Purpose: The most commonly used muscles for free functional transfer are the latissimus dorsi and the gracilis, which have proven their useful application already in large clinical studies. However these two workhorses of functional free muscle transfer lack of some shortcomings regarding the muscle power and the range of motion they can develop. To overcome such problems we have found the rectus femoris muscle an ideal candidate to restore large muscular deficits. It must have been the fear of its donor site that prevented this useful muscle from a broad clinical application and only single case reports appeared in the literature. The purpose of this study was: 1) to show in the first larger clinical series its useful application, 2) to define a standardised indication for this muscle transfer and 3) to analyse potential donor site defects.

Methods: From 5/2000 to 12/2004 we have performed 7 free functional rectus femoris transfers. In three cases a compartment syndrome of the calf was treated, in two brachial plexus patients the biceps function was restored and in two patients a traumatically lost quadriceps femoris was functionally reconstructed with the contralateral rectus femoris. All patients have been followed up clinically and four patients were examined postoperatively by the Con-Trex Leg-press, isometric Power tester, and SP-Force Platforms.

Results: Mean follow up was 48 months (32-55). All flaps healed in with a good functional result (muscle manual test of the limb indicated M4 in all patients). After a training phase of six month the initial weakness of the donor thigh showed in 4 patients no statistical relevant difference in muscle strength compared to the unoperated quadriceps femoris.

Conclusion: The rectus femoris is one of the strongest and most potent muscles suitable for free functional transfer. The expected functional outcome is in selected indications for sure better than the widely preferred latissimus dorsi flap. We have found the compartment syndrome of the calf, biceps reconstruction as well as quadriceps function restoration to be an ideal indication for the rectus femoris transfer. Furthermore we could demonstrate that the initial donor site deficiency can be fully compensated. Thus we recommend the free functional rectus femoris transfer as a powerful enrichment to the plastic surgical armentarium.