Incidence of Adjacent segment degeneration following single level fusion and single level discectomy and single level instrumentation fusion: A Comparative study

Abstract

OBJECTIVES: Determining Incidence of adjacent segment degeneration, its impact on the outcome after fusion and discectomy. Compare the two groups to understand the natural history of degeneration and influence of surgery. METHODS: Patients who underwent single level instrumented posterior lumbar interbody fusion were evaluated with a minimum 2 year follow-up. The incidence of degeneration in the adjacent segment and the remaining lumbar segments were measured radiologically with Pfirrmanns, Bridwell, Fujiwara grading systems, functional outcome were measured with VAS, ODI, and JOA scoring systems, their relationship with certain patient risk factors like age, gender, BMI, co-morbidities, occupation and physiotherapy were checked. The findings were compared with a well matched control group of patients who underwent single level lumbar discectomy with the same follow-up criteria; they were also evaluated with the same parameters. RESULTS: Adjacent segment degeneration occurs both in discectomy and single level fusion surgeries similarly, with the cephalic segment being affected more. There is no relationship between radiological degeneration and clinical outcome