Fixed sagittal imbalance (a syn drome in which the patient is only able to stand with the weight-bearing line in front of the sacrum) has many etiologies. The most commonly reported tech nique for correction is the Smith-Petersen osteotomy. Few reports on pedicle subtraction proce dures (resection of the posterior elements, pedicles, and verte bral body through a posterior ap proach) are available in the peer-reviewed literature. We are aware of no report involving a substan tial number of patients with coex istent scoliosis who underwent pedicle/vertebral body subtrac tion for the treatment of fixed sag ittal imbalance.METHODS:
Twenty-seven consecutive patients in whom sagittal imbalance was treated with lumbar pedicle sub traction osteotomy at one institu tion were analyzed. Radiographic analysis included assessment of thoracic kyphosis, lumbar lordo sis, lordosis through the pedicle subtraction osteotomy site, and the C7 sagittal plumb line. Out comes analysis was performed with use of a before-and-after pain scale, items from the Oswestry questionnaire, and the Scoliosis Research Society (SRS) question naire after a minimum duration of follow-up of two years. Complica tions and radiographic findings were also analyzed for the entire group.RESULTS:
Overall, the average increase in lordosis was 34.1° and the aver age improvement in the sagittal plumb line was 13.5 cm. One pa tient had development of a lumbar pseudarthrosis through the area of pedicle subtraction osteotomy, and six patients had development of a thoracic pseudarthrosis. Two patients had development of in creased kyphosis at L5/S1, caudad to the fusion, resulting in some loss of sagittal correction. There were significant improve ments in the overall Oswestry score (p < 0.0001) and the pain-scale score (p = 0.0002). Most patients reported improvement in terms of pain and self-image as well as overall satisfaction with the procedure.CONCLUSIONS:
Pedicle subtraction osteotomy is a useful procedure for patients with fixed sagittal imbalance. A worse clinical result is associ ated with increasing patient co morbidities, pseudarthrosis in the thoracic spine, and subse quent breakdown caudad to the fusion.