The Clinical And Fundamental Research On The Treatment Of Degenerative Lumbar Spinal Stenosis With Spinous Process Osteotomy And Decompressive Surgery

Objective: To evaluate the surgical outcomes in patients with DLSS with enlargement of the spinal canal through spinous process osteotomy. To offer the basis for the posterior approach with spinous process osteotomy through observing the different pathological changes of the supraspinous ligaments being undergone unilateral or bilateral stripped paraspinous muscles. Methods: Posterior central incision was used for unilateral exposure of lamina. Osteotomy was done at the base of the spinous process; complete exposure of the lamina was done by retracting the interspinous and supraspinous ligaments. Ligamentum flavum was resected at the superior and inferior margin of the lamina. Undermining enlargment of the central spinal canal and the neural canal were then carried out. Forty-three patients suffered from DLSS were treated with the above mentioned procedure. JOA evaluation score were carried out. In fundamental research, three pieces of supraspinous ligament specimens were from three patients with a history of 1~1.5 years after the unilateral stripped paraspinous muscles surgery, the other three from three patients with the same span of history of bilateral strippedparaspinous muscle surgery. The six ligament specimens were made slices and observed what the pathplogical changes had taken place with optical microscope and electronic microscope respectively.Results: Forty-three patients had follow-up for one year and four years. The excellent and good results were 100%. All of osteotomied spinous processes had bony fusion. In the fundamental research, the specimens from the supraspinous ligaments undergone bilateral stripped paraspinous muscles shown that the collagen fibers arranging disorderly were denaturated, inflammatory cells infiltrated, and density were uneven. The specimens from those undergone unilateral stripped took on that collagen fibers arranged orderly, density were even and organelle and nucleolus were normal. Conclusion: Spinal canal-decompression by spinous process osteotomy for patients with DLSS affords easy performing procedure with less complications and satisfactory surgical results. The supraspinous ligament could avoid ischemia denaturalization after the approach of unilateral stripped muscles for its blood-supply had been protected.