Rectus femoris transfer to improve knee function of children with cerebral palsy

Stance phase stability and swing phase clearance, prerequisites for normal ambulation, often are lost in the gait of children with cerebral palsy. Lengthening of the hamstrings usually will improve stance-phase knee extension but will not greatly alter swing-phase knee flexion. This paper presents the outcome of transfer of the distal end of the rectus femoris in conjunction with hamstrings lengthening in 37 knees, and compares it with a control group of 24 knees in which only hamstrings lengthening was done. In the first group swing-phase knee flexion was improved by 16.0 +/- 14.4 degrees, compared to 9.5 +/- 7.5 degrees in the control group, and residual knee flexion in stance was reduced to 8.9 +/- 8.1 degrees, compared to 15.1 +/- 13.8 degrees in the controls. Poor outcome in the transfer-plus-lengthening group was associated mainly with foot rotation in excess of 8 degrees internally or externally, or postoperative knee flexion in stance. Criteria for selection of cases and methods of improving surgical outcome are discussed.