Minimally Invasive Pedicle Screw Fixation Plus PVP With Calcium Phosphate For The Surgical Treatment Of Thoracolumbar Burst Fracture

Presented at SMISS Annual Forum 2014
By Yutong Gu MD, PhD
With Feng Zhang MD, PhD, Robert McGuire MD,

Disclosures: Yutong Gu MD, PhD None Feng Zhang MD, PhD None, Robert McGuire MD None,

Introduction:
Traditional short-segment pedicle instrumentation for the treatments of thoracolumbar burst fracture was frequently applied into the adjacent intervertebral bodies of the injuried vertebrae, but with a high failure rate for the later factors including osteoporosis, insufficient support of anterior column, and lack of enough fixation segments. In addition, the traditional screw implantation, which commonly use a posterior midline approach, resulted in great trauma and blood loss, as well as slow recovery, for the extensive split of muscles.

Aims/Objectives:
we designed minimally invasive pedicle screw fixation (noncannulated pedicle screw insertion under direct vision through minimal-access in a paraspinal sacrospinalis muscle-splitting approach and rod placed over the pedicle screws through subcutaneous soft tissues and muscles) plus PVP with calcium phosphate for treating acute thoracolumbar burst fracture to reduce the trauma and blood loss. The aim of this study was to evaluate the feasibility, safety and efficacy of this method.

Methods:
Twenty-three patients with a mean age of 51.6 years (ranging 40-63 years), who sustained thoracic or lumbar fresh burst fracture without neurologic deficits underwent the procedure of minimally invasive pedicle screw fixation plus PVP with calcium phosphate. Visual analog scale pain scores (VAS) were recorded, and Cobb angles and anterior vertebral body height were measured on the lateral radiographs before surgery and immediately, 1 month, 2 months, 3 months, 6 months, 1 year and 2 years after surgery.

Results:
The mean duration of the operation was 92 minutes (range 75-120 minutes). The mean blood loss was 52 ml (range 40-75 ml), and no blood transfusions were required. The mean stay in the hospital was 5.6 days (range 4-7 days). The patients were followed for an average of 26 months (ranging 24-29 months). The VAS significantly decreased from 8.8±1.2 before surgery to 1.8±0.6 immediately after surgery and 0.4±0.5 (P<0.001) 2 years after surgery. The Cobb angle before surgery was 22.6±1.8° and 3.2±1.7°(P<0.001) immediately after surgery. The compression rate of vertebral body height decreased from 50.4±7.2% before surgery to 6.2±1.5%(P<0.001)immediately after surgery. No significant changes in both kyphosis correction and vertebral body height restoration obtained were observed 2 years after surgery. There was no patient with the failure of instruments during the follow-up.

Conclusions:
Minimally invasive pedicle screw fixation plus PVP with calcium phosphate is a good choice for the treatment of acute thoracolumbar burst fracture.