Kunovsky Radek, Kocis Jan, Navrat Tomas, Vosynek Petr, Pink Tomas, Joukal Marek, Cizmar Igor
Department of Clinical Orthopedics, Trauma Hospital, Brno, Czech Republic.
Department of Trauma Surgery, Faculty of Medicine, Masaryk University, Brno, Czech Republic.
Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2022 Sep;166(3):334-342. doi: 10.5507/bp.2021.025. Epub 2021 May 11.
To assess the results of a biomechanical test of cadaveric specimens, comparing 2 methods of fixation of modified Lapidus arthrodesis in combination with arthrodesis of the first metatarsophalangeal joint.
A total of 12 cadaveric specimens were used in the test. Arthrodesis of the first MTP joint was in all patients fixed with a Variable Angle LCP 1st MTP Fusion Plate 2.4/2.7. Two methods of fixation of the Lapidus arthrodesis were compared, i.e. fixation with two screws in the PS (plate-screw) version versus fixation with X-Locking Plate 2.4/2.7 in the PP (plate-plate) version. Measurements were obtained with the use of a testing machine ZWICK Z 020-TND with an optical device Mercury RT for measuring deformities. Each specimen was subjected to 3 loading options, a. displacement 5 mm, the support is placed under the proximal phalanx, b. displacement 5 mm, the support is placed under the first metatarsal head and c. load to failure, the support is placed under the first metatarsal head.
In all specimens the PS construct showed a statistically considerably higher stiffness than the PP construct. In all specimens treated with the PP construct the load to failure was lower than in the PS construct. For loading mode a., at a significance level of 0.05 (P<0.05), the P-value was 0.036, for mode b. the P-value was 0.007 and for loading mode c. the P-value was 0.006. In addition, age-related decrease in stiffness of the specimen was proved at a significance level of 5% (P=0.004).
In all the three loading modes, the PS (plate-screw) construct showed a statistically higher stiffness than the PP (plate-plate) construct.
评估尸体标本生物力学测试的结果，比较改良Lapidus关节融合术与第一跖趾关节融合术的两种固定方法。
测试共使用了12个尸体标本。所有患者的第一跖趾关节融合均采用2.4/2.7可变角度锁定加压接骨板（Variable Angle LCP 1st MTP Fusion Plate）进行固定。比较了Lapidus关节融合术的两种固定方法，即PS（钢板 - 螺钉）版本的两枚螺钉固定与PP（钢板 - 钢板）版本的2.4/2.7 X锁定钢板固定。使用带有用于测量畸形的Mercury RT光学装置的ZWICK Z 020 - TND测试机进行测量。每个标本接受三种加载方式，a. 位移5毫米，支撑置于近节趾骨下方；b. 位移5毫米，支撑置于第一跖骨头下方；c. 加载至破坏，支撑置于第一跖骨头下方。
在所有标本中，PS结构在统计学上显示出比PP结构显著更高的刚度。在所有采用PP结构治疗的标本中，破坏载荷均低于PS结构。对于加载方式a，在显著性水平0.05（P<0.05）时，P值为0.036；对于方式b，P值为0.007；对于加载方式c，P值为0.006。此外，在5%的显著性水平（P = 0.004）下证明了标本刚度随年龄的降低。
在所有三种加载方式中，PS（钢板 - 螺钉）结构在统计学上显示出比PP（钢板 - 钢板）结构更高的刚度。
