Walking, orthoses and health-related quality of life in children with arthrogryposis multiplex congenita

Sammanfattning: Arthrogryposis Multiplex Congenita (AMC) describes the presence of multiple joint contractures at birth. Muscle weakness is often associated with the joint contractures, and orthoses are often used to enable or facilitate ambulation. The overall aim of this thesis is to evaluate ambulatory function, orthosis use and health-related quality of life (HRQoL) in children with AMC. In the different studies, the children were designated to three different groups depending on the need for joint stabilization due to muscle weakness and joint contractures: 1) use of knee-ankle-foot orthoses with locked knee joints (KAFO-LK), 2) use of knee-ankle-foot orthoses with open knee joints (KAFO-O) or ankle-foot orthoses (AFO) 3) use of shoes. In Study I-III, gait in children walking with their habitual orthoses or shoes was evaluated. In Study I, gait kinematics was evaluated with three dimensional (3D) gait analysis in 15 children with AMC. The children walking with KAFO-LK used greater trunk movements in the frontal and transverse planes than those walking with KAFO-O/AFOs and shoes. Those walking with KAFO-LK were able to compensate for the inability to flex their knees during swing due to their locked orthoses knee joints. In Study III, gait dynamics, including kinematics, moments, and mechanical work, were evaluated with 3D gait analysis in 26 children with AMC and 37 typically developing (TD) children. Excessive trunk movements were found in children who walked with orthoses, particularly in those walking with KAFO-LK. The frontal plane joint moments showed only small differences between the groups in hip abduction and knee valgus moments. The joint work analysis indicated greater contribution from the hip muscles to overall positive work in AMC children, particularly in those with KAFO-LK, than in TD children, which illustrates their reliance on hip musculature. In Study II, energy effort with measurement of oxygen consumption and functional exercise capacity measured with the six-minute walk test (6MWT) were evaluated in 24 children with AMC and in 25 TD children. All AMC groups showed higher oxygen cost than TD children, but only those walking with AFOs/KAFO-O had significantly higher oxygen cost. All AMC groups walked shorter distances than TD children during the 6MWT. In Study IV, 33 children and their parents answered questionnaires that investigated HRQoL (CHQ-PF50 and EQ-5D-Y) and satisfaction with orthoses (QUEST 2.0). The results from the CHQ-Parent Form were compared to those from a Swedish reference group of 60 healthy children. Children with AMC had lower physical functioning than the reference group, particularly in those who were dependent on orthoses for walking. With EQ-5D-Y, no difference was found between children walking with orthoses or with only shoes. Satisfaction with orthoses was high, but the group who were dependent on orthoses for walking was less satisfied with the weight of the orthoses than the group who were not dependent on orthoses. With adequate orthotic support, children with AMC, even with severe weakness and contractures, can achieve walking. The gait pattern deviated in children who walked with orthoses from those walking with shoes and from TD children, and evaluation of the energy effort indicated a less efficient gait in children with AMC than in TD children. The HRQoL was lower, particularly in subscales related to physical health, in children with AMC than in the healthy control group when reported by the parents.