Critical analysis of extensive cervical laminectomy.

Conventional extensive laminectomy has been widely performed to reduce spinal cord compression, and is greatly facilitated by the use of an air drill. Laminectomy is recognized, however, as the occasional cause of problems after surgery, such as spinal instability or deformity, acceleration of spondylotic change, constriction of the dura mater caused by extradural scar formation, and lack of posterior bony protection for the spinal cord. In an effort to eliminate these negative aspects of conventional laminectomy, a surgical technique called suspension laminotomy has been used. Fifty-five patients treated with conventional extensive laminectomy and 55 others treated with suspension laminotomy were followed up clinically and compared. Flexibility and alignment of the cervical spine were assessed by plane radiographs, and dural configuration by computed tomographic scans. Neurologic improvement was also evaluated. Decrease of spinal movement after laminectomy was observed, notably during extension, probably as a result of functional insufficiency of paraspinal muscles. The incidence of postoperative spinal deformity was lower and the relief of dural constriction better in the patients treated with suspension laminotomy than in those treated with conventional laminectomy. Neurological recovery was significantly better in fully decompressed cases than in insufficiently decompressed cases.