The accuracy of two different extra-medullary tibial cutting guides for posterior tibial slope in total knee arthroplasty.

Abstract

This study aims to evaluate the effectiveness of two different external tibial cutting guides with and without a spike anchoring to the intercondylar eminentia to achieve a desired posterior tibial slope. Between January 2008 and December 2011, 120 posterior cruciate ligament protecting total knee arthroplasty (TKA) surgeries of 83 patients in which two different external tibial cutting guides used were included. Fifty-nine knees were included into the spiked and 61 knees were included into the spikeless cutting guide group. Posterior tibial slope angles were measured using the postoperative X-rays. There was no significant difference between two groups in terms of age, sex, and body mass indexes (p<0.05). While the mean postoperative slope angle was 2.66°±2.001°(range 0°-7°) in spiked group, it was 2.46°±2.277° (range 0°-7°) in spikeless group. Both systems had identical accuracy, indicating a low rate. The comparison of variances of two groups showed that both cutting guides had similar precision (p=0.234). There was no effect of body mass index on the results in both groups. Although different extra-medullary tibial cutting guides with and without a spike can reproducibly impart a desired posterior tibial slope in TKA, we concluded that a spiked guide was considered user-friendly.