Two-year follow-up after decompressive surgery with and without implantation of an interspinous device for lumbar spinal stenosis

STUDY DESIGN: Two-arm prospective controlled study.

OBJECTIVE: The aim of our study was to prospectively assess the outcome of symptomatic lumbar spinal stenosis (LSS) treated with decompressive surgery alone in comparison with additional implantation of the Coflex interspinous device.

SUMMARY OF BACKROUND DATA: In symptomatic LSS, decompression surgery is an established treatment. Recently, a number of interspinous devices have been introduced as an alternative to conventional surgical procedures. The theoretical aim of the Coflex device is to unload the facet joints, restore foraminal height, and provide stability to improve the clinical outcome. Published information is limited, and there are no data that prove the superiority of the implant in comparison with traditional surgical approaches.

METHODS: Sixty-two patients with symptomatic LSS were treated with decompressive surgery; 31 of these patients received an additional Coflex device. Preoperatively and postoperatively, disability and pain scores were measured using the Oswestry Disability Index, the Roland-Morris Disability Questionnaire, the Visual Analog Scale, and the pain-free walking distance. Patients underwent postoperative assessments at 3, 6, 12, and 24 month including the above-mentioned scores and patient satisfaction.

RESULTS: There was a significant improvement (P<0.001) in the clinical outcome assessed in the Oswestry Disability Index, the Roland-Morris Disability Questionnaire, the Visual Analog Scale, and the pain-free walking distance at all times of reinvestigation compared with the base line in both groups. Up to 2 years after surgery, there were no significant differences between both groups in all ascertained parameters, including the patient satisfaction and subjective operation decision.

CONCLUSIONS: The results of this first prospective controlled study indicate that the additional placement of a Coflex interspinous device does not improve the already good clinical outcome after decompressive surgery for LSS in the 24-month follow-up interval.