[Radiological analysis of sagittal and torsional changes in the tibia following a medial open wedge high tibial osteotomy].

To investigate the sagittal and torsional changes in the tibia after a medial open wedge high tibial osteotomy (OWHTO) and their correlation with the corrective angle of proximal tibial coronal plane. A prospective analysis was conducted on patients who underwent OWHTO at Department of Orthopaedic Surgery, Beijing Chaoyang Emergency Medical Center from March 2019 to July 2019.The operation were performed by the same surgeon. X-ray and CT were performed before and 3 days after the operation. The mechanical axis angle (mFTA), medial proximal tibial angle (MPTA), posterior tibial slope (PTS) and tibial torsion angle (TTA) were measured and compared by paired -test. Pearson correlation coefficient was used to analyze the correlation between the changes of PTS and TTA and the correction angle of MPTA. A total of 13 patients (19 knees) were recruited. There were 9 males (13 knees) and 4 females (6 knees), aged (39.4±14.4) years (range:20 to 60 years). The mFTA improved from (8.1±2.8) degrees preoperatively to (-1.4±1.6) degrees postoperatively (14.819, 0.000). The MPTA was changed from (81.1±2.4) degrees pre-operatively to (90.4±3.4) degrees postoperatively (-15.579, 0.000). The PTS decreased from (79.6±3.2) degrees to (76.8±3.1) degrees (9.709, 0.000). The differences of mFTA, MPTA and PTS were statistically significant. There was no significant difference in TTA between before and after operation ((28.2±1.5) ° . (27.3±6.3) °,1.925, 0.070). There was no correlation between the correction angle of MPTA and the change of PTS and TTA (0.384, 0.105; 0.321, 0.181). Even if the intra-operative measures were used to control tibial slope, the PTS still increased significantly after OWHTO, while the TTA has no significant change. No correlation was seen between the change of sagittal and torsional and the corrective angle of proximal tibial coronal plane.