Ventral screw osteosynthesis is a common surgical method for treating fractures of the odontoid peg, but there is still no consensus about the number and diameter of the screws to be used. The purpose of this study was to develop a more accurate measurement technique for the morphometry of the odontoid peg (dens axis) and to provide a recommendation for ventral screw osteosynthesis. Images of the cervical spine of 44 Caucasian patients, taken with a 64-line CT scanner, were evaluated using the measuring software MIMICS. All measurements were performed by two independent observers. Intraclass correlation coefficients were used to measure inter-rater variability. The mean length of the odontoid peg was 39.76 mm (. sd. 2.68). The mean screw entry angle α was 59.45° (. sd. 3.45). The mean angle between the screw and the ventral border of C2 was 13.18° (. sd. 2.70), the maximum possible mean converging angle of two screws was 20.35° (. sd. 3.24). The measurements were obtained at the level of 66% of the total odontoid peg length and showed mean values of 8.36 mm (. sd. 0.84) for the inner diameter in the sagittal plane and 7.35 mm (. sd. 0.97) in the coronal plane. The mean outer diameter of the odontoid peg was 12.88 mm (. sd. 0.91) in the sagittal plane and 11.77 mm (. sd. 1.09) in the coronal plane. The results measured at the level of 90% of the total odontoid peg length were a mean of 6.12 mm (. sd. 1.14) for the sagittal inner diameter and 5.50 mm (. sd. 1.05) for the coronal inner diameter. The mean outer diameter of the odontoid peg was 11.10 mm (. sd.  1.0) in the sagittal plane and 10.00 mm (. sd. 1.07) in the coronal plane. In order to calculate the necessary screw length using 3.5 mm cannulated screws, 1.5 mm should be added to the measured odontoid peg length when anatomical reduction seems possible. The cross-section of the odontoid peg is not circular but slightly elliptical, with a 10% greater diameter in the sagittal plane. In the majority of cases (70.5%) the odontoid peg offers enough room for two 3.5 mm cannulated cortical screws. Cite this article: Bone Joint J 2013;95-B:536–42

Fractures of the odontoid peg are common spinal injuries in the elderly. This study compares the survivorship of a cohort of elderly patients with an isolated fracture of the odontoid peg versus that of patients who have sustained a fracture of the hip or wrist. A six-year retrospective analysis was performed on all patients aged > 65 years who were admitted to our spinal unit with an isolated fracture of the odontoid peg. A Kaplan–Meier table was used to analyse survivorship from the date of fracture, which was compared with the survivorship of similar age-matched cohorts of 702 consecutive patients with a fracture of the hip and 221 consecutive patients with a fracture of the wrist. A total of 32 patients with an isolated odontoid fracture were identified. The rate of mortality was 37.5% (n = 12) at one year. The period of greatest mortality was within the first 12 weeks. Time made a lesser contribution from then to one year, and there was no impact of time on the rate of mortality thereafter. The rate of mortality at one year was 41.2% for male patients (7 of 17) compared with 33.3% for females (5 of 15). . The rate of mortality at one year was 32% (225 of 702) for patients with a fracture of the hip and 4% (9 of 221) for those with a fracture of the wrist. There was no statistically significant difference in the rate of mortality following a hip fracture and an odontoid peg fracture (p = 0.95). However, the survivorship of the wrist fracture group was much better than that of the odontoid peg fracture group (p < 0.001). Thus, a fracture of the odontoid peg in the elderly is not a benign injury and is associated with a high rate of mortality, especially in the first three months after the injury. Cite this article: Bone Joint J 2014;96-B:88–93

Background. Fractures of the odontoid peg are one of the commonest spinal injuries in the elderly population. In this population there is a higher risk of morbidity and mortality as a result of the injury. The magnitude of this risk has not been quantified in the literature. Aim. To show a survivorship analysis in a cohort of elderly patients with odontoid peg fractures. Method and Materials. A 6-year retrospective analysis was performed on all patients >65 years old admitted to a spinal unit with an isolated odontoid peg fracture. Actuarial (Life-Table) analysis was used to estimate survivorship from the date of fracture. Results. A total of 32 patients > 65 years of age with isolated odontoid peg fractures were identified. There were 17 male and 15 female. A low velocity mechanical fall was the commonest cause for the injury. The average age for the females was 86.7 years and for the males 78 years. The age distribution was unimodal in both sex, the greatest number occurring for the females in the 85-94 year age group and 75-84 years for the males. Overall, it was estimated that only 62.5 % would be alive by one year. The period of greatest mortality was within the first 12 weeks, a lesser contribution from then to one year, and had no impact on mortality thereafter. Males appeared to suffer a heavier mortality than females within the first year. At one year the male survival rate had fallen to 58.8% compared with a female rate of 66.6%. Conclusion. We observed that odontoid peg fractures in the elderly are not benign injuries and are a cause of high mortality rates within the first three months of the injury. Patients who survived to one year following the injury were observed to have their risk return to age and sex matched rates for this population

Background. Fractures of the odontoid peg are one of the commonest cervical spinal injuries in the elderly population. In this population there is a higher risk of morbidity and mortality as a result of the injury. The magnitude of the mortality risk has not been quantified in the literature. Aim. To show a survivorship analysis in a cohort of elderly patients with odontoid peg fractures. Method & Materials. A 6-year retrospective analysis was performed on all patients >65 years old with isolated odontoid peg fracture. Kaplan-Meir curve was used to estimate survivorship from the date of fracture. Results. A total of 32 patients witha mean age of 82.1 years were analysed. There were 17 male and 15 female with an average follow-up of 20.4 months. A low velocity mechanical fall was the commonest cause for the injury in 93.7% of cases. 81% of cases were treated with rigid collar immobilsation. Overall, it was estimated that only 62.5 % would be alive by one year. The period of greatest mortality was within the first 12 weeks, a lesser contribution from then to one year, and had no impact on mortality thereafter. Multivariate logistic regression demonstrated that age (P= 0.02) was significant factor with an odds ratio of 1.2. There was no significant relationship among gender or treatment with the occurrence of an adverse event. Conclusion. We observed a 3 month and one year mortality rates of 255 and 37.5% respectively. Odontoid peg fractures in the elderly are not benign injuries and are a cause of high mortality rates within the first three months of the injury. Patients who survived to one year following the injury were observed to have their risk return to age and sex matched rates for this population

Purposes of the study. The most common fracture of the cervical spine in the elderly population is a fracture of the odontoid peg. Such fractures are usually not displaced and these are commonly treated non-operatively. Rarely though, peg fractures are displaced and then their management is less straightforward. This is in part because the group of patients who sustain them frequently have complex and pre-existing medical co-morbidities and in part because a new neurological injury may have been sustained as a result of the peg fracture itself. Many options for the management of displaced peg fractures, both operative and non-operative have been described in the literature and discussion continues as to which technique is superior and in which patient population. The purpose of this study was to follow-up those patients who were managed operatively in our unit between 2007 and 2009. Methods and Results. We present our case series of 4 patients who sustained significantly displaced fractures of the odontoid peg with accompanying neurological injury, who were treated with posterior stabilisation using the Harms technique. Conclusions. We have found this method to be safe and reliable. It not only yields a good surgical outcome, but allows patients' rehabilitation to be optimised, maximising functional improvement. We believe the technique is superior to anterior stabilisation in this patient population because it utilises superior posterior bone quality and mechanical fixation. The approach in our unit is to treat elderly patients with displaced odontoid peg fractures according to the same principles as would be followed in managing those that have disabling injuries such as fractures of the femoral neck; early stabilisation and early mobilisation in those patients whose co-morbidities allow it

The management of type two odontoid peg fractures remains controversial. The policy in our unit is to initially manage all of these injuries non-operatively. Patients with displaced fractures (0.2mm translation, > 15° angulation) are placed in halo vests followed by fracture reduction under radiological control. Undisplaced or minimally displaced fractures are treated in either custom-made minerva orthoses or halo vests. We report the results of 42 consecutive cases of type two odontoid peg fractures. There were 24 males and 18 females with a mean age of 53 (range 18–89) years. Twenty-one (50%) of patients were > 65 years of age. In 29 cases the fracture was undisplaced or minimally displaced and in the remaining 13 cases it was displaced (> 2mm translation, > 15° angulation) either posteriorly (extension-type)(6) or anteriorly (flexion type) (7). All displaced cases were treated in halo vests while the remainder were treated in minervas (14) or halo vests (15). Loss of reduction occurred in nine cases necessitating adjustment in five and C1/2 posterior fusion in four. Of these cases five were displaced extension type-fractures, two required fusion. Pin site infection necessitated early removal of halo vest and conversion to minerva in three cases. In all of these cases fracture union was achieved. Overall, union was achieved in 37 patients giving a non-union rate of 12%. The mean age of the five non-unions was 42 years with only one patient over 65 years of age. Four of these patients had C1/2 posterior fusions and the remaining patient refused surgery. Of the 29 patients with displaced or minimally displaced fractures five (17%) required surgery for either non-union (3) or displacement (2), whereas three (23%) of the displaced group required surgery for non-union (1) or displacement (2). All of these were extension type fractures. We conclude that a policy of non-operative management of these fractures resulted in union in a high proportion of patients of all age groups except for those with extension type fractures. This fracture pattern may warrant primary surgical intervention

Fractures of the odontoid peg are relatively common in elderly people. Often they are minimally displaced and can be treated with a collar. However, a fracture which is displaced significantly may be difficult to manage. We describe the case of an 80-year-old man with a fracture of the odontoid peg which was completely displaced and caused respiratory distress. After initial closed reduction and application of a halo jacket, open and internal fixation was undertaken and relieved his symptoms. It is a safe and effective way to manage this injury

Aims

Rates of mortality as high as 25% to 30% have been described following fractures of the odontoid in the elderly population. The aim of this study was to examine whether easily identifiable variables present on admission are associated with mortality.

Introduction: The management atlanto-axial fractures, particularly those of the odontoid peg, remains controversial. We managed patients with C1/C2 fractures non-operatively in rigid immobilization until CT-scanning confirmed bony union, rather than for the standard 3-month period. We examined whether this improved outcomes and reduced the need for surgery. Method: All patients admitted to our unit with atlanto-axial fractures between 2001–2007 were retrospectively analyzed. All fractures had the ‘intention-to-treat’ conservatively in either halothoracic vest (85%) or Aspen collar (15%). Rigid immobilization was maintained until CT-scanning demonstrated bony fusion. Functional stability was subsequently assessed with flexion-extension radiographs after removal of rigid immobilization. Results: Twenty-seven patients were studied. Nineteen had odontoid peg fractures (10 type II; 9 type III). The remainder consisted of 3 Hangman’s, 3 lateral mass and 2 atlas ring fractures. 83% of patients progressed to union at an average of 13.2 weeks (range 5–22). Six complications related to halo immobilization were observed (three skull perforations/pin-site infections). All of these patients progressed to union non-operatively. Failure of non-operative management was deemed as non-union or poor patient tolerance of halo, and occurred in 4 patients (17%). All four had type II odontoid peg fractures, and had transarticular screw fixation. One postoperative complication of screw fracture was recorded. Conclusion: Non-union rates of conservatively managed atlanto-axial fractures with standard 3-month rigid immobilization have been reported as high as 35%. In our series, CT-imaging to confirm bony union prior to removal of the rigid immobilization (prolonging immobilization where necessary) significantly lowered the rate of non-union and therefore the need for subsequent surgery. Ethics approval: None Audit. Interest Statement: None

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

Introduction A tertiary referral centre for spinal injuries will receive referrals from many different centres. The format and quality of imaging that accompanies these patients varies considerably. Methods Two cases are reported where initial imaging demonstrated unstable cervical spine injuries that were subsequently found to be normal. The cases and images are presented. Results A 19-year old female was transferred to our unit having fallen off a wall and sustaining a neck injury. The accompanying CT scan showed a C6 vertebral body fracture with bilateral fracture-subluxations of the facet joints. As there was a discrepancy with the clinical findings, a repeat fine cut CT scan was performed which was completely normal. The previous appearances were entirely due to artifact throughout the scan. A 46-year old male fell down stairs sustaining a neck injury and loss of consciousness. A CT scan of his cervical spine demonstrated an odontoid peg fracture (type II). Subsequent imaging showed the odontoid peg was completely normal. The initial CT appearances were entirely due to artifact caused by the patients’ tongue piercing!. Discussion CT scans are used with increasing frequency in the assessment of cervical spine injuries. In both these case the abnormalities present on the initial scans were entirely due to artifact that was reciprocated through the entire CT scans. Reporting these cases reinforces the importance of careful clinical examination and correlation with appropriate investigations. If there is a discrepancy between the clinical and radiological findings then it is essential that further imaging is performed

Cervical myelopathy is an uncommon but potentially fatal complication of rheumatoid atlanto-axial subluxation. Computerised myelotomography with three-dimensional reconstruction shows that rheumatoid pannus, together with the odontoid peg, contributes significantly to anterior cervico-medullary compression. These findings were the basis for treatment by transoral anterior decompression and posterior occipitocervical fusion, which removes both bony and soft-tissue causes of compression and allows early mobilisation without major external fixation. We report encouraging results from this combined approach in 14 patients who had progressive neurological deterioration

Objective: To reassess whether the Ranawat IIIB (quadriparetic, non-ambulant) rheumatoid arthritis (RA) with cervical myelopathy patients should be surgically treated. Study Design: Retrospective study. Subjects: Over a 12-year period (1988–1999), 51 patients [15 M: 36F; mean age 64 years] in Ranawat IIIB with RA were diagnosed to have cervical myelopathy. These included 47 patients with atlantoaxial subluxation (AAS) [15 with AAS alone, 10 with basilar invagination (BI), 18 with associated subaxial subluxation (SAS) and four patients with BI and SAS] and four patients with SAS alone. Results: Thirty-two patients considered fit for surgery successfully underwent operative treatment (Group 1). All underwent posterior instrumented fixation with or without transoral odontoid peg excision. Postoperatively 22/27 patients were pain free and 21/32 patients initially non-ambulant were able to walk. 3/26 patients died within six months of surgery. 13/19 patients managed conservatively (Group 2) because of medical complications died within six months of presentation. Conclusions: Even in advanced stages of cervical myelopathy in RA, surgical intervention is beneficial with significantly higher morbidity/mortality in conservatively managed patients

Aims

Traumatic central cord syndrome (CCS) typically follows a hyperextension injury and results in motor impairment affecting the upper limbs more than the lower, with occasional sensory impairment and urinary retention. Current evidence on mortality and long-term outcomes is limited. The primary aim of this study was to assess the five-year mortality of CCS, and to determine any difference in mortality between management groups or age.

Aims

Gram-negative infections are associated with comorbid patients, but outcomes are less well understood. This study reviewed diagnosis, management, and treatment for a cohort treated in a tertiary spinal centre.

The April 2014 Spine Roundup³⁶⁰ looks at: medical treatment for ankylosing spondylitis; unilateral TLIF effective; peg fractures akin to neck of femur fractures; sleep apnoea and spinal surgery; scoliosis in osteogenesis imperfect; paediatric atlanto-occipital dislocation; back pain and obesity: chicken or egg?; BMP associated with lumbar plexus deficit; and just how common is back pain?

Aims

Fracture of the odontoid process (OP) in the elderly is associated with mortality rates similar to those of hip fracture. The aim of this study was to identify variables that predict mortality in patients with a fracture of the OP, and to assess whether established hip fracture scoring systems such as the Nottingham Hip Fracture Score (NHFS) or Sernbo Score might also be used as predictors of mortality in these patients.

This study examined spinal fractures in patients admitted to a Major Trauma Centre via two independent pathways, a major trauma (MT) pathway and a standard unscheduled non-major trauma (NMT) pathway. A total of 134 patients were admitted with a spinal fracture over a period of two years; 50% of patients were MT and the remainder NMT. MT patients were predominantly male, had a mean age of 48.8 years (13 to 95), commonly underwent surgery (62.7%), characteristically had fractures in the cervico-thoracic and thoracic regions and 50% had fractures of more than one vertebrae, which were radiologically unstable in 70%. By contrast, NMT patients showed an equal gender distribution, were older (mean 58.1 years; 12 to 94), required fewer operations (56.7%), characteristically had fractures in the lumbar region and had fewer multiple and unstable fractures. This level of complexity was reflected in the length of stay in hospital; MT patients receiving surgery were in hospital for a mean of three to four days longer than NMT patients. These results show that MT patients differ from their NMT counterparts and have an increasing complexity of spinal injury.

Cite this article: Bone Joint J 2015;97-B:235–9.