Malrotation following total knee replacement is directly related to poor outcome. The knowledge of proximal and distal rotational axes and angles of the femur is therefore of high importance. The aim of the study was to determine whether the most used proximal and distal femoral angles; femoral anteversion angle (FAA) and posterior condylar angle (PCA) were different within individuals, between right, left and gender. As well, we studied whether the “inferior condylar angle” is correlated to the PCA and therefore useful in determining the rotation of the distal femur. From 36 cadavers the femora were obtained and after removing the soft tissue a Computed Tomography (CT) scan was made. Three angles were measured: (i) the FAA between femoral columnar line (FHNL) and posterior condylar line (PCL), (ii) the PCA between anatomical transepicondylar line (TEL) and PCL, (iii) the inferior condylar angle (ICA) between the TEL and inferior condylar line (ICL). Statistical analysis of comparative relationships between the different angles was examined by calculating correlation coefficients and a paired t-test.Introduction
Material and Methods
The Kaplan Meier estimator is widely used in orthopedics. In situations where another event prevents the occurrence of the event of interest, the Kaplan Meier estimator is not appropriate and a competing risks model has to be applied. We questioned how much bias is introduced by erroneous use of the Kaplan Meier estimator instead of a competing risks model in a hip revision surgery cohort. In our previously published cohort study, 62 acetabular revisions (58 patients) were performed between January 1979 and March 1986. Twenty to twenty-five years after surgery, no patients were lost to follow-up. Thirteen patients underwent revision surgery. During the 20 to 25 years follow-up, 30 patients (33 acetabular revisions) died of causes unrelated to their hip surgery.Introduction
Methods
