Ponte Osteotomy During Dekyphosis for Indirect Posterior Decompression With Ossification of the Posterior Longitudinal Ligament of the Thoracic Spine.

STUDY DESIGN

Retrospective clinical study.

PURPOSE

To investigate the outcomes after indirect posterior decompression and dekyphosis using multilevel Ponte osteotomies for ossification of the posterior longitudinal ligament (OPLL) of the thoracic spine.

SUMMARY OF BACKGROUND DATA

There are no previous reports on the use of Ponte osteotomy to treat thoracic OPLL.

METHODS

The subjects were 10 patients with an average age at surgery of 47 years, who underwent indirect posterior decompression and dekyphosis using multilevel Ponte osteotomies at our institute. Minimum follow-up period was 2 years, and averaged 2 year 6 months. Using radiographs and CT images, we investigated fusion range, preoperative and postoperative Cobb angles of thoracic fusion levels, intraoperative ultrasonography, and clinical results.

RESULTS

The mean fusion area was 9.8 vertebraes, with average laminectomy of 7.3 laminas. The mean preoperative thoracic kyphosis of fusion levels on standing radiograph measured 35 degrees and was changed to 21 degrees after surgery. The mean number of Ponte osteotomies was 3 levels. The mean preoperative and postoperative (at the 1 y follow-up) JOA scores were 3.5 and 7.5 points, respectively, and the recovery rate was 56%. On intraoperative ultrasonography, 7 of the cases were included in the floating (+) and 3 in the floating (-) groups, and the recovery rates were 66.0% and 33.4%, respectively.

CONCLUSIONS

"The Ponte procedure for indirect spinal cord decompression" is a novel concept used for the first time with thoracic OPLL in our study, and we consider it a useful method to achieve more effectively dekyphosis and indirect spinal cord decompression if there is not the spinal cord free from OPLL on intraoperative ultrasonography after only laminectomies.