Fracture dislocation of the spine after total hip arthroplasty in a patient with ankylosing spondylitis with early pseudoarthrosis.

BACKGROUND CONTEXT: There are no studies suggesting the management of asymptomatic, early pseudoarthrosis with advanced hip and spine deformities in patients with ankylosing spondylitis. Literature advocates the correction of the hip deformity first and that of spine later.
PURPOSE: To highlight the importance of asymptomatic, early pseudoarthrosis lesion in a patient of ankylosing spondylitis with advanced hip and spine deformities. STUDY
SETTING: A 25-year-old female patient suffering from ankylosing spondylitis with 70 degrees of flexion deformity at right hip and rounded kyphosis of thoracolumbar spine was admitted for right total hip arthroplasty.
METHODS: Cementless total hip arthroplasty and flexor tendon release were performed on right hip under general anesthesia and patient was nursed in supine position postoperatively.
RESULTS: The patient developed cauda equina syndrome and loss of sensation below twelfth thoracic segment on the second postoperative day. Radiological evaluation showed a fracture dislocation of the second and third lumbar vertebrae. Retrospective re-examination of preoperative radiographs showed small erosion of the anteroinferior margin of the second lumbar vertebra. Patient's neurological status did not improve after decompression and posterior stabilization of fractured spine.
CONCLUSION: Careful evaluation of the spine in patients with spondyloarthropathy with advanced hip and spine deformities should be done. Any lesion that can potentially destabilize the spine should be treated first before correcting hip deformity.