Method and device for patient specific instruments for one stage and two stages of revision knee arthroplasty using constraint and hinged knee implant

摘要

The surgery of revision knee arthroplasty is complex one for both of one and two stages for constraint and hinged implants. The inventor create a method and device to overcome the difficulties of this surgery as determining the size of the revision prosthesis and position of it on the bone after cut and replacement of the failed primary prosthesis. This method enable the surgeons to overcome the abnormalities, distortions and artifacts on bone surface which resulted from the CT scan due to the primary implant. It enables the surgeons to detect the size and position of the implant, also uses land marks on bone surface to design and product the device which use to perform the bone cutting. The device enables the surgeon to determine and guiding the bone cuts below the cement plane in case of cemented implants. Also guiding to the bone cuts below the implant surface in case of cement-less implants.