Nghiên cứu đặc điểm lâm sàng, chẩn đoán hình ảnh và đánh giá kết quả phẫu thuật gãy c1 c2 do chấn thương tt tiếng anh

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 C1-C2 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 (C 1) 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 objectives: 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 C2 pedicle, then calculated the appropriate screws size in the C1-C2 fixation surgery - Provided the effectiveness of a surgical method and the use of bone-graft 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 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 ring-like, 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 goose-like 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 atlanto-axial joint 1.1.2 The system of articulations and ligaments between C1 and C2 1.1.2.1 The medial atlanto-axial 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 atlanto-axial joint instability 1.1.2.2 The lateral atlanto-axial joints They are plane type synovial joints which are formed by the articulation between the superior facets of C 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 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 (C 0-C1-C2) 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 3-view cervical spine radiography including anteroposterior, lateral and open-mouth 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 < mm in adult and < mm in children 1.4.1.1 Motion X - ray It is applied in chronic C1 – C2 dislocation, suspicion about pseudarthrosis of the dens or transverse ligament rupture to evaluate the ADI index 1.4.2 Computed Tomography (CT scanning) Until now, CT scanning image has been considered as the gold standard in definitive diagnosis and classification of upper cervical spine injuries * Fractures of C1: It is classified according to Levine and Edwards, including types:  Type I: Single C1 posterior arch fracture, the most common, stable fracture, without transverse ligament damage  Type II: Fracture of one anterior and one posterior arch caused by a straight compressed force in tilt-head position, rare  Type III: Burst fracture of C1 (Jefferson fracture), commonly after type I fracture, caused by a straight compressed force in intermediary-head position, fractures of points on anterior arch and or points on posterior arch * Atlanto-axial joint dislocation (C1 - C2) Definitive diagnosis of C1 – C2 dislocation, classification, causes, MSCT reconstructs the 3D image * Odontoid fractures The Anderson and D’Alonzo classification system is the most common Type Obliquely oriented fractures through the tip of the odontoid Type Occur through the base of the dens, where is contiguous to the C2 body Type Fracture runs through the metaphyseal bone of the C body and fracture through the body of the axis 1.4.3 Magnetic Resonance Imaging It is applied in C1 fractures to evaluate the transverse ligament damage A high signal indicates an edema in bone marrow and anterior soft tissues In addition, MRI also evaluates the state of spinal cord contusion, bleeding and edema in anterior C body soft tissues 1.5.2 Posterior surgery for upper cervical spine injuries 1.5.2.1 Posterior C1 - C2 laminar wiring techniques  Gallie technique: The use of posterior cervical wiring of the lamina of C1 and C2 was first described by Gallie in 1939 He used steel wire to twist the posterior arch of C and the spinous process of C2 and a homo-bone- graft between C1 and C2  Brooks – Jenkins technique: Brooks and Jenkins offered an alternative method of posterior C – C2 laminar wiring in 1978, two separate autologous bone pieces were wedged in between the C1 and C2 on both sides of the midline and wrapped the posterior arches of the C1 and C2 - Sonntag technique: Dickman C.A et al described the technique of Sonntag in the 1990s Sonntag modified the Gallie technique to improve the rotational stability 1.5.2.2 Posterior C1 - C2 transarticular screw technique In 1979, Magerl described the technique for the treatment of C1 – C2 dislocation and odontoid fractures 1.5.2.3 Occipital-cervical fusion 13 3.2.2.1 Plain cervical spine X-ray Table 3.9 Damages in conventional X-ray film Conventiona CT Damages l X-ray (n = 33) (n = 33) C1 break (n = 4) Odontoid fracture (n = 31) 23 31 C1 – C2 dislocation (n = 8) 8 Percentage % 50.0 74.2 100 3.2.2.3 Evaluate the C1 - C2 anatomic index in CT Table 3.15 C1 lateral mass width C1 lateral mass width (mm) Position ± SD Right (n = 33) 13.56 ± 1.09 Left (n = 33) p 0.68 13.67 ± 1.05 Table 3.16 C1 lateral mass length Position C1 lateral mass length(mm) ± SD Right ( n = 33) Left (n = 33) p 17.35 ± 1.45 17.41 ± 1.45 0.85 Table 3.17 Distance from the screw fixing position to the C anterior arch Position Right (n = 33) Left (n = 33) Distance from the screw fixing position to the C1 anterior arch (mm) ± SD 29.34 ± 1.97 29.37 ± 2.02 p 0.94 * C2 anatomic characteristics Table 3.19 C2 pedicle diameter Position C2 pedicle diameter(mm) p ± SD Right (n = 33) 5.11 ± 0.47 Left (n = 33) 5.12 ± 0.47 0.78 14 3.3 Surgical outcomes 3.3.1 Near outcomes 3.3.1.1 In operation Operation duration and blood loss: Operation duration (minute) 108.6 ± 17.3 minutes; Blood loss (ml) 211.8 ± 40.9 ml * Bone-graft materials In our study, all patients had a C1 – C2 trans-posterior arches bone-graft and we selected a homograft for 100% of surgery 3.3.1.2 Pre-discharge - Hospital stay: 17.03 ± 6.98 (8 – 33 days) Table 3.26 Evaluate the accuracy of C1 screw C1 screw position Right Num ber (n) Left Percen tage % Numb er (n) Percen tage % Type 31 93.9 30 90.9 Type 2 6.1 9.1 Total 33 100 33 100 Table 3.27 Evaluate the accuracy of C2 screw C2 screw position Right Num ber (n) Left Percen tage % Num ber (n) Percen tage % Type 21 63.6 19 57.6 Type 21.2 11 33.3 Type 12.2 6.1 Type 3.0 3.0 Type 0 0 Total 33 100 33 100 15 3.3.2 Further outcomes * Subjective symptoms improvements Table 3.35 Compared the preoperative subjective symptoms with the last re-examination Preoperative (n = 33) Symptoms Neck pain Limited neck movement Stiff neck Numbness in the occipital region Re-examination after over 12 months (n = 33) Percentag Number Percentag e% (n) e% 27.3 9.1 months after surgery (n = 33) Numbe Percentag Number r (n) e% (n) 33 100 30 90.9 27.3 9.1 10 30.3 9.1 0 6.1 0 0 Table 3.36 Compared the preoperative smooth muscle disorder with the last re-examination Preoperative Re-examination after over 12 months smooth No Percentage Yes Percentag muscle (n) % (n) e% disorder Yes 100 12.1 No 0 29 87.9 Total 33 p < 0.001 Total 29 33 Table 3.37 Compared the preoperative VAS with the last reexamination VAS score Preoperativ e (n = 33) 5.03 ± 1.74 p Re-examination after over 12 months (n = 33) 1.18 ± 0.88 < 16 0.001 * Neck disability index Table 3.38 Compared the preoperative NDI and the last reexamination Preoperative (n = 33) NDI No influence (< 10%) Mild (10 – 29%) Moderate (30 – 49%) Severe (50 – 69%) Complete influence ( 70%) Total months after surgery (n = 33) Numbe Percentag r (n) e% Numbe r (n) Percentag e% 0 0 27.3 25 75.8 21 63.6 21.2 9.1 3.0 0 0 33 100 33 100 Re-examination after over 12 months (n = 33) Numbe Percentag r (n) e% 20 60.6 13 39.1 0 0 0 33 100 Table 3.39 Neurological recovery according to ASIA Re-examination after Preoperative months after surgery over 12 months (n = 33) (n = 33) (n = 33) ASIA Numbe Percentag Numbe Percentage Numbe Percentage r (n) e% r (n) % r (n) % A 0 0 0 B 0 0 0 C 6.1 3.0 0 D 21.2 9.1 6.1 E 24 72.7 29 88.9 31 93.9 Total 33 100 33 100 33 100 * Evaluate the bone healing: In our study, the rate of bone healing at 17 the born-graft site was 100% CHAPTER 4: DISCUSSION 4.1 General parameters 4.2 Clinical symptoms of C1 - C2 unstable fractures 4.2.1 Subjective symptoms In the study, all hospitalized patients had symptoms of a neck pain and limited cervical spine movement, in which a limited neck rotation was the most striking Other movements were less limited due to the pain of patients All 33 patients showed symptoms of neck pain, which caused the patients to have to go to medical clinics Stiff neck only accounted for 30.3% of patients It might be the most suggestive symptom of C1 – C2 injury The less common symptom was numbness in the occipital region (5.2%), which was often seen in patients with severe C1-C2 dislocation due to compression of the C nerve root 4.2.2 Objective symptoms Evaluating the focal neurological deficits, we found that there were out of 33 patients with limb paralysis (27.3%), of which patient had complete arm paralysis with muscle strength 0/5 and the remaining patients had an incomplete paralysis with muscle strength from to 4/5 The causes of neurological deficiencies were identified on the image due to spinal cord contusion, post-traumatic pulmonary edema and C1 – C2 dislocation causing spinal stenosis at the same level 4.2.3 Evaluate the pain level according to VAS score In our study, the preoperative VAS was 5.03 ± 1.74 with the highest score of Most of patients in our study had a moderate pain with average VAS of (5-6 VAS score) and some had a severe pain 18 (7-8 VAS score) 19 4.2.4 Preoperative neck disability index (NDI) In our study, the lowest preoperative NDI was 24% and highest one was 52%, mean NDI was 37.03  9.15 % Most patients had the NDI in the moderate group (63.2%) 4.2.5 Clinical neurological evaluation according to ASIA scale In 33 patients, we found that 24 patients (accounted for 72.7%) had ASIA - E, patients had nerve damage including patients with ASIA – D (21.2%) and patients with ASIA – C (6.1%) No one had complete motor paralysis with ASIA - A and ASIA - B 4.3 Diagnostic imaging characteristics of C1 - C2 unstable fractures 4.3.1 Plain cervical spine X - ray Our results showed a certain value of conventional X-ray film in the diagnosis of C1 – C2 injuries, especially in cases of C odontoid fractures or C1 – C2 dislocation type 2, and We diagnosed 74.2% of patients with odontoid fractures by conventional X-ray (open mouth X-ray film) and 100% of patients with C1-C2 dislocation in the study In case of a single C fracture, conventional X-ray had a limited value 4.3.2 Injury characteristics in CT  C1 fractures characteristics In our study, patients were diagnosed of C1 fracture including patients with type and patients with type according to Levin and Edwards classification Spence index in C1 fracture was used to evaluate the status of the transverse ligament, which was one of the causes leading to C1 – C2 unstable fracture when the Spence index was > 6.9 mm We found single C1 fracture patients with the Spence index > 6.9 mm and C1 fracture patients with type odontoid 20 fracture  Odontoid fractures characteristics In our study, there were 31 out of 33 patients with odontoid fractures including 21 patients with single odontoid fracture, patients with C1 - C2 dislocation (1 patient with pseudarthdosis) and patients with C1 fracture In odontoid fractures patients, the displacement was mainly forward or not accounting for 10/31 and 15/31 respectively, the displacement distance over 5mm accounted for 66.7% They all had upper cervical spine unstable injuries and had a surgery indication coinciding with the view of other authors in in the world Some C1 anatomical features in CT relating to surgery * C1 lateral masses In our study, we measured that the anterior-posterior diameter of the C1 lateral masses was 17.35 ± 1.45mm (right) and 17.40 ± 1.45mm (left) and the mean maximum distance from the screw fixing point to the C1 anterior arch 29.33 ± 1.97 (right) and 28.37 ± 1.97 (left) One important parameter was the C1 lateral mass screw inward angle In our results, it was 12.21 ± 1.27 degree (right) and 12.45 ± 1.30 degree (left) * Some C2 anatomical features in CT relating to surgery In our study, the mean C2 pedicle diameter was 5.11 ± 0.46 and 5.12 ± 0.47 mm, the mean incline angle was 24.79 ± 1.90 and 24.79 ± 1.81 degree and the mean inward angle was 26.36 ± 3.38 and 26.06 ± 2.61 degree According to these anatomical features, the C screw with 3.5 – 4mm diameter could be used without breaking the pedicle 21 4.3.3 Injuries characteristics in MRI MRI had advantage in evaluating the soft tissues, ligament and spinal cord damage In this study, we used magnetic resonance in cases of preoperative neurological deficits to assess the extent of spinal cord injury and recovery prognosis 4.4 Surgical outcomes 4.4.1 Near outcomes 4.4.1.1 In operation * Operation duration In our study, the mean operation duration was 108.6 ± 17.3 minutes * Blood loss The mean blood loss volume was 211.8 ± 40.9 ml, no one required a blood transfusion indication during and after the operation * Bone-graft materials In the study, we used a homograft for 100% of patients It showed a low rate of complication and a good bone healing 4.4.1.2 Discharge * Hospital stay The mean hospital stay was 17.03 ± 6.98 days (min: days, max: 33 days) * The accuracy of C1 lateral mass and C2 pedicle screws Evaluate the accuracy of C1 screw In our study, all C1 lateral mass screws were performed conveniently After the operation, we performed MSCT to assess the accuracy of screw and the condition of vertebral arteries and it showed no case of vertebral arteries damage According to accuracy of C screw classification, in our study, the number of ideal screws was 93.9% on the right and 90.9% on the left without any type screw 22 Evaluate the accuracy of C2 screw In our results, the type and type C pedicle screws were major with 28/33 on the right and 30/33 on the left (81.8%) There were acceptable pedicle screws and unacceptable screws (type 4) with consistent postoperative clinical symptoms Patients did not have worse neurological damage, so we did not perform any intervention 4.4.2 Further outcomes 4.4.2.1 After months of operation  Evaluate the subjective symptoms improvement after months of operation The postoperative cervical spine subjective symptoms improved significantly Before the operation, 100% of patients had a neck pain, but the figure was 9/33 (27.3%) after months of surgery Patients with a limited neck movement and numbness in the occipital region improved after months of operation and there was no new case  Evaluate the objective symptoms improvement after months of operation Symptoms of motor, sensory and smooth muscle disorder improved after months of surgery Before operation, out of 33 patients had a motor disorder and 14 out of 33 patients had a sensory disorder After months of operation, the figures were and out of 33 patients respectively Thus, there was an improvement in objective symptoms  Smooth muscle disorder The clinical assessment showed that there was only out of 33 patients with smooth muscle disorder after months of operation The difference was not statistically significant with p = 0.121 23  Evaluate the improvement in pain level according to VAS score after months of operation Before surgery, patients underwent a moderate pain with 5.03 ± 1.74 VAS score (Min-Max: 2-8 score) After months of operation, the degree of cervical spine pain decreased with 1.52 ± 0.67 VAS score  Evaluate the improvement in neck disability index after months of operation In our study, the cervical spine function was evaluated based on an evaluation sheet and it was estimated in percentage Mean preoperative NDI was 37.03  9.15% and the majority of patients had the NDI in the moderate group After months of surgery, mean NDI was 26.36 ± 7.64%, mainly in the mild group (75.8%), which was higher than preoperative NDI The difference was statistically significant with p