Presently, For different grade of knee osteoarthritis (OA), the knee can be treated with arthroscopy, high tibial osteotomy (HTO), semi- or total knee replacement (TKR). As OA patients are getting younger, and TKR is an unrecoverable surgical procedure, the only choice is a second-revision surgery once the knee is infected or worn. The revision TKR will increase the difficulty of the surgery and sequelae. Therefore, for young patients with early and medium degenerative or traumatic osteoarthritis, HTO is a good choice among the treatments.
HTO realigns the weight bearing line (WBL) of lower limb by cutting from the medial or lateral proximal tibial and extracting or closing the wedge. The use of locking plate can provide stable fixation during weight bearing or knee motion. In the past, surgical failure were mainly caused by the fracture or loosening of plate/screw, leading to wedge collapse and lose of correction, which then decrease surgeons’ confidence. Thus, the stability that the plate can provide is one of the key factors for successful surgery. This project designed a 3d-printed patient-specific instrument (PSI) guide in the vision of improving the above mentioned failure modes, with minimally invasive and anatomical fit, to achieve safe, fast and accurate Osteotomy. The goal is to increase the successful rate of osteotomy. The advantages are: 1) Anatomical bone plate can have similar profile with the patient’s bone surface, 2) Extend the posterior covering area of the bone plate for distributing the stresses, 3) Enhace the mechanical strength and supporting capability to improve postoperative stability, 4) Locking screws are used to avoid loosening of the screws. In addition, 5) Reduce the operation time, 6) Lower the radiation exposure, and 7) Decrease the risk of intraoperative fracture can be achieved through the precision cut by the assistance of PSI.