School of Medicine, China Medical University, Taichung, 404, Taiwan, ROC.
Department of Orthopedic Surgery, China Medical University Hospital, Taichung, 404, Taiwan, ROC.
J Orthop Surg Res. 2022 Feb 5;17(1):72. doi: 10.1186/s13018-022-02963-3.
For oblique metacarpal shaft fracture, if anatomical reduction is achieved through conservative cast immobilization rather than stable fixation, bone malrotation can easily occur, resulting in severe loss in hand prehensile function. However, whether bone plate fixation or only lag screw fixation is more preferable remains unclear. Few studies have evaluated whether screw fixation can provide biomechanical fixation strength similar to bone plate fixation.
We assessed the difference in fixation strength between fixtation with two lag screws and bone plate for oblique metacarpal shaft fractures.
We created oblique metacarpal shaft fractures on 21 artificial bones and fixated them using (1) double lag screw (2LS group), (2) regular plate (RP group), or (3) locked plate (LP group). To obtain the force-displacement data, a cantilever bending test was conducted for each specimen through a material testing machine. One-way analysis of variance and a Tukey test were conducted to compare the maximum fracture force and stiffness of the three fixation methods.
The maximum fracture force of the 2LS group (mean + SD: 153.6 ± 26.5 N) was significantly lower than that of the RP (211.6 ± 18.5 N) and LP (227.5 ± 10.0 N) groups (p < 0.001). However, no significant differences were discovered between the RP and LP groups. The coefficient of variation for the maximum fracture force of the 2LS group (17.3%) was more than twice as high as that of the RP (8.7%) and LP (4.4%) groups. In addition, the stiffness of the three fixation methods was similar.
Compared with bone plate fixation, double lag screw fixation yielded slightly lower maximum bearable fracture force but similar stiffness. Therefore, this technique could be used for treating oblique metacarpal shaft fractures. However, using double lag screw fixation alone is technically demanding and requires considerable surgical experiences to produce consistent results.
对于掌骨斜形骨折，如果通过保守的石膏固定实现解剖复位，而不是稳定固定，很容易发生骨旋转，导致手抓握功能严重丧失。然而，钢板固定还是仅使用拉力螺钉固定更可取尚不清楚。很少有研究评估螺钉固定是否可以提供与钢板固定相似的生物力学固定强度。
我们评估了使用两根拉力螺钉和钢板固定掌骨干斜形骨折的固定强度差异。
我们在 21 个人工骨上制造了掌骨干斜形骨折，并使用（1）双拉力螺钉（2LS 组）、（2）常规钢板（RP 组）或（3）锁定钢板（LP 组）进行固定。为了获得力-位移数据，我们通过材料试验机对每个标本进行了悬臂弯曲测试。采用单因素方差分析和 Tukey 检验比较了三种固定方法的最大骨折力和刚度。
2LS 组的最大骨折力（均值 + 标准差：153.6 ± 26.5 N）明显低于 RP（211.6 ± 18.5 N）和 LP（227.5 ± 10.0 N）组（p < 0.001）。然而，RP 和 LP 组之间没有发现显著差异。2LS 组最大骨折力的变异系数（17.3%）是 RP（8.7%）和 LP（4.4%）组的两倍多。此外，三种固定方法的刚度相似。
与钢板固定相比，双拉力螺钉固定的最大可承受骨折力略低，但刚度相似。因此，该技术可用于治疗掌骨干斜形骨折。然而，单独使用双拉力螺钉固定技术要求较高，需要相当多的手术经验才能获得一致的结果。
