Analysis of difference in posterior slope angle between intra-operation and post-operation of total knee arthroplasty

Objective To analyze the difference of posterior slope angle between intra-operation and post-operation of total knee arthroplasty (TKA) and provide a theoretical basis for adjusting the posterior slope angle. Methods Clinical data about 44 patients with TKA in Chinese PLA General Hospital from June 1 to September 2 in 2013 were collected. Patients were divided into two groups: cruciate-retaining group (n=22, 33 knees) and posterior-stabilized group (n=22, 31 knees) according to the difference of the prosthesis. The difference between posterior slope angle of intra-operation and post-operation were analyzed. Results In the cruciate-retaining group, the posterior slope angle of post-operation was 5.73°±2.81° greater than that of intra-operation (P=0.00); In the posterior-stabilized group, the posterior slope angle of post-operation was 1.66°±1.43° greater than that of intra-operation (P=0.00). Conclusion In the cruciate-retaining group, the posterior slope angle of post-operation is much smaller than that of intraoperation, which indicating that there is no need to adjust the posterior slope angle of intra-operation when it is too small. However, although there shows statistical difference of posterior slope angle between post-operation and intra-operation, the gap is not big, so we can predict the posterior slope angle of post-operation according to that of intra-operation.