Rectus femoris (RF) transfer was long the gold-standard treatment for stiff knee gait (SKG), but efficacy now seems less than that of distal RF release. The aim of the present study was to compare efficacy between the two. The study hypothesis was that both significantly improve 4 knee kinematic parameters at 1 year.

A meta-analysis was performed, using PRISMA criteria, on the Medline, Science Direct, Cochrane Registry, Scopus and Pascal databases. Search was conducted up to March 1, 2020 by two authors (A.J & M.T). Study methodology was assessed on MINORS index. Inclusion criteria comprised patients with SKG, treated by RF transfer or distal release. Endpoints comprised: Peak Knee Flexion in swing phase (PKF_SW), Knee Range of Motion (KROM), time to Peak Knee Flexion (t-PKF_GC), and Maximum Knee Extension in stance phase (MKE_ST). Effect size was assessed on Standard Mean Deviation (SMD).

A total of 695 studies were identified, 16 of which were included: 14 transfer, 5 release. Data were analyzed for 1,079 limbs in 768 patients. Only transfer improved PKF_SW, with small effect size (SMD=0.29). The other three parameters were improved by both techniques, with moderate effect size.

Results showed improved knee kinematics after RF transfer, but with small or moderate effect size. The effect of distal release on PKF could not be assessed, due to publication bias. The heterogeneity of studies and low levels of evidence call for caution in interpreting the present results.

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