Fig. 2

Intraoperative view. a The loose bodies were removed. All of the loose bodies were scattered around the medial epiphysis; the largest one was located near the superior patellar bursa and was a round, well-defined bone osteochondral block 3 cm in diameter. b The articular surface of the distal medial femur of the left knee was exposed, and a very large defect and a very rough joint surface were noted. c The articular surface of the distal medial femur of the right knee was exposed and showed a very similar disorder as that of the left knee. d The loose bodies that were removed