Wheeler D L, Croy T J, Woll T S, Scott M D, Senft D C, Duwelius P J
Division of Orthopaedics and Rehabilitation, Oregon Health Sciences University, Portland 97201, USA.
Clin Orthop Relat Res. 1997 May(338):231-9. doi: 10.1097/00003086-199705000-00031.
Subtrochanteric osteotomies were created in 18 matched pairs of embalmed cadaveric femora. The femora were stabilized with a Synthes, Zimmer, or Richards second generation femoral reconstruction nail with retrograde blade or screws. The femoral pairs were randomly assigned to groups based on nails used: Synthes versus Zimmer, Synthes versus Richards, and Zimmer versus Richards. The reconstructions were cyclically loaded in bending for 2000 cycles and then loaded to failure. The mean stiffness of the Synthes, Zimmer, and Richards reconstructions was 17%, 40%, and 40% of the intact femora, respectively. The Richards construct was the strongest, and predominately failed by fracture at the distal interlocking screw hole. The Zimmer construct failed by bending of the nail at the osteotomy site and fracture of the proximal femoral shaft. The Synthes construct was the most flexible and least strong and failed by bending of the spiral, retrograde blade with concomitant fracture of the femoral neck. This study indicates that fixation of subtrochanteric femur fractures with a Synthes spiral blade or Richards or Zimmer reconstruction nails provides stable fixation for postoperative loading conditions. However, the Richards and Zimmer nails were able to withstand higher loads than was the Synthes nail before failure.
在18对防腐处理的尸体股骨上进行了转子下截骨术。使用Synthes、Zimmer或Richards第二代带逆行刀片或螺钉的股骨重建钉对股骨进行固定。根据所使用的钉子，将股骨对随机分组：Synthes与Zimmer、Synthes与Richards、Zimmer与Richards。对重建物进行2000次循环的弯曲循环加载，然后加载至破坏。Synthes、Zimmer和Richards重建物的平均刚度分别为完整股骨的17%、40%和40%。Richards固定结构最强，主要在远端锁定螺孔处发生骨折而失效。Zimmer固定结构在截骨部位的钉子弯曲和股骨近端骨干骨折处失效。Synthes固定结构最灵活且强度最低，因螺旋逆行刀片弯曲并伴有股骨颈骨折而失效。本研究表明，使用Synthes螺旋刀片或Richards或Zimmer重建钉固定转子下股骨骨折可为术后加载条件提供稳定的固定。然而，在失效前，Richards钉和Zimmer钉比Synthes钉能够承受更高的负荷。
