The impact of the lateral decubitus position in the perioperative period on posterior fixation for thoracolumbar fracture with ankylosing spinal disorder

OBJECTIVE

Patients with ankylosing spinal disorders (ASDs), such as ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis, often have rigid kyphosis of the spine. The fracture site is sometimes unintentionally displaced when surgery is conducted with the patient prone. To prevent this incident, the authors adopted the lateral decubitus position for patients intraoperatively for this pathology. The aim of this study was to retrospectively assess the impact of the lateral decubitus position in the perioperative period on posterior fixation for thoracolumbar fractures with ASD.

METHODS

Thirty-seven consecutive patients who underwent posterior instrumentation for thoracolumbar fracture with ASD at the authors' institute were divided into 15 lateral decubitus positions (group L) and 22 prone positions (group P). Surgical time, estimated blood loss (EBL), number of levels fused, perioperative complications, length of stay (LOS), ratio of fracture voids, and ratio of anterior wall height were investigated. The ratio of fracture void and the ratio of anterior wall height were the radiological assessments showing a degree of reduction in vertebral fracture on CT.

RESULTS

Age, sex, BMI, fracture level, and LOS were similar between the groups. Levels fused and EBL were significantly shorter and less in group L (p < 0.001 and p = 0.04), but there was no significant difference in surgical time. The complication rate was similar, but 1 death within 90 days after surgery was found in group P. The ratio of fracture voids was 85.4% ± 12.8% for group L and 117.5% ± 37.3% for group P. A significantly larger number of patients with a fracture void ratio of 100% or less was found in group L (86.7% vs 36.4%, p = 0.002). The ratio of anterior wall height was 107.5% ± 12.3% for group L and 116.9% ± 18.8% for group P. A significantly larger number of patients with the anterior wall height ratio of 100% or less was also found in group L (60.0% vs 27.3%, p = 0.046).

CONCLUSIONS

The results of this study suggest that the lateral decubitus position can be expected to have an effect on closing or maintaining the fracture void or a preventive effect of intraoperative unintentional extension displacement of the fractured site, which is often seen in the prone position during surgery for thoracolumbar fractures involving ASD.

Thoracolumbar Fracture in Disseminated Idiopathic Skeletal Hyperostosis

Disseminated idiopathic skeletal hyperostosis (DISH) is a form of ankylosing spinal disorders, which is at high risk of fracture because of the rigidity of the spinal column and reduced bone quality. The patients with DISH are at higher risk of fall because of the poor muscle tone, rigid spine column, and positive sagittal balance. The management of spinal fractures in these patients proves to be challenging because of the altered biomechanics and alignment of the spine. Furthermore, most patients have multiple comorbidities with high intraoperative burden, and osteoporosis itself will impair any implant purchase of the bone. Here, we report a case of thoracolumbar fracture in DISH where both conservative and surgical approaches were utilized, with unfortunate results in both, and a brief review of the literature on its management.

Femur Bone Mineral Density and Pentosidine Level Distinguish Ankylosing Spinal Disorder Patients with and without Sacroiliac Ankylosis

Introduction

When spinal fracture occurred in ankylosing spinal disorder (ASD) patients, it is important to evaluate not only the long lever arm but also bone density and bone quality for the determination of treatment strategies. This case-controlled study examined bone mineral density (BMD), bone metabolism markers, and pentosidine levels in patients with ASD.

Methods

Subjects with bridging of minimum four contiguous vertebral bodies were classified into ASD group and the rest into non-ASD group. The former was further divided into two subgroups based on the presence/absence of sacroiliac joint ankylosis (SJA). We compared BMD, bone metabolism markers, and pentosidine levels in these groups.

Results

The BMD T and Z scores of the femur proximal extremity were lower in the ASD with SJA group than those in the ASD without SJA group. When groups were matched for age, weight, and eGFR, compared with the non-ASD group, the ASD with SJA group had lower BMD of the lumbar spine and femur proximal extremity and the ASD without SJA group had significantly higher BMDs of the lumbar spine and femur proximal extremity. After matching, the ASD without SJA group showed a significantly higher pentosidine level than the non-ASD group.

Conclusions

Patients with SJA have low femur proximal extremity BMD, whereas those with ASD without SJA have a higher BMD of the femur proximal extremity with high pentosidine level. Investigating the presence or absence of SJA is important for the determination of treatment strategies in fractured ASD patients.

Spinal fractures in diffuse idiopathic skeletal hyperostosis: Advantages of percutaneous pedicle screw fixation

PURPOSE

To validate the effectiveness of percutaneous pedicle screw (PPS) fixation for spinal fractures associated with diffuse idiopathic skeletal hyperostosis (DISH) by comparing surgical outcomes for PPS fixation and conventional open posterior fixation. Patients with DISH are vulnerable to unstable spinal fractures caused by trivial trauma, and these fractures have high rates of delayed paralysis, postoperative complications, and mortality.

METHODS

This retrospective study assessed surgical outcomes for 16 patients with DISH (12 men; mean age 76.1 ± 9.4 years) who underwent PPS fixation for spinal fractures (pedicle screw (PS) group), and for a control group of 25 patients with DISH (18 men; mean age 77.9 ± 9.9 years) who underwent conventional open fixation (O group) at our affiliated hospitals from 2007 to 2017. We evaluated the preoperative physical condition (American Society of Anesthesiologists (ASA) classification), neurological status (Frankel grade), and improvement after surgery, fusion length, operating time, estimated blood loss, and perioperative complications.

RESULTS

Preoperatively, the PS group consisted of one ASA-1 patient, eight ASA-2 patients, six ASA-3 patients, and one ASA-4 patient; by Frankel grade, there were 2 grade B patients, 13 grade C, 4 grade D, and 6 grade E patients. The O group had 2 ASA-1 patients, 13 ASA-2, 9 ASA-3, and 1 ASA-4 patients. Frankel grades in the O group reflected severe neurological deficits, with 3 grade C patients, 2 grade D, and 11 grade E ( p = 0.032) patients. The two groups had similar rates of neurological improvement (33.3% of PS and 40.0% of O patients; p = 0.410) and mean fusion length (PS 5.1 ± 0.8 segments; O 4.9 ± 1.2). The mean operating time and estimated blood loss were 168.1 ± 46.7 min and 133.9 ± 116.5 g, respectively, in the PS group, and 224.6 ± 49.8 min and 499.9 ± 368.5 g in the O group. Three O-group patients died of hypovolemic shock, respiratory failure, and pneumonia, respectively, within a year of surgery.

CONCLUSION

Conventional open posterior fixation and PPS fixation for DISH-related spinal fractures were similar in fusion length and neurological improvement. However, PPS fixation was less invasive and had lower complication rates.

Vertebral fracture at the caudal end of a surgical fusion for thoracic vertebral fracture in a patient with diffuse idiopathic skeletal hyperostosis (DISH)

The patient was an 86-year-old woman with back pain after a fall. She had no neurological findings at the initial visit. Plain radiographs and magnetic resonance imaging (MRI) showed diffuse idiopathic skeletal hyperostosis (DISH) and a Th10 fracture. Two weeks later, she started gait exercise with immobilization by a rigid orthosis. Twenty-five days later, she presented with paralysis and numbness of her legs. Computed tomography (CT) showed anterior expansion in the vertebral body of Th10. MRI showed an intramedullary high-intensity area on T2-weighted images at the same level. She was diagnosed as having delayed paraplegia after a Th10 fracture and transferred to our hospital for surgery. Laminectomy of Th10, posterior fusion from Th7 to L1 with pedicle screws and hooks to Th6 and L1 laminae, anterior fusion from Th9 to Th11 with a plate, and autologous bone grafting were performed simultaneously. The patient's paralysis improved, and she started gait exercise with no limitation of bed rest and without an orthosis after surgery. At 8 days after surgery, she again presented with low back pain and paralysis in her legs. CT revealed an L1 fracture, which was the caudal end of the surgical fusion. The decreased kyphosis after surgery compared to that at pre-injury might have caused a subsequent horizontal shear force to L1 when the patient sat on the bed and when she walked. In conclusion, to avoid postoperative adjacent vertebral fracture after fusion, appropriate correction of spinal alignment to that at pre-injury is needed for vertebral fractures in patients with DISH.