Schemitsch E H, Kowalski M J, Swiontkowski M F, Senft D
University of Toronto, St. Michael's Hospital, Ontario, Canada.
J Orthop Trauma. 1994 Oct;8(5):373-82. doi: 10.1097/00005131-199410000-00002.
We compared the effects of reamed versus unreamed locked intramedullary nailing on cortical bone blood flow in a fractured sheep tibia model. A standardized spiral fracture was created by three-point bending with torsion, and each tibia was stabilized by insertion of a locked intramedullary nail. Eleven animals were randomized into two groups: one that had reaming before nail insertion and one that did not. Blood flow was measured in real time using laser Doppler flowmetry. Cortical bone perfusion measurements were made at three locations (proximal diaphysis, fracture site, distal diaphysis) and at eight time intervals (prefracture, postfracture, postreaming, postnail insertion, postlocking, and at 2-, 6-, and 12-week follow-up). All animals were killed at 12 weeks postoperatively. After reamed nail insertion, cortical bone perfusion was significantly decreased (p < 0.0009). After unreamed nail insertion, perfusion was decreased less (p < 0.003). Insertion of locking screws did not affect blood flow. Cortical bone perfusion was greater in the unreamed group at completion of the procedure (p < 0.011), at 2-week follow-up (p < 0.006) and at 6-week follow-up (p < 0.027). The findings suggest that cortical revascularization had occurred by 6 weeks in the unreamed group but not until 12 weeks in the reamed group. The study demonstrates that cortical circulation is spared to a greater degree by unreamed nailing. This may be advantageous in severe open tibial fractures where blood supply is already significantly compromised.
我们在绵羊胫骨骨折模型中比较了扩髓与非扩髓带锁髓内钉对皮质骨血流的影响。通过三点弯曲加扭转制造标准化螺旋骨折，每根胫骨通过插入带锁髓内钉进行固定。11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。在三个位置（近端骨干、骨折部位、远端骨干）和八个时间点（骨折前、骨折后、扩髓后、插入髓内钉后、锁定后以及术后2周、6周和12周随访）进行皮质骨灌注测量。所有动物在术后12周处死。插入扩髓髓内钉后，皮质骨灌注显著降低（p < 0.0009）。插入非扩髓髓内钉后，灌注降低较少（p < 0.003）。插入锁定螺钉不影响血流。在手术完成时（p < 0.011）、2周随访时（p < 0.006）和6周随访时（p < 0.027），非扩髓组的皮质骨灌注更高。研究结果表明，非扩髓组在6周时已发生皮质骨再血管化，而扩髓组直到12周才发生。该研究表明，非扩髓髓内钉对皮质骨循环的影响较小。这在严重开放性胫骨骨折中可能具有优势，因为此类骨折的血供已受到严重损害。
