Characteristics of frontal plane lower limb movement during walking in patients with knee osteoarthritis of varying severity

Determinants of Achilles tendon thickness and their influence on knee function and foot alignment in knee osteoarthritis

Knee osteoarthritis (OA) significantly impacts the quality of life of individuals globally. However, the interconnections between Achilles tendon thickness, knee symptoms/functions, and foot alignment remain understudied in knee OA patients. This study determines the relationships between Achilles tendon thickness (ATT), knee symptoms/functions, and foot alignment in knee OA patients, considering their interconnected biomechanical nature. In a cross-sectional analysis involving 122 knee OA patients, Knee injury and Osteoarthritis Outcome Score (KOOS) assessed knee function and symptoms. Forefoot, midfoot, and rearfoot alignment were measured using hallux valgus angle, navicular/foot ratio, and rearfoot angle. The navicular/foot ratio represented the ratio of navicular height to total foot length. ATT was measured using a digital calliper. Pearson correlations and stepwise multiple linear regression models were employed to explore relationships and determinants. Out of 122 participants, 88 (72.1%) were females. ATT correlated significantly with ankle range of motion, forefoot alignment, and midfoot alignment. In stepwise multivariable regression, ankle range of motion, navicular/foot ratio, and age were significantly associated with ATT (adjusted R2 = 0.44). Similarly, KOOS-Symptoms scores were linked to the OA severity, navicular/foot ratio, ankle range of motion, gastrocnemius strength, and age (adjusted R2 = 0.22). KOOS-Function scores were significantly associated with knee OA severity, gastrocnemius strength, ankle range of motion, and age (adjusted R2 = 0.19). Midfoot alignment was significantly associated with ATT and knee symptoms in patients with Knee OA. This suggests potential benefits of interventions targeting both Achilles tendon properties and foot alignment for improved knee OA outcomes.

Biomechanical changes in lower extremity in individuals with knee osteoarthritis in the past decade: A scoping review

Biomechanic studies can provide a powerful theoretical and scientific basis for studies on knee osteoarthritis (OA), which is of great significance for clinical management as it provides new concepts and methods in clinical and research settings. This study aimed to discuss and summarize biomechanical research on lower extremities in individuals with knee OA in the past ten years. The methodology of this review followed the framework outlined in the Joanna Briggs Institute (JBI) guidelines and strictly followed the checklist for drafting the findings. A literature search was conducted using PubMed, Scopus, Cochrane Library, Embase, Web of Science, Grey literature search in Open Library, and Google Academic databases. Relevant literature was searched from 2011 to 2023. Sixteen studies were included in this scoping review. Biomechanical research on knee OA in the last decade demonstrates that the biomechanics of the hip, knee, and ankle have a profound influence on the pathogenesis and treatment of knee OA. Individuals with knee OA have biomechanical changes in hip, knee, and ankle joints such as a significant defect in the strength of ankle varus muscles, weakness of hip abductor muscle, walking with toes outwards, increased knee adduction moment and angle, and decreased knee extensor moment. As the severity of knee OA increases, the tendency of hip abduction positions also increases. Further research with a longitudinal study design should focus on the determination of the relative importance of different biomechanical and neuromuscular factors in the development and progression of the disease.

Detection of kinematic abnormalities in persons with knee osteoarthritis using markerless motion capture during functional movement screen and daily activities

Background: The functional movement screen (FMS) has been used to identify deficiencies in neuromuscular capabilities and balance among athletes. However, its effectiveness in detecting movement anomalies within the population afflicted by knee osteoarthritis (KOA), particularly through the application of a family-oriented objective assessment technique, remains unexplored. The objective of this study is to investigate the sensitivity of the FMS and daily activities in identifying kinematic abnormalities in KOA people employing a markerless motion capture system. Methods: A total of 45 persons, presenting various Kellgren-Lawrence grades of KOA, along with 15 healthy controls, completed five tasks of the FMS (deep squat, hurdle step, and in-line lunge) and daily activities (walking and sit-to-stand), which were recorded using the markerless motion capture system. The kinematic waveforms and discrete parameters were subjected to comparative analysis. Results: Notably, the FMS exhibited greater sensitivity compared to daily activities, with knee flexion, trunk sagittal, and trunk frontal angles during in-line lunge emerging as the most responsive indicators. Conclusion: The knee flexion, trunk sagittal, and trunk frontal angles during in-line lunge assessed via the markerless motion capture technique hold promise as potential indicators for the objective assessment of KOA.

Effect of knee osteoarthritis on the postoperative outcome of proximal femoral nail anti-rotation in the treatment of intertrochanteric fractures in the elderly: a retrospective analysis

BACKGROUND

The proximal femoral nail anti-rotation (PFNA) is a commonly used internal fixation system for intertrochanteric fractures (IFs) in older adults. Knee osteoarthritis (KOA) is a degenerative lower extremity disease that occurs most frequently in the elderly. Some patients have already had KOA before the IFs. However, whether KOA impacts the postoperative outcome of IFs has not been reported.

OBJECTIVE

This study aimed to investigate the effect of KOA on the fracture side on the outcome after PFNA for IFs in the elderly.

METHODS

Between January 2016 and November 2021, 297 elderly patients treated with PFNA for IFs were enrolled in this study. They were divided into two groups according to the American Rheumatism Association KOA clinical and radiographic criteria: the control group and the KOA group. Intraoperative bleeding, operative time, length of hospital stay, postoperative time out of bed, fracture healing time, postoperative complications, postoperative Harris hip function score, and Barthel ability to daily living Score were compared between the two groups. Follow-up was routinely scheduled at 1, 3, 6, and 12 months postoperatively.

RESULTS

Based on the exclusion criteria, 254 patients who met the requirements were left to be included in this study, including the control group (n = 133) and the KOA group (n = 121). Patients were followed up for a mean of 17.5 months (12-24 months). There was no significant difference between the two groups in preoperative demographic data, intraoperative blood loss, operation time, and length of stay in the hospital. The control group was statistically significant compared to the KOA group in terms of postoperative time out of bed (17.8 ± 4.0 days vs. 19.1 ± 5.8 days), fracture healing time (13.7 ± 2.2 weeks vs. 14.6 ± 3.7 weeks), and postoperative complications (12.8 vs. 23.1%). The Harris hip function score and Barthel ability to daily living score were higher in the control group than in the KOA group at 1, 3, 6, and 12 months postoperatively (the control group: 63.8 ± 10.9, 71.8 ± 10.3, 81.5 ± 8.7, and 91.6 ± 6.3 vs. The KOA group 61.0 ± 10.4, 68.6 ± 9.1, 79.0 ± 9.2, and 88.5 ± 5.9).

CONCLUSIONS

In elderly patients with IFs combined with KOA of the fracture side treated with PFNA internal fixation, KOA increases the incidence of postoperative complications of the fracture, prolongs postoperative time out of bed and fracture healing, and reduces postoperative hip function and ability to daily living. Therefore, treating KOA on the fractured side needs to be considered when treating IFs in the elderly.

Clinical and radiographic characterization of three-dimensional gait profiles of patients with knee osteoarthritis

BACKGROUND

Previous authors have utilized gait kinematics to categorize knee osteoarthritis patients into four distinct profiles: (1) flexed knee; (2) externally rotated knee; (3) stiff knee; and (4) knee varus thrust and rotational rigidity. However, the relationship between these gait profiles and patients' characteristics remains poorly understood. Thus, this study aimed to investigate whether differences in clinical and radiographic characteristics were associated with these four gait profiles.

METHODS

This cross-sectional study used available data from a previous biomechanical study. Data on the four gait profiles were collected from 42 patients with advanced knee osteoarthritis. Three-dimensional kinematics of the knee was recorded during gait using an optoelectronic system. Subjects were evaluated for knee strength, range of motion, tibial slope, femorotibial angle, radiographic severity, anthropometric measurements, and patient-reported outcomes. Multiple comparisons were made using Dunn's test. The level of significance was set at 5%, and the effect size was calculated.

FINDINGS

Body mass index (BMI) was the only variable associated with a specific gait profile: profile 4 (P = 0.01; effect size = P1 × P4: -0.62; P2 × P4: -0.41; P3 × P4: -0.40).

INTERPRETATION

Our findings suggest that most clinical and radiographic characteristics commonly measured in clinical practice did not differ significantly among knee osteoarthritis patients with the four different gait profiles. The only exception was a higher BMI noted in those with gait profile 4; however, it remains unclear whether it can cause varus thrust or rotation rigidity. The incorporation of three-dimensional motion analysis to identify gait profiles provided clinical insights beyond the limitations of traditional clinical assessments.

Relationship between the thoracic asymmetry in standing position and the asymmetry of ankle moment in the frontal plane during gait

[Purpose] We aimed to investigate the relationship of thoracic asymmetry in standing position with asymmetry of the internal ankle moment in the frontal plane during gait. [Participants and Methods] The following measurements were recorded in 22 healthy adult males using a 3D motion analyzer and force plates: thoracic lateral deviation, asymmetrical ratios of the upper and lower thoracic shape, internal ankle moment in the frontal plane, mediolateral deviations of the center of mass and center of pressure. [Results] In the standing position, the thorax was deviated to the left relative to the pelvis, and the upper and lower thoracic shapes were asymmetrical. During gait, significant lateralities were observed in the internal ankle moment in the frontal plane, mediolateral deviations of the center of mass and the center of pressure. Significant positive correlations were observed between the asymmetrical ratio of the lower thoracic shape and both the asymmetry of the internal ankle moment in the frontal plane and the mediolateral deviation of the center of pressure. [Conclusion] These results suggest that thoracic asymmetry is associated with mediolateral control of the ankle during gait.