Miller Mark Carl, Redman Christopher N, Mistovich R Justin, Muriuki Muturi, Sangimino Mark J
*Allegheny General Hospital †Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA ‡Children's Medical Center of Dallas, Dallas, TX §University Hospitals of Cleveland, Cleveland, OH ∥Hines Veterans Administration Hospital, Hines, IL.
J Pediatr Orthop. 2017 Sep;37(6):e342-e346. doi: 10.1097/BPO.0000000000001038.
Pin fixation of Salter-II proximal humeral fractures in adolescents approaching skeletal maturity has potential complications that can be avoided with single-screw fixation. However, the strength of screw fixation relative to parallel and diverging pin fixation is unknown. To compare the biomechanical fixation strength between these fixation modalities, we used synthetic composite humeri, and then compared these results in composite bone with cadaveric humeri specimens.
Parallel pinning, divergent pinning, and single-screw fixation repairs were performed on synthetic composite humeri with simulated fractures. Six specimens of each type were tested in axial loading and other 6 were tested in torsion. Five pair of cadaveric humeri were tested with diverging pins and single screws for comparison.
Single-screw fixation was statistically stronger than pin fixation in axial and torsional loading in both composite and actual bone. There was no statistical difference between composite and cadaveric bone specimens.
Single-screw fixation can offer greater stability to adolescent Salter-II fractures than traditional pinning.
Single-screw fixation should be considered as a viable alternative to percutaneous pin fixation in transitional patients with little expected remaining growth.
对于骨骼即将成熟的青少年，采用克氏针固定Salter-II型肱骨近端骨折存在一些潜在并发症，而单螺钉固定可避免这些并发症。然而，相对于平行和发散克氏针固定，螺钉固定的强度尚不清楚。为比较这些固定方式之间的生物力学固定强度，我们使用了合成复合材料肱骨，然后将这些结果与尸体肱骨标本的复合材料骨进行比较。
对模拟骨折的合成复合材料肱骨进行平行克氏针固定、发散克氏针固定和单螺钉固定修复。每种类型的六个标本进行轴向加载测试，另外六个进行扭转测试。五对尸体肱骨用发散克氏针和单螺钉进行测试以作比较。
在复合材料骨和实际骨的轴向和扭转加载中，单螺钉固定在统计学上比克氏针固定更强。复合材料骨标本和尸体骨标本之间无统计学差异。
对于青少年Salter-II型骨折，单螺钉固定比传统克氏针固定能提供更大的稳定性。
对于预期剩余生长很少的过渡期患者，单螺钉固定应被视为经皮克氏针固定的可行替代方法。
