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STUDY DESIGN: Retrospective study with long-term follow-up. PURPOSE: To evaluate the long-term incidence of adjacent segment degeneration (ASD) and clinical outcomes in a consecutive series of patients who underwent spinal decompression associated with dynamic or hybrid stabilization with a Flex+TM stabilization system (SpineVision, Antony, France) for lumbar spinal stenosis. OVERVIEW OF LITERATURE: The incidence of ASD and clinical outcomes following dynamic or hybrid stabilization with the Flex+TM system used for lumbar spinal stenosis have not been well investigated. METHODS: Twenty-one patients with lumbar stenosis and probable post-decompressive spinal instability underwent decompressive laminectomy followed by spinal stabilization using the Flex+TM stabilization system. The indication for a mono-level dynamic stabilization was a preoperative magnetic resonance imaging (MRI) demonstrating evidence of severe disc disease associated with severe spinal stenosis. The hybrid stabilization (rigid-dynamic) system was used for multilevel laminectomies with associated initial degenerative scoliosis, first-grade spondylolisthesis, or rostral pathology. RESULTS: The improvement in Visual Analog Scale and Oswestry Disability Index scores at follow-up were statistically significant (p<0.0001 and p<0.0001, respectively). At the 5-8-year follow-up, clinical examination, MRI, and X-ray findings showed an ASD complication with pain and disability in one of 21 patients. The clinical outcomes were similar in patients treated with dynamic or hybrid fixation. CONCLUSIONS: Patients treated with laminectomy and Flex+TM stabilization presented a satisfactory clinical outcome after 5-8 years of follow-up, and ASD incidence in our series was 4.76% (one patient out of 21). We are aware that this is a small series, but our long-term follow-up may be sufficient to contribute to the expanding body of literature on the development of symptomatic ASD associated with dynamic or hybrid fixation.
RESUMEN
OBJECTIVE: We sought to evaluate the long-term C1-C2 fusion rates, fracture healing, and functional outcomes in geriatric patients with type II odontoid fracture treated with posterior fixation with polyaxial C1 lateral mass screws and C2 pars screws. METHODS: Twenty-one consecutive patients between 2005 and 2011 with Anderson and D'Alonzo type II odontoid fracture underwent a posterior atlantoaxial fixation with polyaxial C1 lateral mass screws and C2 pars screws. A long-term clinical and radiologic follow-up was achieved in all patients with a mean follow-up period of 53.28 ± 15.41 months (range 38-91 months). RESULTS: All 21 patients had bilateral C1 lateral mass screws and bilateral C2 pars screws. Correct positioning of the C1 lateral mass screws and C2 pars screws was observed in all 42 placements by postoperative computed tomography scans. No vascular or neurologic complication was noted. At the last follow-up, 20 patients (95.24%) had a solid fusion (defined as Lenke fusion grade A or B) while 1 patient (4.76%) had a partial fusion (Lenke fusion grade C). Overall, no hardware failures occurred in any patient. Odontoid fracture healing was achieved in 18 patients out of 21 (85.71%). The mean postoperative Neck Disability Index score was 12.73%, and neck motion was within normal physiologic limits at 12 months. CONCLUSIONS: This study adds to the evidence that posterior atlantoaxial fixation with polyaxial C1 lateral mass screws and C2 pars screws is a safe and effective surgical option in the treatment of odontoid fractures including long-term stability.