Use of iliac screw associated with more correction of lumbar lordosis than S2-alar-iliac screw for adult spinal deformity

Qiang Luo; Yong-Chan Kim; Ki-Tack Kim; Kee-Yong Ha; Joonghyun Ahn; Sung-Min Kim; Min-Gyu Kim

doi:10.1186/s12891-021-04568-z

Use of iliac screw associated with more correction of lumbar lordosis than S2-alar-iliac screw for adult spinal deformity

BMC Musculoskelet Disord. 2021 Aug 10;22(1):676. doi: 10.1186/s12891-021-04568-z.

Authors

Qiang Luo^{1

2}, Yong-Chan Kim³, Ki-Tack Kim¹, Kee-Yong Ha¹, Joonghyun Ahn¹, Sung-Min Kim¹, Min-Gyu Kim¹

Affiliations

¹ Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University, 892 Dongnam-ro, Gangdong-gu, Seoul, 05278, South Korea.
² Department of Orthopaedic Surgery, Graduate School of Medicine, Kyung Hee University, Kyungheedae-ro, Dongdaemun-gu, Seoul, South Korea.
³ Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University, 892 Dongnam-ro, Gangdong-gu, Seoul, 05278, South Korea. yckimspine@gmail.com.

Abstract

Background: To date, there is a paucity of reports clarifying the change of spinopelvic parameters in patients with adult spinal deformity (ASD) who underwent long segment spinal fusion using iliac screw (IS) and S2-alar-iliac screw (S2AI) fixation.

Methods: A retrospective review of consecutive patients who underwent deformity correction surgery for ASD between 2013 and 2017 was performed. Patients were divided into two groups based on whether IS or S2AI fixation was performed. All radiographic parameters were measured preoperatively, immediately postoperatively, and the last follow-up. Demographics, intraoperative and clinical data were analyzed between the two groups. Additionally, the cohort was subdivided according to the postoperative change in pelvic incidence (PI): subgroup (C) was defined as change in PI ≥5° and subgroup (NC) with change < 5°. In subgroup analyses, the 2 different types of postoperative change of PI were directly compared.

Results: A total of 142 patients met inclusion criteria: 111 who received IS and 31 received S2AI fixation. The IS group (65.6 ± 26°, 39.8 ± 13.8°) showed a significantly higher change in lumbar lordosis (LL) and upper lumbar lordosis (ULL) than the S2AI group (54.4 ± 17.9°, 30.3 ± 9.9°) (p < 0.05). In subgroup (C), PI significantly increased from 53° preoperatively to 59° postoperatively at least 50% of IS cohort, with a mean change of 5.8° (p < 0.05). The clinical outcomes at the last follow-up were significantly better in IS group than in S2AI group in terms of VAS scores for back and leg. The occurrence of sacroiliac joint pain and pelvic screw fracture were significantly greater in S2AI group than in IS group (25.8% vs 9%, p < 0.05) and (16.1% vs 3.6%, p < 0.05).

Conclusions: Compared with the S2AI technique, the IS technique usable larger cantilever force demonstrated more correction of lumbar lordosis, and possible increase in pelvic incidence. Further study is warranted to clarify the clinical impaction of these results.

Keywords: Adult spinal deformity; Iliac screw; Spinopelvic parameters; s2-alar-iliac screw.

MeSH terms

Adult
Bone Screws
Humans
Ilium / diagnostic imaging
Ilium / surgery
Lordosis* / diagnostic imaging
Lordosis* / surgery
Retrospective Studies
Spinal Fusion* / adverse effects