Patient-specific cutting guides allow 1° precision in asymmetric anterior closing-wedge osteotomy

Abstract

Purpose: Asymmetric anterior closing-wedge high tibial osteotomy (ACWHTO) allows correction of both excessive posterior tibial slope (PTS) and varus deformity. However, the complexity of this surgery requires a high degree of accuracy, which is less likely to be achieved with standard instrumentations. This study aimed to determine the accuracy of 3D patient-specific cutting guides (PSCGs) to provide the accurate planned correction in the frontal and sagittal planes. Methods: Eight sawbones tibiae were identically printed from the same patient data. An ACWHTO with a PSCG was performed on each sawbone. Postoperative measurements of PTS, mechanical medial proximal tibial angle (mMPTA), hinge area and hinge–posterior cruciate ligament (hinge–PCL) distance were compared with the preoperative planned measurements. The precision was defined as the absolute difference (∆) between the target planned values and postoperative values. Results: The mean accuracy was 0.6° ± 0.74° for PTS, 0.8° ± 0.71° for mMPTA, 0.3 ± 0.2 cm2 for hinge area and 0.1 ± 0.06 mm for hinge–PCL distance. Conclusion: In the setting of sawbones, the use of PSCGs was a reliable and accurate method of achieving simultaneous correction in the frontal and sagittal planes during asymmetric ACWHTO. Level of Evidence: Level V, basic science biomechanical laboratory study.