Bipartite/Split Atlas Case Reports
Case Studies
Non-case study articles here.Bipartate/Split Atlas with Atlantoaxial Subluxation/Instability Or other Craniocervical Junction Issues
A case of combined congenital anterior and posterior arch anomaly of C1 vertebra (2017)A very rare case of the craniovertebral junction (CVJ) anomaly is reported owing to its rarity and clinical significance. Computed tomography (CT) and magnetic resonance imaging (MRI) studies of the cervical spine of a 56 -year-old female patient presented with head trauma, revealed an anterior midline arch cleft of atlas with totally aplastic posterior neural arch, as well as anteriorly subluxed right atlantoaxial joint. The coexistence of a total aplasia of the posterior neural arch and anterior arch cleft of atlas is very rare. Congenital anomalies affecting the craniovertebral junction (CVJ) may mimic traumatic injury in the setting of a previous trauma. In this presented case, the absence of an associated bone and soft-tissue edema on the MR imagings helped us to make a differention between the acute traumatic injury and congenital anomalyA rare cause of cervical spinal stenosis: posterior arch hypoplasia in a bipartite atlas (2002)
We describe CT and MRI of a previously unreported combination of atlantoaxial anomalies consisting of posterior arch hypoplasia in a bipartite atlas with an os odontoideum, in a 30-year-old woman presenting with neck and left arm pain. MRI showed the os odontoideum, marked stenosis of the spinal canal at the level of the atlas, with cord compression and evidence of myelopathy. CT revealed a bipartite atlas with midline clefts in anterior and posterior arches, thickening in the anterior arch and hypoplasia of the posterior arch with incurving of both hemiarches. Flexion and extension radiographs demonstrated atlantoaxial instability.
Anomalous Posterior Arch of Atlas: A Rare Cause for Craniovertebral Junction Compression (2016)
Congenital hypoplasia of the anterior and posterior arch of the atlas has been described in the literature. Currarino and associates classified this into various types based on the part of the arch that was hypoplastic. Gin and associates stated that posterior atlantal anomalies were more frequently encountered than anterior arch anomalies. Rarely do these anomalies present in the absence of genetic syndromes. Here, we describe our clinical experience of an anomalous posterior atlantal arch in a nonsyndromic patient.Cervical myelopathy caused by atlantoaxial instability in a patient with an os odontoideum and total aplasia of the posterior arch of the atlas: a case report (2012)
Congenital hypoplasia of the atlas has rarely been reported. Myelopathy caused by the complete absence of the posterior arch of the atlas has not been reported. This case report describes the diagnosis and successful treatment of a myelopathy due to the complete absence of the posterior arch of the atlas. Case presentation: A 59-year-old Japanese man experienced pain in his nuchal region with progressive spasticity, numbness and hypesthesia in his upper and lower limbs. Deep tendon reflexes in his upper and lower limbs were increased. The complete absence of the posterior arch of the atlas and atlantoaxial instability were found in a roentgenogram. Magnetic resonance imaging detected high signal intensity on T2-weighted images in his spinal cord at the level of cervical vertebrae 1 to 2. Our patient underwent posterior occipito-C4 fixation with pedicle screws. After the operation, the pain in his nuchal region disappeared and his symptoms of myelopathy improved. Only slight numbness of his upper limbs remained. Conclusions: This is the first report of myelopathy due to the complete absence of the posterior arch of the atlas.Combined Congenital Anterior and Posterior Midline Cleft of the Atlas Associated with Asymptomatic Lateral Atlantoaxial Subluxation (2006)
Although congenital anomalies of the atlas have been well-documented, atlas anomalies of clefts and aplasia are rare. Anterior and posterior midline clefts of the atlas have been reported separately in some series. However, combined congenital anterior and posterior midline clefts of the atlas are reported rarely. Hence, we report a very rare case of combined congenital anterior and posterior midline clefts of the atlas associated with asymptomatic lateral atlantoaxial subluxation.Congenital absence of the posterior arch of the atlas with concomitant fusion to the axis: a case report (2015)
We present a 52-year-old man with congenital absence of the posterior arch of the atlas and concomitant fusion of the posterior tubercle of the atlas to the spinal process of the axis. He had normal reflexes and no motor deficit. He underwent C3-C7 laminoplasty and achieved good outcome.Congenital Anomaly of the Atlas Misdiagnosed as Posterior Arch Fracture of the Atlas and Atlantoaxial Subluxation (2014)
Partial or complete absence of the posterior arch of the atlas is a well-documented anomaly but a relatively rare condition. This condition is usually asymptomatic so most are diagnosed incidentally. There have been a few documented cases of congenital defects of the posterior arch of the atlas combined with atlantoaxial subluxation. We report a very rare case of congenital anomaly of the atlas combined with atlantoaxial subluxation, that can be misdiagnosed as posterior arch fracture.Congenital anterior midline cleft of the atlas and posterior atlanto-occipital fusion associated with symptomatic anterior atlantoaxial subluxation (2012)
Background Congenital partial anterior arch defect of the atlas is extremely rare. It could be found as an incidental radiological finding or patients can present with neurological deficit after head or neck trauma. Objective To describe an extremely rare presentation of anterior midline cleft at the atlas and congenital posterior atlanto-occipital fusion with symptomatic anterior atlantoaxial subluxation. This report includes a feasible hypothesis for the development of this anomaly on the basis of previous hypotheses and surgical findings. Methods A 46-year-old female presented with a 6-day history of right limbs numb and left upper and lower extremities paraparesis (Frankel D). Radiographs of the cervical spine showed anterior atlantoaxial subluxation with congenital posterior atlanto-occipital fusion. Computed tomography subsequently revealed partial midline absence of the anterior arch of the atlas and the odontoid tip ahead of the anterior arch of the atlas. Magnetic resonance imaging showed that the cervical dura was compressed by the remnant of anterior arch of the atlas. The patient underwent Gardner–Wells tong traction and surgery of occipitocervical fusion with autogenous iliac bone graft because she had definite neurological symptom and congenital posterior atlanto-occipital fusion. Results Atlantoaxial reduction was confirmed with fluoroscopic X-ray evaluation by bed, her neurological deficit was resolved from Frankel D to E, and numb of right limbs completely disappeared 6 days postoperation. No instability has been observed during 2-year follow-up. Conclusion We describe the association between compressive myelopathy and congenital defect of the anterior arch of the atlas with symptomatic anterior atlantoaxial subluxation. Both computed tomography and magnetic resonance image were required to demonstrate the bony configuration and cord compression. And Gardner–Wells tong traction and surgery of occipitocervical fusion with autogenous iliac bone graft were effective as a treatment for this compressive myelopathy caused by the remnant of anterior arch of the atlas.
Unusual cause of high cervical myelopathy-C1 arch stenosis (2018)
High cervical myelopathy can be rarely caused by the developmental anomalies of atlas. Patients with C1 arch stenosis can present in early childhood or later in life. In symptomatic patients, posterior decompression at atlas is mandatory. We report the first clinical series of 20 patients of C1 arch stenosis in the English literature.
Types A & B
A Congenital Anomaly of the Atlas as a Diagnostic Dilemma: A Case Report (2006)Objective: The purpose of this case report is to draw attention to the differences between a Jefferson fracture and a congenital anomaly of the anterior and/or the posterior arch of the atlas. Clinical Features: A 42-year-old woman visited the chiropractic practice complaining of headache, neck pain, dizziness, and numbness in both of her arms after she fell vertically and directly on her head twice on a playground. Before this fall, she had no such complaints. After taking x-rays of the cervical spine, a Jefferson fracture was suspected. Intervention and Outcome: After computed tomography and magnetic resonance imaging scanning, the patient was diagnosed with a congenital anomaly that looked very similar to a Jefferson fracture. After instability of the cervical spine was excluded by the neurosurgeon, chiropractic treatment was delivered. After 6 treatments, the complaints were significantly reduced. Conclusion: It is important to be familiar with the differences between a congenital anomaly of the atlas and a Jefferson fracture and to exclude instability of the upper cervical spine before treatment is started.Anteroposterior spondyloschisis of the atlas. Two case reports and literature review (2007)
Congenital bony defects of the atlas are uncommon; with isolated posterior clefts being the most frequent anomaly and combined anterior and posterior defects the least common, occurring in only 0.3–0.7% of the population. These anomalies can cause confusion, particularly in the setting of trauma when appearances on plain radiography may be misinterpreted as representing a fracture. Two cases of anteroposterior spondyloschisis are presented and the pathology, diagnosis and the clinical relevance of such defects discussed with reference to previous published literature
Anteroposterior Spondyloschisis of Atlas With Incurving of the Posterior Arch Causing Compressive Myelopathy
A case report of a patient with a combined anterior and posterior arch anomaly of atlas leading to compressive myelopathy. Objective. To describe a rare presentation of cervical stenosis at the atlas where congenital defects of the posterior arch with an incurving portion exists. This report includes a feasible hypothesis for the development of this anomaly on the basis of previous hypotheses and surgical findings. Conclusion. We describe the association between compressive myelopathy and combined anteroposterior spondyloschisis of an atlas with incurving of the arch at defect site. Both computed tomography and magnetic resonance image were required to demonstrate the bony configuration and cord compression. And decompressive laminectomy of atlas was effective as a treatment for this compressive myelopathy caused by midline defect in the posterior atlantal arch with bony incurving.Bipartite atlas in a collegiate football player - Not necessarily a contraindication for return-to-play: A case report and review of the literature (2012)
A 19-year-old male collegiate football player presented with neck pain and upper extremity paresthesias after sustaining a tackle that forced neck hyperextension. Computed tomography revealed significant congenital bony anomalies of the cervical spine, with incomplete fusion of the anterior and posterior arches of the atlas; however, there was no evidence for of any acute traumatic injury or fracture. Magnetic resonance imaging revealed increased edema in pre-vertebral soft tissues around C1–C2, with a possible increase in signal within the fibrous ring of the anterior C1 ring. Flexion and extension imaging confirmed reduced range of motion and no instability. Patient was treated non-operatively, and was able to resume normal activity and training regimens, and continued to do well clinically. Conclusion: We describe a rare case of split or bipartite atlas in collegiate football athlete who sustained a neck injury during a tackle. The patient had no atlanto-axial instability or other clinical contraindications and was managed non-operatively, resuming full participation shortly thereafter with a full resolution of symptoms.Complete bipartition of the atlas in the Klippel-Feil syndrome: A radiologically illustrated case report
A patient with the KlippelFeil syndrome is described who presented with pain in the neck after a trauma. No fractures were found. Instead, a midline cleft in both the anterior and posterior atlantic arches was found which represents an extremely rare congenital anomaly.Congenital midline cleft of the posterior arch of atlas: a rare cause of symptomatic cervical canal stenosis (2001)
Developmental symptomatic C1 canal stenosis is very rare. We describe the computed tomography (CT) and magnetic resonance imaging (MRI) appearances in a 8-year-old child who presented with progressive upper and lower limb neurological symptoms and in whom imaging revealed the medial posterior hemiarches of a bifid C1 to be inturned and compressing the cervical cord. This particular configuration of the posterior arch of atlas is frequently associated with other craniocervical bony anomalies and presents with neurological symptoms early in life. Early CT or MRI examination of patients with symptomatic posterior arch of C1 defects is necessary, in order to detect such an appearance, since surgical treatment may prevent neurological deterioration.
Congenital defects of the posterior arch of the atlas are rare, with a reported prevalence of 0.95 to 4%. The defects have been classified into five types (A-E), with type A being most common and types B-E being found only in 0.69% of the general population. Although most patients are asymptomatic, some may present with chronic neck pain, headache, Lhermitte’s sign, transient quadriparesis or even acute neurological deficits. The defects may also mimic a Jefferson fracture leading to a wrong diagnosis. Despite its rarity, knowledge of this congenital posterior arch defect of the atlas is important for avoiding diagnostic errors and to provide information on its management. We are therefore reporting a case with this congenital defect discovered as an incidental finding and provide a literature review about this rare anomaly.Mid-line clefts of the atlas: a diagnostic dilemma (2002)
Congenital clefts and other developmental anomalies of the atlas vertebra are rarely encountered. They are incidental findings discovered while investigating the cervical spine following trauma. Differentiation of developmental variants of the atlas from the burst fracture of Jefferson is essential to prevent unnecessary medical intervention.Persistent torticollis, facial asymmetry, grooved tongue, and dolicho-odontoid process in connection with atlas malformation complex in three family subjects (2007)
Congenital clefts and other malformations of the atlas are incidental findings identified while investigating the cervical spine following trauma. A persistent bifid anterior and posterior arch of the atlas beyond the age of 3–4 years is observed in skeletal dysplasias, Goldenhar syndrome, Conradi syndrome, and Down’s syndrome. There is a high incidence of both anterior and posterior spina bifida of the atlas in patients with metabolic disorders, such as Morquio’s syndrome [Baraitser and Winter in London dysmorphology database, Oxford University Press, 2005; Torriani, Lourenco in Rev Hosp Clin Fac Med Sao Paulo 53: 73–76, 2002]. We report two siblings and their mother, with congenital, persistent torticollis, plagiocephaly, facial asymmetry, grooved tongues, and asymptomatic ‘‘dolicho-odontoid process’’. All are of normal intelligence. No associated Neurological dysfunction, paresis, apnoea, or failures to thrive were encountered. Radiographs of the cervical spine were non-contributory, but 3D CT scanning of this area allowed further visualisation of the cervico–cranial malformation complex in this family and might possibly explain the sudden early juvenile mortality. Agenesis of the posterior arch of the atlas and bifidity/clefting of anterior arch of the atlas associated with asymptomatic ‘‘dolicho-odontoid process’’ were the hallmark in the proband and his female sibling. Some of the features were present in the mother. All the family subjects were investigated. To the best of our knowledge the constellation of malformation complex in this family has not been previously reported.
Post atlantoaxial fusion for unilateral cleft of atlas posterior archassociated with os odontoideum: case report and technique note (2011)
A case of a 34-year-old female with unilateral cleft of atlas posterior arch associated with os odontoideum is reported. The patient had experienced neck pain for 6 months. Five days earlier to admission the pain aggravated as a result of mild head trauma from behind. Imaging examinations revealed C1–2 subluxation as well as the deformity. After 3 days of skull traction, a sound C1–2 reduction was achieved. Post atlantoaxial fusion using bilateral transarticular screws combined with C1 laminar hook on the intact side and autogenous bone graft was performed. On the sixth month of postoperative follow-up, CT revealed solid fusion was achieved. No related complications were detected within 3 years of follow-up. The clinical manifestations and imaging findings were presented. The incidence and etiopathogenesis of hypoplastic posterior arch of the atlas were concisely introduced. Techniques of post atlantoaxial fusion under circumstances of unilateral C1 posterior elements defects were discussed. The authors believe bilateral transarticular screws combined with C1 laminar hook on the intact side and autogenous bone graft can be applicable to atlantoaxial fusion on the premise of preoperative C1–2 reduction and C1 posterior arch remaining[1/2 of its full length.Posterior Arch Defects of the Atlas - A Report of Two Cases and Literature Review (2017)
Developmental abnormalities of the atlas are rare, but benign abnormalities, firstly reported in 1937 by Plaut, Lawrence and Anderson. The authors report two cases of patients with these defects. The first patient had complaints of neck pain and the second consisted on an incidental finding after a traumatic incident. Both patients were treated conservatively with success. Little evidence is available on this pathology and is mostly provided by case reports and guidelines for the treatment still lack, making this a challenging entity to diagnose and treat.Recurrent attacks of headache and neck pain caused by congenital aplasia of the posterior arch of atlas in an adult (2010)
A 47-year-old Chinese woman, with a history of recurrent attacks of vertigo and vomiting for the past 5 years, presented with intermittent radicular pain in the left upper limb for the past 2 years. She also reported recurrent attacks of severe headache and neck pain for more than 10 years. The pain might be aggravated by coughing or sneezing and relieved after sleeping in the decubitus position. The MRI depicted Chiari malformation. A multidetector CT scan and three-dimensional CT reconstruction revealed partial aplasia of the left posterior arch of atlas of a small gap. The patient underwent plastic surgeries in Beijing. The disappearance of the recurrent pain syndrome was confirmed by follow-up after surgery.Split atlas in a patient with odontoid fracture
Malformations of the atlas are rare and include aplasia, hypoplasia, and various arch clefts [1]. The association of a rachischisis in both anterior and posterior atlas arches is usually called ‘‘split atlas’’ and may easily be mistaken for fracture in the radiologic evaluation of patients with history of cervical spine trauma [1, 2, 3]. We report, for the first time, to the best of our knowledge, a unique case of an odontoid fracture associated with clefts in the anterior and posterior arches of atlas, thus mimicking a complex C1–C2 fracture.Three cases of bipartition of the atlas
A bipartite atlas is a rare coincidental finding, and it is reported in only 0.1% of the general population. It is a congenital disorder characterized by incomplete fusion of the anterior and the posterior arches of C1, and it is important to differentiate it from a Jefferson fracture. RESULTS: The CT scans of the three patients show midline clefts of the anterior and the posterior arches of C1 with similar imaging features: smooth margins lined by cortical bone and no lateral offset. The patients had no neurological symptoms relating to the C1 abnormality, and no follow-up was performed. The clefts at level C1 are the result of the failure of three ossification centers to fuse properly. Anterior and posterior clefts are caused by hypoplasia of the hypochordal bow and lateral parts of the C1 sclerotome, respectively. Because of the risk of instability, assessing atlantoaxial stability is advised. However, patients usually have no symptoms and require no specific treatment. CONCLUSIONS: A bipartite atlas is a rare congenital abnormality, caused by a failure of anterior and lateral ossification centers to fuse. It needs to be differentiated from a Jefferson fracture in a trauma setting. It usually requires no specific treatment.Torticollis of a Specific C1 Dislocation With Split Atlas
We report a novel case of torticollis disorder because of a congenital split atlas after minor trauma.Transoral Osteosynthesis C1 as a Function-Preserving Option in the Treatment of Bipartite Atlas Deformity (2009)
A case report about transoral osteosynthesis C1 as a function-preserving option in the treatment of bipartite atlas deformity. Objective. To illustrate a new method, which preserves the function of the C1–C2 joint in young patients. Summary of Background Data. To the authors, knowledge, bipartite atlas deformity are usually treated conservatively by immobilization or traction or surgically by posterior fusion C1–C2. Methods. A 20-year-old man, who complained about occipitocervical pain and cervical activities limitation, and presented with a 3-month history of weakness and numbness of all 4 limbs after sustaining a minor head trauma. Computed tomography scan showed anterior arch midline defect, posterior arch midline aplasia. Steel plate fixation by transoral approach was performed to repair bipartite atlas deformity. Results. In 1-month follow-up, occipitocervical pain disappeared. The patient had significant improvement over next 3 months. In 6-month follow-up, we observed bony union of anterior arch of atlas without abnormal manifestations. The postoperative rotation in the atlantoaxial joint was returned to normal. The patient had no symptoms of postoperative instability of C1–C2. Conclusion. We described a rare association of an anterior arch midline defect, posterior arch midline aplasia. The natural history of patients with bipartite atlas deformity suggests that these people have a potentially precarious existence. Transoral osteosynthesis of the anterior ring and the lateral masses of C1 is a new technique that allows maintenance of rotatory mobility in the C1–C2 joint and restoration of congruency in the atlanto-occipital and atlantoaxial joints.
Upper Cervical Chiropractic Treatment for a Patient Demonstrating a Non-traumatic Bipartite Atlas: A Literature Review and Case Report (2009)
The purpose of this case report is to describe a process to diagnose and to adjust a congenital anomaly known as anteroposterior spondyloschisis (aka bipartite atlas). Clinical Features: A 30-year-old female presented with a history of chronic cervicalgia, uncoordinated reflexes, and whole-body soreness. Radiographic examination demonstrated radiolucent clefts through the anterior and posterior arches of the atlas. Intervention and Outcome: Given no history of trauma to suggest Jefferson fracture, the patient was diagnosed with a bipartite atlas. After demonstrating atlantodental and atlantoaxial stability, the patient consented to upper cervical (Atlas Orthogonal) chiropractic treatment. Conclusion: The patient in this case study responded favorably to upper cervical treatment. Considerations and treatment protocols are outlined in order to assist health care providers, who may encounter this anomaly in other patients.Ventral C1 Fracture Combined with Congenital Posterior Cleft: What to Do? (2018)
We present a treatment approach for a rare condition of patients with a ventral C1 fracture and a congenital cleft in the posterior arch (half-ring Jefferson fracture) with an intact transverse atlantal ligament. Our technique aims to achieve stability of the atlanto-occipital and atlantoaxial joints while preserving mobility of the upper cervical spine.
Types C-D
Objective. To report on a patient presenting with anteroposterior defects of the arch of the atlas with a rare type of posterior arch defect. This report includes a literature review of the hypothesis for the development of this anomaly. Summary of Background Data. Congenital bony defects of the atlas are uncommon. Isolated posterior clefts are the most frequent anomaly, but combined anterior and posterior defects are the least common. In particular, combined anteroposterior defects of the arch of the atlas with other types of posterior arch defects, not including type A, have not been reported. These anomalies can cause confusion, particularly in the setting of trauma when the radiologic fi nding may be misinterpreted as representing a fracture. Results. The patient improved on conservative therapy without a surgical procedure. Conclusion. We describe combined anteroposterior defects of the arch of the atlas along with other types of posterior arch defects. Most congenital defects of the arch of the atlas are found during radiologic evaluation of neck pain after trauma. Careful diagnosis is needed for these patients to avoid confusing these defects with a fracture.Aplasia of the posterior arc of the atlas with persistent posterior tubercle: a case report (2005)
An unusual case of partial aplasia of the posterior arc of the atlas, with persistent posterior tubercle, is presented in a previously healthy individual who sustained a neck trauma. Both plain X-rays and CT findings specified the lesion. Dynamic X-rays in flexion and extension showed an immobile posterior tubercle. The patient did not develop neurological symptoms at any stage during follow-up (1 year).
Aplasia of the posterior arches of the atlas: A presentation of 2 cases (2012)
Aplasia of the posterior arches of the atlas is an uncommon condition caused by a defect in their closure. It is usually associated with different syndromes. Case report: We present 2 asymptomatic patients with aplasia of C1 posterior bodies. Conclusions: Further studies are required on these lesions in order to take possible protection measures against trauma, and the selection between conservative or surgical treatment.Combined asymptomatic congenital anterior and posterior deficiency of the atlas (2001)
Atlas anomalies in terms of clefts and aplasia are rare. They can sometimes simulate fractures and need further evaluation. Imaging in terms of CT and MR can help resolve diagnostic confusion and also outline associated neurological involvement. A rare anomaly of anterior and posterior atlas arch, previously unclassified, is presented.Congenital C1 arch deficiency: Grand Round presentation (2013)
We present an uncommon and yet interesting congenital anomaly and discuss the difficulties with diagnosis and controversies in management. C1 arch deficiency is an important consideration in the differential diagnosis of neck pain in children.Expert’s Comment concerning Grand Rounds Case entitled '‘Congenital C1 arch deficiency: Grand Round Presentation’’ (2013)
As the authors point out in this thought provoking case report [1], absence of the posterior atlantal arch, whilst rare is by no means a unique entity and will present from time to time to spinal surgeons particularly those with a paediatric interest. The radiological appearances are striking yet the clinical presentation may range from no symptoms at all to overt myelopathy. The literature on the subject is sparse and largely restricted to individual case reports and a few small series, however, guided by what literature there is and with reference to the anatomy and embryology of the atlas as well as from experience of other craniovertebral anomalies in childhood it is possible to shed some light on the possible aetiology and implications of this anomaly
Congenital anomalies in arches of the atlas are rare, and are usually discovered incidentally. However, a very rare subgroup of patients with unique radiographic features is predisposed to transient quadriparesis after minor cervical or head trauma. A 46-year-old male presented with a 2-month history of tremor and hyperesthesia of the lower extremities after experiencing a minor head trauma. He said that he had been quadriplegic for about 2 weeks after that trauma. Radiographs of his cervical spine revealed bilateral bony defects of the lateral aspects of the posterior arch of C1 and a midline cleft within the anterior arch of the atlas. A magnetic resonance imaging revealed an increased cord signal at the C2 level on the T2-weighted sagittal image. A posterior, suboccipital midline approach for excision of the remnant posterior tubercle was performed. The patient showed significant improvement of his motor and sensory functions. Since major neurologic deficits can be produced by a minor trauma, it is crucial to recognize this anomaly.Congenital defects of posterior arch of the atlas: a case report (2007)
Our aim was to describe an unusual congenital anomaly of atlas and to emphasize its clinical significance. A 43-year old woman presented with occipital headache that was worse with hyperextension of neck. Patient denied any neck pain and other neurological complain. On examination, the only positive finding on physical examination was moderate pain at the upper cervical and occipital region throughout neck extension. The cranial nerve examination was unremarkable, and motor and sensory findings were normal. Plain cervical radiographs revealed bilateral defects in the posterior arch of atlas. Computed tomography scans in flexion and extension positions showed no displacement or inward mobility of the posterior tubercle during extension of the cervical spine. No evidence of compression of the spinal cord was detected on magnetic resonance imaging. Congenital anomalies of the posterior arch of the atlas are very uncommon and usually asymptomatic. Neurological presentations depend on type of defect of posterior arch of atlas. It is crucial to recognize this defect to prevent major neurological deficitsCongenital Partial Aplasia of the Posterior Arch of the Atlas Causing Myelopathy: Case Report and Review of the Literature (2003)
Congenital defects of the posterior arch of the atlas are uncommon but well described anomalies. Geipel found clefts of the posterior arch in 4% of 1613 autopsies, 97% of which were median clefts.1–4 These defects were considered by some to be a “benign variation,” and indeed, almost all of them are discovered incidentally.5–7 However, a very rare subgroup of patients with unique radiographic features are predisposed to a variety of neurologic symptoms/deficits, including transient quadriparesis following minor cervical or head trauma and Lhermitte sign. We describe such a case and review previous reports in the literature.Congenital posterior atlas defect associated with anterior rachischisis and early cervical degenerative disc disease : A case study and review of the literature (2007)
A rare case of a wide congenital atlas defect is reported. A 25 year-old woman was admitted after complaints of radicular pain in the right arm. Radiographs incidentally revealed aplasia of the posterior arch of the atlas together with anterior rachischisis. A review of the literature is presented and a possible association with early disc degeneration is discussed.Partial agenesis of the posterior arch of the atlas
We report the case of a 54-year-old woman who presented at the emergency department complaining of cervical pain with no irradiation to superior extremities after a low-energy traffic accident. Physical examination was unremarkable, except for tenderness on percussion of cervical spinous process and pain with flexion and extension of the neck. A lateral cervical radiograph showed a congenital malformation (partial agenesis of the posterior arch of the atlas). Congenital defects of the posterior arch are not frequent, and their incidence is not well known.
Partial Aplasia of the Posterior Arch of the Atlas with a Persistent Posterior Tubercle (2010)
Congenital anomalies of the atlas are rare [1]. In most cases, they do not cause symptoms and typically only become apparent in routine or emergency evaluation. Sometimes, the distinction between an acute fracture and a congenital anomaly can be demanding. Here, we present a case of a rare finding in the setting of acute trauma.Partial Aplasia of the Posterior Arch of the Atlas with an Isolated Posterior Arch Remnant: Findings in Three Cases (2000)
We report the imaging findings in three symptomatic cases of partial aplasia of the posterior arch of the atlas with an isolated posterior remnant of the arch. These cases are instructive in illustrating the mechanism of cord impingement produced by the posterior arch remnant during extension of the cervical spine. Additionally, focal increased T2 signal was observed within the cord at the level of the anomaly in two of the patients..Posterior Arch Defects of the Atlas - A Report of Two Cases and Literature Review (2017)
Developmental abnormalities of the atlas are rare, but benign abnormalities, firstly reported in 1937 by Plaut, Lawrence and Anderson. The authors report two cases of patients with these defects. The first patient had complaints of neck pain and the second consisted on an incidental finding after a traumatic incident. Both patients were treated conservatively with success. Little evidence is available on this pathology and is mostly provided by case reports and guidelines for the treatment still lack, making this a challenging entity to diagnose and treat.
Posterior arch defects of the atlas: significance in trauma and literature review (2003)
Neck pain and stiffness after trauma can be caused by congenital defects in the posterior arch of the atlas. A case is described followed by a description of the pathology, classification, diagnosis and treatment of such defects. The importance of differentiating such defects from fractures in an acute trauma situation is discussed.
Type E
A Case of Aplasia of the Posterior Arch of the Atlas Mimicking Fracture: Review of the Literature (2010)
A 25-year-old female patient with a mild head trauma as a result of a syncopal episode and fall is reported in this case. Up on admission she complained only of mild tenderness in the cervical spine and mild headaches without dizziness or vomiting. Her neurological status was normal. The cervical pain would not increase by head turning, flexion, or extension. No irradiating pain was indicated.
To illustrate the radiological findings and review the current literature concerning a rare congenital abnormality of the posterior arch of the atlas. CASE REPORT: An adult female without neurological symptoms presented with an absent posterior arch of the atlas, examined with plain films and helical computerized tomography. Complete agenesis of the posterior arch of the atlas is a rare entity that can be easily identified by means of plain films. Although it is generally asymptomatic, atlantoaxial instability and neurological deficits may occur because of structural instability. Computerized tomography provides a means of assessing the extent of this abnormality and can help evaluate the integrity of neural structures. Although considered to be rare entities, defects of the posterior arch of the atlas may be discovered as incidental asymptomatic findings in routine cervical radiographs. Familiarity with this abnormality may aid medical professionals in the correct management of these cases.
A case report of a young male suffering progressive neurologic dysfunction associated with a previously unreported combination of structural bony abnormalities. A review of the literature is also presented. Objective. To describe a unique presentation of cervical myelopathy related to posterior deficiencies of the atlas and axis, and to report on the successful management of this case.
Congenital abnormalities of the cervical spine are rare findings in trauma victims. Deficiency of the posterior arch of the atlas and coincidental thalassaemia minor are even more unusual. This case report is about a young female trauma victim with both abnormalities, a combination that has previously not been described in literature. The classification, as proposed by Currarino et al in 1994, and the importance of being aware of these abnormalities are discussed.Complete absence of the posterior arch of C1: Case report (2014)
Posterior atlas arch anomalies are relatively common, but have a variety of presentations ranging from partial clefts to complete agenesis of the posterior arch. Partial clefts are prevalent in 4% of patients and are generally asymptomatic. However, complete agenesis of the posterior arch is extremely rare. We report the case of a 46-year-old man who presented with upper cervical spine and occipital pain as well as left sided headaches. Imaging revealed congenital complete absence of the posterior arch of C1 (Type E) without any radiographic evidence of instability. We discuss our case in light of other reported cases and detail its management.Congenital absence of the posterior arch of the atlas associated with a fracture of the anterior arch (2010)
Structural defects of the posterior arch of the atlas are rare, and range from clefts of variable location and size to more extensive defects such as complete agenesis. These abnormalities are usually incidental radiological findings. We present a case of a fracture of the anterior arch of the atlas associated with a congenital abnormality of the posterior arch.Congenital Agenesis of the Posterior Arch of the Atlas- A case report and review of the literature (2014)
Congenital absence of the posterior arch of the Atlas (C1), a developmental failure of chondrogenesis, is a rare but well documented anomaly. It may range from partial cleft to total agenesis of the posterior arch. Th is condition is usually asymptomatic and diagnosed incidentally but sometimes may present with neurological signs and symptoms following head and neck trauma. Our aim to present this unique case of complete agenesis of the posterior arch of the Atlas (C1) is to highlight its importance for the clinicians to be aware of such rare congenital anomaly as it may be associated with vertebral instability and cord compression, and may possibly require surgical intervention.Congenital defect of the atlas and axis. A cause of misdiagnose when evaluating an acute neck trauma
Congenital absence of the posterior arch of the atlas (C1) is rare and even more presenting with a double spinous apophysis of the axis (C2). It is important to keep in mind these cervical congenital abnormalities when evaluating an acute neck trauma because of the possibility of making an erroneous diagnosis of a fracture. This case report is about a 13-year-old boy in the context of a traffic accident who presented both abnormalities, a combination that to our knowledge has not been reported previously in the literature.
