Interspinous Implantation for Degenerative Lumbar Spine: Clinical and Radiological Outcome at 3-yr Follow Up

ABSTRACT

OBJECTIVE: Interspinous devices for dynamic stabilization of lumbar spine are undergoing development and clinical trials. A few short-term outcomes of interspinous devices have been reported but little has been mentioned about longterm outcomes. We reviewed 19 cases of interspinous implantation (Coflex Paradigm spine, Germany) to evaluate clinical long-term outcome and radiologic features. METHODS: From January 2003 to March 2004, 19 patients (13 female and 6 male) who underwent interspinous implantation were included and follow-up data on clinical and radiologic outcomes were obtained at last clinic visit (mean follow-up: 38 months). Clinical outcomes were assessed by Visual analogue scale (VAS) score and Odom..s criteria. RESULTS: Preoperative VAS score for low back pain and leg pain was improved from 4.9+/-2.4 and 7.5+/-2.4 to 2.6+/-1.2 and 3.0+/-1.8 respectively at postoperative last clinic visit (p<0.01). Using Odom..s criteria, 7 and 9 patients showed excellent (36.8%) and good (47.3%) results for low back pain and 7 and 11 showed excellent (36.8%) and good (57.9%) results for leg pain. Anterior and posterior disc height were decreased significantly on postoperative follow-up radiologic data due to discectomy at the level of instrumentation (p<0.01). There were no complications such as infection or device failure. CONCLUSIONS: In this long-term follow-up study, clinical outcome was good but disc degeneration after discectomy at instumented level resulting in decrease of disc height was observed.