胫骨内侧平台塌陷骨折对膝关节接触应力影响的实验研究

Effect of articular step-off on knee joint contact pressures in fractures of the medial tibial plateau

目的探讨胫骨内侧平台塌陷骨折对膝关仃接触应力的影响。方法选取8具成人防腐膝关节标本，先后造成胫骨内侧平台塌陷0、1、2、3mm的骨折塌陷模删（Schatzker IV骨折），应用压敏片技术测量膝关节主要负重区域的接触应力变化。结果胫骨内侧平台塌陷0、1、2、3mm时内侧接触应力分别为（4．04±0．17）MPa、（4．57±0．20）MPa、（5．64±0．20）MPa、（5．64±0．19）MPa，外侧接触应力分别为（3．34±0.05）MPa、（3．48±0．06）MPa、（4．19±0．05）MPa、（4．19±0．04）MPa。当胫骨内侧平台塌陷2mm时，内、外侧接触应力与塌陷0mm时相比分别增加了39．6％和25．4％，差异均仃统计学意义（P〈0．05）。结论胫骨内侧乎白骨折塌陷≥2mm时，应给予复位内固定；胫骨内侧平台骨折塌陷〈2mm时，可考虑保守治疗。

Objective To study the effect of articular step-off on knee joint contact pressures in fractures of the medial tibial plateau. Methods Eight specimens of eml）almed adult knee joint were used to establish models of articular step-off of the medial tibial plateau by 0, 1, 2, 3 mm respectively （Schatzker IV fracture） . The technique of pressure sensitive fihn was used to measure the contact pressures on the weight-bearing area of the knee joint in the 3 models. Results When the step-offs of medial tibial plateau were 0, 1, 2, 3 ram, the average contact pressures on the lateral compartment were respectively 3.34 ± 0.06 MPa. 3.48±0.06 MPa, 4. 19 ±0.05 MPa, 4. 19 ±0.04 MPa, while the average contact pressures on the medial coMPartment were 4.04 ±0. 17 MPa, 4.57 ±0. 20 MPa, 5.64 ±0.20 MPa, 5.64 -0. 19 MPa. Wheu the step-off of medial tibial plateau was 2 mm, the average contact pressures on the medial and lateral plateaus increased by 39.6% and 25.4% compared with the 0 mm step-off, with statistically significant differences （ P 〈 O. 05）. Conclusions If the step-off of the medial tibial plateau reaches ≥ 2mm, open reduction and internal fixation should be indicated to prevent secondary, traumatic arthritis. When the step-off of the medial tibial plateau is 〈 2 mm, conservative treatment ean be a proper choice.