RESUMEN
BACKGROUND: The term degenerative spondylolisthesis, coined by Newman in 1963, refers to the forward slippage of an immediately inferior vertebra without isthmic lysis. It occurs predominantly in individuals over 40 years of age and affects mainly women, with a female:male ratio of 4:1. Prevalence is 7.5% in males and 28% in females among patients over 50 years of age with low back pain. MATERIAL AND METHODS: Assess the one-year results of the use of dynamic spacers for Meyerding grade 1 listhesis with the Oswestry disability scale. The patient's electronic and radiographic records from January 2008 to December 2010 were reviewed according to different criteria to conduct a retrospective, longitudinal and observational cohort study. RESULTS: The preoperative Oswestry score was 3.4% mild, 55.2% moderate, and 42.4% severe; the postoperative score was 79.3% mild and 20.7% moderate. The most common surgical procedure was exploration and release in 72.4% of patients; only 27.6% underwent diskectomy. Pain irradiating to the right pelvic limb occurred in 37.9% of patients, to the left pelvic limb in 44.8%, and to both pelvic limbs in 17.2%. Only 2.4% of patients experienced postoperative pain that irradiated to the pelvic limb, as 100% of cases had some type of irradiating pain. A DIAM spacer was used in 79.3% and a Wallis device in 20.7%. CONCLUSIONS: Treatment with an interspinous spacer results in a low reoperation rate and, at least one year later, it resulted in a significant improvement in the disability rate.