Odontoid Screw Placement Research Articles

O-Arm Assisted Anterior Odontoid Screw Fixation in Type II and Rostral Type III Odontoid Fractures: Single Center Surgical Series of 50 Patients.

Accuracy of screw placement is one of the important factors necessary for adequate union in odontoid fractures with malposition rates as high as 27.2% with standard techniques. To evaluate efficacy of intraoperative O-arm assistance in improving accuracy of anterior odontoid screw placement and clinco-radiological outcome in type II and III odontoid fractures. In this retrospective study, surgery consisted of anterior odontoid screw fixation under intraoperative O-arm assistance over 5 years. Demographical, clinical, radiological, operative details and postoperative events were retrieved from hospital database and evaluated for fusion and surgical outcome. 50 patients (Mean age 34.6 years, SD 14.10, range: 7-70 years; 44 males and 6 females) with Type II and Type III odontoid fracture underwent O-arm assisted anterior screw placement. The mean interval between injury and surgery was 12 days (range 1-65 days). Mean operating time was 132.2 min ± SD 33.56 with average blood loss of 93 ml. ±SD 61.46. With our technique, accurate screw placement was achieved in 100% patients. At the mean follow-up of 26.4 month (SD13.75), overall acceptable fusion rate was 97.8% with non-union in 2.2% patients. Morbidity occurred in two patients; one patient developed fixation failure while other patient had nonunion which was managed with posterior C1-C2 arthrodesis. We had surgical mortality in one patient due to SAH. So overall our procedure was successful in 94% patients and among patients whose follow-up was available, acceptable fusion rates of 97.8% were achieved. We conclude that use of intraoperative three-dimensional imaging using O-arm for anterior odontoid screw fixation improves accuracy and leads to improved radiological and clinical outcomes. It further enables us to extend the indications of odontoid screw fixation to selected complex Type II and rostral Type III odontoid fractures.

Surgical management of fracture odontoid type II by anterior screw fixation: an institutional experience

Fractures of the odontoid process (the dens) of the axis account for 10-20% of acute cervical spine fractures. Recent advances in intra-operative imaging including neuron avigation and O-arm can now increase accuracy and lower morbidity of odontoid screw placement. The present study was done in the department of surgery, in the medical college and associated hospital. During study period, total of 22 patients with type II fracture of odontoid were included in the study. All operations were done with the same technique of Cloward anterior approach using cannulated single lag screw. In the majority of patients, the follow up has been for 2 years and in 3 cases the follow up has been for one year. At the time of presentation, the major complains of the patient included in the study was of pain in neck area. The 14 patients were discharged to home on third postoperative day with Philadelphia neck collar, 6 patients with weakness stayed in hospital one week on physiotherapy and 2 patients were in ICU for three days post-operative due to associated lung contusion. Follow up CT after 1.5 and 3 months show well alignment with good fusion with no signs of mal union or pseudo arthrosis and patients were followed up for six months. Anterior screw fixation is a good technique to practice. It achieves good outcome and good fusion in young generation with horizontal fracture line.

Endoscopic Anterior Odontoid Screw Fixation for the Odontoid Fracture: A Cadaveric Pilot Study.

Introduction:Anterior odontoid screw fixation technique for specific types of odontoid fracture has been proven to be an effective, yet challenging procedure because of threatened damage to the structures in the vicinity. There are few articles suggesting the role of percutaneous and endoscopic technique as an alternative approach to the standard microscopic way. This is the first cadaveric study using existing “EASY GO” endoscopic system-assisted odontoid screw placement.Study Design:This was a cadaveric study.Objective:The objective of the study is to use the endoscope as a safer minimally invasive approach than the standard microscopic anterior approach to odontoid.Methodology:This is a pilot study on 10 fresh-frozen formalin-fixed adult human cadavers. The cadaver was positioned in a way to simulate reduced odontoid fracture. Tubular dilators were used to dock at C2–3 disk space after identifying the landmarks through the microscopic method. The EASY GO endoscopic system was then introduced, and a handheld drill was used to mark the entry point and pass the K-wire through the planned trajectory.Results:No vascular or adjacent vital structures' injury was observed in any of the cadavers. The initial difficulty in attaining the alignment was overcome by the appropriate positioning of the scope.Conclusions:Endoscopic-assisted technique for odontoid screw fixation shall provide a minimally invasive, safe, and easy surgery.

Odontoid screw placement for Anderson type II odontoid fractures: how do duration from injury to surgery and clinical and radiological factors influence the union rate? A multicenter retrospective study.

Anderson type II odontoid fractures are severe conditions, mostly affecting elderly people (≥ 70 years old). Surgery can be performed as a primary treatment or in cases of failed conservative management. This study aimed to investigate how duration from injury to surgery, as well as clinical, radiological, and surgical risk factors, may influence the union rate after anterior odontoid screw placement for Anderson type II odontoid fractures. The authors conducted a retrospective multicenter study. Demographic, clinical, surgical, and radiological data of patients who underwent anterior odontoid screw placement for Anderson type II fractures were retrieved from institutional databases. Study exclusion criteria were prolonged corticosteroid drug therapy (> 4 weeks), polytraumatic injuries, oncological diagnosis, and prior cervical spine trauma. Eighty-five patients were included in the present investigation. The union rate was 76.5%, and 73 patients (85.9%) did not report residual instability. Age ≥ 70 years (p < 0.001, OR 6), female gender (p = 0.016, OR 3.61), osteoporosis (p = 0.009, OR 4.02), diabetes (p = 0.056, OR 3.35), fracture diastasis > 1 mm (p < 0.001, OR 8.5), and duration from injury to surgery > 7 days (p = 0.002, OR 48) independently influenced union rate, whereas smoking status (p = 0.677, OR 1.24) and odontoid process angulation > 10° (p = 0.885, OR 0.92) did not. Although many factors have been reported as influencing the union rate after anterior odontoid screw placement for Anderson type II fractures, duration from injury to surgery > 7 days appears to be the most relevant, resulting in a 48 times higher risk for nonunion. Early surgery appears to be associated with better radiological outcomes, as reported by orthopedic surgeons in other districts. Prospective comparative clinical trials are needed to confirm these results.

The Anterior Transarticular Fixation of C1/C2 in the Elderly With Dens Fractures.

Anterior transarticular screw fixation (ATSF) of C1/C2 can be used for the treatment of unstable dens fractures. Here, we evaluated the feasibility of an anterior C1/C2 fixation in elderly patients with unstable dens fractures. Furthermore, we tried to analyze safe entry zones for ATSF surgery. A consecutive cohort of 13 patients with unstable dens fractures were treated with ATSF of C1/C2 between January 2015 and October 2016. If necessary, an additional screw was placed into the odontoid process. The placement was radiographically analyzed using the 3D Arcadis Orbic (Siemens, Erlangen, Germany). Additionally, computed tomography scans of the cervical spine from 50 trauma patients were analyzed to evaluate safe entry zones for anterior odontoid screw fixation and for ATSF. ATSF was performed in 13 cases (7 female, 6 male; mean age 81.80 years). One screw had to be corrected intraoperatively due to initial malplacement. Neurological deficits or an injury of the vertebral artery were not observed. All patients suffered from swallowing difficulties during the postoperative course, without lesions of the esophagus or the trachea. In 4 patients (30.8%), an additional posterior fixation was offered to the patients due to progressive loosening of the screws.The anatomical-radiographic analyzes revealed a significantly shallower angle of trajectory for anterior odontoid screw fixation (24.9° ± 5.85°) than for ATSF (39.1° ± 6.44° (left); 40.5° ± 6.79° (right) P = 0.02). The ATSF of C1/C2 might be a valuable option in the treatment of instable C1/C2 fractures, especially in the elderly or in patients with short necks and/or high body mass index due to the steeper trajectory compared with odontoid screw placement. Yet available screws seem to be of inferior resistance compared with the biomechanical properties of a dorsal fixation. Further studies should focus on screws with better mechanical properties and probably additional cement augmentation. 4.

Minimally invasive percutaneous anterior odontoid screw fixation: institutional experience with a simple and effective technique.

The aim of this paper was to show a novel modified technique to perform minimally invasive anterior odontoid screw fixation. Twenty-nine patients with a mean age of 45 years were treated with a modified percutaneous anterior odontoid screw fixation. All patients were affected by type II or rostral shallow type III odontoid fractures. A modified guide tube was used in all these patients, with reduction of soft tissue dissection for percutaneous approach. There were no complications related to the modified technique. Good results and optimal screw placement were achieved in 28 out of 29 patients. Only in 1 patient we observed, after mobilization, screw displacement, probably due to severe osteoporosis. In our opinion, this modified percutaneous minimally invasive technique for anterior odontoid screw fixation, along with the use of a soft tissue dilator not fixed to the spine, has not yet been reported in literature and is strongly recommended to reduce invasiveness of odontoid screw placement.

Feasibility of Double Anterior Odontoid Screw: A CT-Based Morphometric Analysis of the Axis in Adult Indian Population

The fractures of the odontoid process constitute 10% of all cervical spine injuries. Odontoid screw placement, although technically challenging, in indicated cases is the ideal treatment. Hence, a thorough knowledge of the odontoid dimensions is necessary prior to the surgical endeavor, more so for planning double odontoid screws. A prospective morphometric analysis of retrospective data of 250 patients was acquired at our institute using Somatom Definition edge 128 slice 64-row detector Siemens CT scanner. The dimensions of the odontoid process were measured at the waist (narrowest portion), widest diameter both in anteroposterior and transverse diameters. The dimensions of the C2 vertebra were measured at the level of the superior and inferior endplate in both the planes. A total of 250 patients were evaluated with age ranging from 1 to 80 years. Males constituted 174 (69.6%) and 76 (30.4%) were females. The mean transverse diameter (TD) at the odontoid waist (narrowest diameter) was 8.66 mm. The mean TD at the widest point of odontoid was 9.68 mm. Mean anteroposterior (AP) diameter 2.5 mm away from the midline on the left side at the level of the waist was 9.51 mm and 2.5 mm on the right of midline was 9.01 mm. The mean AP diameter at the C2 base was 15.824 mm in males and 14.833 mm in females (P < 0.001). Double odontoid screw insertion is feasible in only 36% of Indians in the transverse plane, whereas 98.4% of the odontoids can accommodate double screws in the sagittal plane.

Placement of a single anterior odontoid screw for type II odontoid fractures in a setting with limited resources

BackgroundTreatment of odontoid fractures with odontoid screws is an established method for fusion. However, it is facilitated by using advanced equipment in the operating theatre not always available as in developing countries.ObjectivesIn this study we aim to outline the important key points for successful placement of odontoid screw in the absence of advanced tools, e.g. navigation or O-arm.Materials and methodsFifteen patients suffering from type II odontoid fractures were managed with single odontoid screw. Reduction of the fractures was achieved. A simple instrument set was used with the help of a single plane image intensifier. Longitudinal incision was used in 4 cases, and transverse incision was used in the remaining eleven cases. Anatomical identification of the midline helped to mark the entry point. The entry point used was millimetres below the anteroinferior edge of the axis vertebra. A short-headed screw was used.ResultsRoad traffic accident was the only mechanism of trauma reported in our study. All of the patients were neurologically intact. All of the patients remained neurologically intact after the procedure. There were no instances of wrong trajectory of the screw in our study. During follow-up, we found good union of all the fractures. Only 2 cases suffered from mild dysphagia.ConclusionFixation of odontoid fractures by anterior odontoid screws appears to be a safe and feasible procedure even in underequipped theatres. Anatomical knowledge helps in determining midline. Various modifications can help in overcoming shortcomings.

Perioperative Complications and Mortality Following Anterior Odontoid Screw Fixation in Elderly Patients: A National Database Analysis

To identify predictors of short-term mortality and complications after anterior odontoid screw fixation. This was a retrospective analysis of a national database. The American College of Surgeons National Quality Improvement Database was queried using Current Procedural Terminology codes to identify patients aged ≥60 years who underwent surgery for anterior fixation of odontoid fracture admitted from 2007 to 2016. Univariate analysis and subsequent multivariate analysis were used to analyze risk factors for postoperative complications and 30-day postoperative mortality. Complications were defined as surgical-site infection, wound breakdown, pneumonia, venous thromboembolism, stroke, myocardial infarction, sepsis, renal progressive renal insufficiency/acute kidney injury, or cardiac arrest. A total of 198 patients were identified. Mean age was 77.7 (±8.7) years and 60.6% were female. Overall mortality rate was 7.6%, and the complication rate was 9.1%. In multivariate analysis, dependent functional status (0.012; odds ratio [OR] 5.2; 95% confidence interval [CI] 1.42-18.72) and preoperative systemic inflammatory response syndrome (P= 0.011; OR 6.2; 95% CI 1.52-25.79) predicted mortality. Emergency case status (P= 0.033; OR 3.4; 95% CI 1.10-10.70) predicted perioperative complications. Age was not significantly associated with either complications or mortality in multivariate analysis. Functional dependence and preoperative systemic inflammatory response syndrome predict mortality following odontoid screw placement. Although age often is considered a limiting factor in pursuing surgical intervention in patients with odontoid fracture, age did not independently increase odds of either complications or perioperative mortality in this analysis. Further studies are needed to explore these findings.

Odontoid Fusion.

Anterior odontoid screw fixation allows for the internal fixation of unstable odontoid fractures with low morbidity, good fusion rates, and preservation of the atlanto-axial range of motion when applied in appropriate clinical cases. Advances in surgical techniques have allowed for safer, more minimally invasive approaches that reduce the risk of injury to vital prevertebral structures and minimize soft tissue retraction. Moreover, improvements in surgical image guidance technology for spinal surgery that have been applied to odontoid screw placement have helped improve surgeon confidence about exact screw trajectories. In this chapter, we review traditional screw placement techniques and highlight the trends in technical improvements that improve the safety and efficacy of these procedures.

Balloon kyphoplasty and additional anterior odontoid screw fixation for treatment of unstable osteolytic lesions of the vertebral body C2: a case series

BackgroundUnstable osteolytic lesions of the occipitocervical junction are rare and may occur in hematological malignancy or vertebral hemangioma, among others. Different case reports have been published about vertebroplasty for treatment of spinal metastases of the upper cervical spine. Only few cases concern balloon kyphoplasty of C2. We present a consecutive case series including four patients with an osteolytic lesion of the dens axis and describe a technical note for balloon kyphoplasty of C2 and an additional anterior odontoid screw fixation.MethodsFour consecutive patients with an osteolytic lesion of the vertebral body of C2 were treated by anterior balloon kyphoplasty and additional anterior odontoid screw fixation of the dens axis. The radiological imaging showed a lytic process of the vertebral body C2 with no vertebral collapse but involvement of more than 50% of the vertebral body in all patients.ResultsTwo cases of potentially unstable osteolytic lesions of C2 by myeloma, one case with metastatic osteolytic lesion of C2 by adenocarcinoma of the colon and one patient with vertebral hemangioma located in C2 were presented to our clinic. In all cases, surgical treatment with an anterior balloon kyphoplasty of C2 and an additional anterior, bicortical odontoid screw placement was performed. Control x-rays showed sufficient osteosynthesis and cement placement in the vertebral body C2.DiscussionAnterior balloon kyphoplasty and anterior odontoid screw placement is a safe treatment option for large osteolytic lesions of C2. The additional odontoid screw placement has the advantage of providing more stabilization and may prevent late complications, like odontoid fractures. For patients with potentially unstable or large osteolytic lesions of the dens without spinal cord compression or neurological symptoms we recommend the placement of an anterior odontoid screw when performing a balloon kyphoplasty. Level of evidence: - IV: retrospective or historical series.

Incidence of dysphagia after odontoid screw fixation of type II odontoid fracture in the elderly.

Background:Although surgery may reduce mortality rates from type II odontoid fractures in the elderly population, post-operative dysphagia resulting from screw fixation remains a serious complication.Methods:We retrospectively performed a chart review of patients over 65 years of age who underwent odontoid screw placement for type II odontoid fractures (2009-2014) and sustained post-operative dysphagia. The severity of dysphagia was determined based on the requirements for modified diets, PEG tubes, and prolonged length of stay (LOS), while costs were based upon discharge disposition (e.g. home vs. rehabilitation facilities) and total hospital costs.Results:The incidence of postoperative dysphagia was 80%; 33% required feeding tubes, and 35% warranted PEG placement. The mean LOS for patients with dysphagia was 5 days longer and the total hospital costs averaged $50,000 higher.Conclusions:Age over 65 is a significant predictor of post-operative dysphagia in patients undergoing type II odontoid screw fixation. Notably, with each additional year above 65, the likelihood of post-operative dysphagia increased by 12%. Furthermore, postoperative dysphagia statistically increased the LOS and total costs.

New technique for C1-C2 fixation.

Background:There are several techniques for treating atlantoaxial instability, including the Magerl transarticular screw fixation and the Harms/Goel C1-C2 screw rod techniques. Here, we present a novel technique utilizing a polyaxial screw rod system and a combination of C1 lateral mass and C1-C2 transarticular screws.Methods:We retrospectively reviewed 14 patients (7 women, 7 men; mean age 62) who underwent surgery for type II odontoid fractures (n = 7), pseudarthrosis after anterior odontoid screw placement (n = 3), Os odontoideum (n = 2), atlantoaxial instability after C3-C5 fusion (n = 1), and craniovertebral rheumatoid arthritis (n = 1). Ten patients underwent posterior C1-C2 fixation, three patients with osteoporosis had C1-C4 fixation, and one patient had C1-Th1 fixation. The mean follow-up time was 22 months.Results:Intraoperatively, there were no complications (e.g., vertebral artery, nerve root, or spinal cord injury). Postoperative imaging showed no screw malpositioning, and no screw loosening, fracture, or bone absorption around the screws. Furthermore, all patients exhibited postoperative improvement in neck pain.Conclusions:C1 lateral mass and C1-C2 transarticular polyaxial screw rod fixation techniques were effective in achieving immediate rigid immobilization of the C1-C2 motion segment.

The Corona Dentis: Description of an Anatomic Variant with Technical Implications for Anterior Odontoid Screw Placement.

Type 2 odontoid fractures are the most common cervical fractures among the elderly. Neurologic deficit is usually caused by myelopathy as a result of posterior dens migration. Direct anterior screw placement provides stabilization and can preserve C1-C2 movement. The presence of a bony excrescence on the anterior superior tip of the dens may lead to placement of a screw of incorrect length. Twenty C2 dry specimens were examined for the presence of a corona dentis, which is a bony excrescence in the coronal plane near the apex of the dens. When identified, measurements of the corona dentis were performed using calipers and a ruler. In addition, anteroposterior (AP) and lateral fluoroscopy was performed on all specimens found to have a corona dentis. A corona dentis was found on 20% of our C2 specimens and had an average width of 9 mm and an average height of 4.5 mm. The average width of the dens did not vary as the normal tip of the dens transitioned into the coronae. In no specimen did the corona dentis seem to be composed of trabecular bone and it was seen as a superior projection of cortical bone on fluoroscopy. On fluoroscopy, the corona dentis could be identified on a true AP projection. In angulated AP views, fluoroscopic images overestimated the length of the corona dentis. We describe a new entity termed the corona dentis because of its crownlike feature. It is a superior cortical bone protrusion and should be noted as a variant of the dens during anterior odontoid screw placement. Its propensity to increase the height of the dens markedly can lead to higher rates of neurologic deficits during type 2 odontoid fractures if not appreciated. A true AP view is critical for correct screw size placement.

Anterior single odontoid screw placement for type II odontoid fractures: our modified surgical technique and initial results in a cohort study of 15 patients

Objective: Anterior odontoid screw fixation for type II odontoid fracture is the ideal management option. However in the context of unavailability of an O-arm or neuro-navigation and poor images from the available C-arm may be an obstacle to ideal trajectory and placement of the odontoid screw. We herein detail our surgical technique so as to ensure a correct trajectory and subsequent good fusion in Type II odontoid fractures. This may be advantageous in clinical set ups lacking state of the art facilities. Methods and Results: In this cohort study we included 15 consecutive patients who underwent anterior odontoid screw placement. We routinely dissect the longus colli to completely visualize the entire width of C3 body. We then perform a median C2-C3 disectomy followed by creating a gutter in the superior end of C3 body. We then guide the Kirchsner (K) wire purchasing adequate anterior cortex of C2. Rest of the procedure follows the similar steps as described for odontoid screw placement. We achieved 100% correct trajectory and screw placement in our study. There were no instances of screw break out, pull out or nonunion. There was one patient mortality following myocardial infarction in our study. Conclusion: Preoperative imaging details, proper patient positioning, meticulous dissection, thorough anatomical knowledge and few added surgical nuances are the cornerstones in ideal odontoid screw placement. This may be pivotal in managing patients in developing nations having rudimentary neurosurgical set up.

Navigated odontoid screw placement using the O-arm: technical note and case series.

OBJECTIVE As odontoid process fractures become increasingly common in the aging population, a technical understanding of treatment approaches is critical. 3D image guidance can improve the safety of posterior cervical hardware placement, but few studies have explored its utility in anterior approaches. The authors present in a stepwise fashion the technique of odontoid screw placement using the Medtronic O-arm navigation system and describe their initial institutional experience with this surgical approach. METHODS The authors retrospectively reviewed all cases of anterior odontoid screw fixation for Type II fractures at an academic medical center between 2006 and 2015. Patients were identified from a prospectively collected institutional database of patients who had suffered spine trauma. A standardized protocol for navigated odontoid screw placement was generated from the collective experience at the authors' institution. Secondarily, the authors compared collected variables, including presenting symptoms, injury mechanism, surgical complications, blood loss, operative time, radiographically demonstrated nonunion rate, and clinical outcome at most recent follow-up, between navigated and nonnavigated cases. RESULTS Ten patients (three female; mean age 61) underwent odontoid screw placement. Most patients presented with neck pain without a neurological deficit after a fall. O-arm navigation was used in 8 patients. An acute neck hematoma and screw retraction, each requiring surgery, occurred in 2 patients in whom navigation was used. Partial vocal cord paralysis occurred after surgery in one patient in whom no navigation was used. There was no difference in blood loss or operative time with or without navigation. One patient from each group had radiographic nonunion. No patient reported a worsening of symptoms at follow-up (mean duration 9 months). CONCLUSIONS The authors provide a detailed step-by-step guide to the navigated placement of an odontoid screw. Their surgical experience suggests that O-arm-assisted odontoid screw fixation is a viable approach. Future studies will be needed to rigorously compare the accuracy and efficiency of navigated versus nonnavigated odontoid screw placement.

Anterior single odontoid screw placement for type II odontoid fractures: our modified surgical technique and initial results in a cohort study of 15 patients.

Objective: Anterior odontoid screw fixation for type II odontoid fracture is the ideal management option. However in the context of unavailability of an O-arm or neuro-navigation and poor images from the available C-arm may be an obstacle to ideal trajectory and placement of the odontoid screw. We herein detail our surgical technique so as to ensure a correct trajectory and subsequent good fusion in Type II odontoid fractures. This may be advantageous in clinical set ups lacking state of the art facilities. Methods and Results: In this cohort study we included 15 consecutive patients who underwent anterior odontoid screw placement. We routinely dissect the longus colli to completely visualize the entire width of C3 body. We then perform a median C2-C3 disectomy followed by creating a gutter in the superior end of C3 body. We then guide the Kirchsner (K) wire purchasing adequate anterior cortex of C2. Rest of the procedure follows the similar steps as described for odontoid screw placement. We achieved 100% correct trajectory and screw placement in our study. There were no instances of screw break out, pull out or nonunion. There was one patient mortality following myocardial infarction in our study. Conclusion: Preoperative imaging details, proper patient positioning, meticulous dissection, thorough anatomical knowledge and few added surgical nuances are the cornerstones in ideal odontoid screw placement. This may be pivotal in managing patients in developing nations having rudimentary neurosurgical set up.

Fluoroscopically Guided C2 Percutaneous Vertebroplasty: A Surgical Technique Note on an Anterior Ascending Approach

Background: C2 vertebroplasty is more challenging than transpedicular percutaneous vertebroplasty in the thoracic and lumbar spine. Objective: We report an anterior ascending approach for C2 percutaneous vertebroplasty to avoid potential injury to vital structures surrounding the C2 vertebra. Study Design: A technique note with 5 consecutive cases. Setting: Neurosurgery department of a university hospital. Methods: Fluoroscopically guided manual compression was applied using 3 fingers at the C5 level between the muscle and trachea. The larynx and trachea were displaced medially and the carotid artery laterally. The anterior cervical spine was palpated, and a 15-gauge 4-inch bone marrow biopsy needle was introduced through an anterior ascending approach. When the tip touched the intervertebral disc between C2 and C3, the needle was pushed through the disc until it penetrated into the C2 vertebral body. After confirming adequate needle insertion, vertebroplasty was performed. Results: Pain relief was achieved in 4/5 (80%) patients. One patient possibly did not benefit from percutaneous vertebroplasty, and asymptomatic cement extravasation was detected in 2 patients. Limitations: Sample size; impossibility of placebo control. Conclusion: An anterior ascending approach for C2 percutaneous vertebroplasty is a valuable alternative for relieving pain caused by metastatic spinal tumors. This approach is familiar to surgeons performing anterior cervical discectomies, percutaneous nucleoplasty, or odontoid screw placement surgeries. Key words: Vertebroplasty, pain, axis, cement leak, metastases, palliative medicine, spine, fracture

Progressive quadriparesis caused by anterior odontoid screw upward migration in rheumatoid arthritis

A 70-year-old male known for seropositive rheumatoid arthritis underwent placement of an anterior odontoid screw in 2005 at an outside hospital for a posttraumatic type 2 odontoid fracture (Fig. 1). At the time of the accident, he did not have documented rheumatoid changes in the cervical spine. A postoperative lateral radiograph showed the screw going beyond the distal cortex of the dens (Fig. 2). The patient initially did well and was subsequently lost to follow-up. Fig. 2Sagittal computed tomography (CT) scan reconstruction performed after anterior odontoid screw fixation with satisfactory reduction of odontoid fragment. Despite a screw going 3 mm beyond odontoid tip, it remains extracranial, below the McRae line (dotted line). View Large Image Figure Viewer Download Hi-res image

Age increases the risk of immediate postoperative dysphagia and pneumonia after odontoid screw fixation

IntroductionType II odontoid fractures are the most common spinal fracture in the elderly population and may be managed with halo immobilization, posterior fusion, and anterior odontoid screw fixation. Anterior odontoid screw fixation has several advantages over posterior fusion, including: reduced surgical time, decreased post-operative pain, preserved range of motion, earlier mobilization, and decreased postoperative narcotic requirement. We review our experience using anterior odontoid screw fixation in type II odontoid fractures in the elderly and non-elderly populations. MethodsDemographic and outcome data were retrospectively collected in 30 consecutive patients with type II odontoid fractures treated with anterior odontoid screw fixation. ResultsMean patient age was 70.7 (range 20–92); 18 of the patients were male and 12 were female. All patients had successful placement of a single anterior odontoid screw without intra-operative complication. Complications included pneumonia in nine patients (30%), gastrostomy tube placement due to patient failing swallow evaluation in 13 patients (43%), and vocal cord paralysis in one patient (3.3%). Patients over the age of 75 accounted for 12 of the 13 (92%) gastrostomy tube placements and eight of the nine (88.9%) pneumonias, respectively. The difference in rates of gastrostomy tube placement and pneumonia for the older patients were both found to be statistically significant with P<.0001 for gastrostomy tubes and P<.02 for pneumonias. ConclusionsAnterior odontoid screw fixation is an effective treatment option for patients with Type II odontoid fractures. In the elderly population, however, the benefits of the procedure must be weighed against the risks of postoperative dysphagia requiring gastrostomy and pneumonia.