Correlation Between Mediolateral/Anteroposterior Diameter Of Knee Joint And The Type Of Prosthesis

Bacteround:Total knee arthroplasty has been widely used in China as the most effective treatment in serious knee osteoarthritis.However,prosthesis mismatches often occur when using imported knee prosthesis based on anatomical data of Caucasian.Patient will feel pain when the prosthesis is too large.It will increase the risk of loosening of prosthesis if prosthesis is too small.It is an important role for TKA about how to forecast the appropriate types of prosthesis.Therefore,it is necessary to conduct some research and analysis on some commonly used imported knee prostheses existing in the market,according to the patienfs preoperative examination,and provide a method for guiding the prediction of prosthesis type.Materials and methodsPerformed the TKA for knee osteoarthritis or rheumatoid knee osteoarthritis in our hospital from September 2016 to December 2018 was researched.Inclusion criteria:CDmeet the diagnostic criteria for knee osteoarthritis determined by the Chinese Osteoarthritis Guidelines(2015 edition);?patients have standard X-ray films of the knee joints taken in our hospital;?age,gender,height not limited;?patients with knee prosthesis for the narrow type A or wide type B;?primary total knee arthroplasty.Exclusion criteria:?patient with distal femur or proximal tibia with severe deformity or bone defect;?knee osteophytes hyperplasia,measurement of the diameter is difficult;?knee joint radiograph is not standard,measuring diameter have some errors;?prosthesis mismatches obviously.Preoperative knee femoral and tibial radial lines were measured using imaging software.Statistical analysis was performed based on the measured data 'and the type of prosthesis recorded during the surgery.ResultA total of 123 patients were included in the study,including 39 males and 84 females,37 narrow type A prostheses,and 86 wide type B prostheses.The femoral mediolateral diameter was 84.02±6.357mm,the femoral anteroposterior diameter was 62.20±4.469mm,the tibial mediolateral diameter was 78.11 ±4.987mm,and the tibial anteroposterior diameter was 54.11±4.244mm.Compared with women,men's knees are usually larger,the distal femur is flatter,and there is no significant difference in the ratio oftML/tAP.The choice of knee prosthesis is mainly related to the anatomy of the femoral of the knee.There was no statistically significant in the tibia.When fML/fAP is near to 1.36±0.075,it is more appropriate to choose a wide type B prosthesis,and when fML/fAP is near to 1.32±0.059,it is more appropriate to choose a narrow type A prosthesis.The wide type B prosthesis is more relevant to fML and tML.The narrow type A prosthesis is more relevant to fAP and tAP.ConclusionCompared with women,the male knee joint usually has a larger mediolateral and anteroposterior diameter of the femur and tibia,and fML/fAP.The choice of knee prosthesis i5 mainly related to the anatomy of the distal femur.When fML/fAP is near to1.36±0.075(1.34-1.40),it is more appropriate to choose the wide type B prosthesis.When fML/fAP is near to 1.32±0.059(1.30-1.34),it is more appropriate to choose the narrow type A prosthesis.