Chronic type 2 odontoid fracture with atlantoaxial spondyloptosis in an adult: a case report and literature review
Case Report

Chronic type 2 odontoid fracture with atlantoaxial spondyloptosis in an adult: a case report and literature review

Megan Berube1,2, Emanuela Binello1,2

1Department of Neurosurgery, Boston University Chobanian and Avedisian School of Medicine, Boston, MA, USA; 2Department of Neurosurgery, Boston Medical Center, Boston, MA, USA

Contributions: (I) Conception and design: Both authors; (II) Administrative support: E Binello; (III) Provision of study materials or patients: Both authors; (IV) Collection and assembly of data: Both authors; (V) Data analysis and interpretation: Both authors; (VI) Manuscript writing: Both authors; (VII) Final approval of manuscript: Both authors.

Correspondence to: Emanuela Binello, MD, PhD, ScD. Department of Neurosurgery, Boston Medical Center, 725 Albany Street, Shapiro Suite 7C, Boston, MA 02118, USA; Department of Neurosurgery, Boston University Chobanian and Avedisian School of Medicine, Boston, MA, USA. Email: emanuela.binello@bmc.org.

Background: Type 2 odontoid fractures may be associated with varying degrees of atlantoaxial dislocation (AAD). Atlantoaxial spondyloptosis (AAS) is a rare cervical injury with reported etiologies including congenital, trauma, and rheumatoid disease, defined as having the facets of the atlas fixed anteriorly to the facets of the axis. When associated with a type 2 odontoid fracture, there is complete translocation of the C1 arch and the fractured odontoid process complex, anteriorly to the C2 vertebral body, representing a severe form of fixed or irreducible anterior AAD. The challenging anatomy increases the complexity of surgical decision-making, while the paucity of reported cases increases the challenge in deriving guidance to inform the surgical approach. This report adds to the limited literature on AAS and highlights a unique surgical management strategy.

Case Description: This report presents the case of an adult patient with a chronic type 2 odontoid fracture and AAS after low-impact trauma in the setting of newly diagnosed inflammatory comorbidities of sarcoidosis and latent tuberculosis. The patient had neck pain attributable to the atlantoaxial pathology but was otherwise neurologically intact. The patient was successfully managed with an occipitocervical fusion and posterior decompression without reduction, with resolution of the neck pain.

Conclusions: The choice of surgical approach should be made based on careful preoperative radiographic evaluation of fracture-dislocation morphology and associated vascular anatomy, in addition to patient-specific factors. In the absence of neurological deficits, reduction of the fracture-dislocation may be deferred in favor of stabilization with decompression.

Keywords: Chronic type 2 odontoid fracture; atlantoaxial spondyloptosis (AAS); occipitocervical fusion; case report

Submitted Jan 07, 2025. Accepted for publication Mar 24, 2025. Published online Jul 24, 2025.

doi: 10.21037/jss-25-5

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Key findings

• Rare case of a 71-year-old patient with a chronic type 2 odontoid fracture and atlantoaxial spondyloptosis (AAS) after a low impact fall and newly diagnosed sarcoidosis and latent tuberculosis, who had neck pain but was otherwise neurologically intact.

• Radiographic features suggested that the fracture-dislocation was truly irreducible, while vascular imaging raised concern for vertebral artery abnormalities. The patient was successfully managed with an occipitocervical fusion and posterior decompression without reduction, with resolution of the neck pain.

What is known and what is new?

• AAS is a rare clinical entity previously known to be associated with congenital, trauma and rheumatoid etiologies. Previous cases of reported AAS with chronic odontoid fractures have been managed by posterior atlantoaxial cervical fusion with reduction.

• This report expands the repertoire of known conditions concomitant with AAS to include sarcoidosis and latent tuberculosis and presents a successful outcome from a surgical approach without reduction. It also reviews the spectrum of surgical approaches to chronic type 2 traumatic odontoid fractures with anterior atlantoaxial dislocation and/or associated kyphotic deformities.

What is the implication, and what should change now?

• The choice of surgical approach should be made based on careful preoperative radiographic evaluation of fracture-dislocation morphology and associated vascular anatomy, in addition to patient-specific factors.

• In the absence of neurological deficits, reduction of the fracture-dislocation may be deferred in favor of stabilization with decompression.

Introduction

Type 2 odontoid fractures occur at the junction of the odontoid process and the C2 vertebral body (1). They are considered unstable and managed with immobilization strategies ranging from external bracing with a hard cervical collar to surgical intervention, that can be done either anteriorly and/or posteriorly, depending on fracture, patient and surgeon factors. The variety of strategies is influenced by the breadth of fracture morphologies leading to subclassifications based on fracture obliquity, displacement and comminution (2) as well as by evolving understanding of the implications of nonsurgical management (3). Given the critical role of the odontoid process and surrounding ligaments in maintaining atlantoaxial integrity (4), type 2 odontoid fractures may be associated with varying degrees of atlantoaxial dislocation (AAD) that may be characterized as anterior, posterior, and/or lateral, with a rotatory component, or according to etiology and/or mechanism of injury (5). AAD may also be classified as fixed or irreducible vs. reducible, based on the ability to be successfully reduced with closed traction (6).

Spondyloptosis is the most severe form of spondylolisthesis, with complete translocation of one vertebral body over another. In the absence of the atlas having a vertebral body, atlantoaxial spondyloptosis (AAS) has been defined as having both facets of the atlas fixed anterior to the facets of the axis (7). AAS is a rare cervical injury with reported etiologies including congenital, trauma, and rheumatoid disease (7-9). When associated with a type 2 odontoid fracture, there is complete translocation of the C1 arch and fractured odontoid process complex, anteriorly to the C2 vertebral body. AAS represents a severe form of fixed and/or irreducible anterior AAD that may present with a spectrum of neurological findings. Surgical management is aimed at stabilization and decompression. The challenging anatomy increases the complexity of surgical decision-making, while the paucity of reported cases increases the challenge in deriving guidance to inform the surgical approach. Accrual of cases in the literature is critical to advance the understanding of this clinical entity.

This report presents a nuanced case of an adult patient with a chronic type 2 odontoid fracture and AAS in the context of delayed presentation after low-impact trauma and newly diagnosed inflammatory comorbidities of sarcoidosis and latent tuberculosis, who had neck pain but was otherwise intact. The patient was successfully managed with an occipitocervical fusion and posterior decompression without reduction. We present this case in accordance with the CARE reporting checklist (available at https://jss.amegroups.com/article/view/10.21037/jss-25-5/rc).

Case presentation

The patient is a 71-year-old male with no known past medical history who initially presented to the Emergency Department with poor oral intake, nausea, vomiting and unintentional weight loss, as well as headaches, neck pain and generalized weakness. The patient was wearing a hard cervical collar, that he had been wearing for about 3 months, after a low impact fall with resultant cervical fracture managed conservatively at an outside hospital. On examination, the patient was cachectic and lethargic. His upper and lower extremities were grossly 4+/5. There was no hyperreflexia, clonus or Hoffman’s sign. Imaging work-up included X-rays, computed tomography (CT) and magnetic resonance imaging (MRI) of the cervical spine (Figure 1) that revealed a chronic type 2 odontoid fracture with complete anterior dislocation of the C1 arch and fractured odontoid process complex, and with the facets of the atlas anterior to those of the axis, consistent with AAS and associated severe cervical stenosis with complete effacement of the thecal sac but without significant cord deformation and/or T2 cord signal change. Laboratory evaluation revealed a highly elevated calcium (14 mg/dL after albumin correction), elevated creatinine (3.0 mg/dL) and decreased sodium (131 mEq/L). Additional hypercalcemia workup revealed low vitamin D25 levels and normal D1–24 levels, as well as splenomegaly and diffuse lymphadenopathy on CT of the chest/abdomen/pelvis, raising concern for lymphoma vs. sarcoidosis. A lymph node biopsy confirmed a new diagnosis of sarcoidosis, and the patient was placed on atovaquone, prednisone and a proton pump inhibitor for the sarcoidosis, in addition to intravenous fluids for his kidney injury. The patient required intensive management of his electrolytes after developing refeeding syndrome following his increase in oral intake leading to hypokalemia, hypophosphatemia and hypomagnesemia. As his medical condition improved, the patient’s extremity strength became full, and he was ambulating without difficulty. The patient was ultimately discharged to home in stable condition and in an Aspen cervical collar, after about one month from presentation. The patient required additional extensive outpatient management and repeat inpatient admission for stabilization of his electrolytes. He was also diagnosed with latent tuberculosis via an interferon-gamma release assay (IGRA) requiring isoniazid, and with diabetes mellitus type 2 managed with insulin. During this time, he was followed for symptom checks, neurological examinations, and Aspen cervical collar adherence.

Figure 1 Imaging of the cervical spine at presentation. Sagittal view of the (A) X-ray, (B) CT and (C) MRI cervical spine showing a chronic type 2 odontoid fracture with complete anterior dislocation of the C1 arch and fractured odontoid process complex, and with the facets of the atlas anterior to those of the axis, consistent with AAS, and associated severe cervical stenosis with complete effacement of the thecal sac but without significant cord deformation and/or T2 cord signal change. A, anterior; AAS, atlantoaxial spondyloptosis; CT, computed tomography; MRI, magnetic resonance imaging; P, posterior.

The patient was ultimately medically optimized after about 6–7 additional months, such that he presented for discussion of possible surgical intervention at around 9 months after the initial trauma. At this time, the patient had neck pain. He had no difficulty with balance, gait or handgrip. The patient was engaging in his activities of daily living without difficulty despite external immobilization though he did note some increasing annoyance with the warmth associated with wearing the Aspen cervical collar especially in the summer. On examination, upper and lower extremities were full strength. There were no pathological reflexes and/or long-tract signs. A repeat CT cervical spine (Figure 2) revealed evolving cortication of the fracture edges, with evolving ankylosis and/or union between the posterior aspect of the odontoid fracture fragment to the body of C2 where there was also a bony spicule projecting superiorly, in addition to the atlantoaxial facets. Careful review of the computed tomography angiography (CTA) of the neck (Figure 3) raised concern for high-riding vertebral arteries (HRVAs). At this point, a surgical approach was designed taking into consideration both radiographic and patient-specific factors. Radiographic factors included the evolving ankylosis of the fracture with the superior bony spicule rendering this fracture-dislocation truly irreducible, and the concern for HRVA increasing the risk of hardware placement in C2, in addition to the presence of severe cervical stenosis at C1. Patient-specific factors included the presence of neck pain, absence of neurological deficits, the ability of the patient to engage in his activities of daily living without significant difficulty despite prolonged external immobilization, and the high likelihood of developing osteoporosis, given the concomitant diagnoses of sarcoidosis and latent tuberculosis, that are associated with an increased risk of osteoporosis and need for lifelong steroid administration (10,11). The irreducibility of the fracture and vertebral artery anomalies prompted the occipitocervical approach without reduction or hardware placement at C2, while the severe cervical stenosis at C1 and associated neck pain prompted inclusion of a C1 laminectomy. Finally, concern for suboptimal bone health and/or osteoporosis prompted extension of the fusion down to C5 to minimize hardware failure. Therefore, surgical intervention was offered to the patient in the form of an occipitocervical fusion down to C5, with C1 laminectomy and without reduction or hardware placement in C2. The loss of motion in the craniocervical junction was balanced against the elevated risk from the above radiographic and patient specific factors that would be associated with the alternative surgical approach of an atlantoaxial reduction and fusion. This was specifically discussed with the patient as part of a shared decision-making approach. The alternative of continued external bracing with the Aspen hard cervical collar for an extended period was also discussed with the patient. After thoughtful consideration of the risks, benefits and alternatives, the patient elected to proceed with surgery. The patient was taken to the operating room and underwent the occipitocervical fusion down to C5, and C1 laminectomy with neuromonitoring. The patient tolerated the procedure well and was at his neurological baseline after surgery. Post-operative X-rays of the cervical spine (Figure 4A) confirmed adequate hardware placement with good occipitocervical alignment. The patient was discharged to home on post-operative day 4. The patient was seen at 6 weeks post-operatively, with repeat X-rays of the cervical spine (Figure 4B) that confirmed the absence of interval hardware failure. The patient had mild residual neck pain but was otherwise doing quite well. During the 3-month post-operative visit, the patient stated that he had “no pain” and was doing “very well”. He was no longer consistently wearing the Aspen cervical collar and was engaging in his activities of daily living at his baseline without difficulty. He had no difficulty with balance, gait or handgrip and was ambulating without assistance. The patient’s cervical collar was fully cleared, and the patient declined additional follow-up visits.

Figure 2 Repeat CT cervical spine after 6 months. (A) Sagittal and coronal images show evolving cortication of the fracture edges, with evolving ankylosis and/or union between the posterior aspect of the odontoid fracture fragment to the body of C2 where there was also a bony spicule projecting superiorly. (B) On the sagittal images, there was also evolving ankylosis and/or union of the atlantoaxial facets, that were fixed. A, anterior; CT, computed tomography; L, left; P, posterior; R, right.
Figure 3 CTA of the neck. (A) Sagittal views of the left and right atlantoaxial articulations, showing proximity of the vertebral artery to the isthmus of C2. (B) Axial views of the vertebral artery at the level of C2 and related bony anatomy of C2 including pedicles. (C) Coronal views of the bilateral vertebral arteries, concerning for HRVAs, based on the proximity to the isthmus and pedicle size. A, anterior; CTA, computed tomography angiography; HRVAs, high-riding vertebral arteries; L, left; P, posterior; R, right.
Figure 4 Post-operative X-rays cervical spine. X-rays performed in the (A) immediate post-operative setting, and (B) at 3 months after surgery, demonstrating good and stable hardware placement without evidence of failure. A, anterior; P, posterior.

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent for publication of this case report and accompanying images was not obtained from the patient or the relatives after all possible attempts were made.

Discussion

This report presents a unique case of AAS with a type 2 chronic odontoid fracture that not only expands the range of reported conditions concomitant with this rare clinical entity, but also highlights the nuances of clinical presentation and radiographic factors that informed the approach to surgical management and demonstrates a successful outcome from an occipitocervical fusion down to C5 with a C1 laminectomy and without reduction of the atlantoaxial fracture-dislocation. While restricted range of neck motion is a limitation of this approach, advantages include decreased technical challenge with associated decreased risk of hardware and/or neurological complications, decreased risk of vertebral artery injury resulting from the absence of joint manipulation for reduction and hardware placement, in addition to decreased risk for hardware failure considering the patient’s need for lifelong steroid use for the sarcoidosis and presence of latent tuberculosis, increasing the risk of poor bone quality and/or osteoporosis. The length of the patient’s post-operative follow-up is a limitation of this report. Three months, while sufficient to evaluate for impact on a patient’s symptoms, is insufficient to determine the impact on possible fusion. Occipitocervical fusions are generally reported to have high fusion rates (12), but a longer follow-up time of 6 months or more is needed for a meaningful evaluation of fusion.

Despite the evolving consideration that non-union of chronic type 2 odontoid fractures with conservative management may be a reasonable outcome (3,13), the possibility of developing delayed acute on chronic neurological compromise has been estimated to be up to 17% (14) prompting consideration of surgical intervention, to be balanced against patient-specific factors. The worsening or persistence of neck pain may be indicative of continued microinstability even in the presence of evolving fibrous and/or bony union, rendering it reasonable to offer surgical intervention especially in the setting of cervical collar intolerance prior to completion of bony union, as in our case.

Reports of adult patients identified as having AAS are exceptionally rare, with only five cases presented in three reports (7-9), summarized in Table 1. There is only one case with concomitant etiologies including trauma and congenital, and one case with an inflammatory etiology of rheumatoid arthritis (7), increasing the uniqueness of our case that had concomitant etiologies of trauma and dual inflammatory etiologies of sarcoidosis and latent tuberculosis. Three cases were associated with type 2 odontoid fractures (7-9), of which only two had a similar range of duration of symptoms as in our case (8,9). Both of those cases were successfully treated by stabilization in the form of a posterior C1–2 fusion, with open reduction in the patient with neck pain and neurological deficits (8) and closed reduction in the patient with neck pain and chin on chest deformity and without neurological deficits (9). In contrast, our patient had neck pain alone without either neurological deficit or chin on chest deformity. Also, in contrast, our patient was successfully treated by stabilization in the form of an occipitocervical fusion and C1 laminectomy, without reduction.

Table 1

Summary of cases in the literature of adult patients identified as having AAS, in chronological order

References Age (years) Reported etiology Odontoid fracture present? Duration of symptoms and/or symptom onset after trauma Clinical presentation Attempt at closed reduction with traction? Was closed reduction achieved? Type of surgical intervention (number of stages) Outcome Length of follow-up
Goel et al., 2006 (7) 31 Congenital + trauma No 3 years Quadriparesis with difficulty breathing (Nurrick 4) Yes No Posterior C1–C2 joint distraction, reduction and lateral mass plate and screw fixation, with intraarticular spacers (1 stage) Improved (Nurrick 2) sensory loss in C2 distribution 45 months
24 Rheumatoid disease No 3 years Spastic quadriparesis (Nurrick 5) Yes No Posterior C1–C2 joint distraction, reduction and lateral mass plate and screw fixation, with intraarticular spacers (1 stage) Improved (Nurrick 4) sensory loss in C2 distribution 45 months
Ahuja et al., 2019 (8) 25 Trauma Yes 3 months Impairment of neck extension, monoparesis, bilateral ankle clonus, diffuse hyperreflexia Yes No Posterior C1–C2 fixation and reduction, with C1 lateral mass and C2 pars screws, and intraarticular spacer (1 stage) Improved strength in left upper extremity 5/5 6 months
Lachance et al., 2022 (9) 88 Trauma Yes 7 months Neck pain with chin on chest deformity, otherwise full strength Yes Yes Posterior C1–C2 fixation, with C1 lateral mass and C2 pedicle screws, without spacers (1 stage) Stable exam, improved deformity 2 years
68 Not known/reported Yes 3 days Neck pain with chin on chest deformity, hand weakness and numbness Yes Yes Posterior C1–C2 fixation, with C1 lateral mass and C2 pedicle screws, without spacer Improved exam and improved deformity Lost to follow up

AAS, atlantoaxial spondyloptosis.

Recognizing that AAS is on the spectrum of AAD, and that the surgical management of isolated chronic type 2 odontoid fractures includes a spectrum of surgical management options, the literature review was expanded to place the surgical management of this case in a broader context. Cases with fixed anterior dislocations and/or anterolisthesis were abstracted from reports of AAD with isolated chronic type 2 traumatic odontoid fractures that included both outcome data and representative imaging. This yielded 21 cases (15-23), summarized in Table 2, noting that in reports with more than 2 cases, the extent of the anterior dislocation of the C1-fractured odontoid process was not fully specified for all cases, increasing the chance of variation in morphology of the fracture-dislocation. Cases were also abstracted from reports of chronic type 2 odontoid fractures with associated deformity that included outcomes and representative imaging. This yielded an additional 14 cases (24-27), summarized in Table 3, for a total of 35 cases. Patients presented with a variety of symptoms, ranging from neck pain alone to severe neurological deficits consistent with cervical myelopathy and/or cord compression. About two thirds of cases (23/35) were managed with combined anterior and posterior approaches, including: 4 with transoral release + posterior atlantoaxial fusion, 1 with transoral release + occipitothoracic fusion, 18 with transcervical retropharyngeal or submandibular release + posterior atlantoaxial fusion. The remaining one third of cases (12/35) were managed with either an anterior only approach (2 with transoral release and fusion), or a posterior only approach, including 6 with posterior atlantoaxial fusion and 4 with an occipitocervical fusion and posterior decompression. Outcomes were generally good, with neurological and/or symptoms improvement, except for 1 mortality in the occipitocervical group attributed to respiratory etiology. The majority cases have been treated with combined anterior and posterior approaches, with more recent reports utilizing anterior retropharyngeal and/or submandibular approaches rather than transoral, generally followed by a posterior atlantoaxial fusion except for 1 case followed by an occipitothoracic fusion. Of the posterior only approaches, the occipitocervical fusion was reported with lower frequency than atlantoaxial. Overall, use of the occipitocervical fusion with posterior decompression and reduction was reported in 4/35 or about 10% of cases (17,20,24,26), with clinical presentations characterized by significant neurological deficits. In contrast, our patient had no neurological deficits, such that reduction could be deferred in favor of stabilization alone.

Table 2

Summary of cases in the literature of adult patients identified as having anterior AAD with traumatic chronic type 2 odontoid fractures, in chronological order

References No. of patients [total number if more than 1] Description of fracture-dislocation, with isolated traumatic odontoid fracture Attempt at closed reduction? If yes, was it achieved? Clinical presentation age: symptoms (duration of symptoms and/or onset of symptoms after trauma prior to surgery) Type of surgical intervention (number of stages) Post-operative outcome (length of follow-up)
Kirankumar et al., 2005 (15) 3 [19] Remote, isolated type 2 odontoid fractures with irreducible AAD and fixed anterolisthesis Yes, not achieved Spasticity and weakness in
16–18 y/o patients, not specified for subgroup (6.5–120 months for cohort, not specified for subgroup)		 Anterior transoral odontoidectomy + posterior C1–C2 fusion with reduction (2 stages) Improvement usually seen in cohort, but not specified for subgroup (6–48 months in cohort, not specified for subgroup)
Yin et al., 2005 (16) 2 [5] Irreducible anterior AAD with traumatic old type 2 dens fracture Not specified for subgroup 21 y/o F: neck pain + pathological reflexes. 25 y/o F: above + hemiparesis and spasticity (duration not specified) Anterior transoral atlantoaxial reduction, plate fixation and fusion, and intraarticular facet spacer (1 stage) Improvement in pain, weakness, and in pathological reflexes (3–6 months)
Salunke et al., 2015 (17) 5 [6] Irreducible traumatic AAD with fixed anterolisthesis secondary to isolated odontoid fracture Yes, not achieved 5 patients: worsening neck pain (0.5–2 months). 4 patients: progressive cervical myelopathy with mJOA scores 8–12 (1–3 months) Posterior C1–C2 fusion, with C1 lateral mass and C2 pedicle screws, with reduction and intraarticular facet spacers of bone and/or titanium (1 stage) 5 patients: improvement in neck pain in all (1–24 months). 4 patients: improvement in cervical myelopathy in all with mJOA scores 16–17 (15–24 months)
Chandrakar et al., 2015 (18) 1 Old and neglected odontoid fracture with C1–C2 dislocation No 20 y/o M: worsening neck pain, quadriparesis, initial spinal shock (6 months symptoms, and 9 months before surgery) Occipitocervical fusion down to C2, with C2 lateral mass screws, with partial reduction (1 stage) Improvement in neck pain (12 months)
Aggarwal et al., 2016 (19) 1 [2] Irreducible AAD in neglected odontoid fracture Yes, not achieved 39 y/o M: worsening neck pain, difficulty walking, monoparesis (1-month symptoms, 1 year after trauma) Anterior transoral release + posterior C1–C2 fusion with transarticular screws, after reduction with sublaminar wires (2 stages) Improvement in all neurological symptoms (12 months)
Zitouna et al., 2019 (20) 1 Traumatic AAD with odontoid fracture Yes, not achieved 74 y/o M: worsening neck pain, confusion, and spastic quadriparesis (3 days) Occipitocervical fusion down to C2, including intra-operative external reduction (1 stage) Mortality on day 5 after surgery, due to respiratory complications
Ren et al., 2019 (21) 6 [13] Irreducible AAD with old odontoid fracture Yes, not achieved 30–70 y/o, 3 M and 3 F: neck pain, numbness of extremities, weakness, gait abnormality: mJOA 6–9 (not reported) Anterior retropharyngeal release + posterior C1–2 fusion, with C1 and C2 pedicle screw, with reduction (2 stages) Improvement in neck pain, numbness and weakness, mJOA 10–17, improved by 4–8 points
(12–36 months)
Klimov et al., 2021 (22) 1 Neglected odontoid fracture with anterior AAD Yes, not achieved 34 y/o M: worsening neck pain and chin towards chest deformity (8 months) Anterior submandibular release + posterior C1–C2 fusion with reduction + placement of anterior fracture and intraarticular spacers (3 stages) Improvement in neck pain and in posture (12 months)
Mousavi et al., 2024 (23) 1 Irreducible traumatic AAD secondary to type II odontoid fracture No 30 y/o M: quadriparesis and distal paresthesias of the lower extremities (6 months) Posterior C1–C2 laminectomy and fusion, with C1 lateral mass and C2 pedicle screws, with reduction, without spacers (1 stage) Improvement in quadriparesis (6 months)

AAD, atlantoaxial dislocation; F, female; M, male; mJOA, modified Japanese Orthopaedic Association; y/o, year-old.

Table 3

Summary of cases in the literature of adult patients identified as having traumatic chronic type 2 odontoid fractures with associated deformity, in chronological order

References No. of patients [total number if more than 1] Description of isolated traumatic odontoid fracture with associated atlantoaxial pathology Attempt at closed reduction via traction? If yes, reduction achieved? Clinical presentation age: symptoms (onset of symptoms after trauma and/or duration of symptoms) Type of surgical intervention (number of stages) Post-operative outcome (length of follow-up)
Ho et al., 2010 (24) 1 [6] Stable displaced atrophic nonunion of neglected type 2 odontoid fracture, with kyphotic atlantoaxial deformity Not reported 45 y/o F: quadriparesis, diffuse hyperreflexia, diffuse pathological reflexes, difficulty with balance and gait, spasticity, and impaired daily activities (36 months) Occipitocervical fusion down to C2 with C1 laminectomy (1 stage) Improved ambulation and independence in daily activities (48 months)
Shamji et al., 2016 (25) 1 Chronic hypertrophic nonunion of type 2 odontoid fracture, with kyphotic craniocervical deformity Yes, reduction achieved 68 y/o M: upper extremity paresis, diffuse hyperreflexia, diffuse pathological reflexes, difficulty with balance and gait, broad-based gait: mJOA score 13 (25 years after trauma, 3 months symptoms) Anterior transoral decompression (odontoidectomy) + occipitothoracic decompression and fusion for concomitant subaxial pathology (2 stages) Improvement to functional independence: mJOA score 17 (6 months)
Dumlao and Grozman, 2020 (26) 1 Chronic untreated odontoid neck fracture, with displaced odontoid and C1–2 facet disruption Yes, partial reduction achieved 19 y/o M: quadriplegia, diffuse hyperreflexia, diffuse pathological reflexes, bowel and bladder dysfunction (3 months) Occipitocervical fusion down to C3 with C1 laminectomy (1 stage) Improvement in strength, ambulatory (1.5 months)
Rehman et al., 2022 (27) 11 Neglected, malunited type 2 odontoid fractures, with anterolisthesis of C1/odontoid complex on C2 body Yes, reduction not achieved 33–71 y/o, 8 M and 3 F: worsening neck pain [8], gait abnormality [8], weakness [6], sensory symptoms [7], bladder symptoms [4], mJOA score 9.9±2.7 (6 months to 15 years) Anterior transcervical retropharyngeal release with a C4–C5 level incision + posterior C1–C2 fusion (2 stages) Neurological improvement, mJOA scores 13.8±2.7, P<0.001 (3–6 months)

F, female; M, male; mJOA, modified Japanese Orthopaedic Association; y/o, year-old.

The choice of surgical approach is heavily influenced by the reducibility of the fracture-dislocation, in addition to patient factors. One study aiming to determine the factors associated with true irreducibility indicates that worsening symptoms (neck pain and/or progression of myelopathy), movement on dynamic X-rays and/or absence of a malunion on CT were associated with a higher likelihood of reduction (17). The absence of the worsening symptoms and/or neurological deficits, together with the presence of evolving ankylosis and/or union of the dislocation, were indicative of true irreducibility of the fracture-dislocation in our case and led to choice of the occipitocervical fusion and posterior decompression without reduction. The fusion was extended down to the subaxial spine due to the patient-specific factors associated with higher risk osteoporosis and hardware failure.

Evaluation of vertebral artery anatomy with a CTA is of great importance for complication avoidance (17), given the possibility of vertebral artery abnormalities, such as an HRVA, in inflammatory pathologies and/or other disorders of the craniocervical junction, with downstream impact on the surgical approach (28-32). Recognition of this prompted us to avoid instrumentation to C2 to decrease the risk of vascular injury, especially given the absence of neurological deficits. Therefore, although data has suggested that the occipitocervical fusion has higher complication rates compared to atlantoaxial fusion (33), it remains a reasonable surgical approach in the management of a truly irreducible traumatic AAS with a chronic type 2 odontoid fracture in a patient who has neck pain but is otherwise neurologically intact.

Conclusions

Overall, this report increases the range of etiologies seen with AAS with odontoid fractures to include concomitant inflammatory pathologies of sarcoidosis and latent tuberculosis, also elucidates a reasonable surgical approach in the form of an occipitocervical fusion with posterior decompression and without reduction, for the neurologically intact adult patient with a chronic type 2 odontoid fracture and AAS, with neck pain.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://jss.amegroups.com/article/view/10.21037/jss-25-5/rc

Peer Review File: Available at https://jss.amegroups.com/article/view/10.21037/jss-25-5/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jss.amegroups.com/article/view/10.21037/jss-25-5/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declarationof Helsinki and its subsequent amendments. Written informed consent for publication of this case report and accompanying images was not obtained from the patient or the relatives after all possible attempts were made.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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Cite this article as: Berube M, Binello E. Chronic type 2 odontoid fracture with atlantoaxial spondyloptosis in an adult: a case report and literature review. J Spine Surg 2025;11(3):709-721. doi: 10.21037/jss-25-5

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