Describe the clinical and diagnostic imaging characteristics of unstable traumatic C1 - C2 fracture. Describe the clinical and diagnostic imaging characteristics of unstable traumatic C1 - C2 fracture.
MINISTRY OF EDUCATION MINISTRY OF AND TRAINING NATIONAL DEFENCE MILITARY MEDICAL UNIVERSITY KIEU VIET TRUNG RESEARCH THE CLINICAL, DIAGNOSTIC IMAGING CHARACTERISTICS AND EVALUATE THE SURGICAL OUTCOMES OF TRAUMATIC C1C2 FRACTURE Specialty : Surgery Code : 97 20104 DOCTOR OF MEDICINE DISSERTATION SUMMARY Hanoi 2020 THE RESEARCH WAS COMPLETED AT THE MILITARY MEDICAL UNIVERSITY Scientific instructor: Associate Prof. PhD. Vu Van Hoe Reviewer 1: Associate Prof. PhD. Nguyen Van Thach Reviewer 2: Associate Prof. PhD. Bui Van Lenh Reviewer 3: Associate Prof. PhD. Nguyen The Hao The thesis will be defended before the university grade thesis examination board in military medical university: The thesis can be found at: National library of Viet Nam Library of military medical university INTRODUCTION Upper cervical spine injury is a very serious injury in general, particularly in spinal injury. The mortality or severe sequelae rate caused by cervical spine injury are very high The upper cervical spine including the atlas (C1) and the axis (C2) is the transition area between the skull and the spine, which is one of the most complicated joints in the body. At the Neurosurgery Department of the Da Nang Hospital, we have applied this technique for 10 recent years for unstable C1 – C2 injury treatment. Through clinical practice, we realize that the unsolved problem in C1 – C2 fracture is a full understanding of the injury characteristics, classification, indications for surgery and the selection of techniques and tools for surgery as well as bone graft. In order to make new contributions to the process of diagnosis, selection of treatment method and plan for unstable C1 – C2 injury, we conducted the thesis "Research the clinical, diagnostic imaging characteristics and evaluate the surgical outcomes of traumatic C1 – C2 fracture ” with 2 objectives: 1. Describe the clinical and diagnostic imaging characteristics of unstable traumatic C1 C2 fracture Evaluate the surgical outcomes of C1 C2 stabilization with screw via C1 lateral mass and C2 pedicle combined with bone allograft New contributions of the thesis: Gave the size of C1 lateral mass and C 2 pedicle, then calculated the appropriate screws size in the C1C2 fixation surgery Provided the effectiveness of a surgical method and the use of bonegraft materials which helped patients have no pain at the bone donor site, shorter operation duration and 100% bone healing rate Showed further postoperative outcomes (long time tracking, 18 months); the VAS score, NDI and ASIA were better than before surgery with statistical significance (11.24% compared with 52.8%) The thesis structure: The thesis consists of 137 pages including 45 tables, 68 pictures and charts The layout includes the introduction (3 pages); chapter 1: Overview (35 pages); chapter 2: patients and methods (26 pages); chapter 3: results (28 pages); chapter 4: discussions (41 pages); conclusions (2 pages); the list of research publishes (1 page); references (128 documents including 7 Vietnamese and 121 English documents) and appendices CHAPTER 1: OVERVIEW 1.1. The cervical spine anatomy 1.1.1. The bone structure 1.1.1.1. The atlas C1 The C1 vertebral has no vertebral body. It is ringlike, rugged and consists of two large lateral masses which contain two superior concave facets for articulation with occipital condyles and two inferior concave facets for articulation with the axis C2. The structure of the atlas includes anterior arch, posterior arch, lateral mass, anterior tubercle, posterior tubercle, transverse process, transverse foramen, articular facet with occipital condyles and articular facet with the axis. The anterior and posterior arches are thinner to the two sides and where contact with the lateral masses is the thinnest; therefore it is a weak position and easy to break in trauma 1.1.1.2. The axis C2 The axis is the thickest and strongest vertebra in the cervical spine with a gooselike shape. The axis is easily identifiable due to its dens (odontoid process) which extends superiorly from the anterior portion of the vertebra. The dens is upward cylindrical, about 16.6 mm high and 9.3mm wide The anterior facet of the dens apex contains the facet for articulation with the concave at the posterior facet of the atlas anterior arch and the posterior facet of dens apex contains the facet for articulation with the transverse ligament, which form the medial atlantoaxial joint 1.1.2. The system of articulations and ligaments between C1 and C2 1.1.2.1 . The medial atlantoaxial joint Formed by the articulation of the dens of the axis with the articular facet of the atlas. The cruciform ligament consists of two parts: the transverse ligament connecting the inner facet of the atlas lateral masses and the longitudinal fibers connecting the upper edge of transverse ligament with the occipital bone and the lower edge of transverse ligament with the axis. The transverse ligament of the atlas is stronger than the dens, therefore the odontoid process is often broken before the ligament in trauma However, the transverse ligament is not strong enough in some people and it is one of the pathological causes of atlantoaxial joint instability. 1.1.2.2. The lateral atlantoaxial joints They are plane type synovial joints which are formed by the articulation between the superior facets of C2 and the inferior facets of C1 The movements occur on the three articular facets simultaneously and mostly are rotation. 1.1.3. Nerves: The cervical spinal cord originates in the medulla oblongata and passes through the foramen magnum. It is wider at C3 and widest at C6 with the circumference of 38mm. The spinal cord consists of the white and grey matter that can be distinguished on magnetic resonance imaging At the upper cervical spine, the spinal cord occupies only 2/3 of the spinal canal circumference, so the nervous clinical symptoms are very poor in trauma in spite of the spine dislocation The shape of cervical spinal cord: It is divided into 2 balanced parts by the anterior median fissure and posterior median sulcus. The fissure is deeper and wider than the sulcus The posterior sulcus contains blood vessels and a fold of the pia mater 1.1.4. The blood vessels: The vertebral artery, which originates from the subclavian artery is the main blood supply for cervical cord In most cases, the vertebral artery enters the transverse foramen of C6, goes through the transverse foramen of vertebrae along the sides of cervical spine, bypasses the lateral mass and posterior arch of C1 and enters the foramen magnum 1.2. THE BIOMECHANICS OF C1 C2 STRUCTURE The C1, C2 and occipital cranium form a complex that contains the most complicated joints in the body because they support the head and its movement, protect the spinal cord and other important structures. Most of rotation and a part of nodding and turning of the head movements occur at the superior cervical spine (C0C1C2) The loosening of joints allow the cervical spine to rotate nearly 50%. The tension is enough strong to protect the delicate spinal cord structures, blood vessels and withstand the weight of head and the force of antagonistic muscles. 1.3. THE CLINICAL SYMPTOMS OF C1 – C2 INJURY The clinical symptoms of C1 – C2 injury are often poor, mainly are neck pain, stiff neck, radiating pain and numbness in the occipital region and limited head rotation and flexion movements Patients with C1 – C2 trauma combined with severe spinal cord injury often die before hospitalization because upper spinal cord trauma causes damage to respiratory and circulatory centers in the medulla oblongata 1.4. IMAGING OF C1 C2 INJURY 1.4.1. Plain X ray 1.4.1.1. Conventional X ray A standard 3view cervical spine radiography including anteroposterior, lateral and openmouth odontoid views has a certain value in defining the damage in the C1 C2 area. The Spence index is calculated by the lateral overlap of the C1 lateral masses on both sides against the lateral borders of C 2, normally less than 6.9mm. If the Spence index is > 6.9 mm, it is a definitive diagnosis of a transverse ligament rupture and the damage is unstable and requires surgical treatment The C1 – C2 dislocation was diagnosed based on the ADI index, which was calculated by the distance between the dens and anterior arch of C1. In general, the ADI is