Runyan Christopher M, Vu Anthony T, Rumburg Aaron, Bove Kevin, Racadio John, Billmire David A, Taylor Jesse A
Cincinnati, Ohio; and Philadelphia, Pa. From the Division of Plastic Surgery and the Departments of Pathology and Radiology, Cincinnati Children's Hospital Medical Center; and the Division of Plastic Surgery, Children's Hospital of Philadelphia.
Plast Reconstr Surg. 2015 Oct;136(4):461e-473e. doi: 10.1097/PRS.0000000000001637.
The authors previously described the generation of vascularized bone in a pig model, using a hemimandibular allograft scaffold, adipose-derived stem cells, recombinant human bone morphogenetic protein-2, and periosteum. This study tests the hypothesis that this "allograft revitalization" technique is as effective as vascularized autograft for repairing critical bony defects.
Three groups of pigs had 3-cm defects created in their bilateral tibial diaphyses for repair using rigid fixation and one of three modalities. Negative control tibias were repaired with allograft tibia alone. To simulate repair using vascularized autograft, the osteotomized bone in positive control animals was left in situ, with the posterior periosteum intact. Experimental animals' defects were repaired with allograft tibia packed with autologous adipose-derived stem cells and recombinant human bone morphogenetic protein-2, with native periosteum intact. After 8 weeks, unilateral midgraft osteotomies were performed to assess graft healing potential. Serial radiographs and terminal micro-computed tomography and histology enabled evaluation of healing.
At week 7 after ostectomy, no negative control tibias had healed (zero of six) whereas most positive control (five of six) and all experimental tibias (six of six) had healed. Unilateral midgraft osteotomies were performed at 8 weeks to assess graft ability to heal. As expected, no negative control tibias (three of three) had radiographic union 7 weeks later. However, all positive control (two of two; p = 0.05) and experimental (three of three; p = 0.01) tibias had healed their repeated osteotomies by this time.
Similar to vascularized autograft, revitalized allograft successfully repaired a critical tibial defect, including after refracture, suggesting that this technique may be an alternative to osseous free flaps.
作者之前描述了在猪模型中使用半下颌骨同种异体移植支架、脂肪来源干细胞、重组人骨形态发生蛋白-2和骨膜生成血管化骨的过程。本研究检验了这一“同种异体移植活化”技术在修复严重骨缺损方面与血管化自体移植同样有效的假设。
三组猪的双侧胫骨干中段制造3厘米的缺损，采用刚性固定和三种方式之一进行修复。阴性对照胫骨仅用同种异体胫骨修复。为模拟血管化自体移植修复，阳性对照动物的截骨骨留在原位，保留后侧骨膜完整。实验动物的缺损用填充自体脂肪来源干细胞和重组人骨形态发生蛋白-2的同种异体胫骨修复，保留天然骨膜完整。8周后，进行单侧移植骨中段截骨术以评估移植骨的愈合潜力。连续的X线片、终端微型计算机断层扫描和组织学检查可对愈合情况进行评估。
截骨术后第7周，阴性对照胫骨无一愈合（6例中的0例），而大多数阳性对照（6例中的5例）和所有实验胫骨（6例中的6例）均已愈合。在第8周进行单侧移植骨中段截骨术以评估移植骨的愈合能力。正如预期的那样，7周后阴性对照胫骨无一（3例中的3例）在X线片上显示骨愈合。然而，此时所有阳性对照（2例中的2例；p = 0.05）和实验（3例中的3例；p = 0.01）胫骨均已愈合其再次截骨处。
与血管化自体移植相似，活化同种异体移植成功修复了严重的胫骨缺损，包括再次骨折后的缺损，表明该技术可能是游离骨瓣的一种替代方法。
