Treatment of Osteoporotic Thoracolumbar Burst Fractures by Bilateral Pedicle Vertebroplasty Combined With Postural Reduction

Background: Osteoporotic thoracolumbar burst fracture (OTLBF) is common in seniors. Due to the fracture of the posterior vertebra and spinal canal occupancy, the risk of cement leakage and spine injury is high in OTLBF patients, thus the application of vertebroplasty is limited in these patients. This study aims to investigate the efficacy and safety of vertebroplasty for treating OTLBF via bilateral pedicle approach combined with postural reduction. To determine whether percutaneous vertebroplasty (PVP) combined with body reduction is an alternative method for treating OTLBF that prevents major surgical complications.Methods: Thirteen patients (aged≥65years) with thoracolumbar fractures but without neurological deficits underwent vertebroplasty. In all fracture cases, the anterior and middle columns of the vertebrae were affected and the canal was mildly compressed. To assess the clinical symptoms and the effects of the procedure, patient mobility and pain were assessed prior to the procedure and at 1 day and 3 months after the procedure. Kyphosis correction, wedge angle, and height restoration were also observed and measured. Results: Improvements in pain and mobility were observed immediately after vertebroplasty in all patients. These results were observed for 6 months. Significant improvements were also noted at 1 day and 6 months after vertebroplasty. Pain was reduced by at least 4 levels after 6 months. No comorbidities were observed. Kyphosis Correction, Wedge Angle and height recovery were improved. Postoperative computed tomography revealed polymethylmethacrylate leakage through the endplate fracture site into the disc space and paravertebral spacein one patient. No intraspinal leakage was found in all patients. Conclusions: Vertebroplasty is assumed to be contraindicated in patients with osteoporotic thoracolumbar fractures with posterior body involvement. However, this procedure was successfully performed to safely treat such fractures without causing neurological deficits. PVP combined with body reduction may be an alternative method for treating OTLBF that prevents major surgical complications. Moreover, it helps patients achieve early mobilization and pain relief.

Hyperventilation, cerebral perfusion, and syncope

This review summarizes evidence in humans for an association between hyperventilation (HV)-induced hypocapnia and a reduction in cerebral perfusion leading to syncope defined as transient loss of consciousness (TLOC). The cerebral vasculature is sensitive to changes in both the arterial carbon dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2 the contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced cardiac output brain perfusion becomes jeopardized. Whether, in patients with cardiovascular disease and/or defect, cerebral blood flow cerebral control HV-induced hypocapnia elicits cerebral hypoperfusion, leading to TLOC, remains to be established.

Efficacy of Postural Reduction in Osteoporotic Vertebral Compression Fractures Followed by Percutaneous Vertebroplasty

OBJECTIVE: Vertebroplasty in the symptomatic osteoporotic vertebral fracture has become increasingly popular. However, there have been some limitations in restoring the height of the collapsed vertebrae and in preventing the leaking of cement. In the severely collapsed vertebrae of more than two thirds of their original height, vertebroplasty is regarded as a contraindication. We tried postural reduction using a soft pillow under the compressed level. This study was undertaken to investigate the effectiveness of the combination of postural reduction and vertebroplasty for re-expansion and stabilization of the osteoporotic vertebral fractures. METHODS: A total of 75 patients with single level vertebral compression fracture were treated with postural reduction followed by vertebroplasty. In 30 patients, the vertebral body was severely collapsed more than two-thirds of its original height. We calculated the compression ratio (anterior height/posterior height) and measured the Cobb angle. We analyzed the degree of re-expansion according to the onset duration. RESULTS: The mean compression ratio was 0.60 ± 0.15 initially and increased to 0.75 ± 0.17 after vertebroplasty. The mean Cobb angle was 16.14 ± 11.29° and corrected to 10.71 ± 12.08°. The degree of re-expansion showed significant relation with the onset duration. Twenty-eight of 30 (93%) severely collapsed vertebrae re-expanded after postural reduction, which made vertebroplasty possible. CONCLUSION: This new method of vertebroplasty leads to significant restoration of height and correction of kyphosis. The re-expansion was closely related with onset duration. In cases of severely collapsed vertebrae which is able to be re-expanded by postural reduction, vertebroplasty could be applied safely.

Contributions of MSNA and stroke volume to orthostatic intolerance following bed rest

We examined whether the altered orthostatic tolerance following 14 days of head-down tilt bed rest (HDBR) was related to inadequate sympathetic outflow or to excessive reductions in cardiac output during a 10- to 15-min head-up tilt (HUT) test. Heart rate, blood pressure (BP, Finapres), muscle sympathetic nerve activity (MSNA, microneurography), and stroke volume blood velocity (SVV, Doppler ultrasound) were assessed during supine 30° (5 min) and 60° (5–10 min) HUT positions in 15 individuals who successfully completed the pre-HDBR test without evidence of orthostatic intolerance. Subjects were classified as being orthostatically tolerant (OT, n = 9) or intolerant (OI, n = 6) following the post-HDBR test. MSNA, BP, and SVV during supine and HUT postures were not altered in the OT group. Hypotension during 60° HUT in the post-bed rest test for the OI group ( P < 0.05) was associated with a blunted increase in MSNA ( P < 0.05). SVV was reduced following HDBR in the OI group (main effect of HDBR, P < 0.02). The data support the hypothesis that bed rest-induced orthostatic intolerance is related to an inadequate increase in sympathetic discharge that cannot compensate for a greater postural reduction in stroke volume.