Hoffa骨折内固定相关问题探讨

Hoffa骨折是不稳定关节内骨折,具有明显的再移位倾向,伴有股骨远端髁间或髁上骨折时,易被漏诊,CT扫描是诊断Hoffa骨折的金标准。治疗原则是解剖复位关节面、可靠内固定、早期功能活动。目前主要的治疗方式是经关节面螺钉固定,但螺钉固定时因螺钉尾帽需埋头处理,致关节软骨形成不可愈合的医源性损伤;术后膝关节早期功能活动时骨折块在胫骨平台的作用下反复受到向后、向上的剪切力,是内固定失效的主要原因。钢板辅助螺钉固定可增加局部力学稳定性,但仍不能避免软骨医源性损伤的缺陷,同时因没有专用解剖钢板术中需进行钢板塑形,存在增加手术创伤和手术耗时等问题。Hoffa骨折理想固定方式应兼具:(1)避免关节面软骨医源性损伤。(2)具备后方抗剪切阻挡钢板功能。(3)内固定物更靠近负载界面,以便获得更大的载荷、更好的固定强度。

Discussion on internal fixation of Hoffa fractures

Hoffa fracture is an unstable intra-articular fracture with significant redisplacement tendency. It is easy to be missed diagnosis when accompanied by distal intercondylar or supracondylar fracture of femur. CT scan is the gold standard for the diagnosis of Hoffa fracture. The treatment principles are anatomic reduction of the articular surface,reliable internal fixation,and early functional activity. At present,the main treatment is arthroscopic screw fixation. During screw fixation,the tail cap of screw should be buried,resulting in non-healing iatrogenic injury of articular cartilage. In the early postoperative functional activity of knee joint,fracture block was repeatedly subjected to backward and upward shear force under the action of the tibial plateau,which is the main reason for the failure of internal fixation. Plate assisted screw fixation could increase local mechanical stability,but it still cannot avoid the defects of iatrogenic cartilage injury. At the same time,plate molding is required during the operation due to the absence of special anatomical plates,resulting in increased surgical trauma and time-consuming surgery. The ideal fixation method for Hoffa fracture should include:(1) Avoid iatrogenic injury of articular surface cartilage. (2) With the rear anti-shear barrier plate function.(3) The internal fixator is closer to the load interface,so as to obtain greater load and better fixed strength.