Effect of the rotation angle of femoral prosthesis on the knee joint function after total knee arthroplasty: a 3-year follow-up

Xie Jun; Liu Wei; Yuan Feng-lai

doi:10.3969/j.issn.2095-4344.2017.27.004

Abstract：BACKGROUND: Femoral prosthesis malrotation will lead to various complications, such as femoro-tibial and patellofemoral instability, and maladjustment of patellar movement trajectory, further affecting the recovery of the knee function.OBJECTIVE: To evaluate the influence of the rotation angle of the femoral prosthesis on the knee joint function after total knee arthroplasty (TKA).METHODS: Totally 146 patients (186 knees) undergoing TKA in the Department of Joint Surgery, Zhenjiang First People's Hospital from January 2010 to January 2014 were selected. Afterwards, the femoral condyle torsion angle was measured on CT to evaluate the rotational position of the femoral prosthesis. According to the condyle torsion angle, all the patients were divided into three groups: normal group (n=74, extorsion angle 3°-intorsion angle 3°), intorsion group (n=15, intorsion angle > 3°) and group (n=58, extorsion angle > 3°). All the patients were followed up for 3 years.RESULTS AND CONCLUSION: (1) The order of the activity function score was as follows: the normal group > extorsion group > intorsion group (P < 0.05). The standard activity, free activity and senior activity scores were highest in the normal group, followed by the extorsion group, and lowest in the intorsion group (P < 0.05). However, the standing and walking scores, as well as the satisfaction and expected scores did not differ significantly among groups. (2) That is to say, the rotational position of the femoral prosthesis influences the long-term knee joint function after TKA, so we should pay attention to the femoral prosthesis malrotation.