Reoperation Rate After Posterior Spinal Fusion Varies Significantly by Lenke Type.

Background: Lenke curve types can vary in their response to treatment. We explored potential differences in reoperation rates, causes, and risk factors among patients with different Lenke types who underwent posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

Methods: We studied a multicenter database of patients with AIS who underwent index PSF at ≤21 years of age and had a minimum 2-year follow-up. Baseline and surgical characteristics were collected. Reoperation rates, causes, and risk factors were analyzed by Lenke type.

Results: A total of 3,165 patients were included. The mean age was 14.6 years, and most patients were female (81%) and Caucasian (68%). The mean follow-up period was 4.4 years. A total of 138 patients (4.4%) underwent reoperation. The reoperation rate varied by Lenke type (p = 0.02): patients with type-5 curves had the highest reoperation rate (7.2%), and those with type-1 curves had the lowest (3.0%). The most common cause of reoperation was an instrumentation complication. The rate of reoperation due to an instrumentation complication varied by Lenke type (p < 0.01). Compared with patients with type-1 curves, those with type-5 curves had significantly higher rates of reoperation due to implant prominence (odds ratio [OR], 11.7; p = 0.03), loss of fixation (OR, 3.9; p = 0.01), or a broken rod (OR, 7.8; p = 0.02) and those with type-3 curves had a significantly higher rate of reoperation due to loss of fixation (OR, 4.37; p = 0.01). Independent risk factors for reoperation were a major curve magnitude of ≥60° in patients with type-5 curves (adjusted OR [aOR], 4.18; p = 0.04), a major curve correction of ≥40° in patients with type-5 curves (aOR, 3.6; p = 0.04), and a lowest instrumented vertebra (LIV) at or above L1 in patients with type-1 curves (aOR, 2.8; p = 0.02).

Conclusions: The reoperation rate for patients with AIS who underwent PSF varied by Lenke type. Patients with type-5 curves had the highest reoperation rate, whereas patients with type-1 curves had the lowest. Patients with Lenke type-5 curves had a higher rate of reoperation due to instrumentation complications.

Level of evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.