Muscular Increase and Definition of the Back Contour Through Key Fat Grafting and Liposuction

Abstract Background Fat grafting to enhance the common aesthetic features of the posterior torso is an evolving technique in aesthetic surgery. Dynamic definition liposculpture (HD2) with strategic intramuscular lipoinjection aims to achieve both a slim, athletic posterior torso for the female and a muscular, powerful back for the male. Objectives The authors of this study introduce the muscular improvement and definition of back contour through key fat (MID BACK) grafting to improve the overall aesthetic definition while evaluating its efficacy and safety. Methods The authors conducted an analytical retrospective cohort study at a single plastic surgery institution in Bogotá, Colombia, from February 2023 to July 2024. Inclusion criteria were patients undergoing HD2 liposculpture with fat grafting to the back muscles. Exclusion criteria were American Society of Anesthesiologists (ASA) Class >II, BMI ≥30 kg/m2, collagen- or coagulation-associated diseases, a follow-up period of <1 month and/or incomplete clinical or surgical data. Cadaveric dissections were performed to identify the safest fat injection sites. Patient satisfaction was assessed using a nonstandardized Global Aesthetic Improvement Scale between the third and sixth month postoperative. Results The study cohort included a total of 102 consecutive patients. Most patients were female (66.7%), with median age of 37 years (interquartile range [IQR] 10 years), and mean BMI of 24.6 kg/m2 (IQR 2.96 kg/m2). Fat grafting was done to the Trapezius (median volume 50 cc), erector spinae (median volume 100 cc), and latissimus dorsi (median volume 150 cc) muscles. Mean surgical duration was 265 min (IQR 50). No adverse events related to the fat grafting technique were reported. Minor complications included a superficial burn (3.7%) and a self-limited seroma (3.7%). Conclusions MID BACK graft technique is safe and effective for enhancing the back's muscular definition and amending asymmetries of the spine. This study provides a foundation for future research and potential clinical applications in body contouring procedures. Level of Evidence: 3 (Therapeutic)