A new three‐dimensional patient‐specific cutting guide for opening wedge high tibial osteotomy based on ct scan: preliminary in vitro results

Abstract

Purpose The aim of this study was to evaluate the accuracy of a patient-specific cutting guide on both coronal and sagittal alignment compared to the pre-operative planning in OWHTO. Methods Twelve OWHTO on 6 cadaveric specimens were performed by 3 experienced knee surgeons using patient-specific cutting guides based on 3D pre-operative planning. Since the specimens had no major deformities, a fixed correction of 6° on the left and 10° on the right legs were carried out to simulate different scenarios. A pre-operative and post-OWHTO 3D CT scans were performed, and images were superimposed using the dedicated 3D planning software to align their reference axes. A pre-operative planning was performed considering both Medial Proximal Tibial Angle (MPTA) and Posterior Tibial Slope (PTS), and a patient-specific cutting guide was produced. Planned and post-OWHTO MPTA and PTS were evaluated (mean and standard deviation), and Pearson’s correlation coefficient was calculated to assess precision and accuracy of the whole treatment. Results A mean correction of 6,1° (SD 1,9°) and 1,2° (SD 1°) was obtained respectively in the coronal plane (MPTA) and in the sagittal plane (PTS). The average difference between planned and post-OWHTO MPTA and PTS was respectively 1,2° (SD 0,6°) and 1,2° (SD 1°) in the sagittal plane (PTS). Pearson’s correlation coefficient demonstrated a good accuracy of the treatment in both coronal and sagittal plane (respectively r=0,95 and r=0,86). No lateral hinge fractures were detected at the post-operative CT scan. Conclusion OWTHO performed with the help of 3D patient specific cutting guide on cadaveric specimens demonstrated good accuracy and reliability in obtaining the planned correction. In vivo studies are necessary to confirm these results and evaluate cost-effectiveness of this system. Level of evidence Level IV cadaveric study.

Changes in Patellar Height and Tibial Posterior Slope after Biplanar High Tibial Osteotomy with Computer‐Designed Personalized Surgical Guides: A Retrospective Study

“…Some authors have successfully mitigated these effects through careful preoperative planning and precise intraoperative techniques, 18 , 46 , 47 , 49 , 50 and other technical adjustments to minimize changes in PTSA include intraoperative monitoring of tibial slope with Kirschner wires, ensuring complete osteotomy of the posterior cortex, adequately releasing soft tissues, and maintaining an anterior–posterior cortical gap ratio of 1:2. 46 , 49 , 50 LaPrade et al .…”

“…35,46,47 Generally, these differences are thought to be related to surgical techniques and the placement of the implants. 44,47,48 Some authors have successfully mitigated these effects through careful preoperative planning and precise intraoperative techniques, 18,46,47,49,50 and other technical adjustments to minimize changes in PTSA include intraoperative monitoring of tibial slope with Kirschner wires, ensuring complete osteotomy of the posterior cortex, adequately releasing soft tissues, and maintaining an anterior-posterior cortical gap ratio of 1:2. 46,49,50 LaPrade et al's research indicates that when internal fixation is placed anteriorly, PTSA increases by 4.3 , whereas when internal fixation is posteriorly placed, PTSA only increases by 1 .…”

“…17 Among these, the application of computer-assisted design coupled with 3D-printed osteotomy guides has enhanced surgical standardization, precision, and personalization while reducing surgical time, bleeding, and risk of complications. [18][19][20] Mao et al 21 compared personalized surgical guide plate (PSGP) and conventional manual osteotomy in MOWHTO. The results showed that the PSGP group had shorter surgical times (37.8 min vs. 54.6 min, p < 0.05) and fewer intraoperative radiographic exposures (1.3 vs. 4.1 times, p < 0.05).…”

“… 17 Among these, the application of computer‐assisted design coupled with 3D‐printed osteotomy guides has enhanced surgical standardization, precision, and personalization while reducing surgical time, bleeding, and risk of complications. 18 , 19 , 20 Mao et al . 21 compared personalized surgical guide plate (PSGP) and conventional manual osteotomy in MOWHTO.…”