Comparison of Consecutive, Interval, and Skipped Pedicle Screw Techniques in Moderate Lenke Type 1 Adolescent Idiopathic Scoliosis

Abstract

Objective: To compare perioperative, radiographic, and Scoliosis Research Society-22 (SRS-22) outcomes of consecutive, interval, and skipped pedicle screw techniques in patients with moderate Lenke type 1 adolescent idiopathic scoliosis (AIS).

Methods: We retrospectively reviewed 65 consecutive moderate Lenke type 1 AIS patients at a single institution using all-pedicle screw constructs, with a minimum of 2 years of follow-up. In the consecutive group (C group, n = 22), pedicle screws were instrumented at consecutive levels bilaterally. In the interval group (I group, n = 18), pedicle screws were placed at every level on the concave side while skipping levels on the convex side. In the skipped group (S group, n = 25), pedicle screws were instrumented by skipping levels bilaterally. Perioperative, radiographic, and SRS-22 measurements were analyzed with a 1-way analysis of variance.

Results: No significant differences were found in length of hospital stay, fused levels, coronal correction, and SRS-22 scores among the 3 groups. Increased surgery time was found in the C group compared with the I and S groups (P = 0.001 and P = 0.005, respectively). Decreased blood loss and blood transfusions were found in the S group compared with the C group (P = 0.04 and P = 0.047, respectively). Decreased implant costs were found in the S group compared with the C and I groups (P < 0.001 and P = 0.03, respectively).

Conclusions: Consecutive, interval, and skipped pedicle screw techniques all provide satisfactory deformity correction and SRS-22 outcomes with few complications. With better perioperative outcomes, interval and skipped pedicle screw techniques are the more cost-effective options for patients with moderate Lenke type 1 AIS.

Keywords: Adolescent idiopathic scoliosis; Consecutive pedicle screw; Interval pedicle screw; Skipped pedicle screw.