Druschel Claudia, Sawicki Olga, Cip Johannes, Schmölz Werner, Funk Julia F, Placzek Richard
Center for Musculoskeletal Surgery, Campus Virchow, Charité-University Medicine, Berlin, Germany.
Biomed Tech (Berl). 2012 May 30;57(3):157-62. doi: 10.1515/bmt-2011-0127.
Previous data have shown that due to the technical ease, low-morbidity, and lower complication rates, the in situ single-implant fixation is the current standard for stabilization of slipped capital femoral epiphysis (SCFE) fixation. Multiple-implant fixation is thought to be combined with a higher incidence of serious complications. The purpose of the current study was to evaluate single- vs. multiple-implant fixation regarding strength and stiffness. Furthermore, different screw designs, including telescopic screw, were evaluated regarding the stiffness, strength, and especially fixation failure.
Forty porcine proximal femurs were sectioned through the physeal line using a gigli saw and stabilized with a 7.3-mm stainless steel AO screw, a dynamic telescopic screw, three 1.6-mm Kirschner wires (K-wires), and three 2.0-mm K-wires. The femurs were biomechanically tested to determine failure load (N) and stiffness (N/mm).
No significant differences were found regarding failure load and stiffness between the two screw groups. The 2.0-mm K-wire construct was significantly the strongest and stiffest fixation. The 1.6-mm K-wire fixation had the lowest values, but not statistically significant. Regarding the fixation failure, no femoral shaft fracture occurred.
SCFE stabilization with three 2.0-mm K-wires leads to increased stability over single-screw fixation and 1.6-mm K-wire fixation. However, none of the two screws seemed to be superior in fixation stability and fixation failure.
先前的数据表明，由于技术操作简便、发病率低且并发症发生率较低，原位单植入物固定是目前稳定股骨头骨骺滑脱（SCFE）固定的标准方法。多植入物固定被认为会伴有更高的严重并发症发生率。本研究的目的是评估单植入物与多植入物固定在强度和刚度方面的差异。此外，还评估了不同的螺钉设计，包括伸缩式螺钉，在刚度、强度，尤其是固定失败方面的情况。
使用线锯通过骨骺线将40根猪的近端股骨切开，并用一根7.3毫米不锈钢AO螺钉、一根动态伸缩式螺钉、三根1.6毫米克氏针（K针）和三根2.0毫米K针进行固定。对股骨进行生物力学测试以确定破坏载荷（N）和刚度（N/mm）。
两组螺钉在破坏载荷和刚度方面未发现显著差异。2.0毫米K针结构是最坚固和最具刚性的固定方式。1.6毫米K针固定的值最低，但无统计学意义。关于固定失败，未发生股骨干骨折。
用三根2.0毫米K针进行SCFE固定比单螺钉固定和1.6毫米K针固定具有更高的稳定性。然而，两种螺钉在固定稳定性和固定失败方面似乎都不具有优势。
