Effects of Cervical Rotatory Manipulation (CRM) on Carotid Atherosclerosis Plaque in Vulnerability: A Histological and Immunohistochemical Study Using Animal Model

Effects of cervical rotatory manipulation on the cervical spinal cord complex with ossification of the posterior longitudinal ligament in the vertebral canal: A finite element study

Background: There are few studies focusing on biomechanism of spinal cord injury according to the ossification of the posterior longitudinal ligament (OPLL) during cervical rotatory manipulation (CRM). This study aimed to explore the biomechanical effects of CRM on the spinal cord, dura matter and nerve roots with OPLL in the cervical vertebral canal. Methods: Three validated FE models of the craniocervical spine and spinal cord complex were constructed by adding mild, moderate, and severe OPLL to the healthy FE model, respectively. We simulated the static compression of the spinal cord by OPLL and the dynamic compression during CRM in the flexion position. The stress distribution of the spinal cord complex was investigated. Results: The cervical spinal cord experienced higher von Mises stress under static compression by the severe OPLL. A higher von Mises stress was observed on the spinal cord in the moderate and severe OPLL models during CRM. The dura matter and nerve roots had a higher von Mises stress in all three models during CRM. Conclusion: The results show a high risk in performing CRM in the flexion position on patients with OPLL, in that different occupying ratios in the vertebral canal due to OPLL could significantly increase the stress on the spinal cord complex.

Bilateral medial medullary syndrome following anterior screw fixation of type 2 odontoid fracture, a case report of two patients

INTRODUCTION

Medial medullary syndrome (MMS) has not been reported after anterior screw fixation of an odontoid type 2 fracture.

CASE PRESENTATION

We report on two cases who suffered from an unstable type 2 odontoid fracture following a skiing and a domestic fall accident. Prior to anterior screw fixation surgery both patients presented without neurologic deficits but postoperatively developed a bilateral MMS, including an incomplete tetraparesis, impaired sensation of position and movement as well as tactile discrimination and paralysis of the tongue muscle with deviation to the paralyzed side. MRI showed a typical heart-shaped ischaemic lesion in the medial medulla bilaterally. The search for aetiologic factors was uneventful in both patients except for severe atherosclerosis.

DISCUSSION

Due to the close proximity of the ischaemic area to the surgical site, we here propose the perioperative mechanical manipulation of the upper cervical spine during surgery of patients with atherosclerosis as a new aetiology for MMS.