Outcomes of Instrumented Posterolateral Fusion for Patients Over 70 Years with Degenerative Lumbar Spinal Disease: A Minimum of 2 Years Follow-up

OBJECTIVE: To determine the outcome of posterolateral fusion (PLF) for patients over 70 years of age with degenerative lumbar spinal disease. METHODS: The authors reviewed 18 patients (13 women and 5 men) over 70 years of age who underwent PLF with a minimum 2-years follow-up at a single institution. The parameters for analysis were clinical outcome, intraoperative bleeding, operating time, transfusion amount, fusion rate, decreased disc height at the operated level, and the incidence of adjacent disc degeneration. RESULTS: The mean age and follow-up duration were 74.1 years and 44.7 months, respectively. The mean fusion level was 2.5 levels. 12 patients (66.7%) reported good or excellent outcomes, and 4 patients complained of poor outcomes. The fusion rate was 61.1%. The rate of adjacent segment degeneration was 61.1%. Among all of the patients, 5 had decreased intervertebral disc heights compared to their initial statuses. In correlative comparison analyses of parameters, a significant correlation was observed between a "good" or better clinical outcome and fusion (p=0.034). Also, there were significant relationships between a "fair" or better clinical outcome and fusion (p=0.045) and decreased disc height at the operated level (p=0.017). Other factors did not have a significant relationship with the clinical outcome. CONCLUSIONS: Before performing instrumented PLF in patients over 70 years old, problems related to the low fusion rate and adjacent segment degeneration should be considered and relevant information should be provided to the patients and the family.