RecruitingPhase 2Biological interventionAutologous Volar Fibroblast Injection Into the Stump Site of AmputeesThis study is a clinical trial testing the safety and efficacy of volar fibroblast (skin cells from the palm or sole) injections for thickening the epidermal (skin) layer at the stump site in people with below the knee amputations. The study will enroll adults seen at Johns Hopkins.