Biomechanical and clinical outcomes of 3D-printed versus modular hemipelvic prostheses for limb-salvage reconstruction following periacetabular tumor resection: a mid-term retrospective cohort study.

BACKGROUND: Debates persist over optimal pelvic girdle reconstruction after acetabular tumor resection, with surgeons grappling between modular and 3D-printed hemipelvic endoprostheses. We hypothesize superior outcomes with 3D-printed versions, yet scarce comparative research exists. This study fills the gap, examining biomechanics and clinical results retrospectively. METHODS: From February 2017 to June 2021, we retrospectively assessed 32 patients undergoing en bloc resection for malignant periacetabular tumors at a single institution. PRIMARY OUTCOME: limb function. SECONDARY OUTCOMES: implant precision, hip joint rotation center restoration, prosthesis-bone osteointegration, and complications. Biomechanical characteristics were evaluated through finite element analysis on pelvic defect models. RESULTS: In the 3D-printed group, stress distribution mirrored a normal pelvis, contrasting the modular group with elevated overall stress, unstable transitions, and higher stress peaks. The 3D-printed group exhibited superior functional scores (MSTS: 24.3 ± 1.8 vs. 21.8 ± 2.0, p < 0.05; HHS: 79.8 ± 5.2 vs. 75.3 ± 3.5, p < 0.05). Prosthetic-bone interface osteointegration, measured by T-SMART, favored 3D-printed prostheses, but surgery time (426.2 ± 67.0 vs. 301.7 ± 48.6 min, p < 0.05) and blood loss (2121.1 ± 686.8 vs. 1600.0 ± 505.0 ml, p < 0.05) were higher. CONCLUSIONS: The 3D-printed hemipelvic endoprosthesis offers precise pelvic ring defect matching, superior stress transmission, and function compared to modular endoprostheses. However, complexity, fabrication expertise, and challenging surgical implantation result in prolonged operation times and increased blood loss. A nuanced consideration of functional outcomes, complexity, and patient conditions is crucial for informed treatment decisions. LEVEL OF EVIDENCE: Level III, therapeutic study (Retrospective comparative study).

Reconstrução microcirúrgica em queimaduras / Microsurgical reconstruction in burns

A grande maioria das queimaduras submetidas a tratamento cirúrgico é resolvida com excisão tangencial e enxertia de pele. Uma pequena parcela dos casos cirúrgicos demanda procedimentos microcirúrgicos vasculares. A indicação de microcirurgia em pacientes queimados compreende as queimaduras com exposição de estruturas profundas (osso, articulação, tendão, vasos sanguíneos e nervos), a preservação ou restabelecimento de função (mão), o salvamento de extremidade (traumas elétricos) e ganho de tecido local (cicatrizes instáveis ou retrações extensas). As áreas anatômicas mais frequentes para se realizar transplantes microcirúrgicos são os membros superiores, seguidos pelos inferiores, região cervical, face e tronco. Esta revisão pretende apresentar as indicações de microcirurgia vascular em pacientes queimados e discutir os princípios de microcirurgia, entre eles a indicação do procedimento, a seleção do paciente, a seleção do retalho, a área anatômica envolvida, o período de realização (timing) da cirurgia, a relação com a etiologia da queimadura e a diferenciação entre pacientes agudos e sequelas.

The majority of burns undergoing surgical treatment are managed by tangential excision and skin grafting. A small number of cases require microsurgical procedures. The indications of microsurgery in burned patients are to cover exposed deep structures (bone, joint, tendon, blood vessels and nerves), preserve or restore function (hand), limb salvage (electrical trauma) and gain of local tissue (unstable scars or extensive retractions). The most frequently involved anatomic areas to perform microsurgery are the upper limbs followed by lower limbs, neck, face and trunk. This review addresses indications for microsurgical transplantation in burn patients and discuss principles of microsurgery like the indications, patient selection, flap selection, anatomic area involved, surgery timing, relationship between etiology of burn and differentiation between acute and sequelae.