Spinous process osteotomies to facilitate lumbar decompressive surgery

Study Design. A technique for lumbar decompression using spinous process osteotomies is described, and the outcomes are studied prospectively. Objective. To describe a technique that affords a wide exposure for decompression while minimizing damage to surrounding tissues, and to analyze the outcomes formally using the technique. Summary of Background Data. Commonly used techniques of lumbar decompression, which include bilateral takedown of paraspinal musculature and aggressive bony resection, can result in significant iatrogenic sequelae, whereas minimally invasive techniques often provide inadequate visualization and/or decompression. Method. Unilateral limited takedown of the multifidus is undertaken, followed by spinous process osteotomies at the involved levels. The spinous processes with the attached interspinous/supraspinous ligaments are then retracted. A complete "trumpeted" decompression is then undertaken. Fifty consecutive patients undergoing the procedure were analyzed prospectively and at follow-up by an independent observer using a validated functional outcome measure, a visual analog pain scale, and a patient satisfaction score. Results. Functional outcome scores improved on average by 47%, pain levels were reduced by 66%, and high satisfaction rates were reported by 83% of patients. Conclusions. The technique affords excellent visualization and a wide area available for Kerrison use and angulation while minimizing destruction to tissues not directly involved in the pathologic process, including the paraspinal musculature as well as the interspinous/supraspinous ligament complex and facets. Additionally, it minimizes dead space and improves the cosmetic result.