平台髌骨角测量膝关节表面置换术髌骨高度的变化

目的研究平台髌骨角对于膝关节表面置换手术前后髌骨高度的准确性、可重现性，特点及不足，以及手术影响髌骨高度的变化因素。 方法选取吉林大学中日联谊医院骨科2015年1月到2016年1月资料完整的100例全膝关节置换术的患者作为研究样本，所有患者均为骨关节炎和类风湿性关节炎的病人，选取患者术前术后的膝关节侧位片，膝关节屈曲角度为30°。测量所选患者的术前术后膝关节侧位片平台髌骨角的。运用广泛使用的3种测定髌骨高度方法进行54例全膝关节置换患者手术前后侧位片的测量。3种方法为改良Black-burne-Peel指数，改良Caton-Desehamps指数和改良Insall-Salvati指数。由2名观察者使用标准的方法，独立的方式进行了524个数据的测量。对这2名观察者测量的数据进行组内相关系数(ICC)和95%可信区间的统计，对改良Black-burne-Peel指数，改良Caton-Desehamps指数、改良Insall-Salvati指数和平台髌骨角的术前术后数据进行配对t检验。 结果改良Insall-Salvati指数(术前ICC＝0.75；术后ICC＝0.87)、改良Black-burne-Peel指数(术前ICC＝0.65；术后ICC＝0.88)、改良Caton-Desehamps指数(术前ICC＝0.72；术后ICC＝0.88)和平台髌骨角(术前ICC＝0.86；术后ICC＝0.93)均具有更高的术后组内相关系数。其中，平台髌骨角的组内相关系数是最高的，患者术后的髌骨高度出现了降低。4种方法的术前术后数据比较显示，除了改良Insall-Salvati指数之外，改良Caton-Desehamps(t＝3.69)、改良Black-burne-Peel指数(t＝3.50)和平台髌骨角(t＝7.55)的测量均提示患者手术前后的髌骨高度差异具有统计学意义(均P<0.01)。 结论平台髌骨角在反应膝关节表面置换术的髌骨高度变化具有准确性、可重现性、直观、简洁、快速的优点，可以有效地评估膝关节表面置换术后患者髌骨高度的变化。

Meaning of plateau-patella angle for describing patellar height before and after total knee arthroplasity

ObjectiveTo study the accuracy, reproducibility, characteristics and defects of plateau-patella angle before and after total knee arthroplasity(TKA), and to discuss the factors that influence the patellar height. MethodsAll the samples’ resource were from the patients underwent total knee arthroplasty from Jan.2015 to Jan.2016, 100 case in department of orthopedic from China-Japan Union Hospital of Jilin University, and all patients are patients with osteoarthritis and rheumatoid arthritis. The plateau-patella angle was used to evaluate 100 patients’ radiographs before and after total knee arthroplasty. The preoperative and postoperative modified Black-burne-Peel ratio, modified Caton-Desehamps ratio and modified Insall-Salvati ratio of 54 patients on X ray were measured by two observers. Intraclass correlation coefficient was used to assess the reliability.The preoperative and postoperative data measured by these methods were analyzed by paired t test. ResultsAccording to ICC, the reproducibility of modified Insall-Salvati ratio and modified Black-burne-Peel ratio and modified Caton-Desehamps ratio increased in the postoperative measurements. The reproducibility was the highest for the mPPA (preop ICC=0.65; postop ICC=0.88) compared to the other methods.The results of these four methods showed significant differences in patellar height between pre-and post-operative data in modified Caton-Desehamps ratio (t =3.69, P<0.01), modified Black-burne-Peel ratio(t =3.50, P<0.01)and plateau-patella angle(t =7.55, P<0.01). ConclusionThe plateau-patella angle is highly accurate, reproducible, intuitive simple and rapid; Using plateau-patella angle can effectively evaluate the changes of patella height in patients with TKA.