The Meaning Of Plateau–Patella Angle For Describing Patellar Height Before And After Total Knee Arthroplasity

Objective :To study the accuracy,reproducibility,characteristics and defects of Plateau–Patella Angle Before And After Total Knee Arthroplasity,and to discuss the factors that influence the Patellar Height.Material and Methods:1.Clinical material All of samples' resource is the patients underwent the operation of 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 patient is between 50 and 68 years old,57 right knee,43 left knee,50 male,50 female,91 knee OA,9knee RA.3 patient with Severe flexion contracture deformity(>20°).2.Method The Plateau–Patella Angle was used to evaluate 100patients‘ radiographs before and after total knee arthroplasty.Measurements were made on the lateral radiograph with the knee in at least 30° of flexion.The preoperative and postoperative modifiedBlack-burne-Peel ratio,modified Caton-Desehamps ratio and modified Insall-Salvati ratio of 54 patients on X ray were measured by two observers.Results:The reproducibility ofmodified Insall-Salvati ratio and modified Black-burne-Peel ratio and modified Caton-Desehamps ratio was increased in the postoperative measurements.What's more,the reproducibility was the highest for the mPPA compared to the other methods.Conclusion:The Plateau–Patella Angle is highly accurate,reproducible,intuitive simple and rapid.What's more,the Plateau–Patella Angle is able to effectively evaluate the changes of patella height in patients with total knee arthroplasty.