开放性胫骨骨折外支架二期更换为内固定的安全性研究

Safety evaluation of secondary conversion from external fixation to internal fixation for open tibia fractures

目的评估开放性胫骨骨折自外支架更换为内固定的安全性。方法回顾分析2010年1月—2014年12月收治并符合选择标准的94例(98侧患肢)以外支架为初期固定手段的开放性胫骨骨折患者资料。其中29例(31侧患肢)由于患者主观不适、钉道反应、Schantz针松动及延迟愈合或不愈合等原因,在伤口愈合及红细胞沉降率(erythrocyte sedimentation rate,ESR)、C反应蛋白(C reactive protein,CRP)、白细胞绝对计数及中性粒细胞比例降至正常或接近正常范围后,更换为内固定(试验组);65例(67侧患肢)未更换为内固定(对照组)。两组患者性别、年龄、侧别、受伤至第1次清创时间、初始病原菌类型、接受植皮或皮瓣移位修复肢体数等一般资料比较,差异均无统计学意义(P>0.05);但对照组GustiloⅢ型患者比例明显高于试验组,两组骨折分型比较差异有统计学意义(P=0.000)。计算两组患者总体感染发生率;分别比较两组不同骨折分型患者以及接受过植皮或皮瓣移位手术患者的感染发生率;记录感染患者病原菌信息,并与初始病原菌进行比较;记录试验组患者使用不同内固定物发生感染情况。结果试验组和对照组总体感染发生率分别为9.7%(3/31)和9.0%(6/67),比较差异无统计学意义(χ2=0.013,P=0.909)。Ⅰ、Ⅱ型患者均未发生感染;试验组和对照组ⅢA型患者感染发生率分别为14.3%(1/7)和6.3%(2/32),ⅢB型分别为50.0%(2/4)和14.3%(2/14),ⅢC型分别为0和16.7%(2/12),比较差异均无统计学意义(χ2=0.509,P=0.476;χ2=2.168,P=0.141;χ2=0.361,P=0.548)。发生感染的患肢中,仅试验组1侧金黄色葡萄球菌与术前原始致病菌一致。接受植皮或皮瓣移位手术的患者中,试验组和对照组感染发生率分别为33.3%(2/6)和13.3%(2/15),比较差异无统计学意义(χ2=1.059,P=0.303)。试验组更换为内固定后,采用髓内钉者(11侧)无1例发生感染,而采用钢板(20侧)的患者中4侧发生感染,感染发生率为20%。结论多数情况下,开放性胫骨骨折患者自外支架更换为内固定是安全的。但针对初始创伤伴广泛而严重软组织损伤者,特别是GustiloⅢ型骨折且通过皮瓣或植皮修复获得创面愈合者,术前必须仔细评估患者软组织条件,谨慎选择内固定物类型,术中对软组织进行精细保护。

Objective To evaluate the safety of conversion from external fixation to internal fixation for open tibia fractures. Methods Between January 2010 and December 2014, 94 patients （98 limbs） with open tibia fractures were initially treated with external fixators at the first stage, and the clinical data were retrospectively analyzed. In 29 cases （31 limbs）, the external fixators were changed to internal fixation for discomfort, pin tract response, Schantz pin loosening, delayed union or non-union after complete wound healing and normal or close to normal levels of erythrocyte sedimentation rate （ESR）, C reactive protein （CRP）, and the leucocyte count as well as the neutrophil ratio （trial group）; in 65 cases （67 limbs）, the external fixators were used as the ultimate treatment in the control group. There was no significant difference in gender, age, side of the limbs, interval from injury to the first debridement, initial pathogenic bacteria,the limbs that skin grafting or flap transferring for skin and soft tissue defect between the two groups （P〉0.05）. The incidence of Gustilo type III fractures in the control group was significantly higher than that in the trial group （P=0.000）. The overall incidence of infection was calculated respectively in the two groups. The incidence of infection according to different fracture types and whether skin grafting or flap transferring was compared between the two groups. The information of the pathogenic bacteria was recorded in the infected patients, and it was compared with the results of the initial culture. The incidence of infection in the patients of the trial group using different internal fixation instruments was recorded. Results The overall incidences of infection for the trial and control groups were 9.7% （3/31） and 9.0% （6/67） respectively, showing no significant difference （X2=0.013, P=0.909）. No infection occurred in Gustilo type I and type II patients. The incidence of infection for Gustilo type IIIA patients in the trial group and the control group were 14.3% （1/7） and 6.3% （2/32） respectively, showing no significant difference （x^2=0.509, P=0.476）; the incidence of infection for type IIIB patients in the two groups were 50.0% （2/4） and 14.3% （2/14） respectively, showing no significant difference （x^2=2.168, P=0.141）; and the incidence of infection for type IIIC patients in the two groups were 0 and 16.7% （2/12） respectively, showing no significant difference （x^2=0.361, P=0.548）. Of all the infected limbs, only 1 limb in the trial group had the same Staphylococcus Aureus as the result of the initial culture. In the patients who underwent skin grafting or flap transferring, the incidence of infection in the trial and control groups were 33.3% （2/6） and 13.3% （2/15） respectively, showing no significant difference （X2=1.059, P=0.303）. After conversion to internal fixation, no infection occurred in the cases that fixed with nails （11 limbs）, and infection occurred in 4 of 20 limbs that fixed with plates, with an incidence of infection of 20%. Conclusion Conversion from external fixation to internal fixation for open tibia fractures is safe in most cases. However, for open tibia fractures with extensive and severe soft tissue injury, especially Gustilo type III patients who achieved wound heal after flap transfer or skin grafting, the choice of secondary conversion to internal fixation should carried out cautiously. Careful pre-operative evaluation of soft tissue status, cautious choice of fixation instrument and meticulous intra-operative soft tissue protection are essential for its safety.