经皮微创空心钉内固定治疗后踝骨折

Treatment of posterior malleolar fractures by fixation with minimally invasive percutaneous cannulated screws

目的探讨经皮微创空心钉内固定治疗后踝骨折的操作技巧及疗效。方法2004年3月至2006年9月应用4．0mm钛质空心钉经皮内固定治疗18例合并后踝骨折患者，包括旋后外旋Ⅳ度14例，旋前外旋Ⅳ度4例。所有患者后踝骨折块大小在侧位X线片上均超过胫骨远端关节面的1／4，且移位程度大于2mm。术前常规进行踝关节螺旋CT检查，了解后踝骨折块大小、移位情况以及横断面主骨折线与踝关节水平线所成的角度。术中首先复位并固定外踝和内踝，根据术前CT情况选择术中导针的位置与方向，经皮微创空心钉固定后踝骨折。结果所有患者获得平均16、5个月（6～35个月）随访，后踝骨折均获得骨性愈合。按照美国足踝骨科协会（AOFAS）推荐的足踝评分：优11例，良5例，可1例，差1例，优良率为88．9％。结论经皮微创空心钉内固定是治疗后踝骨折较为理想的内固定方式，具有创伤小、固定可靠等优势；术前根据CT制定详细的术中计划，确保导针的位置及方向正确是手术成功的前提。

Objective To discuss clinical results and techniques of treatment of posterior malleolar fractures by fixation with minimally invasive percutaneous cannulated screws. Methods A total of 18 posterior malleolar fractures were treated with percutaneous cannulated screws （4.0 mm） between March 2004 and September 2006. According to Lauge-Hansen system, 14 were diagnosed as supination external rotation stage Ⅳ, and 4 as pronation external rotation stage Ⅳ. In all cases, the size of fragment exceeded 25% of the articular surface with displacement of more than 2 mm on the lateral radiograph. We studied the preoperative CT to determine the size of the posterior fragment, displacement and the angle between the bimalleolar axis and the major fracture line of the posterior malleolus. After ORIF of outer and medial malleoli, the posterior malleolus was treated by minimally invasive osteosynthesis. Results Follow-ups of 16. 5 （range, 6-35） months on average revealed that all cases healed. According to the Ankle Hindfoot Clinical Rating System of the American Orthopaedic Foot ＆ Ankle Society （AOFAS）, the results were rated as excellent in 11 cases, good in 5 cases, moderate in 1 case, and poor in 1 case, with the good-excellent rate being 88.9%. Conclusions Fixation with minimally invasive percutaneous cannulated screws is a good method with advantages of mini-invasion and rigid fixation. Careful preoperative plan according to CT scan is a prerequisite for good results.