Accuracy of femoral components sizing predicted by standardized digital templating in total knee arthroplasty
10.3760/cma.j.issn.0253-2352.2016.15.003
- VernacularTitle:依据标准化数字X线模板预测股骨假体型号的可行性
- Author:
Qing LIU
;
Yu ZHANG
;
Hui QIAO
;
Dongliang ZHANG
;
Qiang HE
;
Hejun SUN
;
Jixuan XIAO
- Publication Type:Journal Article
- Keywords:
Arthroplasty,replacement,knee;
Radiography;
Prostheses and implants;
Osteoarthritis
- From:
Chinese Journal of Orthopaedics
2016;36(15):964-973
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine the accuracy of femoral components sizing predicted by standardized digital templating in total knee arthroplasty (TKA).Methods Fifty consecutive patients (50 knees),who underwent primary TKAs for endstage 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 18％ 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 mm,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.
