Traumatic canal stenosis should not be an indication for surgical decompression in thoracolumbar burst fracture

Multiple parameters for evaluating posterior longitudinal ligaments in thoracolumbar burst fractures

BACKGROUND

The posterior longitudinal ligament plays a key role in spinal stability. The purpose of this study was to determine the injuries of the posterior longitudinal ligament (PLL) in thoracolumbar burst fractures.

PATIENTS AND METHODS

Patients suffering a thoracolumbar burst fracture from January 2011 to December 2015 were divided into an intact group and a disrupted group according to the status of the PLL. Mid-sagittal canal diameter, width and height of bone fragments, inversion angle and horizontal rotation angle of bone fragments and local kyphosis angle were measured. Anterior, middle and posterior vertebrae compression ratio, mid-sagittal diameter compression ratio, ratio of height of bone fragments occupying the posterior wall of the injured vertebral body and ratio of the width of bone fragment occupying the transverse canal diameter were calculated.

RESULTS

A total of 95 patients were included in the study including 52 patients in the intact group and 43 patients in the disrupted group. There were significant differences on anterior and posterior vertebrae compression ratio, mid-sagittal diameter compression ratio, inversion angle and horizontal rotation angle of bone fragment (P  0.05) between the two groups. Injury of the PLL showed a positive correlation with the mid-sagittal diameter compression ratio and inversion angle of bone fragment (P  0.05).

CONCLUSION

The mid-sagittal diameter compression ratio and inversion angle of bone fragment can be used to assess the status of the PLL in thoracolumbar burst fractures. When the mid-sagittal diameter compression ratio was 52% and the inversion angle of the bone fragment was 33° the PLL was likely to be disrupted.

Surgical treatment of Denis type B thoracolumbar burst fracture with neurological deficiency by paraspinal approach

We aimed to describe the surgical technique and clinical outcomes of paraspinal-approach reduction and fixation (PARF) in a group of patients with Denis type B thoracolumbar burst fracture (TLBF) with neurological deficiencies. A total of 62 patients with Denis B TLBF with neurological deficiencies were included in this study between January 2009 and December 2011. Clinical evaluations including the Frankel scale, pain visual analog scale (VAS) and radiological assessment (CT scans for fragment reduction and X-ray for the Cobb angle, adjacent superior and inferior intervertebral disc height, and vertebral canal diameter) were performed preoperatively and at 3 days, 6 months, and 1 and 2 years postoperatively. All patients underwent successful PARF, and were followed-up for at least 2 years. Average surgical time, blood loss and incision length were recorded. The sagittal vertebral canal diameter was significantly enlarged. The canal stenosis index was also improved. Kyphosis was corrected and remained at 8.6±1.4^o (P>0.05) 1 year postoperatively. Adjacent disc heights remained constant. Average Frankel grades were significantly improved at the end of follow-up. All 62 patients were neurologically assessed. Pain scores decreased at 6 months postoperatively, compared to before surgery (P<0.05). PARF provided excellent reduction for traumatic segmental kyphosis, and resulted in significant spinal canal clearance, which restored and maintained the vertebral body height of patients with Denis B TLBF with neurological deficits.

Decision-Making Process in Patients with Thoracolumbar and Lumbar Burst Fractures with Thoracolumbar Injury Severity and Classification Score Less than Four

STUDY DESIGN

Cross-sectional.

PURPOSE

To develop a strategy to determine a sound method for decision-making based on postoperative clinical outcome satisfaction.

OVERVIEW OF LITERATURE

The ideal management of thoracolumbar and lumbar burst fractures (TLBF) without neurological compromise remains controversial.

METHODS

This was a prospective study. Patients with thoracolumbar injury severity and classification score (TLICS) <4 were treated nonoperatively, with bed rest and bracing until the pain decreased sufficiently to allow mobilization. Surgery was undertaken in patients with intractable pain despite an appropriate nonoperative treatment (surgery group). The Oswestry disability index (ODI) measure was observed at baseline and at the last follow-up. Clinically success was defined at least a 30% improvement from the baseline ODI scores in both the conservative and surgery groups. All case records were assessed for gender, age, residual canal and angulations at the site of the fracture in order to determine which patients benefited from surgery or conservative treatment and which did not.

RESULTS

In all 113 patients with T11-L5, TLBFs were treated. The patients' mean age was 49.2 years. Patients successfully completed either nonoperative (n=99) or surgical (n=14) treatment based on ODI. Clinical examinations revealed that all of the patients had intact neurology. The mean follow-up period was 29.5 months. There was a significant difference between the two groups based on age and residual canal. The mean ODI score significantly improved for both groups (p <0.01). According to the findings, a decision matrix was proposed.

CONCLUSIONS

The findings confirm that TLICS <4, age, and residual canal can be used to guide the treatment of TLBF in conservative decision-making.

Early mobilisation of thoracolumbar burst fractures without neurology

Aims

The authors present the results of a cohort study of 60 adult patients presenting sequentially over a period of 15 years from 1997 to 2012 to our hospital for treatment of thoracic and/or lumbar vertebral burst fractures, but without neurological deficit.

Method

All patients were treated by early mobilisation within the limits of pain, early bracing for patient confidence and all progress in mobilisation was recorded on video. Initial hospital stay was one week. Subsequent reviews were made on an outpatient basis.

Results

The mean duration from admission to final follow-up was three months, and longer follow-up was undertaken telephonically. The mean kyphosis deformity on arrival was 17.4° (5° to 29°); mean kyphosis at final discharge three months later was 19.5° (1° to 28°). Spinal canal encroachment had no influence on successful functional recovery.

Discussion

Pain has not been a significant problem for any patient, irrespective of the degree of kyphosis and no patient has a self-perception of clinical deformity. In all, 11 patients took occasional analgesia. All patients returned to their original work level or better. Two patients died 2.5 years after treatment, from unrelated causes. Take home message: The natural history of thoracolumbar burst fractures without neurology would appear to be benign. Cite this article: Bone Joint J 2016;98-B:97–101.

Relationship between fracture-relevant parameters of thoracolumbar burst fractures and the reduction of intra-canal fracture fragment

OBJECTIVE

Posterior longitudinal ligament reduction (PLLR) has been widely used for treatment of thoracolumbar burst fractures. However, there are no systemic studies assessing the influence of position parameters of intra-canal fracture fragment (IFF) itself on outcome of reduction. The aim of this study was to analyze the relationship between position parameters of IFF and the reduction efficacy of PLLR.

METHODS

Sixty-two patients (average age, 36.9 years) with single thoracolumbar burst fractures and intact posterior longitudinal ligaments were recruited. Patients were divided into reduced and unreduced groups based on IFF reduction situations by PLLR. Preoperative and intraoperative computed tomography (CT) were used to evaluate reduction and location parameters of IFF, such as position, width, height, inversion, and horizontal angle, ratio of width of IFF to the transverse diameter of vertebral canal (R 1), and ratio of height of IFF to height of injured vertebrae (R 2) before and after PLLR.

RESULTS

There were significant differences in width (P < 0.001), height (P = 0.0141; R 1, P < 0.001), and R 2 (P = 0.0045) between the two groups. When width of IFF was more than 75 % of transverse diameter of vertebral canal and height of IFF was more than 47 % of height of injured vertebrae, the IFF could not be reduced by PLLR.

CONCLUSIONS

In patients with thoracolumbar burst fractures, IFF in apterium of the posterior longitudinal ligament cannot be reduced by PLLR. For thoracolumbar burst fractures that cover the posterior longitudinal ligament, the width and height of IFF are important parameters that influence reduction quality.

Finite element study of the mechanical response in spinal cord during the thoracolumbar burst fracture

Background

The mechanical response of the spinal cord during burst fracture was seldom quantitatively addressed and only few studies look into the internal strain of the white and grey matters within the spinal cord during thoracolumbar burst fracture (TLBF). The aim of the study is to investigate the mechanical response of the spinal cord during TLBF and correlate the percent canal compromise (PCC) with the strain in the spinal cord.

Methodology/Principal Findings

A three-dimensional (3D) finite element (FE) model of human T12-L1 spinal cord with visco-elastic property was generated based on the transverse sections images of spinal cord, and the model was validated against published literatures under static uniaxial tension and compression. With the validated model, a TLBF simulation was performed to compute the mechanical strain in the spinal cord with the PCC. Linear regressions between PCC and strain in the spinal cord show that at the initial stage, with the PCC at 20%, and 45%, the corresponding mechanical strains in ventral grey, dorsal grey, ventral white, dorsal white matters were 0.06, 0.04, 0.12, 0.06, and increased to 0.14, 0.12, 0.23, and 0.13, respectively. At the recoiled stage, when the PCC was decreased from 45% to 20%, the corresponding strains were reduced to 0.03, 0.02, 0.04 and 0.03. The strain was correlated well with PCC.

Conclusions/Significance

The simulation shows that the strain in the spinal cord correlated well with the PCC, and the mechanical strains in the ventral regions are higher than those in the dorsal regions of spinal cord tissue during burst fracture, suggesting that the ventral regions of the spinal cord may susceptible to injury than the dorsal regions.