Journal de la colonne vertébrale

Minimally Invasive Surgery for AIS: An Early Prospective Comparison with Standard Open Posterior Surgery

Abstract

Firoz Miyanji, Amer Samdani, Arvindera Ghag, Michelle Marks and Peter O. Newton

Study design: Prospective matched-control comparison study.

Objective: To prospectively compare deformity correction and measures of perioperative morbidity between minimally invasive posterior spinal fusion and conventional open posterior procedures in age- and curve classificationmatched individuals.

Summary of background data: Minimally invasive surgery (MIS) has evolved in an effort to decrease the rate of approach-related morbidity associated with conventional open procedures for spinal disorders. Its widespread use in spinal trauma and degenerative disorders has yielded similar clinical results to open techniques with the added benefit of optimizing peri-operative morbidity. No report has been made comparing the clinical results of MIS to conventional open procedures in the setting of adolescent idiopathic scoliosis (AIS).

Methods: Patients enrolled in a multi-center, longitudinal, prospective AIS study were included in this analysis. Pre-op, peri-op and first erect post-op data was evaluated. 16 MIS patients were matched for age, sex, Lenke classification, and curve size with 16 conventional open posterior procedures. All cases were also matched to a single surgeon to reduce potential surgeon-induced variability. Statistical analysis was done using SPSS v.18.

Results: Age, gender, Lenke classification and curve magnitude were not statistically different between individuals treated with MIS or open surgery (Table 1). Post-op major Cobb was 20 degrees (curve correction 63%) in those treated with MIS and 18 degrees (curve correction 68%) in those treated with open surgery. Both estimated blood loss and length of stay (LOS) were significantly less in the MIS group (277 mL, 4.63 days) compared to the open group (388 mL, 6.19 days); however OR time was significantly longer in the MIS group (444 min) compared to the open group (350 min).

Conclusions: MIS for AIS has similar results to standard open posterior techniques, specifically for curve correction. Although increase in operative time was noted in the MIS group, advantages of MIS over standard open procedures seem to include decreased LOS and blood loss. Further follow-up will be critical to evaluating the longerterm outcomes of the MIS approach to AIS treatment.