# Is the anterior approach still superior to posterior correction in AIS regarding correction, fusion levels and kyphosis when modern posterior systems are used?

## TL;DR

This study compares anterior and posterior surgical approaches for correcting spinal curves in AIS patients using modern posterior techniques.

## Contribution

It shows that modern posterior systems can achieve results comparable to anterior approaches in thoracic correction and better in lumbar lordosis.

## Key findings

- Posterior approach achieved similar thoracic correction and kyphosis as the anterior approach.
- Posterior approach restored better lumbar lordosis compared to the anterior approach.
- Both approaches used similar fusion lengths for thoracic and lumbar curves.

## Abstract

The aim of our study is to compare anterior and posterior corrections of thoracic (Lenke I) and lumbar (Lenke V) curves when modern posterior pedicle screw systems with vertebral derotation techniques are used. Curves that could not be corrected with both systems were excluded.

A thoracic group (N = 56) of Lenke I AIS patients (18 anterior and 38 posterior) and a lumbar group (N = 42) of Lenke V patients (14 anterior and 28 posterior) with similar curves < 65° were identified.

Thoracic group The mean postoperative correction (POC) was 68 ± 13.4% in the anterior and 72 ± 10.5% in the posterior group. The postoperative change in thoracic kyphosis was +4° and +5° respectively. The median length of fusion was eight segments in the posterior and seven segments in the anterior groups. In 89% the LIV was EV or shorter in the anterior, and in 71% of the posterior corrections.

Lumbar group The mean POC was 75 ± 18.3% (anterior) and 72 ± 8.5% (posterior). The postoperative gain in lumbar lordosis was 0.8° (anterior) and 4° (posterior). The median length of fusion was five segments in both groups and there was no difference in relation of the LIV to the EV.

With modern implants and derotation techniques, the posterior approach can achieve similar coronal correction, apical derotation and thoracic kyphosis with similar length of fusion and better lumbar lordosis restoration.