PurposeThe purpose of this study was to analyze the influence of rotational alignment of the femoral and patellar components on patellar tilt after total knee arthroplasty (TKA).Materials and MethodsA total of 56 patients (76 knees) who underwent TKA using Advance Medial Pivot Knee system between May 2009 and April 2011 and were available for minimum 1-year follow-up were enrolled in this study. Whiteside's line and the transepicondylar line were used to determine the rotational alignment of the femoral component. Patella cut was aimed to be parallel to the anterior patellar cortex during surgery. Radiographic evaluation was performed using plain axial radiographs. The rotational alignment of the femoral component was measured as the angle between the anterior condylar axis and the surgical transepicondylar axis. The patellar resection angle was measured between the patellar resection axis and the anterior cortical line of the patella. Patellar tilt was evaluated to investigate the correlation with the rotation of the femoral component and patellar resection angle.ResultsThe mean rotation of the femoral component was 0.42°±3.18° of internal rotation. The mean patellar resection angle was 1.82°±3.44°, indicating medial overresection. The mean patellar tilt was 6.12°±4.31° of lateral tilt. The rotational angle of the femoral component showed a negative correlation with patellar tilt in the linear regression analysis (p=0.749), but the patellar resection angle showed a positive correlation with patellar tilt (p<0.001).ConclusionsAccurate patellar resection is recommended for proper patellar tracking in TKA.

PurposeTo analyze minimum 2-year clinical and radiological follow-up results of primary total knee replacement arthroplasty (TKRA) with metal block augmentation for tibial bony defect.Materials and MethodsWe analyzed 67 cases (52 patients) of primary TKRA with metal block augmentation for tibial bony defects from March 1999 and March 2008. Clinical results were evaluated using the Knee Society clinical rating system and the Western Ontario and McMaster University (WOMAC) score. Radiologic results were evaluated using the Knee Society roentgenographic evaluation system.ResultsThe mean knee score and function score improved from 42.0 and 45.6 preoperatively to 94.5 and 85.4 postoperatively. At last follow-up, the mean WOMAC score was 16.8. The incidence of radiolucent lines was 10% (7 cases) during the follow-up period, but there was no case of progression. There were no statistically significant differences between the groups divided according to the block size (below 5 mm and over 8 mm) and between the stem and no-stem groups for all parameters.ConclusionsPrimary TKRA with a metal block produced satisfactory results for the minimum 2-year follow-up and can be considered as a simple and effective method for the treatment of tibial bony defect in primary TKRA.