Gait Acquisition with a Quadrilateral Socket after Ultra-short Transfemoral Amputation because of Staphylococcal Toxic Shock Syndrome.

Background: Streptococcal toxic shock syndrome (STSS) is a notifiable disease under Japan's Infectious Disease Control Law and has become a pandemic following COVID-19. STSS often leads to necrotizing fasciitis, with a mortality rate exceeding 30%. Even in surviving patients, limb amputations are common. Case: A 39-year-old woman developed STSS. She underwent 18 surgeries and vacuum-assisted closure therapy, which resulted in ultra-short right transfemoral amputation. With a strong desire to walk again, she began fitting for a provisional prosthesis 3 months post-amputation. Given the preserved hip muscle strength, an ultra-short transfemoral prosthesis was selected over a hip disarticulation prosthesis. The key components included a plug-in quadrilateral socket, a belt used to suspend the transfemoral prosthesis, a hydraulic knee joint, and an energy-storing foot. She regained walking ability using crutches. To address pain and skin issues in the stump load-bearing area, compression and adhesion were improved using thick fabric spats. Muscle mass, including that of the paraspinal muscles, was maintained during follow-up evaluations using computed tomography, dual-energy X-ray absorptiometry, and bioelectrical impedance analysis. The phantom limb pain in the right leg diminished with medication and prosthetic training. Her quality-of-life scores measured using the 36-item Short Form Questionnaire and the Prosthesis Evaluation Questionnaire also showed improvement. She was discharged home 5 months post-amputation. Discussion: This case highlights the importance of high motivation, multidisciplinary collaboration, preservation of the trunk muscle reserve from pre-illness exercise habits, and early trunk rehabilitation to achieve successful gait acquisition with a customized transfemoral prosthesis.