Effect of chemodenervation of the rectus femoris muscle in adults with a stiff knee gait due to spastic paresis: a systematic review with a meta-analysis in patients with stroke.

Objective: To determine the effect of motor branch block (MBB) or neuromuscular block (NMB) of the rectus femoris on knee kinematics during swing, functional outcome, and energy cost in adults with spastic paresis presenting a stiff knee gait.

Data Sources: PubMed, Embase, CINAHL, and Cochrane Library were searched. Studies were collected up to February 26, 2013. Reference lists were additionally scrutinized.

Study Selection: No restrictions were applied regarding study design. Patients were adults suffering from a central neurological disorder. Interventions had to include MBB or NMB. Outcome measures had to include knee kinematics during the swing phase. Study selection was independently performed by 2 reviewers.

Data Extraction: Two reviewers independently assessed the methodological quality of included studies. Data on kinematics, functional outcome, and energy cost from patients with stroke were extracted from the total population and when possible pooled.

Data Synthesis: A total of 9 articles describing 12 different studies were included. Knee kinematics (peak knee flexion or knee range) during swing improved significantly in all the included studies. The average increase in peak knee flexion varied from 1.9° to 15.4°. Data pooling of peak knee flexion in patients with stroke showed a significant improvement of 7.37° (P=.000) in NMB studies and of 9.35° (P=.002) in MBB studies. Data pooling of knee velocity at toe-off showed a significant improvement of 53.01°/s in NMB studies. In MBB studies, this improvement was not significant. Data pooling of knee range of motion, functional outcomes, and energy cost showed no significant difference.

Conclusions: According to this review, chemodenervation of the rectus femoris shows a significant improvement in peak knee flexion during swing. The effect on functional outcomes and energy cost is still unclear.