Patient Height, Weight, BMI and Age as Predictors of Gracilis Muscle Free-Flap Mass in Lower Extremity Reconstruction

Background: Gracilis muscle flap is commonly used for the reconstruction of defects of the lower extremities. Preoperative evaluation of gracilis muscle dimension is a key aspect in surgical planning. This study aimed to determine whether patient height, weight, body mass index (BMI) and age are reliable proxy measurements of the mass of gracilis muscle flap. Patients and Methods: Twenty- two patients treated for lower extremity reconstruction with free gracilis flap between December 2010 and December 2014 were considered. The relationships between the mass of gracilis muscle and patient height, weight, BMI and age were assessed with Pearson's product moment correlation coefficient. Defect size, mass of gracilis muscle resected and surgical outcomes were also evaluated. Results: There was a moderate correlation between the mass of the gracilis muscle and patient height (r=0.4), weight (r=0.4), and BMI (r=0.3), and moderate inverse correlation with age (r=-0.04). Lower extremities defects ranged in size from 3x4 cm (12 cm(2)) to 26x11 cm (286 cm(2)) with a mean of 81.6 cm(2). All defects were reconstructed with the gracilis muscle, which required a resection ranging between 3 g and 105 g (mean=37.4 g) to adapt the flap to the recipient site. Complete flap loss was observed in one case. Conclusion: In our series, the mass of the gracilis muscle flap was predictable in relation to height, weight, BMI, and age, which can be considered reliable proxy measurements. This will contribute to adequate flap selection for microsurgical reconstruction of lower extremity defects.