The effect of rectus femoris transfer on kinematics and functional outcomes in adult stroke patients walking with a stiff knee gait

Background: Stiff knee gait is characterized by a reduced peak knee flexion during swing. Overactivity of the rectus femoris is often cited as a main cause for stiff knee gait. Little is known about the effect of an isolated rectus femoris transfer treatment on kinematic and functional outcomes in a group of stroke survivors. Objective: To perform an experimental study to evaluate the effect of an isolated rectus femoris transfer on knee and hip kinematics and functional outcomes in adult stroke patients walking with a stiff knee gait. Method: In this experimental study, 10 stroke survivors were included. During the surgical procedure, the distal rectus femoris tendon of the affected side was transferred to the medial knee flexors to improve knee flexion during swing. Knee and hip kinematics and a variety of functional outcomes were measured within 3 weeks before surgery and between 6 and 7 months after the surgery. Results: We found a statistically significant improvements in peak knee flexion during swing and knee range of motion of 10.6° (sd 4.7, p=0.000) and 10.5° (sd 6.2, p=0.001) post-surgery, respectively. Hip kinematics showed no significant differences. In addition, we found statistically significant improvements on the 6-minute walk test (42.5, sd 36.7, p=0.008), 10-meter walk test (1.26, sd 1.4, p=0.030), Timed up-and-go test (1.34, sd 1.18, p=0.009), L-test (2.97 sd 2.85, p=0.014) and on a subjective BORG scoring of foot clearance (1.8, sd 0.6, p=0.006). No significant differences were found on other measured functional outcomes. Conclusions: Rectus femoris transfer is a valuable treatment option for stroke patients walking with a stiff knee gait to improve knee kinematics and a selection of functional outcomes. There are no detrimental side effects on hip kinematics.