Case: A 73-year-old woman with advanced ankylosing spondylitis (AS) underwent closed reduction and internal fixation using antegrade intramedullary nailing because of midshaft fracture of her right femur. After the surgery had been performed, a fracture and dislocation at T12-L1 was detected. Therefore, emergency spinal decompression and posterior instrumentation placement from T11 to L5 were then performed.

Conclusion: Patients with advanced AS have a high risk of vertebral fracture, so special care must be taken not to transmit excessive stress on the spine for surgical reduction and manipulation of the lower extremity.