Kyphosis After Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

Prevalence, Features, and Predictive Factors of Spontaneous Spinal Arthrodesis in Posttraumatic Thoracolumbar Kyphosis

OBJECTIVE

Spontaneous spinal arthrodesis (SSA) is a phenomenon of spontaneous fusion, and SSA is not rare in posttraumatic thoracolumbar kyphosis (PTK). However, few reports have focused on SSA in patients with PTK. The objective of this study was to investigate the prevalence, features, and predictive factors of SSA in patients with PTK.

METHODS

In this retrospective study, 70 patients with PTK were included. Data on the clinical and radiologic parameters were obtained and evaluated. According to whether there was SSA or not, patients were divided into an SSA group (n = 45) or a non-SSA group (n = 25). A binary logistic regression analysis was used to identify the predictive factors for SSA.

RESULTS

The incidence of SSA in PTK was 64%. Among 45 patients with PTK with SSA, SSA was present as a solid bridging anterior osteophyte along the vertebral bodies in 11 patients, posterior contiguous bony growth through the facet joints bilaterally in 13 patients, bony formation in both anterior and posterior elements in 18 patients, and direct contiguous bony formation from the injured vertebral body to the adjacent one in 3 patients. Patients with longer disease duration, larger local Cobb angle, and anterior wall height loss (AWHL) ratio of injured vertebral body, and less kyphosis flexibility index were significantly more likely to develop SSA. The parameter of AWHL remained significant in binary logistic regression analysis.

CONCLUSIONS

SSA in PTK was common, and the SSA sign presented in various patterns, which might have implications for surgical decisions. AWHL was the independent predictor for SSA.

Factors influencing vertebral collapse in osteoporotic vertebral fractures: a case-control study of symptomatic patients attended in the emergency department

This study aimed to identify risk factors for the collapse of osteoporotic vertebral fractures (OVFs). We analyzed data from conventional radiography and computed tomography in patients with OVFs and found that older age and two radiological measurements were predictive for vertebral collapse. These factors can be useful for clinical practice.

PURPOSE

To identify risk factors for collapse of osteoporotic vertebral fractures (OVF) on computed tomography (CT) and conventional radiography (CR).

METHODS

This is a retrospective case-control study including a series of patients with OVF diagnosed at the emergency department of our institution from January to September 2019. Inclusion criteria were to have standing CR and supine CT within 2 weeks after the diagnosis of OVF and a follow-up CR at 6 months or later. We evaluated different imaging measurements at the initial diagnostic examinations, including vertebral height loss, local kyphosis, vertebral density, and fracture type according to the grading systems of Genant, Sugita, Association of Osteosynthesis (AO) Spine, and the German Society for Orthopaedics and Trauma. Vertebral collapse was defined as loss of ≥ 50% of vertebral area or height. Cases and controls were defined as OVFs which collapse and do not collapse, respectively, on follow-up.

RESULTS

Fifty-six patients were included in the study, with a mean age of 72.6 ± 1.2 years, including 48 women. Twenty-five (44.6%) OVFs developed collapse on follow-up. None of the fracture classification systems were found to be predictive of collapse. Multivariate analysis showed that older age, increased density ratio (≥ 2) between the fractured and non-fractured vertebral bodies, and a ≥ 6% difference in posterior vertebral height (PVH) loss between standing CR and supine CT exhibited 88% discriminative power in predicting vertebral collapse.

CONCLUSIONS

Age over 72.5 years, a density ratio ≥ 2 between the fractured and non-fractured vertebral bodies, and a difference equal to or higher than 6% in PVH loss between standing CR and supine CT, are risk factors for developing vertebral collapse after OVF.

Difference in the Cobbs Angle Between Standing and Supine Position as a Prognostic Factor After Vertebral Augmentation in Osteoporotic Vertebral Compression Fractures

Objective

We retrospectively analyzed patients with osteoporotic vertebral compression fracture (OVCF) undergoing vertebral augmentation to compare the Cobb angle changes in the supine and standing positions and the clinical outcomes.

Methods

We retrospectively extracted the data of OVCF patients who underwent vertebral augmentation. Back pain was assessed using a visual analogue scale (VAS). Supine and standing radiographs were assessed before treatment to determine the Cobb angle and compression ratio. Receiver operating characteristic curve analysis was performed to determine the optimal cutoff to predict favorable outcomes after vertebral augmentation.

Results

A total of 249 patients were included. We observed a statistically significant increase in the VAS score change with increasing Cobb angle and compression ratio (p < 0.001), and multivariate logistic regression analysis showed that a difference in the Cobb angle (odds ratio [OR], 1.27) and compression ratio (OR, 1.12) were the independent risk factors for predicting short-term favorable outcomes after vertebral augmentation. In addition, we found that the difference in the Cobb angle (OR, 1.05) was the only factor for predicting midterm favorable outcomes after vertebral augmentation. The optimal cutoff value of the difference in the Cobb angle for predicting midterm favorable outcomes was 35.526°.

Conclusion

We found that the midterm clinical outcome after vertebral augmentation was better when there was a difference of approximately 35% or more in the Cobb angle between the standing and supine positions. Surgeons should pay attention to the difference in the Cobb angle depending on the posture when deciding to perform vertebral augmentation in patients with OVCFs.

Analysis of the Classification Systems for Thoracolumbar Fractures in Adults and Their Evolution and Impact on Clinical Management

Although they represent a significant chapter of traumatic pathology with a deep medical and social impact, thoracolumbar fractures have proven to be elusive in terms of a definitive classification. The ever-changing concept of the stability of a thoracolumbar injury (from Holdsworth’s two-column concept to Denis’ three-column theory), the meaningful integration of neurological deficit, and a reliable clinical usability have made reaching a universally accepted and reproductible classification almost impossible. The advent of sophisticated imaging techniques and an improved understanding of spine biomechanics led to the development of several classification systems. Each successive system has contributed significantly to the understanding of physiopathological mechanisms and better treatment management. Magerl et al. developed a comprehensive classification system based on progressive morphological damage determined by the following three fundamental forces: compression, distraction, and axial torque. Vaccaro et al. devised the thoracolumbar injury severity score based on the following three independent variables: the morphology of the injury, posterior ligamentous complex (PLC) integrity, and neurological status at the time of injury. However, there are limitations to the classification system, especially when magnetic resonance imaging yields an uncertain status of PLC. The authors review the various classification systems insisting on their practical relevance and caveats and illustrate the advantages and disadvantages of the most widely used systems with relevant cases from their practice.