The healing of canine vascularized segmental tibial osteotomies: the effect of retained endosteal circulation

Forty-eight pairs of canine tibial segmental osteotomies, 4 cm in length, were investigated to determine the progress of regeneration. The tibial segment was stripped of all soft tissue in one limb and the vascular pedicle was preserved in the contralateral limb. This allowed the healing of the tibial segments, vascular versus nonvascular, to be compared using sequential blood flow and roentgenographic and angiographic data. The blood flow to the vascular bone segment quadrupled at three weeks and then gradually decreased to 1.5 times baseline at one year. The nonvascular tibial segment showed a linear increase in flow for three months, achieving a level comparable to the contralateral vascular tibia segment. Peak flow in the vascular tibia at three weeks was four times that of the nonvascular tibia. Blood-vessel ingrowth from each osteotomy site progressed at a linear rate but was three times faster in the vascular bone. The deposition of callus and the rate of osteotomy healing were accelerated significantly in the vascular group. At three months 87% of the vascular tibial osteotomies healed versus 43% of the nonvascular osteotomies; these results represent significant advantages in the rate of healing in vascular versus nonvascular segmental tibial osteotomies. Segmental vascular bone grafts that are internally fixed with plate and screws can preserve the vascular structure and its advantages in bone regeneration.