Introduction Description odontoid fractures are relatively common fractures of the C2 vertebral body (axis) that can be seen in low energy falls in eldery patients and high energy traumatic injuries in younger patients. treatment depends on the location of the fracture within the C2 vertebrae as described by the Anderson and D'Alonzo classification system and the patient's risk factors for nonunion (failed bone healing). Epidemiology incidence most common fracture of the axis account for 10-15% of all cervical fractures demographics occur in bimodal fashion in elderly and young patients elderly common, often missed, and caused by simple falls associated with increased morbidity and mortality compared to younger patients with this injury young patients result from blunt trauma to head leading to cervical hyperflexion or hyperextension Pathophysiology mechanism displacement may be anterior (hyperflexion) or posterior (hyperextension) anterior displacement is associated with transverse ligament failure and atlanto-axial instability posterior displacement caused by direct impact from the anterior arch of atlas during hyperextension biomechanics a fracture through the base of the odontoid process severely compromises the stability of the upper cervical spine. Associated conditions Os odontoideum appears like a type II odontoid fx on xray previously thought to be due to failure of fusion at the base of the odontoid evidence now suggests it may represent the residuals of an old traumatic process treatment is observation Anatomy Axis Osteology axis has odontoid process (dens) and body embryology develops from five ossification centers subdental (basilar) synchondrosis is an initial cartilaginous junction between the dens and vertebral body that does not fuse until ~6 years of age the secondary ossification center appears at ~ age 3 and fuses to the dens at ~ age 12 Axis Kinematics CI-C2 (atlantoaxial) articulation is a diarthrodial joint that provides 50 (of 100) degrees of cervical rotation 10 (of 110) degrees of flexion/extension 0 (of 68) degrees of lateral bend C2-3 joint participates in subaxial (C2-C7) cervical motion which provides 50 (of 100) degrees of rotation 50 (of 110) degrees of flexion/extension 60 (of 68) degrees of lateral bend Occipital-C1-C2 ligamentous stability provided by the odontoid process and its supporting ligaments transverse ligament limits anterior translation of the atlas apical ligaments limit rotation of the upper cervical spine alar ligaments limit rotation of the upper cervical spine Blood Supply a vascular watershed exists between the apex and the base of the odontoid apex is supplied by branches of internal carotid artery base is supplied from branches of vertebral artery the limited blood supply in this watershed area is thought to affect healing of type II odontoid fractures. Classification Anderson and D'Alonzo Classification Anderson and D'Alonzo Classification Type I Oblique avulsion fx of tip of odontoid. Due to avulsion of alar ligament. Although rare, atlantooccipital instability should be ruled out with flexion and extension films. Type II Fx through waist (high nonunion rate due to interruption of blood supply). Type III Fx extends into cancellous body of C2 and involves a variable portion of the C1-C2 joint. Grauer Classification of Type II Odontoid fractures Type IIA Nondisplaced/minimally displaced with no comminution. Treatment is external immobilization Type IIB Displaced fracture with fracture line from anterosuperior to posteroinferior. Treatment is with anterior odontoid screw (if adequate bone density). Type IIC Fracture from anteroinferior to posterosuperior, or with significant comminution. Treatment is with posterior stabilization. Presentation Symptoms neck pain worse with motion dysphagia may be present when associated with a large retropharyngeal hematoma Physical exam myelopathy very rare due to large cross-section area of spinal canal at this level Imaging Radiographs required views AP, lateral, open-mouth odontoid view of cervical spine optional views flexion-extension radiographs are important to diagnose occipitocervical instability in Type I fractures and Os odontoideum instability defined as atlanto-dens-interval (ADI) > 10mm < 13mm space available for cord (SAC) findings fx pattern best seen on open-mouth odontoid CT study of choice for fracture delineation and to assess stability of fracture pattern CT angiogram required to determine location of vertebral artery prior to posterior instrumentation procedures MRI indicated if neurologic symptoms present Treatment Treatment Overview Os Odontoideum Observation Type I Cervical Orthosis Type II Young Halo if no risk factors for nonunionSurgery if risk factors for nonunion Type II Elderly Cervical Orthosis if not surgical candidatesSurgery if surgical candidates Type III Cervical Orthosis Nonoperative observation alone indications Os odontoideum assuming no neurologic symptoms or instability hard cervical orthosis for 6-12 weeks indications Type I Type II in elderly who are not surgical candidates union is unlikely, however a fibrous union should provide sufficient stability except in the case of major trauma Type III fractures no evidence to support Halo over hard collar halo vest immobilization for 6-12 weeks indications Type II young patient with no risk factors for nonunion contraindications elderly patients do not tolerate halo (may lead to aspiration, pneumonia, and death) Operative posterior C1-C2 fusion indications Type II fractures with risk factors for nonunion Type II/III fracture nonunions Os odontoideum with neurologic deficits or instability anterior odontoid osteosynthesis indications Type II fractures with risk factors for nonunion AND acceptable alignment and minimal displacement oblique fracture pattern perpendicular to screw trajectory patient body habitus must allow proper screw trajectory outcomes associated with higher failure rates than posterior C1-2 fusion transoral odontoidectomy indications severe posterior displacement of dens with spinal cord compression and neurologic deficits Surgical Techniques Halo immobilization in children and adults C1-C2 posterior fusion techniques approach posterior midline cervical approach stabilization technique sublaminar wiring techniques (Gallie or Brooks) require postoperative halo immobilization and rarely used posterior C1-C2 transarticular screws construct contraindicated in patients with an aberrant vertebral artery posterior C1 lateral mass screw and C2 pedicle screw construct modern screw constructs do not require postoperative halo immobilization outcomes C1-C2 fusion will lead to 50% loss of neck motion Higher fusion rate in elderly compared to anterior fusion Anterior odontoid screw osteosynthesis approach anterior approach to cervical spine technique single screw adequate pros & cons associated with higher failure rate than posterior C1-2 fusion advantage is preservation of atlantoaxial motion Transoral odontoidectomy technique usually combined with posterior stabilization procedure Complications Nonunion increased risk in Type II fractures due to poor blood supply average nonunion rate 33% (up to as high as 88%) risk factors for nonunion include ≥ 6 mm displacement (>50% nonunion rate) strongest reason to opt for surgery age > 50 years fx comminution fracture gap > 1 mm angulations > 10° delay in treatment ( > 4 days) posterior re-displacement ( > 2 mm) smoker Mortality Nonoperative treatment in the elderly Especially with halo orthosis
QUESTIONS 1 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK You have 100% on this question. Just skip this one for now. Take This Question Anyway (OBQ12.103) A young boy is involved in a motor vehicle accident and presents with neck pain. A CT scan is performed and is negative for fractures. Based on the presence of the ossification center shown in Figure A, what is the most likely age bracket of this patient. Review Topic | Tested Concept QID: 4463 FIGURES: A Type & Select Correct Answer 1 < 1 years of age 0% (9/3211) 2 1-3 years of age 7% (217/3211) 3 3-6 years of age 33% (1067/3211) 4 8-10 years of age 50% (1599/3211) 5 > 12 years of age 9% (295/3211) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 You have 100% on this question. Just skip this one for now. Take This Question Anyway (OBQ12.116) A 67-year-old male smoker was involved in a motor vehicle accident and presents with neck pain. On initial presentation his neurologic exam was intact. Injury films are shown in Figure A and B. The patient was evaluated and surgical treatment was recommended. The patient left the hospital against medical advice. Seven months later he returns with continued neck pain. His current neurologic exam shows no deficits. A current CT scan and MRI is performed and shown in Figure C and D. What is the most appropriate treatment at this time? Review Topic | Tested Concept QID: 4476 FIGURES: A B C D Type & Select Correct Answer 1 Physical therapy and NSAIDS 15% (628/4243) 2 Hard Cervical Orthosis 3% (118/4243) 3 Halo Immobilization 2% (75/4243) 4 Anterior screw osteosynthesis 7% (313/4243) 5 Posterior C1-C2 fusion 72% (3072/4243) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 You have 100% on this question. Just skip this one for now. Take This Question Anyway (OBQ12.65) A 45-year old male is involved in a motor vehicle accident and presents to the emergency room with complaints of neck pain. Physical exam shows he is an ASIA E. An open-mouth cervical radiograph is shown in Figure A. A sagittal CT scan is shown in Figure B. A CT axial angiogram is shown in Figure C. Which of the following treatment options is contraindicated in this patient. Review Topic | Tested Concept QID: 4425 FIGURES: A B C Type & Select Correct Answer 1 Anterior screw osteosynthesis with single cannulated screw 12% (538/4579) 2 Halo immobilization 15% (670/4579) 3 Anterior screw osteosynthesis with two cannulated screws 10% (440/4579) 4 C1-C2 transarticular screws 50% (2301/4579) 5 Posterior C1-C2 wiring with autograft 13% (588/4579) L 4 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK You have 100% on this question. Just skip this one for now. Take This Question Anyway (OBQ11.263) In Figures A-E, which of the following fracture patterns is at greatest risk for nonunion with nonoperative treatment? Review Topic | Tested Concept QID: 3686 FIGURES: A B C D E Type & Select Correct Answer 1 Figure A 2% (50/3154) 2 Figure B 54% (1713/3154) 3 Figure C 3% (87/3154) 4 Figure D 19% (596/3154) 5 Figure E 22% (691/3154) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK You have 100% on this question. Just skip this one for now. Take This Question Anyway (OBQ10.130) In patients who are neurologically intact, all of the following cervical spine injuries can be appropriately managed with external immobilization in a rigid cervical orthosis EXCEPT Review Topic | Tested Concept QID: 3223 FIGURES: A B C D E Type & Select Correct Answer 1 Figure A 1% (23/3723) 2 Figure B 1% (48/3723) 3 Figure C 5% (174/3723) 4 Figure D 4% (157/3723) 5 Figure E 89% (3308/3723) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 You have 100% on this question. Just skip this one for now. Take This Question Anyway (OBQ10.185) In elderly patients with type II odontoid fractures, which of the following treatment modalities has the highest morbidity and mortality? Review Topic | Tested Concept QID: 3278 Type & Select Correct Answer 1 Hard cervical collar 2% (42/2342) 2 Anterior screw osteosynthesis 6% (144/2342) 3 Halo vest immobilzation 82% (1914/2342) 4 Posterior cervical stabilization 4% (86/2342) 5 Soft cervical orthosis 6% (145/2342) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 You have 100% on this question. Just skip this one for now. Take This Question Anyway (OBQ08.78) A 37-year-old male was involved in a motorcycle accident. He is neurologically intact. A coronal and sagittal CT scan is shown in Figure A. What is the most appropriate management? Review Topic | Tested Concept QID: 464 FIGURES: A Type & Select Correct Answer 1 Posterior C1-C2 fusion 5% (159/2896) 2 Anterior odontoid screw fixation 19% (559/2896) 3 Transoral anterior odontoid resection 0% (7/2896) 4 Cervical immobilization for 6-8 week in an external orthosis 73% (2117/2896) 5 Treatment in a soft cervical orthosis for two weeks followed by range of motion exercises 2% (45/2896) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 You have 100% on this question. Just skip this one for now. Take This Question Anyway (OBQ06.263) A 36-year-old male falls while intoxicated two weeks ago and has had persistent neck pain ever since. For unclear reasons he did not seek medical attention. He now reports persistent neck pain, but denies symptoms in his upper and lower extremities. On physical exam he has Grade 5 motor strength in his upper and lower extremities, normal reflexes, and his sensory exam is normal. A CT scan is shown in Figure A. All of the following place this patient at an increased risk of nonunion EXCEPT: Review Topic | Tested Concept QID: 274 FIGURES: A Type & Select Correct Answer 1 Fracture gap of 2 mm 3% (90/3093) 2 Posterior displacement of > 5mm 2% (56/3093) 3 Delay in treatment of 2 weeks 4% (109/3093) 4 Age < 40 years 89% (2764/3093) 5 Posterior angulation 2% (63/3093) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4
All Videos (7) Podcasts (3) Login to View Community Videos Login to View Community Videos Seattle Science Foundation Video Collection- Spine Odontoid Screw Fixation by Rick C. Sasso, M.D. Spine - Odontoid Fracture 4/16/2017 378 views Login to View Community Videos Login to View Community Videos Seattle Science Foundation Video Collection- Spine Posterior Options for C1-2 Fixation by Andrew T. Dailey, M.D. Spine - Odontoid Fracture 4/16/2017 228 views Upgrade to View Premium Videos Upgrade to View Premium Videos Odontoid Fractures Anterior Treatment - Daniel Fassett, MD Derek Moore Spine - Odontoid Fracture 12/17/2016 166 views Spine⎪Odontoid Fracture Orthobullets Team Spine - Odontoid Fracture Listen Now 17:30 min 12/11/2019 27 plays Question Session⎜Odontoid Fractures, Radial Head Fractures & TKA Coronal Plane Balancing Orthobullets Team Spine - Odontoid Fracture Listen Now 30:6 min 11/11/2019 8 plays Spine⎜Odontoid Fracture (ft. Dr. Derek Moore) Team Orthobullets 4 Spine - Odontoid Fracture Listen Now 22:34 min 10/18/2019 25 plays See More See Less
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