Recommendations on Ensuring Safety in Lower Limb Fat Grafting: Physiological Insights, Risk Assessment, and Advanced Surgical Techniques.

Background: Calf fat grafting has grown with body contouring advances, but robust safety and long-term outcomes data remain limited. This review synthesizes current evidence to guide safe practice.

Methods: Narrative review of recent studies and cadaveric data focused on injection plane (subcutaneous vs intramuscular), graft volume, complications (fat embolism, vascular events, compartment syndrome), and the role of ultrasound guidance.

Results: Intramuscular fat grafting markedly increases intramuscular pressures and carries higher risks of embolism and thrombosis. Subcutaneous/suprafascial grafting shows lower pressure changes and fewer serious events, though volume retention may require staged procedures. Cadaveric and in vivo pressure studies corroborate compartment-salient concerns with intramuscular approaches, emphasizing cautious technique and volume limits.Ultrasound aids anatomy but does not negate deeper-plane risks.

Conclusion: To minimize thromboembolic and ischemic complications, calf fat grafting should prioritize subcutaneous/suprafascial deposition, conservative graft volumes, and careful patient selection. Intramuscular fat grafting warrants extreme caution or avoidance due to elevated compartment pressures and embolic risk. Ultrasound guidance, while helpful for anatomy, does not mitigate deeper-plane risks and should not justify intramuscular injections. Consider staging extensive augmentation and educate patients about realistic outcomes. These guidelines aim to enhance safety and inform evidence-based practice in calf fat grafting.

No level assigned: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies.