Study Design. Retrospective, radiographical analysis.
Objective. To evaluate pedicle subtraction osteotomy (PSO) as a means of correcting severe degenerative sagittal imbalance in elderly patients.
Summary of Background Data. PSO in patients with degenerative sagittal imbalance is likely to cause more complications than in patients with iatrogenic flatback deformity.
Methods. This study analyzed 34 patients who underwent fusion to the sacrum, with a minimum 2-year follow-up. Age of the patients were in the range from 58 to 73 with the mean at 65.5 years. PSO was performed at one segment in all cases, consisting of L3 (n = 26), L4 (n = 4), L2 (n = 3), and L1 (n = 1). The average number of levels fused was 8.15. Ten patients had structural interbody fusion at the lumbosacral junction.
Results. Applying PSO at one segment, the mean correction of the lordotic angle at the osteotomy site was 33.3°, of which the loss of correction (LOC) was 4.0° at the last visit. The correction of lumbar lordosis was 33.7° and the LOC was 8.5°. The sagittal C7 plumb was 215.9 mm before surgery, corrected to 35.1 mm after surgery, and changed to 95.9 mm by the last visit. The correction of the sagittal C7 plumb was 119.9 mm and the LOC was 60.9 mm. There was substantial LOC in lumbar lordosis and sagittal C7 plumb. In 10 patients with addition of posterior lumbar interbody fusion, the LOC of lumbar lordosis was 7.4°, which was less than 9° in those without it.
Conclusion. PSO for the correction of degenerative sagittal imbalance in elderly patients resulted in correction of sagittal alignment with a significant LOC of lumbar lordosis and sagittal C7 plumb. The LOC of lumbar lordosis occurred at both the osteotomy and non-osteotomy site. The addition of anterior column support is helpful to maintain correction and reduce complications.
Level of Evidence: N/A
Thirty-four patients underwent pedicle subtraction osteotomy (PSO) at one segment. The mean correction of the lordotic angle at the osteotomy site was 33.3&#x00B0;, of which the loss of correction (LOC) was 4.0&#x00B0;. PSO for elderly patients resulted in a significant LOC. This occurred at both the osteotomy and nonosteotomy site.
*Department of Orthopaedic Surgery, School of Medicine, Inha University, Incheon, Korea
†Department of Orthopedic Surgery, School of Medicine, Kyung Hee University, Seoul, Korea; and
‡Department of Orthopaedic Surgery, Eulji University School of Medicine, Daejeon, Korea.
Address correspondence and reprint requests to Kyu-Jung Cho, MD, Inha University Hospital, Incheon Korea; E-mail: firstname.lastname@example.org
Acknowledgment date: January 18, 2013. First revision date: June 11, 2013. Second revision date: July 22, 2013. Acceptance date: July 22, 2013.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work.
No relevant financial activities outside the submitted work.