Stiff Knee and Knee Extension Deformities in Cerebral Palsy

Abstract

Knee function in children with cerebral palsy (CP) has continued to be one of the major focus areas in the musculoskeletal management. The knee motion is important for the individual who is ambulatory. It is very important to have adequate knee flexion during swing phase to clear the foot. It is also important for the individual who is primarily seated to be able to flex the knee but also to come to full extension when lying or getting into a standing position. For the individual who is ambulatory, the importance of knee flexion in swing phase to avoid toe drag and allow for foot clearance is most important for a functional and safe gait. It is also important to be able to have the knee extended during stance phase and not to have it collapse into flexion. The primary problem related to swing phase is the issue of having adequate knee flexion which is primarily controlled by the knee extensor mechanism. The goal of this chapter is to address the deficiency of swing phase knee flexion caused by spasticity and lack of power to cause knee flexion which leads to tripping, toe drag, and walking difficulty. The inability to flex the knee caused by fixed knee extension contractures prevents comfortable seating and may need to have surgical release.