三种不同内固定治疗胫骨平台后内侧骨折的生物力学研究

Biomechanical analysis of three fixations for the posteromedial tibial plateau fracture

目的设计一种与胫骨平台后内髁解剖形态匹配的钢板,比较其与5孔L型有限接触动力加压钢板(LCDCP)和7孔直型重建接骨板治疗胫骨平台后内侧骨折的稳定性。方法将18具胫骨平台后内侧骨折的标本随机分为3组,每组6具。其中,A组标本模型采用前内侧5孔L型LC-DCP固定,B组标本模型采用后内侧7孔直型重建接骨板固定,C组标本模型采用新设计的胫骨平台后内侧锁定钢板固定。分别测量各组标本在轴向载荷为500、1000、1500 N下的垂直位移及失效载荷。结果 A组标本分别在500、1000、1500 N下的垂直位移是(1.035±0.140)mm、(1.721±0.149)mm、(2.263±0.134)mm,B组标本分别在500、1000、1500 N下的垂直位移是(0.268±0.702)mm、(0.788±0.507)mm、(1.518±0.111)mm,C组标本分别在500、1000、1500 N下的垂直位移是(0.180±0.049)mm、(0.578±0.103)mm、(0.760±0.055)mm。在同一载荷下,三组标本骨折块垂直位移组间比较差异均有统计学意义(<0.05)。A组标本失效载荷为(1234.3±56.009)N,B组标本失效载荷为(2065.8±102.098)N,C组标本失效载荷为(2544.2±92.982)N,三组间比较差异均有统计学意义(<0.05)。结论新设计的胫骨平台后内侧锁定钢板在治疗胫骨平台后内侧骨折上,较5孔L型LC-DCP和7孔直型重建接骨板具有更好的生物力学优势。

Objective Designed a new type of posteromedial plate that matching the morphology of the posteromedial condyle of tibial plateau, and compared its biomechanical properties with 5 holes L-limited contact dynamic compression plate and 7 holes straight reconstruction plate for the posteromedial tibial plateau fracture. Methods 18 patients with posteromedial tibial plateau fractures were randomly divided into 3 groups, each group with 6 cases. Among them, the group A was treated with the 5 holes L-limited contact dynamic compression plate, group B was treated with the 7 holes straight reconstruction plate, group C was treated with the new design of the posteromedial tibial plateau locking plate. The vertical displacements of the posteromedial fragments and failure loads of each specimen in the three group were measured respectively under axial loads of 500, 1000 and 1500 N. Results The vertical displacements of group A under axial loads of 500, 1000 and 1500 N was （1.035±0.140）, （1.721±0.149）, （2.263±0.134） mm, the vertical displacements of group B under axial loads of 500, 1000 and 1500 N was （0.268±0.702）, （0.788±0.507）, （1.518±0.111） mm, the vertical displacements of group C under axial loads of 500, 1000 and 1500 N was （0.180±0.049）, （0.578±0.103）, （0.760±0.055） mm. Under the same load, comparing the vertical displacements, there were significant differences between the three groups （P 〈 0.05）. The failure load of group A was （1234.3 ＋ 56.009） N, the failure load of group B was （2065.8±102.098） N, The failure load of group C was （2544.2±92.982） N, comparing the failure load, there were significant differences between the three groups （P〈0.05）. Conclusion Comparing with the 5 holes L-limited contact dynamic compression plate and 7 holes straight reconstruction plate, the new design of the posteromedial tibial plateau locking plate has better biomechanical advantages in the treatment of posteromedial tibial plateau fracture.