3-D打印技术辅助经皮撬拨空心钉内固定治疗移位的跟骨关节内骨折

Application of three-dimensional printing technology for closed reduction and percutaneous cannulated screws fixation of displaced intraarticular calcaneus fractures

目的探讨3-D打印技术辅助经皮撬拨复位空心钉内固定治疗移位的跟骨关节内骨折的临床疗效。方法回顾分析2015年3月—2016年5月收治的移位的跟骨关节内骨折19例(19足),其中男13例,女6例;年龄24~73岁,平均38.2岁。开放性骨折3例,闭合性骨折16例。根据跟骨骨折Sanders分型:Ⅱ型12例,Ⅲ型7例;根据跟骨骨折Essex-Lopresti分型:舌型13例,关节压缩型6例。受伤至手术时间1~10 d,平均4.7 d。术前行双侧跟骨薄层CT扫描,计算机辅助镜面成像技术对健侧跟骨镜像处理,按1∶1比例打印出健侧镜像及患侧跟骨模型,对比观察骨折块的移位情况,模拟撬拨复位。跟骨骨折均采用经皮斯氏针撬拨复位空心螺钉内固定治疗。在X线片上测量术后即刻及末次随访时B?hler角和Gissane角,并与术前比较;采用美国矫形足踝协会(AOFAS)踝与后足评分系统评价患足术后功能。结果手术时间25~70 min,平均45 min;术中出血量10~40 mL,平均14.5 m L。术后患者切口均Ⅰ期愈合,无皮肤坏死、钉道感染、骨髓炎等并发症发生。19例患者术后获12~25个月(平均14.6个月)随访。患者骨折均获愈合,愈合时间8~14周,平均10.3周。随访期间无螺钉退出、断裂发生;除1例SandersⅡ型骨折患者术后6周跟骨高度部分丢失外,其余患者无复位丢失及骨折再移位,无创伤性关节炎发生。术后即刻及末次随访时B?hler角和Gissane角均较术前显著改善(P<0.05),术后即刻与末次随访时比较差异无统计学意义(P>0.05)。末次随访时AOFAS踝与后足评分为76~100分,平均88.2分,其中优10足、良7足、可2足,优良率89.5%。结论 3-D打印技术辅助经皮撬拨复位空心钉内固定治疗跟骨关节内骨折,减少了手术创伤,提高了复位质量及固定强度,使手术方案更安全、精确、个体化。

Objective To evaluate the effectiveness of three-dimensional（3-D） printing assisting minimally invasive for intraarticular calcaneal fractures with percutaneous poking reduction and cannulate screw fixation.Methods A retrospective analysis was performed of the 19 patients（19 feet） with intraarticular calcaneal fracture who had been treated between March 2015 and May 2016. There were 13 males and 6 females with an average age of 38.2 years（range, 24-73 years）. There were 3 open fractures and 16 closed fractures. By Sanders classification, 12 cases were type Ⅱ,7 cases were type Ⅲ. By Essex-Lopresti classification, 13 cases were tongue type, 6 cases were joint-depression type. The time from injury to surgery was 1-10 days（mean, 4.7 days）. A thin slice CT scan was taken of bilateral calcaneus in patients. By using the mirror imaging technique, the contralateral mirror image and the affected side calcaneus model were printed according to 1∶1 ratio. The displacement of fracture block was observed and contrasted, and the poking reduction was simulated. Calcaneal fracture was treated by percutaneous minimally invasive poking reduction and c annulate screw fixation. The B？hler angle and Gissane angle at immediate after operation and last follow-up wasmeasured on X-ray films, and compared with preoperative measurement. The functional recovery was evaluated by American Orthopaedic Foot and Ankle Society（AOFAS） scores. Results The operation time was 25-70 minutes（mean,45 minutes）. The intraoperative blood loss was 10-40 m L（mean, 14.5 m L）. All the incisions healed by first intention and had no relevant postoperative complications such as skin necrosis, nail tract infection, and osteomyelitis. All the patients were followed up 12-25 months（mean, 14.6 months）. All patients obtained fracture healing, and the fracture healing time was 8-14 weeks（mean, 10.3 weeks）. No screw withdrawal or breakage occurred during follow-up; only 1 patient with Sanders type Ⅱ fracture, whose calcaneus height was partially lost at 6 weeks after operation, the other patients had no reduction loss and fracture displacement, and no traumatic arthritis occurred. The B？hler angle and Gissane angle at immediate after operation and last follow-up were significantly improved when compared with preoperative ones（P0.05）, but there was no significant difference between at immediate after operation and last follow-up（P0.05）. The AOFAS score was 76-100（mean, 88.2）, and the results were excellent in 10 feet, good in 7, and fair in 2, the excellent and good rate was 89.5%. Conclusion 3-D printing assisting minimally invasive for intraarticular calcaneal fractures with percutaneous poking reduction and cannulate screw fixation can reduce the surgical trauma, improve the quality of reduction and fixation, and make the operation more safe, accurate, and individualized.