Visser Noortje, Rezaie Elisa, Ducharme Alexandra, Shin Alexander Y, Bishop Allen T
Microvascular Research Laboratory, Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Department of Plastic and Reconstructive Surgery, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
J Orthop Res. 2023 Apr;41(4):815-822. doi: 10.1002/jor.25422. Epub 2022 Aug 6.
Cryopreserved bone allografts(CBA) are susceptible to infection, nonunion, and late stress fracture. Although surgical revascularization by intramedullary implantation of an arteriovenous bundle (AV bundle) generates a neoangiogenic blood supply, there is potential for vascular ingrowth-mediated bone resorption to weaken the graft. For this reason, we have evaluated changes in CBA mechanical properties of structural tibial allografts with and without surgically induced angiogenesis. Cryopreserved tibia bone allografts were transplanted to reconstruct a 3.5 cm segmental tibial defect in 16 Yucatan mini pigs. Surgical revascularization was performed in half by implantation of a cranial tibial AV bundle, (revascularization group). A control group of identical size had a ligated AV bundle implanted, (ligated group). At 20 weeks micro-computed tomography (CT) measured bone mineral density (BMD) as well as bone union. Reference point indentation (RPI) compared cortex material properties, and axial compression determined the allotransplant compressive modulus. Seven of eight tibiae in the angiogenesis group were healed at both junction points at 20 weeks. Only four of eight tibiae healed in the ligated control group. There was no significant difference between the revascularization and ligated control groups in BMD and axial compression test. Similarly, RPI parameters were statistically equal. In paired comparisons with contralateral tibias, however, some RPI values were significantly worse in the ligated control group tibiae. This study demonstrates no adverse effect of surgical angiogenesis on cryopreserved structural bone allograft biomechanical properties in a large animal orthotopic segmental tibial defect model. These data suggest the potential value of surgical angiogenesis in clinical limb-sparing reconstructive surgery.
冷冻保存的同种异体骨移植（CBA）易发生感染、骨不连和晚期应力性骨折。尽管通过髓内植入动静脉束（AV束）进行手术血运重建可产生新生血管供血，但血管长入介导的骨吸收有可能削弱移植物。因此，我们评估了有或无手术诱导血管生成的结构性胫骨同种异体骨移植的CBA力学性能变化。将冷冻保存的胫骨同种异体骨移植到16只尤卡坦小型猪体内，以重建3.5厘米的节段性胫骨缺损。其中一半通过植入胫骨前AV束进行手术血运重建（血运重建组）。相同大小的对照组植入结扎的AV束（结扎组）。在20周时，通过微型计算机断层扫描（CT）测量骨密度（BMD）以及骨愈合情况。参考点压痕（RPI）比较皮质材料特性，轴向压缩测定同种异体移植骨的压缩模量。血运重建组8只胫骨中有7只在20周时两个连接点均愈合。结扎对照组8只胫骨中只有4只愈合。血运重建组和结扎对照组在BMD和轴向压缩试验方面无显著差异。同样，RPI参数在统计学上相等。然而，与对侧胫骨进行配对比较时，结扎对照组胫骨的一些RPI值明显更差。本研究表明，在大型动物原位节段性胫骨缺损模型中，手术诱导血管生成对冷冻保存的结构性同种异体骨生物力学性能无不良影响。这些数据表明手术诱导血管生成在临床保肢重建手术中的潜在价值。
