依据标准化数字X线模板预测股骨假体型号的可行性  

Accuracy of femoral components sizing predicted by standardized digital templating in total knee arthroplasty

作　　者：刘青[1] 张宇[2] 乔辉[3] 张东亮[4] 贺强[5] 孙和军[4] 肖继萱 

机构地区：[1]天津市北辰医院放射科,300400 [2]天津中医药大学第一附属医院骨科,300381 [3]天津市人民医院放射科,300121 [4]天津市人民医院关节外科,300121 [5]天津市北辰医院关节外科,300400

出　　处：《中华骨科杂志》2016年第15期964-973,共10页Chinese Journal of Orthopaedics

基　　金：天津市卫生局科技基金（2012KZ045,2014KZ057）

摘　　要：目的探讨标准化数字X线模板预测全膝关节置换股骨假体型号的精确性。方法2014年1月至2015年12月，使用Vanguard髁间开放式高屈曲后稳定型假体对50例骨关节炎患者行单侧全膝关节置换术。以直径25mm的金属球作为放大倍率标尺、在透视监视下摄手术前后膝关节标准正侧位X线片。在术前MRI图像中测量股骨后内侧髁软骨厚度。借助Orthosize在线模板测量系统，于术前X线图像上分别以两种方法测量股骨远端前后径：不包括或包括后内侧髁软骨厚度，并预测可能的股骨假体型号；在术后标准侧位x线片中逐步校正各种截骨误差，分别测量每一步校正后的股骨远端前后径并据此重新选择相应的股骨假体型号。比较两组预测术中使用型号及每一步校正后假体型号的准确率。结果在截骨操作误差逐步校正的过程中，不包括软骨厚度组股骨假体型号预测的完全一致率为18％-44％、包括软骨厚度组为26％-34％；预测值（0±1）号的一致率两组分别为54％-84％、58％-84％。后内侧髁软骨厚度、股骨假体外旋、前髁截骨量不足、股骨假体屈曲、后髁截骨量过多分别使股骨远端前后径改变（1．97±0．85）mm、（1．56±2．06）mm、（1．15±1．31）mm、（-2．86±1．52）mm及（-0．87±0．77）mm。不包括软骨厚度组预测值与各种可能使用型号之间的差异为（0±4）号，包括软骨厚度组为（O±3）号。结论后内侧软骨厚度及各种术中截骨误差均可在不同程度上影响预测股骨假体型号的精确性。标准化X线数字模板技术不能准确预测TKA术中的股骨假体型号。Objective To determine the accuracy of femoral components sizing predicted by standardized digital ternplating in total knee arthroplasty （TKA）. Methods Fifty consecutive patients （50 knees）, who underwent primary TKAs for end- stage osteoarthritis, were prospectively studied. The intra-operative and radiographic data were collected. All operations were performed by the same surgical techniques with PS type, open box Vanguard Complete Knee System. All patients underwent lateral and AP radiography of the involved knee under fluoroscopy before and after surgery. The distal femoral anteroposterior dimension （DFAP） were measured and the femoral components size were predicted on preoperative radiographs by two different methods： measurement of DFAP did not include （group A） the cartilage thickness of the medial posterior condyle or included that （group B）. Cutting errors were corrected gradually, and DFAP was measured consequently. The most appropriate size was chose after each step respectively based on postoperative radiographs. The accuracy of femoral size predicted under different conditions was compared within two groups. Results During correction of cutting errors, the correct rate ranged from t 8% to 44% in group A and from 26% to 34% in group B, the accuracy within one size ranged from 54% to 84% in group A and from 58% to 84% in group B. The cartilage thickness of medial posterior condylar, external rotation of femoral component, under-resected of anterior condylar, flexion of femoral component, and over-resected of posterior condylar can change the DFAP by 1.97±0.85 ram, 1.56±2.06 mm, 1.15±1.31 mm,-2.86±1.52 mm, and -0.87±0.77 mm, respectively. Conclusion Variation of intraoperative cutting errors and the cartilage thickness of medial posterior condyles can influence the accuracy of templating to some extent. Standardized digital radiography templating cannot predict femoral sizes accurately.

关 键 词：关节成形术 置换 膝 放射摄影术 假体和植入物 骨关节炎 

分 类 号：R687.4[医药卫生—骨科学] R816.8[医药卫生—外科学]