Motion Preservation Following Vertebral Body Tethering: An Analysis of 103 Patients

Area of Science:

• Spine surgery
• Orthopedics
• Adolescent idiopathic scoliosis

Background:

• Vertebral body tethering (VBT) is an increasingly popular motion-sparing surgical technique for scoliosis.
• Limited data exists on motion preservation following different VBT approaches.
• This study investigated spinal motion post-VBT in thoracic, lumbar, and bilateral procedures.

Purpose of the Study:

• To evaluate spinal motion preservation in both sagittal and coronal planes after VBT.
• To compare preoperative and postoperative coronal range of motion in adolescent idiopathic scoliosis (AIS) patients.
• To assess preserved sagittal arc of motion following VBT.

Main Methods:

• Retrospective comparison study of AIS patients who underwent VBT.
• Coronal range of motion measured using microdose slot-scanning.
• Flexion/extension radiographs used to assess sagittal motion.
• Patients with cord breakage excluded.

Main Results:

• Mean follow-up was 2.8 years; 26.9% achieved skeletal maturity.
• Coronal motion decreased by 59% in the thoracic spine and 51% in the lumbar spine.
• Sagittal motion was preserved, with 20-25 degrees of arc in instrumented segments.
• Flexion exceeded extension in sagittal motion.

Conclusions:

• VBT leads to a significant decrease in coronal spinal motion (57-60%).
• Sagittal plane motion is largely preserved after VBT.
• Further research is needed to determine the functional benefits of VBT-induced motion preservation.