Division of Orthopaedic Surgery, Biomechanics Lab, Oslo University Hospital, Pb. 4950 Nydalen, 0424 Oslo, Norway; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Pb. 1171 Blindern, 0318 Oslo, Norway.
Division of Orthopaedic Surgery, Biomechanics Lab, Oslo University Hospital, Pb. 4950 Nydalen, 0424 Oslo, Norway.
Clin Biomech (Bristol). 2020 Jun;76:104995. doi: 10.1016/j.clinbiomech.2020.104995. Epub 2020 Apr 21.
Stable fixation promotes union in the common femoral neck fractures, but high non-union rates due to fixation failure remain with traditional fixations. To enhance stability, a plate interlocking pins, but without further fixation to femur has been developed. To our knowledge, no comparison to other conventional fixation methods has been performed. We tested the hypothesis that the novel implant biomechanically leads to a more stable femoral neck fixation.
Fifty synthetic femurs with a cervical wedge osteotomy were allocated to intervention with three hook-pins interlocked in a plate (Hansson Pinloc® System) or standard fixations with a two-hole Dynamic Hip Screw® plate with an anti-rotational screw, three cannulated screws (ASNIS® III) or two screws (Olmed® or Cannulated Hip Screws®). Quasi-static non-destructive torsion around the neck, anteroposterior bending and vertical compression were tested to detect stiffness. The specimen's deformation was evaluated after cyclic compression simulating weight-bearing. Local deformation of implant channels was measured. Fixation failure was defined by fissure formation.
Compared to the conventional implants all together, the interlocked pins enhanced mean stiffness 130% in torsion and 33% in bending (P < 0.001), while compressive stability was increased by a reduced deformation of 62% in average of the global test specimen and 95% decreased local implant channel deformation after cycling (P < 0.001). In comparisons with each of the standard fixations the interlocking pins revealed no signs of adverse effects.
The novel femoral neck interlocking plate allowed dynamic compression and improved multi-directional stability compared to the traditional fixations.
稳定固定可促进股骨颈骨折愈合，但传统固定方法因固定失败导致的非愈合率仍然较高。为了增强稳定性，已经开发出一种带有锁定钉的钢板，但没有对股骨进行进一步固定。据我们所知，尚未与其他常规固定方法进行比较。我们假设新型植入物在生物力学上可导致更稳定的股骨颈固定，并对此进行了测试。
将 50 个带有颈楔形截骨的合成股骨分配到干预组，采用带有锁定钉的钢板（Hansson Pinloc® System）或标准固定装置（带抗旋转螺钉的两孔动力髋螺钉® 钢板、三个空心螺钉（ASNIS® III）或两个螺钉（Olmed®或空心髋螺钉®）进行固定。测试围绕颈部的准静态非破坏性扭转、前后弯曲和垂直压缩，以检测刚度。在模拟负重的循环压缩后，评估标本的变形。测量植入物通道的局部变形。固定失败的定义为裂隙形成。
与所有传统植入物相比，锁定钉可使扭转刚度提高 130%，弯曲刚度提高 33%（P<0.001），而循环后整体试验标本的变形减少 62%，植入物通道的局部变形减少 95%，从而提高了压缩稳定性（P<0.001）。与每种标准固定装置相比，锁定钉均未显示出不良影响。
新型股骨颈锁定钢板与传统固定装置相比，允许动态压缩并提高了多方向稳定性。
