Fig. 4

Another instance of SPR. A Standing anteroposterior and lateral radiographs of the right knee exhibit narrowing of the medial compartment, indicative of osteoarthritic (OA) changes. B Post-TKA anteroposterior and lateral radiographs of the right knee demonstrate a prosthesis that is well-positioned with normal alignment. C Axial radiograph post-TKA confirms the alignment of the prosthetic components. D Triple-phase bone scan reveals radioactive concentration within the right knee joint. E SPECT/CT imaging identifies focal radionuclide concentration on the articular surface of the patella. F Intraoperative exploration discloses wear on the articular surface of the right patella accompanied by metal debris. G Standing anteroposterior and lateral radiographs following SPR. H Axial radiograph post-SPR. I Full-length functional radiograph post-SPR. J Radiographs at a seven-year follow-up post-SPR