Sagittal Alignment Reciprocal Changes After Thoracolumbar/Lumbar Anterior Vertebral Body Tethering

Area of Science:

• Spine surgery
• Orthopedics
• Pediatric orthopedics

Background:

• Anterior vertebral body tethering (AVBT) is an increasingly utilized technique for adolescent idiopathic scoliosis (AIS) that preserves spinal mobility.
• This technique aims to avoid fusion-related complications common in traditional spinal fusion methods.

Purpose of the Study:

• To evaluate the early-to-midterm postoperative radiological outcomes of thoracolumbar/lumbar AVBT on sagittal alignment in AIS patients.
• To compare AVBT with selective thoracic fusion (STF) and non-selective fusion (NSF) in terms of radiological and functional results.

Main Methods:

• Retrospective evaluation of AIS patients undergoing AVBT (n=17), NSF (n=19), or STF (n=15).
• Radiological parameters including major curvature, coracoid height difference (CHD), pelvic parameters (SS, PT, PI), spinal curves (LL, TK, CL), C7 tilt, SVA, TPA, and T1SPI were measured.
• Functional outcomes assessed using Scoliosis Research Society-22 (SRS-22) and Oswestry Disability Index (ODI) scores.

Main Results:

• AVBT group showed significant improvement in coracoid height difference (CHD) and cervical lordosis (CL) postoperatively.
• Significant differences were noted in T1SPI between NSF and STF groups.
• No significant differences were found between AVBT, NSF, and STF groups in most radiological parameters (CHD, SS, PT, PI, LL, TK, CL, C7 tilt, SVA, TPA) or functional scores (SRS-22, ODI).

Conclusions:

• Thoracolumbar/lumbar AVBT effectively improves shoulder asymmetry and cervical lordosis in the early postoperative period for AIS.
• AVBT did not demonstrate superiority over spinal fusion techniques in sagittal alignment or functional outcomes.
• Further investigation is required to ascertain the mid- to long-term efficacy of thoracolumbar/lumbar AVBT.