Exploring the Role of Anatomical Imaging Techniques in Preoperative Planning for Orthopaedic Surgeries.

Introduction: The incorporation of a three-dimensional (3D) framework enables the surgeon to strategically plan their surgical intervention through the utilisation of the printed model. This encompasses the process of ascertaining the surgical approach, choosing the suitable reduction technique, finding the required implant dimensions, defining the ideal placement and alignment of the implant, and conducting a simulated practise of the procedure using a 3D printed duplicate of the anatomical structures. Therefore, we designed this study to evaluate the role of two imaging modalities (computed tomography (CT) and magnetic resonance imaging (MRI)) for pre-surgical planning for orthopaedic surgeries.

Methodology: The present investigation entailed a prospective analysis of total knee arthroplasties (TKAs) that were performed using patient-specific instrumentation (PSI) from 2019 to 2022. After performing the bone resection operation utilising a customised cutting jig specific to each patient, the exact thickness of the resected bone was evaluated using a vernier calliper. In the MRI group, the researchers directly compared the cutting thickness during surgery with the consistency planned before the operation. In contrast, the CT group added the presumed cartilage thickness (2 mm) to the actual thickness of the bone that was removed from the lateral condyles.

Results:  The planned incision thickness in the distal femoral was 8.5 ± 0.8 in the CT group and 8.9 ± 0.5 in the MRI group, while the actual incision thickness was reported as 9.8 ± 0.54 in CT and 8.3 ± 1.1; however, no significant mean difference was found between both groups. The planned incision thickness was 2.6 ± 1.1 in the CT group and 2.43 ± 1.66 in the MRI group, while the actual thickness was observed as 2.5 ± 0.6 and 2.88 ± 1.12 without significant difference (p = 0.86).

Conclusion: While magnetic resonance imaging (MRI) allows for the visualisation of cartilage, it has been observed that the MRI-based patient-specific instrumentation (PSI) system does not exhibit superior accuracy in projecting bone incision thickness compared to the computed tomography (CT)-based PSI system.