Analysis of locomotor adaptations in young children with limb loss in an early prosthetic knee prescription protocol

Background: Traditionally, clinical protocols for the treatment of young children who require a knee prosthesis have favored stability, with the prosthetic knee locked into full extension until after the child has learned to walk. Recently, an Early Knee protocol has been investigated, in which children receive an articulating knee in their first prosthesis and use it while learning to crawl and walk. Objectives: This study investigated the presence of swing phase clearance adaptations in the walking gait of seven young children aged 18-92 months, who had been fitted according to the Early Knee protocol. Study design: Before-and-after experimental design. Methods: Each subject completed walking trials with the knee freely flexing and trials with the knee locked into full extension to mimic a traditional knee protocol. Results: Subjects utilized the articulating knee in walking, with an average of 70.4 degrees of peak swing phase knee flexion. Some clearance adaptations were present with the flexing knee; more were present and their magnitude was increased when the knee was locked. In particular, there was a statistically significant increase in circumduction. Conclusions: These results suggest that the Early Knee protocol can reduce the adoption of clearance adaptations while walking is developing. Clinical relevance Treatment of young children who require a knee prosthesis is inconsistent. Traditionally, no knee is provided until independent walking is achieved. A newer Early Knee protocol provides an articulating knee in the first prosthesis. This study found that children use the articulating knee in walking and develop fewer clearance adaptations.