Inverted V-Shaped High Tibial Osteotomy Decreases the Posterior Tibial Slope More but Shortens the Tibia Less Than Closed-Wedge High Tibial Osteotomy

Abstract

To assess the postoperative anatomical changes in the lower extremity after inverted V-shaped high tibial osteotomy (IVHTO) using 3-dimensional (3D) computed tomography (CT) bone models and compare those changes after closed-wedge high tibial osteotomy (CWHTO). Preoperative and 3-week postoperative CT scanning of the lower extremity were obtained from patients who underwent IVHTO and CWHTO between October 2019 and March 2021. 3D CT bone models were reconstructed using ZedKnee software. The postoperative changes (Δ) in (1) posterior tibial slope (PTS), (2) knee rotation angle (KRA), (3) tibial torsional angle (TTA), (4) patella tilt (PT), (5) Insall-Salvati ratio (ISR), and (6) tibial length (TL) were compared between IVHTO and CWHTO. Thirty-seven knees (18 IVHTO and 19 CWHTO) in 34 patients were retrospectively enrolled in this study. ΔPTS at the medial and lateral tibial plateau in the IVHTO group (-6.5° and -5.0°) was larger compared with that in the CWHTO group (-3.3° and -2.0°; P=.024 and P= .002, respectively). No significant differences exist between the IVHTO and CWHTO groups in ΔKRA (0.8± 4.5° and -1.5 ± 6.5°; P= 0.631), ΔTTA (-3.9 ± 6.2° and -4.1 ± 7.3°; P= .951), ΔPT (-2.0 ± 4.8° and -0.6 ± 4.1°; P=.353), and ΔISR (0.0 and 0.0; P= .829). ΔTL in the IVHTO group (-1.6 ± 2.3 mm) was smaller compared with that in the CWHTO group (-4.1 ± 1.6 mm; P < .001). (1) The postoperative PTS in the IVHTO group was further decreased compared to the CWHTO group; (2) no significant differences in ΔKRA, ΔTTA, ΔPT, and ΔISR exist between the 2 groups; and (3) the ΔTL in the IVHTO group was significantly smaller compared with the CWHTO group. Level III, retrospective cohort study.