Influence of body mass index on sagittal hip range of motion and gait speed recovery six months after total hip arthroplasty

A novel and objective tool for determining total and shear joint contact forces after primary total hip arthroplasty

Background and purpose

Total hip arthroplasty, a common surgical procedure in orthopedics, is used in patients with severe hip osteoarthritis to relieve pain and to restore the function. The surgery has been shown to be effective, but patients may experience gait limitations after surgery. We used a novel and innovative tool, Computed MyoGraphy (CMG), to analyse the gait kinematics and forces acting within the musculoskeletal system after total hip arthroplasty. Data obtained at different time points before and after surgery were compared with those of healthy subjects.

Methods

The gait patterns of patients with primary hip osteoarthritis patients and healthy subjects were compared using the Xsens Awinda system in combination with the CMG system. Joint contact forces and shear joint contact forces were assessed preoperatively at the 5th postoperative day as well as after the rehabilitation examining two types of movements, "walking" and "squatting".

Results

As revealed by CMG during both, normal walking and in particular during squatting, pre- and postoperative patients showed lower values for total and shear hip joint contact forces on both sides of the body when compared to healthy subjects. These initial differences in the total and shear joint contact forces at the hip vanished after the completion of the rehabilitation process.

Conclusions

Total hip arthroplasty patients are initially limited to squat and walk normally, as they exert lower total and shear hip joint contact forces, interestingly not only on the affected side but also on the contralateral side. Rehabilitation improves the force development to a degree similar to healthy patients. CMG provides clinical usability that objectifies gait analyses and provide useful additional functional information for clinical practice.

Trial registration

Prospective study of gait analysis after primary total hip arthroplasty measured by Computed MyoGraphy (CMG) using Myonardo, DRKS00028175. Registered February 16, 2022 - Prospectively registered. Trial registration number DRKS00028175.

Functional assessment in patients undergoing total hip arthroplasty

Aims

Conventional patient-reported surveys, used for patients undergoing total hip arthroplasty (THA), are limited by subjectivity and recall bias. Objective functional evaluation, such as gait analysis, to delineate a patient's functional capacity and customize surgical interventions, may address these shortcomings. This systematic review endeavours to investigate the application of objective functional assessments in appraising individuals undergoing THA.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied. Eligible studies of THA patients that conducted at least one type of objective functional assessment both pre- and postoperatively were identified through Embase, Medline/PubMed, and Cochrane Central database-searching from inception to 15 September 2023. The assessments included were subgrouped for analysis: gait analysis, motion analysis, wearables, and strength tests.

Results

A total of 130 studies using 15 distinct objective functional assessment methods (FAMs) were identified. The most frequently used method was instrumented gait/motion analysis, followed by the Timed-Up-and-Go test (TUG), 6 minute walk test, timed stair climbing test, and various strength tests. These assessments were characterized by their diagnostic precision and applicability to daily activities. Wearables were frequently used, offering cost-effectiveness and remote monitoring benefits. However, their accuracy and potential discomfort for patients must be considered.

Conclusion

The integration of objective functional assessments in THA presents promise as a progress-tracking modality for improving patient outcomes. Gait analysis and the TUG, along with advancing wearable sensor technology, have the potential to enhance patient care, surgical planning, and rehabilitation.

Acute effects of transcranial direct current stimulation combined with physical therapy on the balance and gait in individuals with Parkinson's disease: A randomized controlled trial

Application methods of transcranial direct current stimulation (tDCS) in Parkinson's disease (PD) are quite divergent making it difficult to define the clinical effectiveness of the tDCS on PD. Thus, the aim of this study was to verify the acute effects of tDCS when applied to different targets (Cz or C3-Cz-C4) combined to physical therapy to improve balance and gait in individuals with PD. A randomized controlled trial was conducted, with 50 individuals who were separated into four groups: 1) Real tDCS (Cz) + physical therapy, 2) Real tDCS (C3-Cz-C4) + physical therapy, 3) Sham tDCS + physical therapy and 4) Educational lecture + physical therapy. The current intensity was 2 mA, applied for 20 min. For the instrumental assessment of balance and gait, the 3D motion analysis system was used. For the biomechanical analysis of gait, three different conditions were performed: normal gait, dual task gait and obstacle gait. For balance analysis, the following positions were utilized: Romberg with eyes opened, Romberg with eyes closed, Tandem with eyes opened and Tandem with eyes closed. All evaluations were performed pre-intervention, post-intervention (immediately at the end of the intervention) and were followed-up on (24 h after the end of the intervention). No statistically significant differences were found for all gait and balance outcomes when considering the interaction between time (pre, post and follow-up assessments) versus group (Education, Sham, Cz and C3-Cz-C4). In conclusion, it was found that one session of tDCS, stimulating Cz or C3-Cz-C4 combined with physical therapy, was not effective in improving the balance and gait in people with PD as compared to sham tDCS or educational lecture plus physiotherapy.

Direct Anterior Approach Provides Superior Prosthesis Adaptability in the Early Postoperative Period of Total Hip Arthroplasty

OBJECTIVES

Prosthesis awareness is the perception of foreign bodies, which has a critical effect on the function of the prosthetic joint. In total hip arthroplasty (THA), the direct anterior approach (DAA) has more advantages than the posterior approach (PA), including superior rehabilitation outcomes. This study was to evaluate the recovery of "prosthesis awareness" through these two approaches.

METHODS

Three hundred and seventy-six patients who received THA with either DAA (n = 41) or PA (n = 335) from January 2016 to December 2017 were retrospectively analyzed. The Forgotten Joint Score-12 (FJS-12), Harris hip score (HHS), and visual analog scale (VAS) analyses were used to evaluate the recovery of "prosthesis awareness" in these patients 2 weeks, 1, 3, 6, and 12 months after surgery. The student t-test, Wilcoxon rank sum test, chi-square test, and MANOVA were used to compare the differences among groups.

RESULTS

We found that DAA patients had higher FJS-12 scores than PA patients at 2 weeks (42.15 ± 3.36 vs. 38.09 ± 3.28, p = 0.042), 1 month (49.06 ± 5.14 vs. 41.11 ± 5.21, p = 0.038), and 3 months (53.23 ± 4.07 vs. 48.09 ± 3.71, t = 3.152, p = 0.045). And the recovery rates of FJS-12 scores in DAA and PA groups at 2 weeks, 1 month, and 3 months after surgery were 75.46% ± 6.04%, 84.05% ± 6.57%, 91.37% ± 7.13%, and 74.14% ± 5.54%, 78.16% ± 6.01%, 88.23% ± 6.42%, respectively. To compare the recovery effects of the two procedures in more detail, we classified the 12 items in FJS-12 that evaluate different types of gravity center motions into three categories: low-movement group (LG), middle-movement group (MG), and high-movement group (HG). Interestingly, DAA patients had significantly higher HG than PA patients at 2 weeks, 1 month, and 3 months after operation (t = 3.225, p = 0.022 at 2 weeks, t = 3.081, p = 0.041 at 1 month and t = 2.783, p = 0.046 at 3 months), whereas no significant differences were observed in LG- and MG-related items. In addition, there were no significant differences in HHS and VAS scores between DAA and PA patients at 2 weeks (p = 0.102, p = 0.093), or from 1 month to 12 months (each p > 0.05).

CONCLUSIONS

DAA-mediated THA is superior to PA in terms of prosthesis adaptability and recovery of hip joint motion in the first 3 months after surgery, especially concerning high-movement gravity center motions.

Do patients with well-functioning total hip arthroplasty achieve typical sagittal plane hip kinematics? A proof of concept study

BACKGROUND

Total hip arthroplasty (THA) patients have been shown to not achieve normal sagittal plane hip kinematics. However, previous studies have only conducted group level analysis and as such lack the sensitivity to highlight whether individual patients do achieve normal hip kinematics. As such this study looked to determine whether some patients with well-functioning THA achieve typical sagittal plane hip kinematics.

METHODS

Sagittal plane hip kinematics were collected on 11 well-functioning THA patients (Oxford Hip Score = 46 ± 3) and 10 asymptomatic controls using a 3-dimensional motion analysis system during self-paced walking. High-functioning THA patients were identified as those who displayed sagittal plane hip kinematics that were within the variance of the control group on average, and low-functioning patients as those who did not.

RESULTS

5 THA patients were identified as high-functioning, displaying hip kinematics within the variance of the control group. High-functioning THA patients displayed peak hip flexion and extension values more closely aligned to asymptomatic control group than low-functioning patients. However, hip range of motion was comparable between high- and low-functioning total hip arthroplasty patients and reduced compared to controls.

CONCLUSION

The presence of high-functioning THA patients who display comparable sagittal plane hip kinematics to controls suggests these patients do achieve normative function and challenges the conclusions of previous group level analysis. Understanding why some patients achieve better function post-operatively will aid pre- and post-operative practices to maximise functional recovery.

Functional recovery after total hip/knee replacement in obese people: A systematic review

OBJECTIVE

Several studies have investigated the influence of body mass index (BMI) on functional gain after total hip replacement (THR) or total knee replacement (TKR) in osteoarthritis, with contradictory results. This systematic literature review was conducted to ascertain whether obesity affects functional recovery after THR or TKR in the short (<1 year), medium (<3 years) and long term (>3 years).

METHODS

The study was registered with PROSPERO and conducted according to the PRISMA guidelines. A systematic literature search was conducted across Medline and EMBASE databases for articles published between 1980 and 2020 that investigated patient-reported measures of functional recovery after THR and TKR in participants with osteoarthritis and obesity (defined as BMI ≥30 kg/m²).

RESULTS

Twenty-six articles reporting on 68,840 persons (34,955 for THR and 33,885 for TKR) were included in the final analysis: 5 case-control studies, 21 cohort studies (9 for THR only, 10 for TKR only and 2 for both). The average minimum follow-up was 36.4 months, ranging from 6 weeks to 10 years. Most studies found significantly lower pre-operative patient-reported functional scores for participants with obesity. After THR, there was a small difference in functional recovery in favor of those without obesity in the short term (<6 months), but the difference remained below the minimal clinically important difference (MCID) threshold and disappeared in the medium and long term. After TKR, functional recovery was better for those with obesity than those without in the first year, similar until the third year, and then decreased thereafter.

CONCLUSIONS

Although there is a paucity of high-quality evidence, our findings show substantial functional gains in people with obesity after total joint replacement. Functional recovery after THR or TKR does not significantly differ, or only slightly differs, between those with and without obesity, and the difference in functional gain is not clinically important.

PROSPERO NUMBER

CRD42018112919.

Automated detection and explainability of pathological gait patterns using a one-class support vector machine trained on inertial measurement unit based gait data

BACKGROUND

Machine learning approaches for the classification of pathological gait based on kinematic data, e.g. derived from inertial sensors, are commonly used in terms of a multi-class classification problem. However, there is a lack of research regarding one-class classifiers that are independent of certain pathologies. Therefore, it was the aim of this work to design a one-class classifier based on healthy norm-data that provides not only a prediction probability but rather an explanation of the classification decision, increasing the acceptance of this machine learning approach.

METHODS

The inertial sensor based gait kinematics of 25 healthy subjects was employed to train a one-class support vector machine. 25 healthy subjects, 20 patients after total hip arthroplasty and one transfemoral amputee served to validate the classifier. Prediction probabilities and feature importance scores were estimated for each subject.

FINDINGS

The support vector machine predicted 100% of the patients as outliers from the healthy group. Three healthy subjects were predicted as outliers. The feature importance calculation revealed the hip in the sagittal plane as most relevant feature concerning the group after total hip arthroplasty. For the misclassified healthy subject with the lowest probability score the knee flexion and the pelvis obliquity were identified.

INTERPRETATION

The support vector machine seems a useful tool to identify outliers from a healthy norm-group. The feature importance examination proved to provide valuable information on the musculoskeletal status of the subjects. In this combination, the present approach could be employed in various disciplines to identify abnormal gait and suggest subsequent training.

Kinematics Adaptation and Inter-Limb Symmetry during Gait in Obese Adults

The main purpose of this study is to characterize lower limb joint kinematics during gait in obese individuals by analyzing inter-limb symmetry and angular trends of lower limb joints during walking. To this purpose, 26 obese individuals (mean age 28.5 years) and 26 normal-weight age- and sex-matched were tested using 3D gait analysis. Raw kinematic data were processed to derive joint-specific angle trends and angle-angle diagrams (synchronized cyclograms) which were characterized in terms of area, orientation and trend symmetry parameters. The results show that obese individuals exhibit a kinematic pattern which significantly differs from those of normal weight especially in the stance phase. In terms of inter-limb symmetry, higher values were found in obese individuals for all the considered parameters, even though the statistical significance was detected only in the case of trend symmetry index at ankle joint. The described alterations of gait kinematics in the obese individuals and especially the results on gait asymmetry are important, because the cyclic uneven movement repeated for hours daily can involve asymmetrical spine loading and cause lumbar pain and could be dangerous for overweight individuals.

Impact of Obesity on the Forgotten Joint Score Following Primary Total Hip Arthroplasty

BACKGROUND

Obesity is a growing public health concern. This study aims to identify the association of body mass index (BMI) on postoperative Forgotten Joint Score-12 (FJS-12) in patients undergoing primary total hip arthroplasty (THA).

METHODS

We retrospectively reviewed 2130 patients at a single urban, academic, tertiary institution who underwent primary THA from 2016-2020 with available postoperative FJS-12 scores. Patients were stratified into two groups based on their BMI (kg/m²):<30 (nonobese) and ≥30 (obese). FJS-12 scores were collected postoperatively at 3 months, 1 year, and 2 years. Demographic differences were assessed with chi-square and independent sample t-tests. Mean scores between the groups were compared using multilinear regression analysis, controlling for demographic differences.

RESULTS

Of the 2130 patients included, 1378 were nonobese, and 752 were obese. Although obese patients reported lower FJS-12 scores all time periods, there were no statistical differences between the two groups at 3 months (53.61 vs 49.62;P = .689), 1 year (68.11 vs 62.45; P = .349), and 2 years (73.60 vs 65.58; P = .102). A subanalysis comparing patients who were of normal BMI (<25), overweight (25.0-29.9), and obese (≥30) followed a similar inverse trend in scores but showed no statistical differences at all postoperative time points (3m:P = .612,1y:P = .607,2y:P = .253). Mean improvement in FJS-12 scores from 3 months to 1 year (14.50 vs 12.83; P = .041), 1 year to 2 years (5.49 vs 3.13; P = .004), and from 3 months to 2 years (20.00 vs15.96; P < .001) were significantly greater for nonobese patients compared to obese patients.

CONCLUSION

While obesity trended toward lower FJS-12 scores, the differences in scores were not statistically significant compared to nonobese patients. BMI did not influence overall FJS-12 scores; however, obese patients achieved a slightly smaller statistical improvement during the first 2 years, though this may not be clinically significant.

LEVEL III EVIDENCE

Retrospective Cohort Study.

Towards an Inertial Sensor-Based Wearable Feedback System for Patients after Total Hip Arthroplasty: Validity and Applicability for Gait Classification with Gait Kinematics-Based Features

Patients after total hip arthroplasty (THA) suffer from lingering musculoskeletal restrictions. Three-dimensional (3D) gait analysis in combination with machine-learning approaches is used to detect these impairments. In this work, features from the 3D gait kinematics, spatio temporal parameters (Set 1) and joint angles (Set 2), of an inertial sensor (IMU) system are proposed as an input for a support vector machine (SVM) model, to differentiate impaired and non-impaired gait. The features were divided into two subsets. The IMU-based features were validated against an optical motion capture (OMC) system by means of 20 patients after THA and a healthy control group of 24 subjects. Then the SVM model was trained on both subsets. The validation of the IMU system-based kinematic features revealed root mean squared errors in the joint kinematics from 0.24° to 1.25°. The validity of the spatio-temporal gait parameters (STP) revealed a similarly high accuracy. The SVM models based on IMU data showed an accuracy of 87.2% (Set 1) and 97.0% (Set 2). The current work presents valid IMU-based features, employed in an SVM model for the classification of the gait of patients after THA and a healthy control. The study reveals that the features of Set 2 are more significant concerning the classification problem. The present IMU system proves its potential to provide accurate features for the incorporation in a mobile gait-feedback system for patients after THA.