# Double claw construct with hooks for proximal fixation in adolescent idiopathic scoliosis: a randomized controlled trial

**Authors:** J. J. M. Renkens, A. Willems, M. Reijman, P. de Baat, L. W. L. de Klerk, J. P. H. J. Rutges

PMC · DOI: 10.1007/s43390-025-01161-5 · Spine Deformity · 2025-08-28

## TL;DR

A study compared two surgical methods for adolescent scoliosis and found both were equally effective in correcting spine curvature.

## Contribution

A randomized controlled trial comparing all screw and double hook-claw constructs for proximal fixation in AIS surgery.

## Key findings

- No significant difference in Cobb angle correction between all screw and double hook-claw constructs after two years.
- Both methods showed similar improvements in thoracic kyphosis and patient-reported outcomes.
- Complication rates were comparable between the two groups.

## Abstract

Proximal fixation in adolescent idiopathic scoliosis (AIS) surgery is a matter of discussion. All screw (AS) constructs provide better coronal correction than hybrid constructs, but high thoracic pedicle screw placement can be challenging. This study investigated whether an AS-construct provides better correction than a proximal double hook-claw (PH) construct.

AIS patients undergoing posterior spinal fusion (PSF) were randomized to AS-construct or PH-construct from 2016 to 2020 with a two-year follow-up. Primary outcome is the main thoracic (MT) Cobb angle correction after two years. Secondary outcomes are thoracic kyphosis (TK), proximal junctional angle (PJA), proximal thoracic (PT) Cobb angle, SRS-22r, and complications after two years.

60 patients (30 AS, 30 PH) were included. No baseline differences were found. Preoperative MT Cobb angle was 62° ± 11° (AS) vs. 65° ± 12° (PH). There was no statistical difference in MT Cobb angle after two years: 25° ± 9° (AS) vs. 27° ± 7° (PH) (p = 0.247). No difference in PT Cobb angle was found: 20° ± 9° (AS) vs. 21° ± 9° (PH) and TK: 23° ± 9° (AS) vs. 22° ± 7° (PH). SRS-22r improved in both groups with no statistical difference: 3.9 ± 0.5 to 4.3 ± 0.5 (AS) vs. 3.7 ± 0.5 to 4.3 ± 0.5 (PH). There were 13 complications (ten patients) in AS group and 17 (13 patients) in PH group, including 1 major complication in each group (deep wound infection).

AS-construct does not provide better coronal Cobb correction after two years after surgery. A PH-construct is a reliable and safe option for proximal fixation AIS patients. TRN: NTR-NL5552 (2016).

Overview of medical research in the Netherlands (OMON): NL-OMON43852.

## Linked entities

- **Diseases:** adolescent idiopathic scoliosis (MONDO:0005488)

## Full-text entities

- **Diseases:** wound infection (MESH:D014946), TK (MESH:D007738), AIS (OMIM:181800)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

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Source: https://tomesphere.com/paper/PMC12815994