Patients with ankylosing spondylitis suffering from AO Type B3 traumatic thoracolumbar fractures are associated with increased frailty and morbidity when compared with patients with diffuse idiopathic skeletal hyperostosis

Perioperative risk stratification of spine trauma patients with ankylosing spinal disorders: a comparison of 3 quantitative indices

OBJECTIVE

Patients with ankylosing spinal disorders (ASDs), including ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH), have been shown to experience significantly increased rates of postoperative complications. Despite this, very few risk stratification tools have been validated for this population. As such, the purpose of this study was to identify predictors of adverse events and mortality in ASD patients undergoing surgery for 3-column fractures.

METHODS

All adult patients with a documented history of AS or DISH who underwent surgery for a traumatic 3-column fracture between 2000 and 2020 were identified. Perioperative variables, including comorbidities, time to diagnosis, and number of fused segments, were collected. Three instruments, including the Charlson Comorbidity Index (CCI), modified frailty index (mFI), and Injury Severity Score (ISS), were computed for each patient. The primary outcomes of interest included 1-year mortality, as well as postoperative complications.

RESULTS

A total of 108 patients were included, with a mean ± SD age of 73 ± 11 years. Of these, 41 (38%) experienced at least 1 postoperative complication and 22 (20.4%) died within 12 months after surgery. When the authors controlled for potential known confounders, the CCI score was significantly associated with postoperative adverse events (OR 1.20, 95% CI 1.00-1.42, p = 0.045) and trended toward significance for mortality (OR 1.19, 95% CI 0.97-1.45, p = 0.098). In contrast, mFI score and ISS were not significantly predictive of either outcome.

CONCLUSIONS

Complications in spine trauma patients with ASD may be driven by comorbidity burden rather than operative or injury-related factors. The CCI may be a valuable tool for the evaluation of this unique population.

Which frailty scales for patients with adult spinal deformity are feasible and adequate? A systematic review

BACKGROUND CONTEXT

Frailty as a concept is not yet fully understood, and is not the same as comorbidity. It is associated with an increased risk of adverse events and mortality after surgery, which makes its preoperative assessment significant. Despite its relevance, it still remains unclear which scales are appropriate for use in patients with spinal pathology.

PURPOSE

To evaluate the feasibility and measurement properties of frailty scales for spine patients, specifically with adult spinal deformity (ASD), and to propose adequate scales for primary triage to prevent surgery in too frail patients and for preoperative assessment to modify patients' condition and surgical plans.

STUDY DESIGN/SETTING

Systematic review.

METHODS

Systematic search was performed between 2010 and 2021 including terms relating to spinal disorders, frailty scales, and methodological quality. Characteristics of the studies and frailty scales and data describing relation to treatment outcomes were extracted. The risk of bias was determined with the QAREL score.

RESULTS

Of the 1993 references found, 88 original studies were included and 23 scales were identified. No prospective interventional study was found where the preoperative frailty assessment was implemented. Predictive value of scales for surgical outcomes varied, dependent on spinal disorders, type of surgeries, patients' age and frailty at baseline, and outcomes. Seventeen studies reported measurement properties of eight scales but these studies were not free of bias. In 30 ASD studies, ASD-Frailty Index (ASD-FI, n=14) and 11-item modified Frailty Index (mFI-11, n=11) were most frequently used. These scales were mainly studied in registry studies including young adult population, and carry a risk of sample bias and make their validity in elderly population unclear. ASD-FI covers multidisciplinary concepts of frailty with 40 items but its feasibility in clinical practice is questionable due to its length. The Risk Analysis Index, another multidisciplinary scale with 14 items, has been implemented for preoperative assessment in other surgical domains and was proven to be feasible and effective in interventional prospective studies. The FRAIL is a simple questionnaire with five items and its predictive value was confirmed in prospective cohort studies in which only elderly patients were included.

CONCLUSIONS

No adequate scale was identified in terms of methodological quality and feasibility for daily practice. Careful attention should be paid when choosing an adequate scale, which depends on the setting of interest (eg triage or preoperative work-up). We recommend to further study a simple and predictive scale such as FRAIL for primary triage and a comprehensive and feasible scale such as Risk Analysis Index for preoperative assessment for patients undergoing spine surgery, as their adequacy has been shown in other medical domains.

Association of Continuous Vertebral Bone Bridges and Bone Mineral Density with the Fracture Risk in Patients with Diffuse Idiopathic Skeletal Hyperostosis

Study Design

Cross-sectional study.

Purpose

To examine whether the number of continuous vertebral bone bridges and bone mineral density (BMD) influence the fracture risk in diffuse idiopathic skeletal hyperostosis (DISH) patients.

Overview of Literature

Bone bridges connecting through the intervertebral body in DISH create long lever arms that can increase the risk of fractures from minor trauma. DISH patients have a BMD that is higher than or comparable to those of age-matched healthy subjects.

Methods

We examined the computed tomography scans from the thoracic vertebra to the sacrum used to diagnose DISH in 140 patients (98 men and 42 women; average age, 78.6 years). We compared patients who did (n=52) and did not have (n=88) fractures at the continuous vertebral bodies fused by bone bridges. The relationship between the vertebral fractures and the maximum number of vertebrae that are bony cross-linked with contiguous adjacent vertebrae (max VB) from the thoracic vertebra to the sacrum or from the lumbar vertebra to the sacrum and proximal femur BMD were analyzed using a logistic regression model.

Results

We found that after adjusting for the confounding factors, higher max VB, both from the thoracic vertebrae to the sacrum and the lumbar vertebrae to the sacrum, was associated with a higher risk of vertebral fractures. This difference was statistically significant. The risk was higher when only the lumbar vertebrae to the sacrum was considered (thoracic vertebrae to the sacrum: odds ratio, 1.21; p<0.05; lumbar vertebrae to the sacrum: odds ratio, 2.78; p<0.01). Moreover, low proximal femur BMD in DISH patients raises the fracture risk (odds ratio, 0.47; p<0.01).

Conclusions

Many continuous vertebral bone bridges, especially those that extend to the lumbar spine and low proximal femur BMD, are risk factors for fracture in DISH patients.

Spinal trauma in DISH and AS: is MRI essential following the detection of vertebral fractures on CT?

BACKGROUND

Both ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) cause a rigid spine, but through different pathophysiology. Recent data has shown that characteristic fracture patterns may also differ following trauma since the posterior osseous and soft tissue elements are often spared in DISH. CT and MRI are important in diagnosing spine injury, but given the differences between AS and DISH, the utility of obtaining both studies in all patients warrants scrutiny.

PURPOSE

To assess the prevalence of posterior element injury on CT and MRI in DISH and AS patients with known vertebral body injury detected on CT; to determine whether MRI demonstrates additional injuries in neurologically intact patients presumed to have isolated vertebral body injuries on CT.

STUDY DESIGN

Multicenter, retrospective, case-control study.

PATIENT SAMPLE

DISH and AS patients presenting after spine trauma between 2007 and 2017.

OUTCOME MEASURES

Review of CT and MRI findings at the time of presentation.

METHODS

One hundred sixty DISH and 85 AS patients presenting after spine trauma were identified from 2 affiliated academic hospitals serving as level 1 trauma and tertiary referral centers. A diagnosis of DISH or AS was verified by a board-certified emergency radiologist with 3 years of experience. Age, gender, mechanism of injury, fracture type, spine CT and MRI imaging findings, surgical intervention, and neurologic deficit were recorded. The CT and MRI studies were reviewed by the same radiologist for fracture location and type using the AO spine classification. No funding source or conflict of interest was present.

RESULTS

Median age was 72 and 79 years old for the AS and DISH groups, respectively. Both were predominantly male (81%) and most presented after a low energy mechanism of injury (74% and 73%). Type C AO spine injuries were seen in 52% of AS patients but only 4% of DISH patients. In patients with known vertebral body injury on CT, additional injury to the posterior elements on CT or MRI in DISH patients was 51% versus 92% in AS patients. However, in patients with an isolated vertebral body fracture on CT and no neurological deficit, MRI identified posterior element injury in only 4/22 (18%) DISH patients compared to 5 of 7 (71%) AS patients. None of the MRI findings in the DISH patients were considered clinically important while all 5 AS patients eventually underwent operative treatment despite having no neurological deficit. Epidural hematoma on MRI was seen in 43% of AS patients as opposed to 5% of DISH patients.

CONCLUSION

Based on our small sample size, CT alone may be adequate in DISH patients with isolated vertebral body fractures and no neurologic deficit, but an additional MRI should be considered in the presence of an unclear neurological exam or deficit. MRI should be strongly considered for any AS patient regardless of neurologic status.