Fig. 1

Characteristics of bilateral lower limb and knee DR at admission. a Long-leg radiograph showed bilateral femur and tibia dysplasia with deformation of the shafts. The right varus angulation was 21.5°, and the FMAA was 11.3°. The mechanical axis of the left lower limb was normal. b–e Bilateral knee joint AP & LAT showed that the extensive subchondral bones of the knees were sclerotic, and the articular surfaces were out of flatness. Ambilateral joint gaps were significantly narrowed, especially in the lateral left knee and medial right knee. A couple of loose bodies were seen in the left knee