A Robotic Nondestructive Osteochondral Tissue Harvesting for Autograft Transplantation

Osteoarthritis is the degeneration of bone-cartilage. Healthy cartilage absorbs mechanical stress and provides smooth limb movement. Cartilage has poor healing capabilities due to the absence of blood, lymphoid tissue, and nerve that makes treatment of the damaged cartilage difficult, making surgical intervention an inevitable solution. Mosaicplasty is a popular surgical practice involving transplantation of small cylindrical bone-cartilage plugs to refill the lesion. A lack of custom-shaped donor harvesting mechanism makes it impossible to fill the lesion with a single graft. The success of transplanting a customized autograft to replace the osteochondral lesion lies in effective extraction of the autograft from the donor site. Currently, no method exists to harvest such grafts since it requires access to the root side of donor. In this paper, we propose a robotic cartilage-bone removal mechanism to harvest a custom-shaped autograft. Our method involves drilling a profile determined from the lesion to be removed and slicing off the desired cartilage-bone graft from the root. We designed a new graft removal mechanism capable of inserting a thin wire saw and slicing through the root of the prepared profile to extract an intact autograft. The device can be attached to a standard 6- DOF robotic arm that can provide profile drilling and gross positioning of the graft removal device.