Biomechanical Changes Following Knee Arthroplasty During Sit-To-Stand Transfers: Systematic Review

Objective Clinical Measurement Tools for Functional Evaluation of the Surgical Patient

Following knee surgery, clinicians have traditionally used visually rated or time-based assessments of lower extremity movement quality to measure surgical outcomes, plan rehabilitation interventions, and measure success. These methods of assessment are prone to error and do not fully capture a patient's inefficient movement patterns post surgery. Further, currently available systems which objectively measure kinematics during these tasks are expensive and unidimensional. For these reasons, recent research has called for the development of objective and low-cost precision rehabilitation tools to improve clinical measurement of movement tasks. The purpose of this article is to highlight two such tools and their applications to knee surgery. The systems highlighted within this article are the Mizzou Point-of-Care Assessment System (MPASS) and the Mizzou Knee Arthrometer Testing System (MKATS). MPASS has demonstrated high levels of agreement with the gold-standard Vicon system in measuring kinematics during sit-to-stand (R > 0.71), lateral step-down (intraclass correlation coefficient [ICC] > 0.55, apart from ankle flexion), and drop vertical jump tasks (ICC > 0.62), as well as gait (R > 0.87). MKATS has been used to quantify differences in tibiofemoral motion between groups during lateral step-down, step-up-and-over, and step-up/step-down tasks. Objective measurement of clinical tasks using portable and inexpensive instruments, such as the MPASS and MKATS, can help clinicians identify inefficient movement patterns and asymmetries which may damage and wear down supporting structures within the knee and throughout the kinetic chain causing pain and discomfort. Identifying these issues can help clinicians to plan interventions and measure their progress at a lower cost than currently available systems. The MPASS and MKATS are useful tools which have many applications to knee surgery.

Contralateral knee pain exacerbation after total knee arthroplasty and its impact on functional activity

INTRODUCTION

The purposes of the present study were to (1) describe the prevalence of contralateral knee pain exacerbation after total knee arthroplasty (TKA), (2) explore the risk factors for pain exacerbation, and (3) verify the association of contralateral knee pain with future functional activity.

MATERIALS AND METHOD

We consecutively recruited outpatients with osteoarthritis of both knees who had primary TKA planned. The contralateral knee pain using a Numerical Rating Scale (NRS) and the functional activities subdomain of the new Knee Society Knee Scoring System (KSS) were assessed preoperatively and at 1, 3, and 6 months postoperatively. Among patients with < 5 NRS points preoperatively, we described the frequency of the contralateral knee pain exacerbation, defined as a ≥ 2-point increase from preoperative pain at each postoperative visit. An exploratory analysis was performed to identify preoperative risk factors for contralateral knee pain exacerbation. A linear mixed model was fit to examine the association of the contralateral knee pain with KSS functional activities at subsequent visits.

RESULTS

Among 315 patients, 14.6%, 24.1%, and 27.6% of patients experienced contralateral knee pain exacerbation at 1, 3, and 6 months postoperatively, respectively. The identified preoperative risk factors were low quadriceps strength and higher Kellgren-Lawrence grade on the non-operative knee, along with severe pain on the operative knee. The magnitude of the association between contralateral knee pain and worsening KSS functional activities increased with subsequent visits (p for interaction < 0.001).

CONCLUSION

The frequency and impact of pain exacerbation on the contralateral knee increase after TKA and should be carefully evaluated for a prolonged period of time.

Inter-limb kinetic asymmetries during sit-to-stand performance persist following unilateral total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Kinetic asymmetries during sit-to-stand have been consistently observed early after total knee arthroplasty; however, the longer-term outcomes are less clear. The purpose of this systematic review and meta-analysis was to analyze the results of studies examining inter-limb kinetic symmetry during sit-to-stand performance among individuals who were at least one-year post unilateral total knee arthroplasty.

METHODS

PubMed, SPORTDiscus, CINAHL, and Health Source databases were searched. Studies were included if they were published in a peer-reviewed journal, included subjects who had undergone unilateral total knee arthroplasty at least one-year prior, and examined vertical ground reaction forces and/or knee extension moments for the involved and uninvolved limbs during sit-to-stand performance. Data were transformed into a limb symmetry index, which expressed the ratio of the peak forces/moments for the involved limb, relative to the uninvolved limb (1.0 reflects perfect symmetry). These ratios were meta-analyzed using the ratio of means method.

FINDINGS

Seven studies were deemed eligible for inclusion. Ground reaction force data was pooled from seven studies and knee extension moment data was pooled from two studies. For the peak vertical ground reaction forces, the pooled limb symmetry index was 0.96 (CI95% = [0.93, 0.99]). For the peak knee extension moments, the pooled limb symmetry index was 0.91 (CI95% = [0.84, 0.98]). In both cases this reflects greater limb/knee loading for the uninvolved limb, relative to the involved limb.

INTERPRETATION

Asymmetries in limb/knee loading persist beyond the one-year post-operative period following total knee arthroplasty, potentially contributing to degenerative changes for the uninvolved limb.

Clinical utility of markerless motion capture for kinematic evaluation of sit-to-stand during 30 s-CST at one year post total knee arthroplasty: a retrospective study

BACKGROUND

Although the importance of kinematic evaluation of the sit-to-stand (STS) test of total knee arthroplasty (TKA) patients is clear, there have been no reports analyzing STS during the 30-s chair sit-up test (30 s-CST) with a focus on kinematic characteristics. This study aimed to demonstrate the clinical utility of kinematic analysis of STS during the 30 s-CST by classifying STS into subgroups based on kinematic parameters, and to determine whether differences in movement strategies are expressed as differences in clinical outcomes.

METHODS

The subjects were all patients who underwent unilateral TKA due to osteoarthritis of the knee and were followed up for one year postoperatively. Forty-eight kinematic parameters were calculated using markerless motion capture by cutting STS in the 30 s-CST. The principal components of the kinematic parameters were extracted and grouped by kinematic characteristics based on the principal component scores. Clinical significance was examined by testing whether differences in patient-reported outcome measures (PROMs) were observed.

RESULTS

Five principal components were extracted from the 48 kinematic parameters of STS and classified into three subgroups (SGs) according to their kinematic characteristics. It was suggested that SG2, using a kinematic strategy similar to the momentum transfer strategy shown in previous studies, performed better in PROMs and, in particular, may be associated with achieving a "forgotten joint", which is considered the ultimate goal after TKA.

CONCLUSIONS

Clinical outcomes differed according to kinematic strategies used STS, suggesting that kinematic analysis of STS in 30 s-CST may be useful in clinical practice.

TRIAL REGISTRATION

This study was approved by the Medical Ethical Committee of the Tokyo Women's Medical University (approval number: 5628 on May 21, 2021).

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

An Embodied Sonification Model for Sit-to-Stand Transfers

Interactive sonification of biomechanical quantities is gaining relevance as a motor learning aid in movement rehabilitation, as well as a monitoring tool. However, existing gaps in sonification research (issues related to meaning, aesthetics, and clinical effects) have prevented its widespread recognition and adoption in such applications. The incorporation of embodied principles and musical structures in sonification design has gradually become popular, particularly in applications related to human movement. In this study, we propose a general sonification model for the sit-to-stand (STS) transfer, an important activity of daily living. The model contains a fixed component independent of the use-case, which represents the rising motion of the body as an ascending melody using the physical model of a flute. In addition, a flexible component concurrently sonifies STS features of clinical interest in a particular rehabilitative/monitoring situation. Here, we chose to represent shank angular jerk and movement stoppages (freezes), through perceptually salient pitch modulations and bell sounds. We outline the details of our technical implementation of the model. We evaluated the model by means of a listening test experiment with 25 healthy participants, who were asked to identify six normal and simulated impaired STS patterns from sonified versions containing various combinations of the constituent mappings of the model. Overall, we found that the participants were able to classify the patterns accurately (86.67 ± 14.69% correct responses with the full model, 71.56% overall), confidently (64.95 ± 16.52% self-reported rating), and in a timely manner (response time: 4.28 ± 1.52 s). The amount of sonified kinematic information significantly impacted classification accuracy. The six STS patterns were also classified with significantly different accuracy depending on their kinematic characteristics. Learning effects were seen in the form of increased accuracy and confidence with repeated exposure to the sound sequences. We found no significant accuracy differences based on the participants' level of music training. Overall, we see our model as a concrete conceptual and technical starting point for STS sonification design catering to rehabilitative and clinical monitoring applications.

Predicting Knee Joint Kinematics from Wearable Sensor Data in People with Knee Osteoarthritis and Clinical Considerations for Future Machine Learning Models

Deep learning models developed to predict knee joint kinematics are usually trained on inertial measurement unit (IMU) data from healthy people and only for the activity of walking. Yet, people with knee osteoarthritis have difficulties with other activities and there are a lack of studies using IMU training data from this population. Our objective was to conduct a proof-of-concept study to determine the feasibility of using IMU training data from people with knee osteoarthritis performing multiple clinically important activities to predict knee joint sagittal plane kinematics using a deep learning approach. We trained a bidirectional long short-term memory model on IMU data from 17 participants with knee osteoarthritis to estimate knee joint flexion kinematics for phases of walking, transitioning to and from a chair, and negotiating stairs. We tested two models, a double-leg model (four IMUs) and a single-leg model (two IMUs). The single-leg model demonstrated less prediction error compared to the double-leg model. Across the different activity phases, RMSE (SD) ranged from 7.04° (2.6) to 11.78° (6.04), MAE (SD) from 5.99° (2.34) to 10.37° (5.44), and Pearson’s R from 0.85 to 0.99 using leave-one-subject-out cross-validation. This study demonstrates the feasibility of using IMU training data from people who have knee osteoarthritis for the prediction of kinematics for multiple clinically relevant activities.

Analysis of 15 different pelvis marker protocols during sit-to-stand

Sit-to-stand (STS) is a common transition movement needed to perform daily tasks. Previously, the kinematics of the STS movement has been investigated using optical motion capture. This method uses cameras and reflective markers on the body to capture movements. During STS, these markers can be difficult to measure due to blocked vision from the chair's arm- and backrest. This can result in poor data quality. The aim of this study was to investigate 15 different marker protocols and compare them in terms of visibility and selected outcome measures: hip flexion mean angle and range of motion (ROM). Fourteen healthy subjects completed five successful trials of STS. Marker protocols consisted of three anterior marker protocols and five posterior marker protocols, combined into a total of 15 marker protocols. For visibility, the traditional pelvis marker protocol proved unsuitable for STS tracking. Marker pins or additional markers anteriorly, and sacrum markers posteriorly, proved to be more suitable alternatives. For hip flexion mean angle and ROM, the estimates had similar tendencies. Hence, marker protocols were not outcome measure specific. Anteriorly, marker pins resulted in similar estimates as the traditional pelvis marker protocol. Posteriorly, sacrum markers estimated a smaller hip flexion angle, compared to the traditional pelvis marker protocol. In conclusion, marker pins can be used instead of regular ASIS markers at anterior pelvis. Posteriorly, sacrum markers can be used instead of PSIS markers.

What You Should Know About Osteoarthritis Rehabilitation: A Bibliometric Analysis of the 50 Most-Cited Articles

Background:

Osteoarthritis is a degenerative disease that commonly occurs in middle-aged and elderly people. High-quality articles in the field of osteoarthritis rehabilitation have not been studied in detail.

Objective:

To identify and conduct a qualitative and quantitative analysis of the 50 most-cited articles on osteoarthritis rehabilitation and provide valuable scientific information for researchers.

Methods:

Fifty articles related to the rehabilitation of individuals with osteoarthritis were retrieved from the Web of Science Core Collection. Basic information, such as the authors, title, number of citations, year of publication, journal, country/territory, and research type, was extracted. CiteSpace was used to visualize the keywords.

Results:

The average number of citations per article was 244.54. The top 50 articles were published in 27 journals and published by 262 authors. Most of the top 50 articles were published in the United States. The top 50 articles included 23 randomized controlled trials, 21 cohort studies, 2 case series, and 4 expert opinion articles. The most commonly studied topics in osteoarthritis rehabilitation included rehabilitation for pain, gait abnormalities, muscle strength deficiencies, and other functional impairments caused by osteoarthritis in elderly people.

Conclusions:

The top articles in the field of osteoarthritis rehabilitation have a high level of evidence. Collaboration between authors was high for highly-cited articles. Moreover, the eminent articles can provide important information for the education of doctors and therapists specializing in osteoarthritis rehabilitation.