Development of a Patient-Specific Plate for Hoffa Fracture: CT-Based Segmentation and Additive Manufacturing Workflow

Abstract

Hoffa fractures coronal fractures of the femoral condyle present a significant surgical challenge due to their intra-articular nature and anatomical complexity. Traditional fixation methods using generic implants often result in suboptimal fit, prolonged surgical time, and increased risk of malalignment. This study presents a complete digital workflow for the design, prototyping, and evaluation of a patient-specific implant (PSI) for Hoffa fractures using computed tomography (CT) data and additive manufacturing. The pipeline begins with segmentation of knee joint anatomy from DICOM-format CT scans using 3D Slicer, followed by conversion into STL models for mesh processing. Eight cases were evaluated, with one representative model selected for PSI design using Autodesk Meshmixer. The fracture surface was isolated, and a custom implant was designed to conform precisely to the patient’s distal femur geometry. Screw placement and structural reinforcements were incorporated based on orthopedic fixation principles. The PSI and bone model were prototyped using fused deposition modeling (FDM) for validation. The 3D-printed implant demonstrated accurate anatomical fit and alignment, confirmed through visual inspection and feedback from an orthopedic surgeon. This workflow demonstrates a cost-effective and reproducible method for personalized orthopedic implant fabrication, with potential future applications in metal additive manufacturing using biocompatible materials such as Ti-6Al-4V.