INTRODUCTION: Severe local kyphosis due to osteoporotic vertebral collapse causes delayed myelopathy, and many patients are unable to stand at their first visit. This study aimed to investigate correction loss after posterior spinal shortening and lumbar sagittal alignment using decubitus radiographs.
METHODS: Ten patients (6 female and 4 male) who underwent posterior spinal shortening for kyphosis due to osteoporotic vertebral collapse were included in this study. The mean age at surgery was 72.7 years, and the mean follow‐up period was 35.8 months. Seven cases had a fractured Th12 or L1 vertebra. Thoracolumbar sagittal alignment was assessed on plain radiographs pre‐ and post‐operatively, and at final follow‐up. Two angles were measured: one, the local kyphosis angle, the angle between the inferior endplate of the vertebra above and the superior endplate of the vertebra below the fractured vertebral body (FVB); and the other the caudal (cont'd) curve below the FVB (the angle between the superior endplate of the three caudal vertebrae and the superior endplate of the vertebra below the FVB). Although all cranial curves above the FVB were kyphotic preoperatively, the caudal curves below the FBV were lordotic (S curves) in 6 cases, and kyphotic (C curves) in 4 cases.
RESULTS: The mean local kyphosis angles measured pre‐ and post‐operatively, and at final follow‐up were 15.6, ‐6.2, and 0.7 degrees, respectively. In S curve patients, the local kyphosis angles pre‐ and post‐operatively, and at final follow‐up were 17.1, ‐6.0, and ‐3.3 degrees (correction loss 12%), and in C curve patients 13.2, ‐6.5, and 6.7 degrees (correction loss 67%), respectively.
DISCUSSION: Loss of correction with short‐segment posterior spinal shortening due to osteoporotic vertebral collapse can be predicted from presurgical thoracolumbar sagittal alignment. Although good results were achieved with S curve patients, other surgical options are necessary for C curve patients.