Adult spondylolisthesis treated with posterolateral lumbar fusion and pedicular instrumentation with AO DC plates.

Attainment of successful lumbar fusion in adults with spondylolisthesis has historically been unpredictable. Recent results and conclusions have been conflicting regarding the role of instrumentation in improving the fusion rate and clinical outcome in this patient population. In a retrospective multicenter clinical study, we assessed the outcome of 42 adults with spondylolisthesis who underwent posterolateral lumbar fusion by using pedicular instrumentation with AO DC plates. No attempt was made to reduce slippage. Follow-up clinical outcome was obtained from a patient questionnaire administered and assessed by an independent reviewer. Fusion status was assessed by anteroposterior, lateral, and oblique radiographs at the most recent follow-up examination. Spondylolisthesis was classified as degenerative in 21 patients and isthmic in 21 patients. Solid fusion was achieved in 32 (76%) patients; pseudoarthrosis occurred in two (5%) patients; the fusion mass was indeterminate in eight (19%) patients. Clinical outcome parameters rated 73% excellent to good and 27% fair to poor. Complications included four infections and two screw breakages. Poor results correlated strongly with cigarette smoking and multiple previous surgeries. In this study, fusion rate and clinical outcome were consistent with previous reports of adult spondylolisthesis. Rates of successful fusion varied according to the type of spondylolisthesis.