The relationship between urinary C-Telopeptide fragments of type II collagen, knee joint load, pain, and physical function in individuals with medial knee osteoarthritis.

OBJECTIVE: Considering the osteoarthritis (OA) model that integrates the biological, mechanical, and structural components of the disease, the present study aimed to investigate the association between urinary C-Telopeptide fragments of type II collagen (uCTX-II), knee joint moments, pain, and physical function in individuals with medial knee OA. METHODS: Twenty-five subjects radiographically diagnosed with knee OA were recruited. Participants were evaluated through three-dimensional gait analysis, uCTX-II level, the WOMAC pain and physical function scores, and the 40m walk test. The association between these variables was investigated using Pearson's product-moment correlation, followed by a hierarchical linear regression, controlled by OA severity and body mass index (BMI). RESULTS: No relationship was found between uCTX-II level and knee moments. A significant correlation between uCTX-II level and pain, physical function, and the 40m walk test was found. The hierarchical linear regression controlling for OA severity and BMI showed that uCTX-II level explained 9% of the WOMAC pain score, 27% of the WOMAC physical function score, and 7% of the 40m walk test. CONCLUSION: Greater uCTX-II level is associated with higher pain and reduced physical function and 40m walk test performance in individuals with medial knee OA.

The role of hip abductor strength on the frontal plane of gait in subjects with medial knee osteoarthritis.

OBJECTIVE: This study aimed to investigate the relationship of hip abductor strength with external hip and knee adduction moments, pain and physical function, and trunk, pelvis, and hip kinematics in the frontal plane during walking in subjects with medial knee osteoarthritis. METHODS: Twenty-five subjects with medial knee osteoarthritis were evaluated through an isokinetic strength test for hip abductor, three-dimensional gait analysis (kinetics and kinematics), and pain and physical function scores. Regression models were used to control the influence of other parameters such as pain, age, gender, severity, walking speed, mass, and height. RESULTS: No relationship was found of hip abductor strength with peak of external knee adduction moment and knee adduction angular impulse. Hip abductor strength explained 17% of contralateral pelvic drop and 21% of hip adduction angle. In addition, hip abductor strength explained 4% and 1% of the variance in the WOMAC physical function score and 40-m fast paced walk test, respectively. CONCLUSION: Considering the relationship of hip abductor strength with contralateral pelvic drop and hip adduction angle, specific exercises might improve physical function and lower limb dynamic alignment during gait.

The relationship between external knee moments and muscle co-activation in subjects with medial knee osteoarthritis.

PURPOSE: External knee moments are reliable to measure knee load but it does not take into account muscle activity. Considering that muscle co-activation increases compressive forces at the knee joint, identifying relationships between muscle co-activations and knee joint load would complement the investigation of the knee loading in subjects with knee osteoarthritis. The purpose of this study was to identify relationships between muscle co-activation and external knee moments during walking in subjects with medial knee osteoarthritis. METHODS: 19 controls (11 males, aged 56.6±5, and BMI 25.2±3.3) and 25 subjects with medial knee osteoarthritis (12 males, aged 57.3±5.3, and BMI 28.2±4) were included in this study. Knee adduction and flexion moments, and co-activation (ratios and sums of quadriceps, hamstring, and gastrocnemius) were assessed during walking and compared between groups. The relationship between knee moments and co-activation was investigated in both groups. FINDINGS: Subjects with knee osteoarthritis presented a moderate and strong correlation between co-activation (ratios and sums) and knee moments. INTERPRETATION: Muscle co-activation should be used to measure the contribution of quadriceps, hamstring, and gastrocnemius on knee loading. This information would cooperate to develop a more comprehensive approach of knee loading in this population.

Frontal plane corrective ability of a new unloader orthosis for medial compartment of the knee.

BACKGROUND: Patients with medial compartment osteoarthritis of the knee suffer from pain and stiffness. However, current unloader braces are not being used for extended periods by knee osteoarthritis patients due to interface problems, so compliance is an issue. The aim of this study was to design a new bespoke orthosis that could be comfortable to wear while also providing the required correction to reduce medial compartment loading. CASE DESCRIPTION AND METHODS: A new knee orthosis design was initially tested for its frontal plane correction of knee varus using a surrogate knee model. It was then assessed by a volunteer subject with grade 2 medial compartment knee osteoarthritis using a static standing radiograph. FINDINGS AND OUTCOMES: When fitted to the surrogate knee model, the brace corrected the knee from 10° of varus to neutral alignment in the frontal plane. When worn in situ during static stance on the affected leg of the volunteer patient, it corrected the knee by 6° to a less varus position. CONCLUSION: The orthosis provided frontal plane correction of the knee during static standing. It could therefore prove to be suitable for use by knee osteoarthritis patients.

Outcome mapping for health system integration.

Health systems around the world are implementing integrated care strategies to improve quality, reduce or maintain costs, and improve the patient experience. Yet few practical tools exist to aid leaders and managers in building the prerequisites to integrated care, namely a shared vision, clear roles and responsibilities, and a common understanding of how the vision will be realized. Outcome mapping may facilitate stakeholder alignment on the vision, roles, and processes of integrated care delivery via participative and focused dialogue among diverse stakeholders on desired outcomes and enabling actions. In this paper, we describe an outcome-mapping exercise we conducted at a Local Health Integration Network in Ontario, Canada, using consensus development conferences. Our preliminary findings suggest that outcome mapping may help stakeholders make sense of a complex system and foster collaborative capital, a resource that can support information sharing, trust, and coordinated change toward integration across organizational and professional boundaries. Drawing from the theoretical perspectives of complex adaptive systems and collaborative capital, we also outline recommendations for future outcome-mapping exercises. In particular, we emphasize the potential for outcome mapping to be used as a tool not only for identifying and linking strategic outcomes and actions, but also for studying the boundaries, gaps, and ties that characterize social networks across the continuum of care.

Effect of an antipronation foot orthosis on ankle and subtalar kinematics.

INTRODUCTION/PURPOSE: The aim of this study was to describe the effect of an antipronation foot orthosis on motion of the heel relative to the leg and explore the individual contributions of the ankle and subtalar joints to this effect. METHODS: Five subjects were investigated using invasive intracortical pins to track the movement of the tibia, talus, and calcaneus during walking with and without a foot orthosis. RESULTS: The antipronation foot orthosis produced small and unsystematic reductions in eversion and abduction of the heel relative to the leg at various times during stance. Changes in calcaneus-tibia motion were comparable with those described in the literature (1°-3°). Changes at both the ankle and subtalar joints contributed to this orthotic effect. However, the nature and scale of changes were highly variable between subjects. Peak angular position, range of motion, and angular velocity in frontal and transverse planes were affected to different degrees in different subjects. In some cases, changes occurred mainly at the ankle; in other cases, changes occurred mainly at the subtalar joint. CONCLUSION: The changes in ankle and subtalar kinematics in response to the foot orthosis contradict existing orthotic paradigms that assume that changes occur only at the subtalar joint. The kinematic changes due to the orthosis are indicative of a strong interaction between the often common function of the ankle and subtalar joints.