[Survival of bone after osteomuscular transposition. Histological study in man and an experimental model]

Most bone cells in homografts fail to survive, and several months are required before live bone tissue structures develop in the graft. Various attempts have been made to preserve or re-establish homograft vascularization. One method involves the use of free bone transfer with revascularization of the supply artery or the total periosteal network, this enabling the majority of the bone cells to survive. Another procedure uses osteomuscular transplants in which the muscle acts as a pedicle for the transplanted bone segment, but whether bone elements in these flaps remain viable is a very debatable point. Experimental and clinical studies were conducted to evaluate, histologically, the viability of bone after osteomuscular transplantation. Fluorescence examination of bone sections from 40 osteomuscular flaps in the rat demonstrated bone formation on the external cortical surface but marked diminution of endosteal moulding in other zones. Examination of bone biopsies from 10 patients treated by mandibular reconstitution using an osteomuscular flap provided data comparable with those obtained during the experimental study. These findings demonstrate that osteomuscular transplantation is responsible for endosteal ischemia, preventing survival of cells other than those lying most externally to the cortex.