Re-exploration of the rectus femoris tendon to sartorius transfer in children with spastic cerebral palsy

Background: The rational of rectus femoris tendon transfer is to use a spastic rectus femoris tendon as a knee flexor during swing phase of gait cycle. However, the concept of the rectus femoris tendon transfer has been challenged by the evidence of scar tissue formation along the transferred tendon route.

Objective: Examine the surgical technique for rectus femoris tendon transfer to the sartorius at the index procedure and report the findings at the anchoring site during the re-exploration.

Methods: Three knees were examined in two patients with spastic cerebral palsy who developed recurrent flexion contracture at 18 months after the rectus femoris tendon to sartorius surgery. They underwent femoral shortening procedures and re-exploration at the rectus femoris tendon to sartorius transfer site simultaneously to correct flexion contracture. The transferred tendon route was examined. The anchoring site at the sartorius was manually tested. The follow-up period after the re-exploration procedure ranged from 7-60 months (mean: 37 months).

Results: All three rectus femoris tendons were in a straight line, and glided smoothly on the new route with minimal scar tissue formation. The anchoring site at the sartorius was well healed, and the knee flexion was observed upon manual testing. Degree of knee flexion contracture ranged from 15 to 35 degrees (mean: 27 degrees) before re-exploration procedure. It was 5 to -5 degrees (mean: 0 degree) at the recent follow-up. All patients maintained their ambulatory status.

Conclusion: The present technique for rectus femoris tendon to sartorius transfer gave a straight-line transfer over smooth gliding path and provided a secure anchoring site. It converted the function of the transferred tendon from a knee extensor to a knee flexor and created minimal scar formation with smooth gliding path.