Table 1 Sequence of events throughout diagnosis and follow-up treatment process

2018 February

Hyperuricemia, pain in the second metatarsophalangeal joint of the right foot.

2018 June

Insufficiency fractures of the base of the first metatarsal bone of the left foot, the proximal second metatarsal bone, and the second metatarsal head of the right foot.

2019 January

Lumbar degenerative osteoarthropathy, L4/5 intervertebral disc bulging. L5 vertebral body left spondylolysis.

2019 April

Chest CT: normal; MRI: avascular necrosis of the left femoral head; bone density: osteoporosis (lumbar spine T-2.0, hip joint T-0.8); ALP = 190 U/L, UA = 460 μmol/L.

2019 September

MRI: double tibial plateau, thoracolumbar insufficiency fracture, double foot; CT: gouty arthritis; ALP = 158 U/L.

2020 May

MRI and/or CT: multiple insufficiency fractures of the thoracolumbar and ribs; bone density: osteoporosis (lumbar spine T-2.3, hip joint T-2.6); ALP increased to 216 U/L, UA = 477 μmol/L, IP = 0.52 mmol/L, parathyroid hormone = 116.5 pg/mL; bone metabolism: ALP = 205.7 U/L, normal calcium, and normal magnesium; clinical diagnosis of TIO.

2020 August

PET-CT: right iliac wing TIO nodules; MRI: right iliac bone abnormal nodules; ALP increased to 185.3 U/L; IP decreased to 0.50 mmol/L; surgical resection.

2021 January

ALP = 102 U/L (normal), osteocalcin = 23.2 μg/L, calcium = 2.32 mmol/L, IP = 1.22 mmol/L (normal). Bone density: overall T value of the lumbar spine was − 0.5, T value of the hip joint was − 0.3, and bone quality was normal.