Mikrochirurgische, interspinosale Dekompression mit Implantation eines dorsalen Kraftträgers zur Therapie der lumbalen Spinalkanalstenose: prospektive Analyse der Behandlungsergebnisse

Abstract

Introduction: Magnet-Resonance-Imaging reveals patients with stenosis predominantly caused by hypertrophy of the ligamentum flavum. In those cases exstensive bony decompression should be avoided. The interspinous approach should be assumed in combination with dorsal interspinous implants. The efficiency of this approach was prospectively analysed in our study. Patients and method: A microsurgical interspinous approach was performed in 27 patients (12 female, 15 male) in age of 48 to 80 years (average 67). Patients with spinal stenosis caused by trauma, infection or patients who had a spinal operation before were excluded. This approach was completed by resection of lig. flavum and osteophyts in cranio-caudal and lateral direction. In all patients an interspinous implant (CoflexR) was set. Follow-up examinations were performed 6 months later, including clinical, functional and radiological parameters. Results: There was a significant reduction of local back and leg pain (p < 0,0001) as well as a significant increase of walking distance (p < 0,0001). There were siginificant improvements (p < 0,0001) in the Oswestry Disability Index (ODI) and the Zurich Claudication Questionnaire (ZCQ). In radiological analysis (CT), the diameter of the intervertebral foramina was significantly enlarged (p < 0,001) and the height of the dorsal parts of the intervertebral disc was increased. Nevertheless, no parameter of the clinical and functional improvement was significantly correlated with radiological data. Midline dural injuries with emission of liquor occurred in 2 subjects. However, there was no clinical deterioration in these patients. Discussion: Pain relief and increase of walking distance as well as improvement of functional scores are the consequences of the procedure. The interspinosal spacer leads to radiological improvements, especially widening of the intervertebral foramina. Backpain relief after decompression is not common; this could be a positiv effect of the spacer.