Comparison of Two-Dimensional and Three-Dimensional Preoperative Planning Measurements for High Tibial Osteotomy

Knee osteoarthritis (KOA) is a prevalent condition characterized by cartilage degeneration, tissue destruction, and bone hyperplasia, with pain being the primary symptom. High tibial osteotomy (HTO) has emerged as an effective treatment for symptomatic unicompartmental KOA, focusing on realigning force vectors to redistribute mechanical stress and alleviate pain. This study aims to address the question of whether two-dimensional (2D) and three-dimensional (3D) preoperative planning methods yield different correction angles and distraction distances in open-wedge high tibial osteotomy (OWHTO). By comparing these methodologies, we seek to evaluate their impact on surgical outcomes and patient prognosis.

A retrospective analysis was conducted involving patients diagnosed with unicompartmental medial knee osteoarthritis (KOA) who exhibited deviations in the mechanical axis of the lower limbs. These patients underwent OWHTO between January 2021 and August 2022. Both 3D and 2D preoperative planning procedures for OWHTO were employed, targeting an ideal alignment with the weight-bearing line (%WBL) set at 62.5%. The study quantitatively assessed the differences in correction angles and distraction distances associated with the two surgical planning methods using paired t-tests and non-parametric Wilcoxon signed-rank tests.

The study comprised a total of 102 patients. It was observed that the mean correction angle in the 2D approach was significantly greater than that recorded in the 3D approach (p < 0.001), with an average difference of 1.49° ± 1.70°. The medial opening gap differences for OWHTO between the two approaches measured 2.1 ± 2.06 mm.

To summarize, the 2D preoperative planning method for OWHTO necessitates a larger correction angle and a wider medial opening gap relative to the 3D planning approach when aiming for the same WBL. Therefore, it is crucial for surgeons to take into account the variances between 2D and 3D planning and to evaluate potential correction errors during the surgical procedure while strategizing for OWHTO.