Inverse laminoplasty for the treatment of lumbar spinal stenosis.

STUDY

DESIGN

Fifteen patients with lumbar spinal stenosis were treated by a new technique, inverse laminoplasty, and the results were evaluated clinically and radiologically.

OBJECTIVE

To present the advantages of inverse laminoplasty over laminectomy for the treatment of lumbar spinal stenosis.

SUMMARY AND BACKGROUND DATA: Laminectomy has been used widely in the treatment of lumbar spinal stenosis. Destruction of the spinal bony structure, instability, and peridural scar formation are the main problems with this procedure. To overcome these disadvantages, a practical technique is presented here.

MATERIAL AND

METHODS

In a prospective study, 15 patients who underwent surgery with the inverse laminoplasty technique were evaluated clinically and radiologically. The Oswestry Disability Index was used for clinical assessment. L4-L5 spinal stenosis was detected in all patients. As the operative technique, the L4 lamina was elevated en bloc using a high-speed drill and rongeur. After removal of the ligamentum flavum, the roof of the foramina, and/or disc, the lamina was rotated 180 degrees, rested on facets, and reattached by use of a titanium miniplate.

RESULTS

All patients improved clinically and neurologically after this procedure. The mean Oswestry Disability Score was 38.33 preoperatively and 7.0 postoperatively. The mean follow-up time was 17.3 months. Spinal canal diameters were calculated by preoperative and postoperative computed tomography, and the mean enlargement was 77.8%. No complications were observed.

CONCLUSION

With this technique, the important integrity of the spinal osseous structures is preserved, and a significant enlargement of the spinal canal area is achieved. This technique prevents peridural scar formation after laminectomy caused by a mechanical barrier effect. Long-term follow-up is needed to evaluate spinal stability in these patients.