Pedicled Latissimus Dorsi Flap and Gracilis Free Flap for Restoration of Elbow Flexion: Systematic Review and Indirect Comparative Meta-Analysis of Functional Outcomes.

[INTRODUCTION] Pedicled latissimus dorsi flap (PLDF) and gracilis free flap (GFF) are techniques for restoration of elbow flexion after brachial plexus injuries with late presentation or poor outcomes following nerve surgery, as well as after traumatic or oncological loss of arm flexor muscles. The aim of this study is to compare the results of both techniques.

[MATERIAL AND METHODS] A systematic review was conducted following PRISMA guidelines, including articles providing information on the maximum degrees of elbow flexion or flexion strength according to the MRC scale. Outcomes were synthesized through single-arm meta-analyses using random-effects models, with indirect comparisons between PLDF and GFF performed using Z-tests. Study quality was appraised with MINORS and JBI tools, and publication bias was assessed using funnel plots and Egger's test.

[RESULTS] Forty-seven studies comprising 814 patients were included: 19 on PLDF (n = 122) and 28 on GFF (n = 692). PLDF achieved a higher mean elbow flexion angle (119.2°; 95% CI 112.5°-125.9°) compared to GFF (91.4°; 95% CI 82.9°-99.9°), a difference that was statistically significant. Likewise, mean muscle strength was greater with PLDF (MRC 3.85; 95% CI 3.61-4.09) than with GFF (MRC 2.95; 95% CI 2.72-3.18). In terms of functional thresholds, 95% of patients in the PLDF group achieved at least MRC ≥ 3 and 87% reached ≥ 4, whereas in the GFF group the corresponding rates were 72% and 65%. Heterogeneity across studies was moderate but consistent with the direction of effect.

[CONCLUSION] PLDF was associated with higher pooled flexion angles and strength values than GFF; however, due to the absence of direct comparative studies, these findings should be interpreted as comparative trends rather than evidence of superiority.