[Treatment of symptomatic degenerative lumbar spinal stenosis by a percutaneous stand-alone lumbar interspinous implant. Preliminary experience with the Aperius device].

BACKGROUND AND PURPOSE

Surgery for degenerative spinal stenosis classically involves decompression by laminectomy or foraminotomy. The use of interspinous process devices has been described for these indications in recent years. This study evaluates the efficacy and morbidity of a percutaneous interspinous device to define whether this technique would be a suitable alternative to classical surgery.

METHOD

Twenty-two patients with degenerative lumbar spinal stenosis were studied prospectively. Pre- and postoperative symptoms were assessed using the Visual Analogic Score (VAS), the Zurich Claudication Questionnaire (ZCQ), physical activity, and patient satisfaction. The implant was positioned under biplanar fluoroscopic control after progressive distraction of the interspinous space using trocars. The patients were reviewed after 7 days, 6 weeks, and 6 months.

RESULTS

All patients showed improved gait perimeter: 90 % could walk more than 1000 m 6 months after surgery, whereas only 50 % could walk this distance preoperatively. The mean symptom severity scores of 2.71 and physical activity scores of 2.38 improved to 1.87 (p=0.0003) and 1.53 (p<0.0001), respectively, after 6 months. The VAS decreased 3.5 points (p=0.0008) 6 months after surgery for leg pain. Ninety-one percent of the patients declared they were satisfied with the operation.

CONCLUSION

The Aperius stand-alone and percutaneous interspinous device proved to be effective and safe in treating symptomatic lumbar spinal stenosis. This could be a good alternative to classic decompression surgery, but long-term follow-up studies are needed as well as subgroup analysis to define which patients could benefit from this technique.