THREE DIMENSIONAL LINEAR MEASUREMENT OF PROXIMAL TIBIA IN MEDIAL AND LATERAL APPROACH FOR BONE HARVESTING

Purpose : The aim of this study was simply assessing linear measurements in the lateral and medial approach, respectively, for bone harvesting using anatomic and three-dimensional (3D) computed tomographic (CT) analyses on a dried cadaveric proximal tibia. In addition, the availability of the three-dimensional computed tomographic (3D-CT) analysis was also estimated. Materials and methods : Ten dried proximal tibia were obtained from five Korean cadavers. Four the reference points, the SM (superior-medial), IM (inferior-medial), SL (superior-lateral), and IL (inferior-lateral) were marked around the tibial tuberosity. The PM (posterior-medial) and PL (posterior-lateral) points were randomly marked at points farthest from the lateral and medial reference points, respectively, in the posterior border of the superior articular surface of both condyles. All measurements were obtained on the dried proximal tibia. After computed tomography had been performed, the three dimensional images were reconstructed using V works 4.0 (TM) (Cybermed Inc., Seoul, Korea), and the length between the reference points were measured three dimensionally using the method described above. The error between the mean actual and mean 3D-CT measurements was calculated in order to determine the availability of the three dimensional computed tomographic analysis. Results : The length between the reference points was greatest at the IL-PM, which averaged 65.39 mm +/- 10.35. This was followed by the SL-PM with 63.24 mm +/- 8.10, the IM-PL with 58.09 mm +/- 10.02, and the SM-PL with 51.99 mm +/- 9.06. The differences between the IL-PM and SM-PL were 13.4 mm. The mean values were 55.04 mm in the medial approach and 64.32 mm in the lateral approach, and the differences between medial and lateral were 9.28 mm. The error between the mean actual and mean 3D-CT measurements was 0.31% and the standard deviation was 0.28%. Conclusion : The anatomical and three dimensional computed tomographic analysis indicates that there was only a 9.28 mm linear difference between the lateral and medial approach. This is consistent with previous studies, which showed that there was little difference between the two approaches in terms of the bone volume. In addition, the error (0.31%) and the standard deviation (0.28%) were considered low, demonstrating high accuracy of 3D-CT. Therefore it can be used in preoperative treatment planning.