Comparison of the Outcomes between AO Type B2 Thoracolumbar Fracture with and without Disc Injury after Posterior Surgery

Abstract

Objective The type AO B2 thoracolumbar fracture is a kind of flexion‐distraction injury and the effect of disc injury on treatment results of patients with B2 fracture remains unclear. The objective of the current study was to compare and analyze the outcomes in AO Type B2 thoracolumbar fracture patients with and without disc injuries in terms of the Cobb angle of kyphosis, the incidence of complication, and the rate of implant failure. Methods This is a retrospective study. Of the 486 patients with thoracolumbar fractures who underwent posterior fixation, 38 patients with AO type B2 injuries were included. All the patients were divided into two groups according to changes in the adjoining discs. Disc injury group A included 17 patients and no disc injury group included 21 patients. Clinical and radiologic parameters were evaluated before surgery, after surgery, and at follow‐up. Clinical outcomes included visual analogue scale (VAS) scores, incidence of complications, and incidence of implant failure. Radiologic assessment was accomplished with the Cobb angle (CA), local kyphosis (LK), percentage of anterior vertebral height (AVBH%), intervertebral disc height, and intervertebral disc angle. Fisher's precision probability tests were employed and chi square test were used to compare categorical variables. Paired sample t tests and independent‐sample t tests were used to compare continuous data. Results Disc injury mainly involved the cranial disc (15/19, 78.9%). The mean follow‐up period for the patients was 30.2 ± 20.1 months. No neurologic deterioration was reported in the patients at the last follow‐up. Radiological outcomes at the last follow‐up showed significant differences in the CA (18.59° ± 13.74° vs 8.16° ± 9.99°, P = 0.008), LK (12.74° ± 8.00° vs 6.55° ± 4.89°, P = 0.006), and %AVBH (77.16% vs 90.83%, P = 0.01) between the two groups.Implant failure occurred after posterior fixation in five patients with disc injury who did not undergo interbody fusion during the initial surgery. Additionally, in the subgroup analysis, interbody fusion in the implant failure group were significantly different than in the no implant failure group (0% vs 75%, P = 0.009). Conclusions AO B2 fracture patients with disc injury have higher risk of complications, especially implant failure after posterior surgery. Interbody fusion should be considered in AO type B2 fracture patients with disc injury.

Comparison of the Clinical and Radiologic Outcomes of Two Treatment Methods in Patients with Thoracolumbar Junction Distraction Fracture: Short- versus Long-Segment Posterior Stabilization

“…25,26 Hu et al compared the local kyphosis and Cobb angle between patients with disk injuries in AO Spine type B2 thoracolumbar fracture and without disk injuries. 27 They found that there was a significant difference between the groups regarding the Cobb angle (p ¼ 0.008) and LKA (p ¼ 0.006) at the last follow-up visit. Joseph et al reported the data of 15 patients who were treated with posterior stabilization using pedicle screws for the treatment of thoracic spine flexion-distraction injuries with a follow-up duration of 16.1 months.…”

“…The management of distraction thoracolumbar fracture generally requires the use of the posterior approach, fixation and fusion for the prevention of local kyphotic deformities or nonunions [21,27]. Hu et al reported a study which compare the local kyphosis and cobb angle between patients with disc injuries in AO Type B2 thoracolumbar fracture and without disc injuries [15]. In that study, they found that there was significant difference between the groups regarding cobb angle (p= 0.008) and LKA (p=0.006) at the last follow-up visit.…”