胫骨平台Hoffa骨折损伤机制的初步研究

A study on injury mechanism of tibial plateau Hoffa fracture

目的通过模拟高处坠落伤和交通伤两种受伤模式,了解和验证胫骨平台Hoffa骨折损伤的力学机制。方法选取下肢膝关节标本10具,男6例,女4例;年龄42~65岁,平均57.4岁。平均分为高处坠落伤组和交通伤组,每组5例,分别模拟高处坠落伤和交通伤两种受伤模式。试验后,伸直位行膝关节标准正、侧位X线和CT扫描检查,观察是否骨折、骨折的部位和骨折线的走行。结果6例成功模拟出胫骨平台Hoffa骨折,4例未能模拟出,失败原因包括股骨骨折、胫骨平台其他类型骨折。模拟高处坠落伤成功的3例骨折中,骨折线均位于后内侧,分别累及胫骨平台后1/3、2/5和1/2,骨折线与冠状面成角分别为21°、19°和12°,1例在X线片不显示骨折,在CT上显示出后内侧骨折;模拟交通伤成功的3例骨折中,骨折线分别累及胫骨平台后侧1/6、1/4和1/3,骨折线与冠状面成角分别为47°、56°和63°,1例在X线上无明显骨折征象,CT显示冠状面骨折。结论本研究首次证实了高处坠落伤和交通伤均可导致胫骨平台Hoffa骨折,但骨折累及范围和骨折形态有明显差异。X线片不足以完全诊断该类型骨折,提示有明确膝关节屈曲和轴向暴力损伤史者,应常规行CT扫描以减少漏诊和治疗不足的情况发生。

Objective To understand and verify the biomechanical mechanism of tibial plateau Hoffa(coronal)fracture by simulating high-altitude falls and traffic injuries using knee joint specimens.Methods Ten specimens of lower limb knee joint were used.They were from 6 males and 4 females,with an average age of 57.4 years(from 42 to 65 years).They were divided into 2 equal groups:one subjected to simulation of high-altitude falls(fall group)and the other to simulation of traffic injury(traffic injury group).After injury simulation,standard orthographic and lateral X-ray examinations and CT scans were performed of the knee joints in the extended position to observe whether there was a fracture,where the fracture occurred,and how the fracture line went.Results A tibial plateau coronal fracture was successfully simulated in 6 cases,but not in the other 4 cases.The failure was attributed to femoral fractures and other types of tibial plateau fracture.In the 3 successful fractures simulated by high-altitude fall,the fracture line was located all on the posterior medial side,involving the posterior 1/3,2/5,and 1/2 of the tibial plateau,respectively.The fracture line and the coronal plane formed angles of 21°,19°and 12°,respectively.The fracture was not shown on X-ray film in one case which was a posterior medial fracture on CT.In the other 3 successful fractures simulated by traffic injury,the fracture line involved 1/6,1/4 and 1/3 of the posterior tibial plateau,respectively.The angles between the fracture line and the coronal plane were 47°,56°and 63°,respectively.One case showed no obvious fracture signs on the X-ray but a coronal fracture on CT.Conclusions This study has confirmed for the first time that both high-altitude falls and traffic injuries can cause coronal fractures of the tibial plateau which vary significantly in the extent of involvement and morphology.X-rays are not sufficient to fully diagnose this type of fractures,suggesting that patients with a clear history of knee flexion or axial violence injury should be routinely scanned by CT to reduce risks of missed diagnosis and insufficient treatment.