Gait and lower limb muscle strength in women after triple innominate osteotomy

Shear stress in the medial meniscus posterior root during daily activities

BACKGROUND

Medial meniscus posterior root (MMPR) tears have been reported to occur in middle-aged patients with minor trauma. However, the injury mechanism of MMPR tears remains unclear. The purpose of this study was to evaluate the shear stress in the MMPR during daily activities using a finite-element analysis.

METHODS

Subject-specific finite-element models of the knee joint of a healthy middle-aged subject were developed from computed tomographic and magnetic resonance images. A three-dimensional motion capture system "VICON" was used to capture four daily activities: walking, jogging, descending stairs, and landing. The knee joint reaction force was estimated using the AnyBody modeling system. Based on these procedures, the shear stress in the MMPR was calculated during each motion. The shear stress in the lateral meniscus posterior root (LMPR) was also measured to compare the stress between the MMPR and LMPR.

RESULTS

The shear stress in the MMPR increased as the knee flexion angle increased during each motion. Descending stairs caused more than two-fold greater stress in the MMPR than walking and a similar or greater amount of stress than jogging. The LMPR tended to receive more shear stress than the MMPR throughout each motion.

CONCLUSIONS

The present study showed that descending stairs confers almost the same amount of shear stress to the MMPR as jogging. The results of the present study may suggest that descending motion of the knee is an important cause of MMPR tear, and the initiation of descending stairs should be delayed after MMPR repair.

Postsurgical Analysis of Gait, Radiological, and Functional Outcomes in Children with Developmental Dysplasia of the Hip

BACKGROUND

Children undergoing DDH correction surgery may experience gait abnormalities following soft tissue releases and bony procedures. The purpose of this study was to compare the residual gait changes, radiological outcomes, and functional outcomes in children who underwent DDH surgery with those in healthy controls.

METHODS

Inertial motion sensors were used to record the gait of 14 children with DDH and 14 healthy children. Pelvic X-ray was performed to determine the Severin classification and the presence of femoral head osteonecrosis (Bucholz-Odgen classification). For functional evaluation, the Children's Hospital Oakland Hip Evaluation Scale (CHOHES) was used.

RESULTS

There was no difference in spatial parameters between the two groups. In terms of temporal parameters, the DDH-affected limbs had a shorter stance phase (p < 0.001) and a longer swing phase (p < 0.001) than the control group. The kinematic study showed that the affected limb group had smaller hip adduction angle (p = 0.002) and increased internal rotation (p = 0.006) with reduced upward pelvic tilt (p = 0.020). Osteonecrosis was graded II, III, and IV in five, three, and one patients, respectively. Five patients had no AVN changes. The Severin classification was grade I, II, and III for six, three, and five patients, respectively. Most patients had good functional outcomes on the CHOHES, with a mean total score of 96.64 ± 5.719. Multivariate regression analysis revealed that weight, height, and femoral osteotomy were independent predictors for gait, radiological and functional outcome.

CONCLUSION

Despite good functional scores overall, some children had poor radiological outcomes and gait abnormalities. Our results identified the risk factors for poor outcomes, and we recommend specified rehabilitative strategies for long-term management.

Clinical assessments and gait analysis for patients with Trimalleolar fractures in the early postoperative period

Background

Trimalleolar fracture is a common ankle fracture with serious complications and costly healthcare problem. Most studies used clinical assessments to evaluate the functional status of the patients. Although clinical assessments are valid, they are static and subjective. Dynamic, objective and precise evaluations such as gait analysis are needed. Ankle biomechanics studies on gait in patients with trimalleolar fractures are still rare. This study aimed to investigate the clinical outcomes and gait biomechanics in patients with trimalleolar fractures in the early postoperative period and compared to healthy controls.

Methods

This was a cross-sectional study. 12 patients with trimalleolar fractures were recruited, and 12 healthy people served as controls. All patients underwent clinical assessments: Olerud and Molander ankle score (OMAS), ankle swelling and passive range of motion (ROM) of ankle, and completed gait biomechanical analysis when weight-bearing was allowed: temporal-spatial parameters, plantar pressure distributions, and surface electromyography (sEMG). The control group only performed gait test.

Results

Patients had poor outcomes of clinical assessments in the short-term. During gait analysis, patients presented compromised gait patterns: shorter step length, larger step width, slower walking speed and shorter single support compared to healthy controls (P < 0.001), and patients showed asymmetrical gait. Symmetry index of step width and walking speed were mainly correlated with the difference of ankle inversion ROM between two sides (R = -0.750, P = 0.005; R = -0.700, P = 0.011). During walking, patients showed abnormal dynamic plantar pressure features (mainly in the hindfoot and forefoot regions), and the IEMG (integrated electromyography) of tibial anterior muscle (TA) and peroneal longus muscle (PL) were larger than healthy controls (P = 0.002, 0.050).

Conclusions

Patients with trimalleolar fractures showed physical impairments of the ankle, and presented altered gait parameters compared to healthy subjects in the short-term. The ankle stability of patients declined, and deficits in TA and PL muscle ability might contribute to it. Restoring complete muscle functions and improving passive ankle ROM are significant to promote the recovery of a normal gait pattern.

Experimental Characterization of A-AFiM, an Adaptable Assistive Device for Finger Motions

Robot rehabilitation devices are attracting significant research interest, aiming at developing viable solutions for increasing the patient’s quality of life and enhancing clinician’s therapies. This paper outlines the design and implementation of a low-cost robotic system that can assist finger motion rehabilitation by controlling and adapting both the position and velocity of fingers to the users′ needs. The proposed device consists of four slider-crank mechanisms. Each slider-crank is fixed and moves one finger (from the index to the little finger). The finger motion is adjusted through the regulation of a single link length of the mechanism. The trajectory that is generated corresponds to the natural flexion and extension trajectory of each finger. The functionality of this mechanism is validated by experimental image processing. Experimental validation is performed through tests on healthy subjects to demonstrate the feasibility and user-friendliness of the proposed solution.

Changes in muscle strength of the hip after rotational acetabular osteotomy: a retrospective study

AIMS

Rotational acetabular osteotomy (RAO) is an effective joint-preserving surgical treatment for acetabular dysplasia. The purpose of this study was to investigate changes in muscle strength, gait speed, and clinical outcome in the operated hip after RAO over a one-year period using a standard protocol for rehabilitation.

PATIENTS AND METHODS

A total of 57 patients underwent RAO for acetabular dysplasia. Changes in muscle strength of the operated hip, 10 m gait speed, Japanese Orthopaedic Association (JOA) hip score, and factors correlated with hip muscle strength after RAO were retrospectively analyzed.

RESULTS

Three months postoperatively, the strength of the operated hip in flexion and abduction and gait speed had decreased from their preoperative levels. After six months, the strength of flexion and abduction had recovered to their preoperative level, as had gait speed. At one-year follow-up, significant improvements were seen in the strength of hip abduction and gait speed, but muscle strength in hip flexion remained at the preoperative level. The mean JOA score for hip function was 91.4 (51 to 100)) at one-year follow-up. Body mass index (BMI) showed a negative correlation with both strength of hip flexion (r = -0.4203) and abduction (r = -0.4589) one year after RAO. Although weak negative correlations were detected between strength of hip flexion one year after surgery and age (r = -0.2755) and centre-edge (CE) angle (r = -0.2989), no correlation was found between the strength of abduction and age and radiological evaluations of CE angle and acetabular roof obliquity (ARO).

CONCLUSION

Hip muscle strength and gait speed had recovered to their preoperative levels six months after RAO. The clinical outcome at one year was excellent, although the strength of hip flexion did not improve to the same degree as that of hip abduction and gait speed. A higher BMI may result in poorer recovery of hip muscle strength after RAO. Radiologically, acetabular coverage did not affect the recovery of hip muscle strength at one year's follow-up. A more intensive rehabilitation programme may improve this. Cite this article: Bone Joint J 2019;101-B:1459-1463.

Gait symmetry and hip strength in women with developmental dysplasia following hip arthroplasty compared to healthy subjects: A cross-sectional study

Introduction

Untreated unilateral developmental dysplasia of the hip (DDH) results in asymmetry of gait and hip strength and may lead to early osteoarthritis, which is commonly treated with a total hip arthroplasty (THA). There is limited knowledge about the obtained symmetry of gait and hip strength after the THA. The objectives of this cross-sectional study were to: a) identify asymmetries between the operated and non-operated side in kinematics, kinetics and hip strength, b) analyze if increased walking speed changed the level of asymmetry in patients c) compare these results with those of healthy subjects.

Methods

Women (18–70 year) with unilateral DDH who had undergone unilateral THA were eligible for inclusion. Vicon gait analysis system was used to collect frontal and sagittal plane kinematic and kinetic parameters of the hip joint, pelvis and trunk during walking at comfortable walking speed and increased walking speed. Furthermore, hip abductor and extensor muscle strength was measured.

Results

Six patients and eight healthy subjects were included. In the patients, modest asymmetries in lower limb kinematics and kinetics were present during gait, but trunk lateral flexion asymmetry was evident. Patients’ trunk lateral flexion also differed compared to healthy subjects. Walking speed did not significantly influence the level of asymmetry. The hip abduction strength asymmetry of 23% was not statistically significant, but the muscle strength of both sides were significantly weaker than those of healthy subjects.

Conclusions

In patients with a DDH treated with an IBG THA modest asymmetries in gait kinematics and kinetics were present, with the exception of a substantial asymmetry of the trunk lateral flexion. Increased walking speed did not result in increased asymmetries in gait kinematics and kinetics. Hip muscle strength was symmetrical in patients, but significantly weaker than in healthy subjects. Trunk kinematics should be included as an outcome measure to assess the biomechanical benefits of the THA surgery after DDH.

Factors predicting the outcomes of incomplete triple pelvic osteotomy

INTRODUCTION

In the present study, we identified factors affecting the outcomes of patients who underwent incomplete triple pelvic osteotomies due to acetabular dysplasia.

METHODS

Data on a total of 58 hips in 50 patients for whom adequate data were available and who had undergone appropriate follow-up were retrospectively evaluated. We used Ömeroğlu scores for radiological evaluation, Harris Hip Scores for clinical evaluation, Tönnis scores to evaluate osteoarthritis progression and a modified Clavien-Dindo classification to evaluate complications.

RESULTS

The average patient age was 23.26 (14-47) years, and the average follow-up duration 105.59 (18-191) months. The complication rate was 10.3%, and complications negatively influenced clinical outcomes. Patients with radiologically poorer outcomes had more advanced osteoarthritis. We found minimal improvements in lateral centre edge angle (LCEA), refined centre-edge angle (RCEA), and lateral acetabulum head index (LAHI) were associated with osteoarthritis progression and that good improvements in LCEA, RCEA, acetabular angle (AA), and LAHI were associated with radiological outcomes. Neither patient age at the time of operation nor development of a postoperative relative crossover sign affected osteoarthritis progression or clinical or radiological outcomes.

CONCLUSIONS

The most important factors influencing clinical outcomes were complications. However, neither postoperative acetabular retroversion nor a positive supra-equatorial crossover sign (often viewed as prognostically negative) directly affected clinical outcomes.When treating patients with acetabular dysplasia, either inadequate correction or overcorrection may negatively affect outcomes. In such patients, an incomplete triple pelvic osteotomy (allowing controlled correction) is both safe and effective.

Sphygmomanometer test to evaluate muscle strength in individuals with lower limb amputation: validity and reliability

Abstract Introduction: The sphygmomanometer test is an alternative and inexpensive method for assessment of muscle strength. This instrument was considered valid and reliable to measure the isometric strength in different health conditions, however, in individuals with limb amputations the properties of this instrument for this purpose, have not been investigated. Objective: To investigate the concurrent criterion validity, test-retest and inter-rater reliabilities of the aneroid sphygmomanometer test (AST) without modification, for assessment of the strength of subjects with lower limb amputations. Methods: Twenty-two subjects (57.6 ± 15.2 years) with lower limb amputations were included in this study. Maximum isometric force was assessed with a handheld dynamometer (microFet2®) and the AST. To identify differences between trials, one-way ANOVA was applied. To assess the concurrent criterion validity, test-retest and inter-rater reliabilities of the AST, Pearson’s correlation coefficients of determination and intra-class correlation coefficient (ICC) were calculated. Results: For all muscle groups, no differences were observed between the trials (0.00001 ≤ F ≤ 0.10; 0.90 ≤ p ≤ 0.99). Significant, positive, and high to very high correlations were found between the HHD and the AST measures for the different numbers of trials for all assessed muscles (0.76 ≤ r ≤ 0.93; p ≤ 0.02). Test-retest (0.67 ≤ ICC ≤ 0.97) and inter-rater reliabilities (0.78 ≤ ICC ≤ 0.97) were adequate. The values obtained with the AST were good predictors of those obtained with HHD (0.58 ≤ r2 ≤ 0.85). Conclusion: For individuals with lower limb amputation, the AST showed adequate concurrent criterion validity, test-retest reliability and inter-rater reliability for the assessment of lower limbs muscle strength.

MUSCLE FORCE MAGNITUDES IN THE HUMAN LEG FOR ISOMETRIC EXERCISES WITH VARIOUS RESULTANT FORCE DIRECTIONS AND JOINT ANGLES

Using a gradient-based numerical optimization routine, the force magnitudes required of 10 major sagittal plane leg muscles to create a constant magnitude isometric resultant force against a fixed surface at the toe directed anteriorly, posteriorly, superiorly, and inferiorly were quantitatively predicted for three sets of joint angles: a straight leg configuration, with the knee flexed, and with both the hip and knee flexed. Comparisons over the conditions studied for each individual system muscle found that the maximum variation occurred in knee and hip extensor forces (up to two orders of magnitude). Comparisons within the set of active muscles for each studied condition identified dominant muscles and muscle functions. All anteriorly-directed and posteriorly-directed resultants required a small number of muscles with common functions (mainly knee or hip extensors) and large force magnitudes (O(1000[Formula: see text]N)). In contrast, a large number of muscles, with wide-ranging synergistic and antagonistic functions, acting across multiple joints with relatively small magnitudes (O(100[Formula: see text]N)) were needed to create the superiorly-directed resultant with flexed hip and knee. With good correlation to experimentally measured trends in the interrelationships between leg joint angles and isometric forces, the systematic muscle force prediction and analysis presented in this work can be used to guide the design of targeted muscle strengthening exercises and study of muscle-specific injury.