Schemitsch E H, Kowalski M J, Swiontkowski M F, Harrington R M
Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada.
J Orthop Res. 1995 May;13(3):382-9. doi: 10.1002/jor.1100130312.
This study was performed to compare the effects of reamed and unreamed locked intramedullary nailing on blood flow in the callus and early strength of union in a fractured sheep tibia model. After the creation of a standardized short spiral fracture by three-point bending with torsion, each tibia was stabilized by the insertion of a locked intramedullary nail. Ten animals were allocated randomly into two groups: one that had reaming prior to nail insertion and one that did not. Blood flow was measured in real time with use of laser Doppler flowmetry. Endosteal perfusion was determined at the fracture site before and after nail insertion. Perfusion of the callus was measured at three locations (proximal diaphysis, fracture site, and distal diaphysis) and at three time intervals (2, 6, and 12 week follow-up). All animals were killed 12 weeks postoperatively, and the tibiae were tested to failure in four-point bending. Nailing with reaming resulted in a larger decrease in overall endosteal perfusion than nailing without reaming (p < 0.015). The presence or absence of reaming did not affect blood flow within fracture callus. Perfusion of callus was greatest at 6 weeks of follow-up. Bending strength and stiffness were the same in both groups at 12 weeks. The study demonstrated that perfusion of callus and early strength of union are similar following intramedullary nailing with or without reaming.
本研究旨在比较扩髓与非扩髓带锁髓内钉对绵羊胫骨骨折模型骨痂血流及早期愈合强度的影响。通过三点弯曲加扭转制造标准化短螺旋骨折后，每只胫骨均通过插入带锁髓内钉进行固定。将10只动物随机分为两组：一组在插入髓内钉前进行扩髓，另一组不进行扩髓。使用激光多普勒血流仪实时测量血流。在插入髓内钉前后测定骨折部位的骨内膜灌注。在三个位置（近侧骨干、骨折部位和远侧骨干）以及三个时间间隔（随访2、6和12周）测量骨痂的灌注。所有动物在术后12周处死，胫骨在四点弯曲试验中测试至失效。与非扩髓髓内钉固定相比，扩髓髓内钉固定导致骨内膜总体灌注下降幅度更大（p < 0.015）。扩髓与否不影响骨折骨痂内的血流。随访6周时骨痂灌注最大。两组在12周时的弯曲强度和刚度相同。该研究表明，扩髓与非扩髓髓内钉固定后骨痂灌注及早期愈合强度相似。
