.

Association Between Preoperative Shoulder Strength and Clinical Outcomes After Primary Reverse Total Shoulder Arthroplasty

INTRODUCTION

We aimed to determine whether preoperative shoulder strength predicts postoperative values and improvement in strength, range of motion (ROM), and outcome scores after primary reverse total shoulder arthroplasty (rTSA).

METHODS

We retrospectively reviewed 264 shoulders with a minimum of 2-year follow-up after primary rTSA. Preoperative external rotation (ER) strength, supraspinatus strength, and abduction strength were analyzed to establish their correlation with postoperative values and improvement in strength, ROM, and outcome scores (Constant score, American Shoulder and Elbow Surgeons Shoulder score, Shoulder Pain and Disability Index, Simple Shoulder Test, and the University of California, Los Angeles score). Multiple linear regression models were used to identify the preoperative shoulder strength measures that most affected postoperative outcomes and improvement in outcomes.

RESULTS

Preoperative measures of shoulder strength were positively correlated with all measures of postoperative shoulder strength, active abduction and elevation, and all outcome scores studied. On multivariate analysis, greater preoperative ER, supraspinatus, and abduction strength were significantly associated with greater corresponding postoperative values (P = 0.009, P = 0.041, and P = 0.008, respectively); however, they were also associated with less respective improvement (P < 0.001 for all) because the weakest patients tended to see the largest improvements. Notably, preoperative values of ER and supraspinatus strength exceeding 17.5 and 20.5 lbs were associated with a decline in their respective values postoperatively, but no limit was identified for ROM or outcome score measures. On multivariate analysis, reduced preoperative abduction strength was markedly associated with greater improvement in 3 of 4 ROM measures and 4 of 5 outcome scores.

CONCLUSION

Preoperative shoulder strength, especially abduction strength, predicts superior postoperative outcomes and greater improvement in shoulder strength, ROM, and outcome scores after primary rTSA. However, a minority of patients with well-preserved strength may lose strength after surgery, and patients who are weaker preoperatively tend to see larger improvements in postoperative outcomes.

LEVEL OF EVIDENCE

Ⅳ, prognostic study.

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.

Preoperative shoulder strength is associated with postoperative primary anatomic total shoulder arthroplasty outcomes and improvement

BACKGROUND

Although numerous preoperative factors that influence postoperative outcomes after anatomic total shoulder arthroplasty (aTSA) have been identified, preoperative shoulder strength has not been studied. The purpose of this study was to determine whether preoperative shoulder strength is predictive of postoperative outcomes and improvement after primary aTSA.

METHODS

We conducted a retrospective review of prospectively collected data from 160 shoulders with minimum 2-year follow-up after primary aTSA. Preoperative external rotation (ER) strength, supraspinatus strength, and abduction strength score were analyzed to determine their correlation with postoperative outcomes and improvement in shoulder strength, range of motion (ROM), and outcome scores. Multiple linear regression models were subsequently used to adjust for covariates and determine the preoperative measures of shoulder strength that most influenced postoperative outcomes and improvement.

RESULTS

Preoperative ER strength, supraspinatus strength, and abduction strength score were each moderately correlated with their respective postoperative values and improvement (P < .001 for all). A decrease in ER strength, supraspinatus strength, and abduction strength score postoperatively was identified for preoperative strength values > 8.2 kg, > 6.6 kg, and > 4.5 kg, respectively. In contrast, no upper limit of preoperative shoulder strength led to a decrease in ROM or outcome scores postoperatively. On multivariate analysis, the baseline abduction strength score was a statistically significant predictor of postoperative values and improvement for all 3 measures of shoulder strength, raw and normalized Constant scores, and improvement in active abduction and active elevation.

CONCLUSION

Preoperative shoulder strength is moderately associated with postoperative outcomes and improvements in shoulder strength, ROM, and outcome scores after primary aTSA. It is important to note that we identified preoperative strength values that led to a decrease in strength postoperatively but not ROM or outcome scores. The results of our study demonstrate that abduction strength may be a useful indicator of patient outcomes after aTSA. Our findings will provide surgeons with useful prognostic insight to aid in guiding patient expectations.

Effects of Preoperative Telerehabilitation on Muscle Strength, Range of Motion, and Functional Outcomes in Candidates for Total Knee Arthroplasty: A Single-Blind Randomized Controlled Trial

This study aims to investigate the effect of a preoperative telerehabilitation (PT) program on muscle strength, knee range of motion (ROM), and functional outcomes in candidates for total knee arthroplasty (TKA). Sixty patients (all women, mean age 70.53 ± 2.7 years) scheduled for bilateral TKA participated in this study. The PT and preoperative patient education (PE) groups participated in a 3-week intensive exercise program (30 min/session, 2 times/day, 5 days/week), whereas the control group received the usual care before TKA. Quadriceps muscle strength, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), ROM of knee flexion, pain, and time up-and-go (TUG) test time were evaluated at 4 weeks preoperatively, post-interventionally, and 6 weeks after TKA. Significant differences were found in the time-by-group interaction for 60°/s extension peak torque [F(4, 100) = 2.499, p = 0.047, η²_p = 0.91], 180°/s extension peak torque [F(4, 100) = 3.583, p = 0.009, η²_p = 0.125], ROM [F(4, 100) = 4.689, p = 0.002, η²_p = 0.158], TUG time [F(4, 100) = 7.252, p < 0.001, η²_p = 0.225], WOMAC pain [F(4, 100) = 9.113, p < 0.001, η²_p = 0.267], WOMAC functional outcome [F(4, 100) = 6.579, p < 0.001, η²_p = 0.208], and WOMAC total score [F(4, 100) = 10.410, p < 0.001, η²_p = 0.294]. The results of this study demonstrate the early benefits of a PT program in elderly female patients with end-stage osteoarthritis. The PT program improved muscle strength, ROM, and functional outcomes before TKA, which contributed to better functional recovery after TKA.

Quadriceps muscle group function and after total knee arthroplasty-asystematic narrative update

BACKGROUND

This article systematically summarizes the present evidences, published in the last 20 years, regarding the pre- and post-operative factors, which may influence recovery of the function of the quadriceps muscle group following total knee arthroplasty (TKA). We following the PRISMA methodology, including meta-analyses and high-level evidence studies (prospective trials, and, when unavailable, retrospective studies).

SOURCES OF DATA

Pubmed and Cochrane databases: 582 articles were identified and 54 of them were selected.

AREAS OF AGREEMENT

Tourniquets inflated at high pressure exert a detrimental effect on the quadriceps muscle group. Faster quadriceps recovery takes place using mini-invasive approaches, an eight-week rehabilitation period including balance training and the use of nutraceuticals.

AREAS OF DISAGREEMENT

Pre-habilitation and pre-operative factors, analgesic methods and different TKA implants.

GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH

Telerehabilitation seems a cost-effective tool for rehabilitation after TKA. Patients' optimization protocols before TKA should include standardized nutraceuticals intake.

Higher Disability in Women Than Men Scheduled for Total Knee Arthroplasty for Degenerative Osteoarthritis: A Cross-Sectional Analysis From India

Objective

Higher level impairments and activity limitation among those scheduled for total knee arthroplasty (TKA) is known. Sex differences in participation restriction which is the final domain of disablement pathway is not known. No data from developing countries exist on sex differences in disability levels at the time of TKA.

Methods

In a cross‐sectional analysis of 240 patients (188 women; 72 men) scheduled for TKA, impairment (pain, symptoms, quadricep muscle strength, and knee range of motion [ROM]), activity limitation (self‐reported and objective performance‐based measurements), and participation restriction were compared. Multivariable regression analyses were used to adjust for key sociodemographic and clinical characteristics. Associations between impairments and participation restriction were analyzed.

Results

Compared with men, women were more likely to have higher levels of impairment (knee injury and osteoarthritis outcome pain score adjusted mean difference [aMD]: −6.9 [95% confidence interval {CI} −13.7 to −0.18]; flexion ROM of less than 100° adjusted odds ratio: 5.7 [95% CI 1.6‐20.3]; and 36% lower muscle strength [95% CI 24%‐49%]) and lower objectively measured functional ability (walking speed aMD: −0.12 m/s [95% CI −0.23 to −0.02]; stair climbing time aMD: 9.5 s [95% CI 1.5‐17.5]). Participation restriction was higher in women compared with men. Of the impairment measures (pain, ROM, and muscle strength), pain contributed to participation restriction in both sexes.

Conclusion

This study demonstrated higher levels of disability in women than in men at the time of TKA. Effect of pain on participation restriction was higher compared with muscle strength and ROM. Evidence of delay in decision‐making to undergo TKA and reasons for delay need to be studied specifically in the context of lower middle–income countries.

Being Underweight Is Associated with Worse Surgical Outcomes of Total Knee Arthroplasty Compared to Normal Body Mass Index in Elderly Patients

Purpose

Being underweight has never been studied in relation to the radiologic and clinical outcomes of total knee arthroplasty (TKA) in elderly patients. The aim of this study was to determine the effect of being underweight on TKA radiological and clinical outcomes and to investigate whether being underweight influences postoperative complications compared to normal body mass index (BMI) in elderly patients.

Patients and Methods

A total of 118 female patients aged 65 years or older with BMI < 25 kg/m² who underwent primary TKA were divided into two groups based on BMI: group A: 18.5 kg/m² < BMI < 25 kg/m²; group B: BMI < 18.5 kg/m². The radiologic and clinical outcomes were evaluated at follow-up of 6, 12, and 24 months after surgery such as the hip-knee-ankle angle, the American Knee Society (AKS) score, Western Ontario and McMaster University score (WOMAC), and patellofemoral (PF) scale. Moreover, postoperative complications during follow-up were investigated.

Results

Preoperative clinical scores did not differ significantly between the two groups. Postoperative WOMAC pain (1.8 ± 1.9 versus 3.4 ± 2.6, p = 0.02), WOMAC function (12.4 ± 8.1 versus 16.5 ± 8.5, p = 0.012) and PF scales (26.1 ± 3.6 versus 23.7 ± 4.1, p = 0.002) were worse in the underweight group at 12 and 24 months after surgery. The frequency of postoperative complications did not differ significantly between groups. In multivariate linear regression analysis, underweight patient group was significantly associated with worse postoperative WOMAC and PF scores (p = 0.002, 0.005).

Conclusion

Although postoperative complications of TKA did not differ between groups, underweight patients had worse clinical outcomes of TKA compared to patients with normal BMI in elderly patients. Therefore, care should be taken when performing TKA in elderly underweight patients.