Spinous process-plasty following lumbar laminectomy as a contributing factor to spine stability.

A 10-year retrospective study of 41 consecutive patients who underwent "spinous process-plasty" is presented. We carried out laminectomy of the lumbar spine in cases of spinal stenosis, dorsomedial herniated disc and recurrent disc herniation with firm scars (traumatic and tumour cases are not included). To forestall the development of laminectomy's negative effects on spine stability, we initiated the spinous processes' reconstruction. Two groups of patients who underwent laminectomy form the basis of this presentation, one group with "spinous process-plasty" (41 patients) and the other (11 patients) without it. On postoperative neutral and dynamic X-ray films we paid attention to horizontal displacements larger than 3 mm and to negative intervertebral angular displacement. Considering such criteria, only 3.8% of those with "spinous process-plasty" developed a radiographic instability in contrast to 25% of patients without "spinous process-plasty". These results support the use of this technique, which provides postlaminectomy lumbar spine stability.