儿童McFarland骨折术后踝内翻畸形的危险因素分析

Risk factors for varus ankle deformity after McFarland fracture surgery in children

目的分析儿童McFarland骨折术后踝内翻畸形的危险因素。方法回顾性分析2015年1月至2022年12月于福州市第二总医院接受手术治疗的McFarland骨折患儿48例,男24例、女24例,年龄(11.2±3.2)岁(范围2~14岁),左侧19例,右侧29例。Salter-Harris分型:Ⅲ型34例、Ⅳ型14例。受伤原因:运动损伤28例、摔伤15例、车祸伤5例。受伤至手术时间为(2.6±1.7)d(范围1~7d)。复位方式:闭合复位38例、切开复位10例,骨折初始移位为(5.1±1.8)mm(范围2~10mm)。腔骨内固定方式:空心螺钉42例、克氏针6例。合并排骨骨折30例,采用钢板固定20例、克氏针固定8例、未行内固定治疗2例。内固定存留时间为(6.4±2.8)个月(范围1~12个月)。采用胫骨远端外侧角(lateral distal tibial angle,LDTA)判断患儿是否出现踝关节内翻畸形。比较两组患儿的一般资料和围手术期指标,将差异有统计学意义的指标纳人二分类logistic回归分析,确定儿童McFarland骨折术后踝内翻畸形的独立危险因素。绘制受试者工作特征曲线,计算各独立危险因素的曲线下面积。结果所有患儿均顺利完成手术并获得随访,随访时间为(39.2±21.8)个月(范围15~98个月)。48例McFarland骨折患儿至末次随访时骨折均骨性愈合且内固定均顺利取出,其中5例发生踝内翻畸形。踝内翻畸形组患侧LDTA为98.6°±4.8°(范围94~106°),无踝内翻畸形组为89.0°±0.8°(范围87~91°)。踝内翻畸形组患儿年龄为(6.6±5.1)岁,小于无踝内翻畸形组的(11.7±2.5)岁,差异有统计学意义(t=3.772,P<0.001);踝内翻畸形组患儿内固定存留时间为(4.4±2.2)个月,小于无踝内翻畸形组的(6.6±2.8)个月,差异有统计学意义(t=1.750,P=0.087)。两组患儿的性别、侧别、致伤原因、骨折分型、初始移位距离、有无排骨骨折、受伤至手术时间、复位方式、固定方式的差异无统计学意义(P>0.05)。将年龄、内固定存留时间纳人二分类变量logistic回归分析,结果显示年龄(0R=0.717,95%CI:0.543,0.945,P=0.018)是导致儿童McFarland骨折术后踝内翻畸形的独立危险因素。绘制独立危险因素预测儿童McFarland骨折术后踝内翻畸形的受试者工作特征曲线并计算曲线下面积,结果显示年龄的最佳截断值为5.5岁、曲线下面积为0.807,预测模型的预测效能为良。结论仑年龄<5.5岁是儿童McFarland骨折术后踝内翻畸形的独立危险因素。

Objective To analyze the risk factors for ankle varus deformity after McFarland fracture surgery in children.Methods A total of 48 children with McFarland fracture who underwent surgical treatment in the Second General Hospital of Fuzhou from January 2015 to December 2022 were retrospectively analyzed,including 24 males and 24 females,aged 11.2±3.2 years(range,2-14 years),19 cases on the left side and 29 cases on the right side.Salter-Harris classification:34 cases of type Ⅲ and 14 cases of type Ⅳ.Causes of injuries:28 cases of sports injuries,15 cases of fall injuries,and 5 cases of car accident injuries.The time from injury to operation was 2.6±1.7 d(range,1-7 d).The reduction methods included closed reduction in 38 cases and open reduction in 10 cases.Tibial internal fixation:42 cases of hollow screws,6 cases of Kirschner pins.There were 30 cases of combined fibula fracture,20 cases were fixed with plate,8 cases were fixed with Kirschner's pin,and 2 cases were not treated with internal fixation.The internal fixation survival time was 6.4±2.8 months(range,1-12 months).The lateral distal tibial angle(LDTA)was used to determine whether the child had ankle varus deformity.The general data and perioperative indicators of the two groups were compared,and the indicators with statistically significant differences were included in binary logistic regression analysis to determine the independent risk factors for ankle varus deformity after McFarland fracture surgery in children.The receiver operating characteristic curve was drawn and the area under the curve of each independent risk factor was calculated.Results All patients successfully completed the operation and were followed up for 39.2±21.8 months(range,15-98 months).At the last followup,all the 48 children with McFarland fracture had bone union and the internal fixation was successfully removed,and 5 of them had ankle varus deformity.The LDTA of the affected side was 98.6°±4.8°(range,94°-106°)in the ankle varus deformity group and 89.0°±0.8°(range,870-910)in the non-ankle varus deformity group.The age of children in the ankle varus deformity group was 6.6+5.1 years,which was younger than that in the non-ankle varus deformity group(11.7±2.5 years),and the difference was statistically significant(t=3.772,P<0.001).The survival time of internal fixation in the ankle varus deformity group was 4.4±2.2 months,which was shorter than that in the non-ankle varus deformity group(6.6±2.8 months),and the difference was statistically significant(t=1.750,P=0.087).There was no significant difference in gender,side,cause of injury,fracture type,initial displacement distance,fibular fracture,time from injury to operation,reduction method,or fixation method between the two groups(P>0.05).Age and duration of internal fixation were included in binary logistic regression analysis.The results showed that age(OR=0.717,95%CI:0.543,0.945,P=0.018)was an independent risk factor for postoperative ankle varus deformity in children with Mc-Farland fracture.The receiver operating characteristic curve of independent risk factors predicting postoperative ankle varus deformity in children with McFarland fracture was drawn and the area under the curve was calculated.The results showed that the best cut-off value of age was 5.5 years,and the area under the curve was 0.807,and the prediction efficiency of the prediction model was good.Conclusion Age<5.5 years is an independent risk factor for postoperative varus ankle deformity in children with Mc-Farland fracture.