Clinical analysis following lumbar interspinous devices implant: where we are and where we go

Study design: Retrospective study. Objectives: We present our experience with patients treated with interspinous devices who are affected by neurogenic intermittent claudication (NIC) or lumbar disc herniation (LDH) where the interspinous system has been inserted following microdiscectomy. Methods: This study included patients (n = 100) with NIC secondary to lumbar spinal stenosis (group 1), and patients (n = 100) with LDH (group 2) in whom the interspinous device has been implanted following radicular decompression in a period spanning 6 years. The latter have been compared with a homogenous group of patients (n = 100) where no interspinous system has been implanted following microdiscectomy (group 3). Clinical findings have been observed preoperatively and 3, 6, 12 months and every year post-operatively using dedicated questionnaires (Zurich Claudication Questionnaire, Visual Analog Scale and Oswestry Disability Index). Results: Six years following surgical treatment, 85% of the patients of group 1 presented good improvement of symptoms and 90% of the patients referred satisfaction for surgery. Only few cases needed reoperation. In one case, the device was removed and in two cases, we changed the surgical strategy. Overall, patients of group 2 presented significantly less lumbar disc recurrences compared with group 3 (P<0.05) and better clinical outcome when compared with the same group (P<0.01). Conclusion: According to our features, interspinous systems showed significant and clinically meaningful improvements in pain and disability for up to 6 years. Furthermore, interspinous devices have shown better clinical outcome and less lumbar disc recurrences when associated with standard microdiscectomy. These data, however, need further studies and a longer period of follow-up.