case_images: PMC8520886_01
case_images: Clinical pictures of the knee. There was no obvious sign of infection and these pictures show markedly limitations of knee motion. Knee flexion was limited to 80 degree and extension limited to 30 degrees.
case_images: IMCRJ-14-725-g0001.jpg
case_images: PMC8520886_01_IMCRJ-14-725-g0001.jpg
case_images: f0001
case_images: The physical examination revealed a painful, swollen knee without sinus discharge and limitations in knee flexion-extension that ranged from 30 to 80 degrees (Figure 1).
case_images: Plan X-ray of the knee shows early arthritic changes on the affected right knee compared to the left knee. On lateral view there is a button that remain on its position on the femoral side.
case_images: IMCRJ-14-725-g0002.jpg
case_images: PMC8520886_01_IMCRJ-14-725-g0002.jpg
case_images: f0002
case_images: This kind of plain x-ray of the knee resembles a picture of the degenerative condition of joints (Figure 2).
case_images: Knee joint MRI of T2 weighted sagittal view show a nodular tissue formation on the posterior part of tibiofemoral joint (white arrow).
case_images: IMCRJ-14-725-g0003.jpg
case_images: PMC8520886_01_IMCRJ-14-725-g0003.jpg
case_images: f0003
case_images: The previous graft is nowhere to be seen in Figure 3.
case_images: Arthroscopic finding: (A) Abundant crystal urate attached to the entire surface of synovium; (B) Crystal urate envelop the articular surface; (C) Intraarticular tophus formation; (D) Crystal urate comes out from the broken tophus.
case_images: IMCRJ-14-725-g0004.jpg
case_images: PMC8520886_01_IMCRJ-14-725-g0004.jpg
case_images: f0004
case_images: During the surgery, surprisingly, an abundant amount of gouty crystal was found almost on the entire surface of the joint cartilage and synovial tissue (Figure 4).
case_images: This arthroscopic view shows that loss of ACL graft on its femoral footprint, there was a suture left on the tunnel surface.
case_images: IMCRJ-14-725-g0005.jpg
case_images: PMC8520886_01_IMCRJ-14-725-g0005.jpg
case_images: f0005
case_images: ACL graft was no longer found and disappeared (Figure 5). A tissue sample was obtained for pathologic anatomy, and revealed pieces of tissue with a needle-shaped structure under a light microscope, respectively.