Odontoid Peg Research Articles

Mortality in ASIA Impairment Scale grade A to D Patients With Odontoid Fracture and Magnetic Resonance Imaging Evidence of Spinal Cord Injury.

Odontoid fractures are common, often presenting in the elderly after a fall and infrequently associated with traumatic spinal cord injury (tSCI). The goal of this study was to analyze predictors of mortality and neurological outcome when odontoid fractures were associated with signal change on magnetic resonance imaging (MRI) at admission. Over an 18-year period (2001-2019), 33 patients with odontoid fractures and documented tSCI on MRI were identified. Mean age was 65.3 years (standard deviation [SD] = 17.2), and 21 patients were male. The mechanism of injury was falls in 25 patients, motor vehicle accidents in 5, and other causes in 3. Mean Injury Severity Score (ISS) was 40.5 (SD = 30.2), Glasgow Coma Scale (GCS) score was 13 (SD = 3.4), and American Spinal Injury Association (ASIA) motor score (AMS) was 51.6 (SD = 42.7). ASIA Impairment Scale (AIS) grade was A, B, C, and D in 9, 2, 3, and 19 patients, respectively. Mean intramedullary lesion length was 32.3 mm (SD = 18.6). The odontoid peg was displaced ventral or dorsal in 15 patients. Twenty patients had surgical intervention: anterior odontoid screw fixation in 7 and posterior spinal fusion in 13. Eleven (33.3%) patients died in this series: withdrawal of medical care in 5; anoxic brain injury in 4; and failure of critical care management in 2. Univariate logistic regression indicated that GCS score (p < 0.014), AMS (p < 0.002), AIS grade (p < 0.002), and ISS (p < 0.009) were risk factors for mortality. Multi-variate regression analysis indicated that only AMS (p < 0.002) had a significant relationship with mortality when odontoid fracture was associated with tSCI (odds ratio, 0.963; 95% confidence interval, 0.941-0.986).

Surgery for basilar invagination with and without Chiari I malformation.

The surgical treatment for Chiari I malformation and basilar invagination has been discussed with great controversy in recent years. This paper presents a treatment algorithm for these disorders based on radiological features, intraoperative findings, and analyses of long-term outcomes. Eight-five operations for 82 patients (mean ± SD age 40 ± 18 years; range 9-75 years) with basilar invagination were evaluated, with a mean follow-up of 57 ± 55 months. Apart from the radiological features and intraoperative findings, findings on neurological examinations before and after surgery were analyzed. Long-term outcomes were evaluated with Kaplan-Meier statistics. All 77 patients with a Chiari I malformation underwent foramen magnum decompression with arachnoid dissection and duraplasty. Patients with ventral compression by the odontoid peg were managed with posterior realignment and C1-2 fusion. Patients without ventral compression did not undergo C1-2 fusion unless radiological or clinical signs of instability were detected. Thirty-three patients without ventral compression or instability underwent foramen magnum decompression without additional fusion, whereas 52 operations on 49 patients involved posterior fusion at C0-2 or C1-2 after realignment of ventral compression and/or treatment of C1-2 instability. Postoperatively, gait ataxia, swallowing functions, and suboccipital pain improved significantly in both treatment groups. In total, 79% and 73% of patients reported that their condition improved after foramen magnum decompression alone and after fusion with or without foramen magnum decompression, respectively. Progression-free survival rates at 10 years were 83% and 81%, respectively. Among the patients with basilar invagination, a subgroup consisting of 40.2% of the included patients underwent successful long-term treatment with foramen magnum decompression alone and without additional fusion. This subgroup was characterized by the absence of a ventral compression and no atlantoaxial dislocation or other signs of craniocervical instability. The remainder of patients underwent C1-2 fusion with posterior realignment of ventral compression if required. In the presence of basilar invagination, Chiari I malformation should be treated with foramen magnum decompression and duraplasty.

Comparison of Hard and Soft Cervical Collars for the Management of Odontoid Peg Fractures in the Elderly.

IntroductionOdontoid peg fractures (OF) are the most common cervical spine fracture in the elderly. This retrospective analysis aimed to compare the outcomes of older patients with OF who had been managed non-operatively with either a hard or soft cervical collar.Materials and MethodsWe analysed the retrospective data of the clinical and radiographic records of patients 60 years or older who presented over a 10-year period with OF and were treated non-operatively with a cervical collar. Mortality was the primary outcome measure with mechanism of injury, complications, and fracture healing secondary measures.Results45 patients (hard collar n = 22; soft collar n = 23) were included with comparable demographics for frailty and co-morbidities in each group; age was significantly higher in the soft collar group (80.6 vs 86.4 years; P = .0065). Associated injuries and complications were not significantly different overall, or when Type II fractures were separately analysed (P = .435 associated injuries, P = .121 complications). All-cause mortality was greater in the soft collar group (30-day mortality hard: 0%, soft: 9%; 1-year mortality hard: 18%, soft: 48% P = .035). However, once corrected for age, this proved not to reach significance (P = .333) in any fracture type. Non-union was common (77%) but was not significantly different (hard = 70%; soft = 87%; P = .419).DiscussionConsistent with other reports, non-union rates remained substantial regardless of which collar was used. After controlling for age, there was no difference in all-cause mortality between elderly patients treated with a hard or soft cervical collar for odontoid peg fractures.ConclusionsSoft collars appear suitable for the treatment of odontoid peg fractures in the elderly without compromising outcome. Larger cohort analyses will help confirm this finding.

Intraoperative Positioning in Maxillofacial Trauma Patients With Cervical Spine Injury - Is It Safe? Radiological Simulation in a Healthy Volunteer.

Observational. To investigate the effects on the cervical spine of positioning patients for maxillofacial procedures by simulating intraoperative positions for common maxillofacial procedures. Magnetic resonance imaging was used to assess the effects of head position in common intraoperative configurations - neutral (anterior mandible position), extended (tracheostomy position) and laterally rotated (mandibular condyle position) on the C-spine of a healthy volunteer. In the tracheostomy position, maximal movement occurred in the sagittal plane between the cervico-occipital junction and C4-C5, as well as at the cervico-thoracic junction. Minimal movement occurred at C2 (on C3), C5 (on C6) and C6 (on C7). In the mandibular condyle position, C-spine movements occurred in both rotational and sagittal planes. Maximal movement occurred above the level of C4, concentrated at atlanto-occipital and atlanto-axial (C1-2) joints. Neck extension is likely to be relatively safe in injuries that are stable in flexion and extension, such as odontoid peg fracture and fractures between C5 and C7. Head rotation is likely to be relatively safe in fractures below C4, as well as vertebral body fractures, and laminar fractures without disc disruption. Early dialogue with the neurosurgical team remains a central tenet of safe management of patients with combined maxillofacial and C-spine injuries.

Management of C2 odontoid peg fragility fractures – A UK survey of spinal surgeons

PurposePatients sustaining fragility fractures of the C2 odontoid peg have 30-day mortality rates as high as 10% rising up to 34.1% at 1 year. Substantial controversy exists regarding optimal management of these fractures and there is a lack of national guidance to inform best practice.The aim of this study was to determine current practice in the management of these fractures throughout the United Kingdom. MethodsA UK wide, cross sectional survey was conducted, asking 10 questions regarding the initial management, imaging and follow-up of an elderly patient with a type 2 fragility odontoid peg fracture. This was publicised through the British Orthopaedic Association website and sent to all members of the Society of British Neurological Surgeons (SBNS) via email. Results107 Responses were received. 56% from orthopaedic consultants, 29% from neurosurgical consultants and 15% from senior spine fellows.86% (92) of respondents choose treatment with a cervical orthosis, with 84% (77) of these opting for a semi rigid Aspen or Philadelphia collar compared to 16% (15) opting for a soft cervical collar. Three (3%) opted for operative intervention with a further three (3%) choosing Halo fixation. Nine respondents (8%) opted for no orthosis and treatment with analgesia alone.Length of immobilisation in cervical orthosis ranged from 6 to 12 weeks. Initial follow-up ranged from 1 week to 6 weeks, with 6% (6) discharged without follow up.There was also marked variation in the use of follow-up imaging with 17% (18) using plain radiographs, 62% (66) requesting lateral flexion / extension radiographs, 10% (11) using CT and 11% (12) not performing any imaging at final follow up.In 60% (64) of cases respondents did not change subsequent management as a result of imaging. ConclusionType-2 fragility peg fractures have high morbidity and mortality. There is marked variation in the treatment modalities used, follow-up regime and use of imaging throughout the UK.Given the rapidly increasing incidence of these injuries and the associated mortality this should be a high priority field for further research. Further large scale studies are urgently required to inform best practice and standardise management of these injuries.

Anterior Odontoid Screw Fixation for Pediatric and Adolescent Odontoid Fractures: Single-Center Experience Over a Decade

Management of pediatric odontoid fractures is tricky and controversial. This study will enrich world literature with intricacies of anterior odontoid screw (OS) fixation in the pediatric population learned over the last decade. In this retrospective study, all patients with pediatric odontoid fracture who underwent anterior odontoid screw fixation from January 2010 to December 2019 were included and evaluated for surgical outcome. Thirteen patients were included in this study (mean age, 15 years; range, 6-18 years; male/female, 11:2; type II, 10; type IIA, 1; type III, 2). Common causes of injury were motor vehicle accidents (61.5%) followed by fall from height (38.5%) and all were acute fractures (2-30 days). Five patients had neurologic deficits. Accurate placement of screw was achieved in 92.3% of patients, including all 9 patients who used intraoperative O-arm. K wire migration during bicortical drilling resulted in neurovascular injury, with 1 mortality (7.7%). The remaining 12 patients were available for follow-up (mean, 36 months; range, 20-72 months) and all had preservation of neck movements. Successful OS fixation was achieved in 84.6% of patients, including 1 patient (7.7%) who had a fibrous union. One patient (8.3%) had nonunion because of migration of the screw head in the C2 body. Anterior odontoid screw fixation in the pediatric population provides good functional outcomes with instant fixation by direct osteosynthesis. However, the surgeon should be meticulous in the surgical approach and should achieve a lag effect. The surgeon should stop after engaging the outer cortex of the odontoid peg with K wire to avoid cranial migration. Intraoperative O-arm guidance is useful.

Long term PROMs (patient reported outcome measures) in the non-operative management of odontoid peg fractures in the elderly

Long term PROMs (patient reported outcome measures) in the non-operative management of odontoid peg fractures in the elderly

Clinical and radiological outcome after minimally invasive surgical approach for type II unstable odontoid fractures

IntroductionAnterior odontoid screw fixation is a valid surgical option for unstable odontoid fractures, as type II Anderson D’Alonzo fractures. Grauer further divided type II fractures in subtypes according to the fracture line, providing recommendations for implementation of screw fixation techniques. ObjectivePrimary endpoint of our study is to evaluate the postoperative results of minimally invasive odontoid screw insertion in terms of outcome, fusion rate and stability of cranio-cervical junction. Secondary endpoint was to investigate the influence of age or fractures’ features on outcome and fusion rate. Materials and methodsWe report the clinical and radiological features of 32 patients harbouring unstable type II fractures operated by a minimally invasive odontoid screw insertion technique. All patients underwent a high resolution multiplanar CT in order to assess fracture features according to Grauer's classification; the integrity of ligaments was investigated by MRI. In addition, a preoperative neurological performance (modified Rankin Scale, mRS) was evaluated for patients either directly or interviewing their families. Follow-up at one, three and six months and 1 year have been performed (averaging 13.5 months) by cervical CT (fusion rate and stability) and mRS update. In order to investigate the influence of age on postoperative neurological performance, two groups (≤50 yrs, 9 pts/>50 yrs, 23 pts) were separately considered and analysed. Overall, we observed no surgery related complications. We also analysed the fusion rate and its correlation with patient age and Grauer's subtype of fracture. ResultsAt last available clinical follow-up, the preoperative performance was preserved (mRS 0/1: 24, 75%; mRS 2–4: 9, 15%) although with slight reduction of intact patients (mRS 0: 22 vs. 19; 71.8 vs. 59.3%). Younger patients (≤50 yrs) fared significantly better than older ones, achieving a good clinical outcome (mRS 0/1) in 100% vs. 69.5% (9/9 vs. 16/23 pts). Statistical analysis showed a fair correlation between age and outcome. Other factors such as sex and Grauer's type did not influence significantly the clinical outcome. Nine patients did not complete a full radiological follow-up and were therefore excluded from analysis of radiological outcome. Among the remaining 23 patients, only 25% of those who were followed three months or less showed fusion; conversely, all patients who have been examined from 6 to 48 months fused. Among the non-union patients, two underwent a second surgery by posterior approach. ConclusionsIn our recent experience, the minimally invasive AOSF proved safe and effective in treating odontoid peg fractures. Selection based on Grauer's type is mandatory to achieve best results. While in the elderly, an anterior approach is well accepted as the first choice treatment, we recommend that this option should be offered as a suitable alternative to Halo or orthosis also in younger patients since it provides prompt, excellent clinical outcome and high fusion rate especially in this age group.

Tumours of the odontoid peg revisited.

Introduction:Tumours of the odontoid peg are rare but can potentially cause significant morbidity and mortality.Methods:A retrospective review of oncology and radiology database of tertiary orthopaedic oncology centre for all lesions affecting the odontoid peg over the last 12 years was performed.Results:We identified a total of 15 tumours involving the odontoid peg, majority being malignant. Myeloma was the most common tumour.Conclusion:Tumours of the odontoid peg are rare. Spinal surgeons and Radiologists need to be aware of them.

Cement augmentation of odontoid peg fractures: the effect of cement volume and distribution on construct stiffness.

The cement augmentation of a conventional anterior screw fixation in type II odontoid process fractures for elderly patients significantly increased stiffness and load to failure under anterior-posterior load in comparison with non-augmented fixation. The amount and quality of bone cement are usually taken ad hoc in clinical practise. In this study, we wanted to clarify the role of bone cement amount and its quality to the stiffness of odontoid and vertebrae body junction. Finite-element method was used to achieve different scenarios of cement augmentation. For all models, an initial stiffness was calculated. Model (1) the intact vertebrae were virtually potted into a polymethylmethacrylate base via the posterior vertebral arches. A V-shaped punch was used for loading the odontoid in an anterior-posterior direction. (2) The odontoid fracture type IIa (Anderson-D'Alonzo classification) was achieved by virtual transverse osteotomy. Anterior screw fixation was virtually performed by putting self-drilling titanium alloy 3.5mm diameter anterior cannulated lag screw with a 12mm thread into the inspected vertebrae. A V-shaped punch was used for loading the odontoid in an anterior-posterior direction. The vertebrae body was assumed to be non-cemented and cemented with different volume. The mean cement volume was lowest for body base filling with 0.47 ± 0.03ml. The standard body filling corresponds to 0.95 ± 0.15ml. The largest volume corresponds to 1.62 ± 0.12ml in the presence of cement leakage. The initial stiffness of the intact C2 vertebrae was taken as the reference value. The mean initial stiffness for non-porous cement (E = 3000MPa) increased linearly (R2 = 0.98). The lowest stiffness (123.3 ± 5.8N/mm) was measured in the intact C2 vertebrae. However, the highest stiffness (165.2 ± 5.2N/mm) was measured when cement leakage out of the odontoid peg occurred. The mean initial stiffness of the base-only cemented group was 147.2 ± 8.4N/mm compared with 157.9 ± 6.6N/mm for the base and body cemented group. This difference was statistically significant (p < 0.0061). The mean initial stiffness for porous cement (E = 500MPa) remains constant. Therefore, there is no difference between cemented and non-cemented junction. This difference was not statistically significant (p < 0.18). The present study showed that the low porous cement was able to significantly influence the stiffness of the augmented odontoid screw fixation in vitro, although further in vivo clinical studies should be undertaken. Our results suggest that only a small amount of non-porous cement is needed to restore stiffness at least to its pre-fracture level and this can be achieved with the injection of 0.7-1.2ml of cement. These slides can be retrieved under Electronic Supplementary Material.

Non-Operative Treatment of Odontoid Peg Fractures

Objective: The aim of this study was to review the results of non-operative treatment of odontoid fractures in Steve Biko Academic Hospital, Pretoria. Methods: Records for all patients treated for odontoid fractures from 2008 to 2018 were reviewed. 28 patients met the study criteria. Demographic data, mechanism of injury, associated injuries, neurology, imaging studies and treatment were reviewed. Results: There were 23 males and 5 females. The average age at presentation was 39.5 years. 25 patients were injured in road traffic accidents. Associated injuries were present in 21 patients, mostly involving the spine and head. 18 fractures were classified as Type II and 15 as Type III. Fracture comminution (5), angulation (6) and translation (10) were noted. Primarily treatment modalities were cones callipers, Philadelphia collar or halo vest. Fracture union was assessed radiologically at 3, 6 and 9 months. Type II and III fractures had high union rates at 6 and 9 months. Significantly displaced fractures had a statistically lower union rate (p = 0.0285) at 6 months. Conclusion: Minimally displaced odontoid Type II and III fractures can be effectively treated non-operatively in young adults. Extent of fracture displacement is the single important factor in non-union rate.

Stent augmentation of an anterior odontoid screw for type 2 odontoid fracture-dislocation in the elderly population: Report of two cases and literature review

The fixation of type 2 odontoid fractures poses significant challenges in the elderly population due to coexistent osteoporosis and communition resulting in a high failure rate with conventional anterior screw fixation. Two elderly patients with unstable odontoid peg fractures and coexistent osteoporosis were treated with stentoplasty and anterior odontoid screw fixation. Additional anterior transarticular C1–2 screws were placed to address C1–2 instability. Both patients made an uneventful clinical recovery. One of the anterior C1–2 screws loosened due to the poor purchase in the osteoporotic bone in one patient. This did not affect the final outcome, and both the patients demonstrated maintained reduction and good alignment of odontoid peg after 2 years of follow-up. There was no intraoperative cement leak, pseudoarthrosis, or loss of reduction. Stentoplasty coupled with the anterior odontoid screw is a safe technique that can provide a biomechanically sound fixation of type 2 odontoid fractures in the presence of osteoporosis and significant communition.

P03-1 - Acute C2 Odontoid peg fracture in the cardiac surgical patient

P03-1 - Acute C2 Odontoid peg fracture in the cardiac surgical patient

Assessment of cervical range of motion in patients after axis fracture

BackgroundSurgical treatment of odontoid fractures with posterior C1/C2 fusion always leads to severe limitations in mobility of the cervical spine and head. PurposeTo assess the mobility of the cervical spine in patients treated with various surgical methods after an axis body fracture. Material and methodsA group of 61 subjects receiving surgical treatment in a group of 214 subjects treated for odontoid fractures at one ward of neurosurgery at a regional hospital. Studies also included odontoid peg and Hangman fractures. The range of motion of the head was compared to standards by the International Standard Orthopedic Measurements (ISOM) and to head mobility in a control group of 80 healthy subjects without any pathologies or complaints associated with the cervical spine. Ranges of motion were measured with the CROM goniometre with regard to flexion, extension, right and left lateral flexion and right and left rotation. The functional status was evaluated with Neck Disability Index (NDI) standard questionnaires indicated for patients with cervical spine pain. ResultsExcept for flexion and extension, patients after odontoid fractures had a statistically significantly smaller range of motion of the cervical spine in all planes compared to the control group and ISOM standards. ConclusionsOdontoid fractures lead to limitations in mobility of the cervical spine even after treatment with methods that in theory should preserve the C1/C2 mobility.

29. Crowned Dens Syndrome – pseudo-rheumatoid of the odontoid peg presenting as acute infective discitis

29. Crowned Dens Syndrome – pseudo-rheumatoid of the odontoid peg presenting as acute infective discitis

Atlantoaxial instability: An exceptional complication of ankylosing spondylitis

BackgroundAtlantoaxial instability (AAI) and more rarely odontoid pannus formation, similar to the one observed in Rheumatoid Arthritis, are seldom reported in ankylosing spondylitis (AS). We report a new case of a patient with AS with a pannus in the atlanto-axial region and cervical C1-C2 instability. Case presentationThe patient, now aged 41, was diagnosed with AS in 2010. She was put on different non steroidal anti inflammatory treatments with persistent spinal pain. She was referred to our department in 2015 with severe cervical pain and stiffness since 3months. On examination, the patient had severely limited cervical spine movements. Lumbar spine movements were moderately affected. There was no neurological deficit. Her Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) was 4.9/10 and Bath Ankylosing Spondylitis Functional Index (BASFI) was 5/10. Plain Radiographs of the pelvis showed bilateral grade 4 sacroilitis and bilateral coxitis. Dorsal and lumbar spine plain radiographs showed squaring of vertebral bodies. Cervical spine radiographs showed an increased atlanto-axial distance. Spinal MRI confirmed the atlantoaxial subluxation with an anterior distance of 8mm, with marked intraspinal pannus formation and synovitis around the odontoid peg. Synovial thickening exerted an anterior mark on the bulbo-medullary junction with no evidence of oedema signs. Posterior zygapophysial ankylosis involving all cervical levels was also observed. The patient had a cervical collar with anti-tumor necrosis factor-α (cerolizumab-pegol) prescription with favorable outcome. ConclusionOdontoid pannus formation is rare in AS. Clinical and radiological follow-up are important to assess the impact on the cervical spine.

Conservative Management of Odontoid Peg Fractures, long term follow up.

The aim of the study was to look at the long-term effects of conservative management of odontoid peg fractures. We reviewed 48 consecutive patients with type II (32) and 16 type III, odontoid peg fractures. The clinical & radiological outcomes were assessed over an average period of follow up of 8 years. Union rate was determined and we discussed several factors that may affect it. Patients were treated conservatively with an average period of bed rest of 4 weeks followed by bracing for an average of 9 weeks. Bony union was established in 25 of 32 (78%) type II fractures. Of 7 cases of no bony union 4 were stable probably with fibrous union. 3 remained unstable. In 13 of 16(83%) type III fractures bony union was established. 2 of the 3 with no bony union were considered stable. Osseous non-union was higher in patients with displacement of >5mm, but there is no correlation between union and age, gender or angulation of the fracture in both types.

Predictors of mortality following odontoid peg fractures in the elderly

Predictors of mortality following odontoid peg fractures in the elderly

Spine

The October 2015 Spine Roundup360 looks at: Traumatic spinal cord injury under the spotlight; The odontoid peg nonunion; Driving and spinal surgery; Drains and antibiotics post-spinal surgery; Vertebroplasty and kyphoplasty equally effective; Who will benefit from steroid injections?; Back pain following lumbar discectomy

A rare case of os odontoideum from an Early Intermediate period tomb at the Huacas de Moche, Peru

Os odontoideum is an uncommon vertebral anomaly where there is a smoothly corticated ossicle independent from a shortened odontoid peg. An example of os odontoideum was observed in an Early Intermediate period skeleton excavated from the Huacas de Moche (Moche IV, AD 400–700), Peru. The affected individual is a middle adult male who presents additional minor developmental anomalies of the axial skeleton. This individual was interred with a middle adult female who also has developmental anomalies of the axial skeleton, including block cervical vertebra (Klippel–Feil). Os odontoideum is infrequently reported in the medical literature and there continues to be debate about whether it is acquired or congenital. Unlike clinical cases, archaeological cases present an opportunity to examine the entirety of the skeleton. In the present case, there does not appear to be macroscopic or radiographic evidence for a healed fracture, and since the individual has multiple minor axial developmental anomalies, a congenital etiology is plausible. This case is the first to be described from the archaeological context of South America and one of few paleopathological examples worldwide.