Patient-Specific 3D-Printed Drill Guides for an Ovine Osteochondral Allograft Transplantation Model.

Proper alignment between donor and recipient cartilage in osteochondral allograft transplantation supports tissue integration and the formation of a stable articulating surface. This study evaluated the use of patient-specific 3D-printed drill guides to improve alignment in an ovine model of osteochondral allograft transplantation when used in place of a free-hand drilling technique. Fourteen female Arcott sheep underwent bilateral osteochondral allograft transplantation. Drill guides were used to transplant 51 grafts (6.5 mm diameter), while the freehand drilling technique was used to transplant 32 grafts. After a 9-month survival time, tissues were harvested. Cross-sectional confocal microscopy images and histological sections were used to quantify height differences between donor and recipient tissues. Grafts transplanted with the drill guides showed significantly reduced (p = 0.0005) height differences between donor and recipient tissues compared to the freehand drilling technique. However, the guide technique was associated with increased osteophyte development (p = 0.0180) and synovial inflammation (p = 0.0451). These findings demonstrate that patient-specific 3D-printed drill guides improve graft alignment in an ovine model of osteochondral allograft transplantation. Methodological improvements are proposed to minimize osteophyte formation and inflammation in future studies.