Comparison of Rectus Femoris Transfer Surgery Done Concomitant With Hamstring Lengthening or Delayed in Patients With Cerebral Palsy.

Background: Children with spastic cerebral palsy frequently develop stiff knee gait. A common treatment of flexed knee gait is lengthening of the hamstring tendons. It has been shown that minimum knee extension improves after hamstring surgeries. However, it has been observed that a decreased peak knee flexion in swing may be a complication of hamstring lengthening (HSL). This has been noted to occur because of an overactive rectus femoris during the swing phase of gait. A common treatment of decreased knee flexion in swing is distal rectus femoris transfer (DRFT). The purpose of this study is to compare the differences between doing DRFT concomitantly with HSL and doing delayed DRFT after HSL.

Methods: A total of 111 children with cerebral palsy (74 males and 37 females) who underwent HSL were reviewed retrospectively. All patients who met the inclusion criteria were divided into 3 groups, 28 subjects in the HSL alone group (H), 57 subjects in the HSL with concomitant rectus femoris transfer group (C), and 26 subjects in the HSL with delayed rectus femoris transfer group (D).

Results: The groups had similar minimum knee flexion in stance preoperatively and postoperatively. Group D's minimum knee flexion in stance improved to 5.5±12.7 degrees after HSL, but increased to 8.8±11.6 degrees after DRFT. Groups D and H had statistically significant reduction in maximum knee flexion in swing after HSL (P<0.05). Maximum knee flexion in swing was statistically significantly reduced in the D group after DRFT (P<0.05), but the C group was not statistically different from preoperative after DRFT (P>0.05). The C and D groups had similar total knee excursion postoperatively. The H group had less knee excursion than the other 2 groups, but it was not significant.

Conclusions: The group that had DRFT concomitantly with HSL maintained maximum knee flexion in swing phase postoperatively. Although the group that had delayed DRFT had a reduction in maximum knee flexion after isolated HSL, gains in swing phase motion were achieved after delayed DRFT (comparable to that of the simultaneous group).

Level Of Evidence: Level II.