Related Experiment Video
Updated: Aug 16, 2025
Three-Dimensional Preoperative Virtual Planning in Derotational Proximal Femoral Osteotomy
Published on: February 17, 2023
In slope-changing osteotomy one millimeter is not one degree: results of an artificial intelligence-automated
Chia Zi Yang1, Mohammed Anter Abdelhameed2, Bandar Nasser AlMaeen3
1Department of Orthopaedic Surgery, Singapore General Hospital, 20 College Road, Academia Level 4, Singapore, 169856, Singapore.
Background:
Anterior closing wedge osteotomies (ACWO) are performed in revision anterior cruciate ligament (ACL) surgery to correct an excessive posterior tibial slope (PTS).
Purpose:
With the help of automated planning software, this study investigates the assumption that 1mm of wedge height gives 1° of slope correction (1:1).
Methods:
Fifty patients underwent ACWO, with the wedge height calculated using the 1:1 formula. Pre- and postosteotomy PTS were measured manually, and the achieved post-operative PTS was compared with the target PTS of 5.3° ± 1.9. The X-ray analysis was repeated virtually with the automated software, which also recommended a resection height. These parameters were then compared with the manually obtained parameters.
Results:
Using a 1:1 formula, wedge heights of 8.5mm ± 2.3 was resected to achieve a PTS of 4.2° ± 0.32. This showed an overcorrection of 1.6° ± 0.8 from the target slope. This was consistent with the data from the automated software, which recommended a lower wedge height of 7.7mm ± 2.9.
Conclusion:
In trans-tubercle ACW, using a wedge height (mm) to slope correction (°) ratio of 1:1 can lead to slight over-correction. Automated software planning is useful for planning correction osteotomies in the sagittal plane.
