Osteochondral lesions are injuries which affect the bone and articular cartilage of knee joints. Osteochondral allografts procedures are commonly used to repair damaged articular cartilage. Due to inconsistent cut angles of the recipient and donor sites, surface incongruities after an allograft procedure can lead to poor outcomes. The purpose of this project was to develop a process that would produce surface-matching surgical guides from CT scans, which would ensure that allograft cutting tools were normal (perpendicular) to the articular cartilage when performing the procedure, therefore reducing surface incongruities.

In order to achieve this, image processing software was developed to automatically orient CT scans of femurs in a standard way, additional software was developed to produce surface normal vectors from a defect site, and CAD models of surgical guides were created, prototyped, and tested for edge offset improvements compared with unguided procedures.