Abstract and Introduction
Study Design: Meta-analysis.
Objective: To compare the clinical, functional, and radiological outcomes of posterior-only versus combined anterior-posterior instrumentation in order to determine the optimal surgical intervention for thoracolumbar burst fractures.
Summary of Background Data: Unstable thoracolumbar burst fractures warrant surgical intervention to prevent neurological deterioration and progressive kyphosis, which can lead to significant pain and functional morbidity. The available literature remains largely inconclusive in determining the optimal instrumentation strategy.
Methods: Electronic searches of MEDLINE (1948–May 2020), EMBASE (1947–May 2020), The Cochrane Library (1991–May 2020), and other databases were conducted. Cochrane Collaboration guidelines were used for data extraction and quality assessment. Outcomes of interest were divided into three categories: radiological (degree of postoperative kyphosis correction; loss of kyphosis correction at final follow-up), functional (visual analogue scale [VAS] pain score; Oswestry Disability Index [ODI] score), and clinical (intraoperative blood loss; length of stay [LOS]; operative time; the number and type of postoperative complications).
Results: Four randomized control trials (RCTs) were retrieved, including 145 randomized participants. Seventy-three patients underwent posterior-only instrumentation and 72 underwent combined instrumentation. No significant difference was found in the degree of postoperative kyphosis correction (P = 0.39), VAS (centimeters) at final follow-up (P = 0.67), ODI at final follow-up (P = 0.89) or the number of postoperative complications between the two approaches (P = 0.49). Posterior-only instrumentation was associated with lower blood loss (P < 0.001), operative time (P < 0.001), and LOS (P = 0.01). Combined instrumentation had a lower degree of kyphosis loss at final follow-up (P = 0.001). There was heterogeneity in the duration of follow-up between the included studies (mean follow-up range 24–121 months).
Conclusion: The available literature remains largely inconclusive. In order to reliably inform practice in this area, there is a need for large, high-quality, multicenter RCTs with standardized reporting of outcomes, with a particular focus on outcomes relating to patient function and severe complications causing long-term morbidity.
Level of Evidence: 2
Approximately 90% of spine fractures occur in the thoracolumbar spine (T11–L2).[1,2] The thoracolumbar spine represents the junction between a relatively immobile, kyphotic thoracic spine and a mobile, lordotic lumbar spinal segment, resulting in a concentration of stress forces and predisposition to injury.[2,3] Of all fractures that occur in the thoracolumbar spine, 10% to 20% are burst fractures.[2,3] The incidence in males is estimated to be four times higher than in females. The most common cause is motor vehicle accidents, followed by falls and sport-associated injuries. Thoracolumbar burst fractures (TLBFs) confer a significant degree of morbidity, with up to 50% associated with an injury to a second organ system.
TLBFs can range in severity. Stable injuries can be effectively managed nonoperatively with bracing and early mobilization.[4,5] Unstable burst fractures with a significant degree of retropulsion and spinal canal compromise can lead to neurological injury in up to 60% of patients. TLBFs with a Thoracolumbar Injury Classification and Severity (TLICS) score greater than or equal to five warrant surgical intervention. Many options exist for the surgical stabilization of TLBFs. Fixation can be accomplished by posterior pedicle-screw and rod fixation, or by corpectomy and decompression of the anterior column with reconstruction using a static or expandable cage filled with autologous or synthetic graft. Supplemental anterior fixation with a plate and screw construct can also be used.[2,8–10]
A significant degree of uncertainty exists in relation to the optimal strategy for the surgical management of TLBFs. Advantages of anterior instrumentation include the ability to perform a thorough decompression of the spinal canal and reconstruction of the anterior and middle spinal columns. Posterior-only fixation is associated with hardware loosening, which is postulated to be due to the fact that the anterior column of the spine accounts for 80% of its stability.[8,11] As a result, the rate of combined anterior-posterior instrumentation has increased by approximately 15% from 2000 to 2009. Evidence has shown that circumferential fusion provided by combined anterior-posterior instrumentation is superior in maintaining postoperative kyphosis compared with posterior-only fixation.[6,12] However, studies to date have been unable to demonstrate superiority in relation to clinical outcomes.[6,13] The morbidity associated with the anterior approach may account for this to some degree.
The evidence to date comparing posterior and combined instrumentation for TLBFs has been inconclusive.[6,14] In light of this, we endeavored to systematically review existing evidence from randomized control trials (RCTs) to compare the clinical, functional, and radiological outcomes of these approaches for patients with TLBFs through the methodology of meta-analysis.
Spine. 2021;46(15):E840-E849. © 2021 Lippincott Williams & Wilkins