Screw Fixation Of Odontoid Fractures Research Articles

Comparison of mechanical stress on implants in anterior single and double screw fixation of odontoid fractures in a finite element model

Comparison of mechanical stress on implants in anterior single and double screw fixation of odontoid fractures in a finite element model

Anterior Screw Fixation for Odontoid Fractures - A Case Series.

Fractures of the odontoid process are common cervical spine injuries, accounting for 10-20% of all cervical spine fractures. Anterior screw fixation of odontoid fractures is an osteosynthetic technique that can give immediate stability and preserve normal mobility. The study was conducted in Government Mohan Kumaramangalam Medical college in the period 2017-2020. Five patients with Anderson and D'Alonzo type II odontoid Fractures were included in the study. Through anterior approach, using a horizontal skin incision, a K wire is inserted from the inferior edge of C2 through the incision and impacted into the odontoid process. A cannulated screw with non-threaded proximal shaft is inserted and tightened firmly to allow the distal fragment to compress on the body of C2. All the patients were reviewed postoperatively at 3, 6, and 12 months. Out of the five patients, all the patients had successful anatomical union at the end of 16 weeks. No neurological sequelae were reported. Anterior screw fixation provides a reasonable approach to odontoid fractures. Posterior stabilization using multiple techniques has been described with good union rates but has several disadvantages. Anterior screw fixation provides direct fracture fixation without the need for bone grafts. In addition, it reduces post-operative discomfort and length of hospital stay. Anterior odontoid screw fixation was associated with relatively low complication rates and a high union rate in our study. We conclude that this shall be the preferred treatment method for Type II odontoid fractures.

Outcomes of Patients Undergoing Anterior Screw Fixation for Odontoid Fracture and Analysis of the Predictive Factors for Surgical Failure.

ObjectiveAnterior odontoid screw fixation (AOSF) is a safe and effective treatment for type II and rostral type III odontoid fracture. This study aimed to report the outcomes of the AOSF surgery and evaluate the potential risk factors of surgical failure. MethodsWe enrolled 63 patients who underwent AOSF. Follow-up computed tomography was performed 6 months after the surgery and once a year thereafter to evaluate the union. Clinical data including the age, sex, presenting symptoms, cause of injury, fracture gaps, dislocation position, degree of displacement, screw direction angle, and time interval from injury to operation were collected. ResultsSuccessful fusion was achieved in 55 patients (87.3%) and surgical failure occurred in 8 patients (12.7%). Variables such as age, sex, dislocation position, degree of displacement, screw direction angle, and time interval from injury to operation were not significantly associated with the surgical failure. However, surgical failure was statistically significantly associated with the fracture gap. The overall mean fracture gap at the time of injury was 1.29 mm (range, 0–3.11 mm), and the incidence of surgical failure was 8.3 times higher when the fracture gap at the time of injury was > 2 mm (p=0.019). ConclusionWhen performing AOSF in patients with type II or rostral shallow type III odontoid fractures, the displacement of the odontoid fracture fragment should be appropriately reduced to the aligning position before screw insertion and downward reduction should be achieved by perforation of the apical cortex of the odontoid during screw fixation, even if the surgery is delayed.

Screw Fixation for Odontoid Fracture: How I Do it

Screw Fixation for Odontoid Fracture: How I Do it

Advantages of Direct Insertion of a Straight Probe Without a Guide Tube During Anterior Odontoid Screw Fixation of Odontoid Fractures.

A retrospective cohort study. The aim of this study was to compare the anterior odontoid screw fixation (AOSF) with a guide tube or with a straight probe. AOSF associates with several complications, including malpositioning, fixation loss, and screw breakage. Screw pull-out from the C2 body is the most common complication. All consecutive patients with type II or rostral shallow type III odontoid fractures who underwent AOSFs during the study period were enrolled retrospectively. The guide-tube AOSF method followed the standard published method except C3 body and C2-3 disc annulus rimming was omitted to prevent disc injury; instead, the guide tube was anchored at the anterior inferior C2 vertebra corner. After 2 screw pull-outs, the guide-tube cohort was analyzed to identify the cause of instrument failure. Thereafter, the straight-probe method was developed. A guide tube was not used. A small pilot hole was made on the most anterior side of the inferior endplate, followed by insertion of a 2.5 mm straight probe through the C2 body. Non-union and instrument failure rates and screw-direction angles of the guide-tube and straight-probe groups were recorded. The guide-tube group (n = 13) had 2 screw pull-outs and 1 non-union. The straight-probe group (n = 8) had no complications and significantly larger screw-direction angles than the guide-tube group (60.5 ± 4.63 vs. 54.8 ± 3.82 degrees; P = 0.047). Straight-probe AOSF yielded larger direction angles without injuring bone and disc. Complications were absent. The procedure was easier than guide-tube AOSF and assured sufficient engagement, even in horizontal fracture orientation cases. 3.

Cement-augmented anterior odontoid screw fixation for osteoporotic type II odontoid fractures in elderly patients: prospective evaluation of 11 patients.

Osteoporosis is considered to be a relative contraindication for anterior screw fixation of odontoid fractures because of reduced screw purchase. In the presence of osteoporosis, the most frequent mode of implant failure is via cut-out through the anterior wall of C2. Under in vitro conditions, cement-augmented odontoid screws show significant biomechanical advantages as compared to non-augmented screws. Against this background, we present our prospectively collected data on cement-augmented anterior screw fixation of osteoporotic odontoid fractures in elderly patients. 11 patients (8 female, 3 male, median age 83 years, range 73-89 years) with an isolated, osteoporotic type II odontoid fracture were treated. After closed reduction and standard anterior approach to the C2/3 level, a self-tapping, short-threaded 3.5-mm lag screw was placed. High-viscosity polymethylmethacrylate cement was injected via a cannulated Jamshidi needle into the base of the C2 vertebral body around the screw shaft and the screw was further tightened. Thin slice CT reconstructions for follow-up evaluation were done consistently postop and 12 months after surgery. Anatomic fracture reposition was achieved in all patients. Cement application was uneventful and well controllable. Cement leakage towards the fracture gap was not detectable. There were no major perioperative complications and no early revision surgeries. After 1 year, thin slice CT with three-dimensional reconstruction demonstrated solid osseous healing of the odontoid fracture in 8 out of 10 patients. Additional cement augmentation for anterior odontoid fracture repair is technically easy and safe. In elderly people with osteoporotic odontoid fractures, the procedure seems to be a useful supplementary option.

Posterior reduction and temporary fixation for odontoid fracture: a salvage maneuver to anterior screw fixation.

A prospective study. To evaluate the outcomes of posterior reduction and temporary fixation using the C1-C2 screw-rod system for odontoid fracture unsuitable for anterior screw fixation. Anterior screw fixation has become the most widely used surgical procedure for the stabilization of odontoid fractures. However, if there is any contraindication for anterior fixation, posterior atlantoaxial fusion is preferred, eliminating the normal rotation of the atlantoaxial complex. A consecutive series of 22 patients with odontoid fracture unsuitable for anterior screw fixation were involved in this study. Posterior reduction and fixation without fusion using the C1-C2 screw-rod system was performed. Once fracture healing was obtained, instrumentation was removed. The visual analogue scale of neck pain, neck stiffness, American Spinal Injury Association impairment scale, patient satisfaction, and neck disability index were recorded. The range of motion of C1-C2 in flexion-extension and rotation was calculated. The average age at internal fixation surgery was 40.2±11.3 years. The mean duration of follow-up was 41.8±26.8 months. There were no complications associated with instrumentation. All patients returned to their preoperative work. Fracture healing was observed in 21 patients and the instrumentation was removed. After removing the instrumentation, the visual analogue scale was reduced and neck stiffness were relieved (all P<0.01). Patient satisfaction and neck disability index had improved (all P<0.01). The range of motion of C1-C2 returned to 4.75°±1.62° and 25.70°±5.51° in flexion-extension and in rotation, respectively. No osteoarthritis was observed at the C1-C2 lateral mass joints. Posterior reduction and temporary fixation using the C1-C2 screw-rod system was an optimal salvage maneuver to anterior screw fixation for odontoid fracture. It could effectively avoid the motion loss of C1-C2 caused by posterior atlantoaxial fusion. 3.

Anterior screw fixation for an odontoid fracture using an Acutrak 4/5 screw: a case report

The direct anterior screw fixation of odontoid fractures by a single cancellous screw, especially for osteoporotic vertebrae, has a potential risk of leading to insufficient stability and implant failures. We experienced good results following surgery using a single Acutrak 4/5 screw to obtain sufficient stability for an odontoid fracture in a patient with osteopenia. The screw is a cannulated self-tapping headless screw and has a tapered profile and full threads with variable pitches, and it can yield sufficient compression force as the screw is inserted. The preoperative severe neck pain of the patient was diminished immediately after the surgery. The patient achieved bone union in a short time and had a good clinical result for at least 3 years. Some biomechanical studies showed that the compression force of Acutrak standard screws was stronger than that of both 4.0-mm cancellous screws inserted with the lag screw technique and Herbert screws, and other studies showed that the compression force of Acutrak 4/5 screws was equivalent to that of 4.5-mm cortical screws. However, there has been no clinical report of surgery using an Acutrak 4/5 screw for odontoid fractures. This is the first clinical report of fixation by an Acutrak 4/5 screw.

Comparative Analysis of Isocentric 3-dimensional C-arm Fluoroscopy and Biplanar Fluoroscopy for Anterior Screw Fixation in Odontoid Fractures

Retrospective clinical study. To compare long-term radiographic and clinical outcomes of patients undergoing anterior odontoid screw placement using traditional biplanar fluoroscopy or isocentric 3-dimensional C-arm (iso-C) fluoroscopy-assisted techniques. Anterior screw fixation of odontoid fractures preserves motion at the C1-C2 joint, but accurate screw positioning is essential for successful outcomes. Biplanar fluoroscopy image guidance is most often used; however, iso-C imaging improves the ease and accuracy of screw placement with less radiation exposure. Fifty-one patients underwent anterior odontoid screw fixation for type II (48 patients) and rostral type III fractures (3 patients). Procedures were guided by biplanar fluoroscopy in 25 (49%) patients, and with iso-C assistance in 26 (51%). Length of surgery, complications, and clinical outcomes based on the Smiley-Webster score were evaluated. Computed tomography confirmed adequate screw placement. Follow-up ranged from 3 to 9 months. At 3-month follow-up, screw position and fusion across the fracture were evident in 87% of the cases treated with biplanar fluoroscopy and in 100% treated by iso-C. The average outcome score in the iso-C group was superior to that of the biplanar group (1.08 vs. 1.33, respectively), although not statistically significant. At last follow-up, the rate of successful fusion was 88% in the biplanar group and 95% in the iso-C group. Length of surgery was significantly lower in the iso-C group compared with the biplanar group (P=0.05). The significantly longer preparation time in the iso-C group (P=0.04) accounted for no overall difference in total operating room occupancy time between the 2 groups. Iso-C significantly decreased surgical time. At last follow-up iso-C assistance was associated with improved rates of radiographic fusion with comparable outcome and complication profiles. This series represents the largest cohort of patients treated with intraoperative real-time navigation assistance for odontoid fractures.

Anterior Screw Fixation for Odontoid Fracture Using the Direct Approach at the C2-C3 Level: Case Report and Literature Review

Fractures of the odontoid process comprise 10–15% of all cervical fractures. Almost two thirds of all dens fractures are classified as type II according to Anderson and D’Alonso classification system. Currently, the direct anterior odontoid screw fixation provides the best anatomical and functional results for this type of fracture and it is considered as the treatment of choice. Regarding the approach to the C2 vertebra, about 80% of authors usually make a skin incision at the lower cervical level (C4-C5 or C5-C6) for creating a working corridor. However, the required exposure and the relatively blind passage of the screw can damage the surrounding soft tissue. The direct approach at the C2- C3 level could be a shorter and safer working corridor to the odontoid screw fixation with less soft tissue retraction. Here we present a case report of a 62-year-old man who presented with Type II odontoid fracture and subsequently underwent a direct anterior odontoid screw fixation through a mini-open approach at the C2-C3 level. The literature available in the English language on related-approach complications of anterior odontoid screw fixation is reviewed.

Does the Third Cervical Vertebra Need to be Rimmed for Odontoid Screwing? A Hypothetical Study of Anatomic Landmarks

The superoanterior portion of the third cervical vertebra may need to be rimmed during anterior odontoid screw fixation procedures. We, therefore, retrospectively evaluated radiological data to analyze the anatomical relation between the second and third cervical vertebra of the patients who were operated by an anterior cervical approach with respect to the question if odontoid screw fixation would have been possible without rimming or not. Patients in whom the anterior approach for cervical disc prolapse and/or cervical stenosis was used between 2008 and 2010 were included in this study. The odontoid screw angle, and the angle between the lower second and the upper third cervical vertebral endplate were measured on intraoperative cervical lateral radiographs. If the screw line passed through the superior anterior portion of the third vertebral body, it was determined that the third cervical vertebra would have been needed to be rimmed if odontoid screwing would have been planned. 100 patients were included. There were 50 males and 50 females with a mean age of 47.9 years (mean ± SD: 47.9 ± 12.6 years). The mean odontoid screw angle, and the angle between the lower second and the upper third cervical vertebral endplate were 65.61° ± 3.75° and 15.24° ± 4.85° (nonparallel vertebral endplates only), respectively. The odontoid screw angle, in which the third cervical vertebra would not have been needed to be rimmed, was 63.87° ± 2.84°. In addition, the odontoid screw angle in which the third cervical vertebra would have been needed to be rimmed was 67.28° ± 3.77°. The odontoid screw angle may be easily measured on lateral radiographs. In cases in which the odontoid screw angle is 67.28° ± 3.77° or higher, the superoanterior portion of the third cervical vertebra would be needed to be rimmed for proper screw fixation of odontoid fractures.

Observation of the anterior surgery treatment effect on high cervical spine trauma

Objective To explore the anterior surgery treatment effect on high cervical spine trauma. Methods Collected 7 patients who were in our hospital, 5 males and 2 females, aged from 23 to 62 years, with high cervical injury, from 2006 to 2010; among them, 3 cases had odontoid fractures, 4 csses had odontoid fractures with atlantoaxial dislocation. The group were reset by releasing anterior cervical approach, and cannulated screw fixation of odontoid fractures. Results All patients were followed for 6 months to 4 years; the group adopted high anterior approach to expose the complete fixation placement had no case of hypoglossal nerve, carotid artery, carotid sheath, superior laryngeal nerve injury, and posterior wall injury of pharynx; after the operation, it had little influence on cervical rotation, and didn' t have vertebral artery and spinal cord injury; what's more, neurological symptoms were obviously relieved after surgery. Conclusion The anterior cannulated screw fixation of odontoid process fracture and dislocation of atlantoaxial joint can improve the stability of high cervical spine, has exact fixation, does not affect the activities of C1 and C2, has fewer complications, and whose clinical results were satisfactory. Currently,there are many surgical treatments of high cervical injury; each has its own advantages and disadvantages;choosing a different surgical treatment should base on the injury characteristics of patients and whether the patients have vertebrae dislocation; except that, also should strictly control its indication, and give the patients stable fixation and tell them to do some exercise not affecting the joint before the relieving of the symptoms. Key words: High cervical spine injury ; Anterior approach ; Odontoid process fracture

Computed tomographic evaluation of odontoid process: implications for anterior screw fixation of odontoid fractures in an adult population

Odontoid diameter in some individuals may not be large enough to accommodate two 3.5-mm cortical screws for anterior odontoid fracture fixation. The study was performed to evaluate, in a Brazilian population, the diameter of the odontoid process and the feasibility of using two 3.5-mm cortical screws for anterior odontoid fracture fixation. Computed tomographic (CT) scans of 88 adult patients (aged 18-78years) were analyzed; 40 patients (45%) were male (mean age: 43.08years) and 48 (55%) were female (mean age: 43.39years). The minimum external and internal anteroposterior and transverse diameters of the odontoid process on sagittal and coronal planes were measured on CT multiplanar reconstructions of the cervical spine. The mean value of the minimum external anteroposterior diameter was 10.83±1.08 and 7.53±1.10mm for the minimum internal anteroposterior diameter. The mean value of the minimum external transverse diameter was 9.19±0.91 and 6.07±1.08mm for the minimum internal transverse diameter. The mean AP diameter was significantly larger than the mean transverse diameter; 57 (65%) individuals had the minimum external transverse diameter >9.0mm that would allow the insertion of two 3.5-mm cortical screws with tapping, and five (6%) individuals had the minimum internal transverse diameter >8.0mm that would allow the insertion of two 3.5-mm cortical screws without tapping. The insertion of two 3.5-mm cortical screws was possible for anterior fixation of odontoid fracture in 57 (65%) individuals of our study, and there was no statistical difference between males and females.

Anterior single screw fixation of odontoid fracture with intraoperative iso-C 3-dimensional imaging

The purpose of this study was to assess the value of isocentric C-arm three-dimensional (Iso-C 3D) fluoroscopy for the insertion of an anterior odontoid screw. The results of the Iso-C 3D group were compared with that of an historic control group using conventional fluoroscopy. Twenty-nine patients diagnosed with type II or rostral-type III odontoid fractures were treated with a single anterior screw fixation in this study. The Iso-C 3D group included 13 patients and the other 16 patients were in the historic control group. All operations were performed by a single surgeon using standard procedure and manner. The clinical and radiographic results were recorded and compared between the two groups. The fluoroscopy time in the Iso-C 3D group was 42.9s as compared to 68.1s in the control group (P<0.01). The mean operative time was 91.5min in the Iso-C 3D group when compared with 81.6min in the control group (P=0.20). The rate of bony fusion was 96.6% (28/29), the failure rate of reduction or fixation was 13.8% (7.7% in Iso-C 3D group; 18.8% in control group). The Smiley-Webster scale showed that 90% of patients achieved good or better outcomes In conclusion, this technique can be safely extended to the treatment of technically difficult to treat spinal injuries and at the same time reduce total radiation exposure time both for the patient and the surgeon.

Surgical Results of Anterior Screw Fixation for Odontoid Fracture

Surgical Results of Anterior Screw Fixation for Odontoid Fracture

Direct anterior screw fixation for recent and remote odontoid fractures

The management of odontoid fractures remains controversial. Only direct anterior screw fixation provides immediate stabilization of the spine and may preserve normal C1-2 motion. To determine the indications, optimum timing, and results for direct anterior screw fixation of odontoid fractures, the authors reviewed the surgery-related outcome of patients who underwent this procedure at two institutions. One hundred forty-seven consecutive patients (98 males and 49 females) who underwent direct anterior screw fixation for recent (< or = 6 months postinjury [129 patients]) or remote (> or = 18 months postinjury [18 patients]) Type II (138 cases) or III (nine cases) odontoid fractures at the University of Utah (94 patients) and National Institute of Traumatology in Budapest, Hungary (53 patients) between 1986 and 1998 are included in this study (mean follow up 18.2 months). Data obtained from clinical examination, review of hospital charts, operative findings, and imaging studies were used to analyze the surgery-related results in these patients. In patients with recent fractures there was an overall bone fusion rate of 88%. The rate of anatomical bone fusion of recent fractures was significantly (p < or = 0.05) higher in fractures oriented in the horizontal and posterior oblique direction (compared with anterior oblique), but this finding was independent (p > or = 0.05) of age, sex, number of screws placed (one or two), and the degree or the direction of odontoid displacement. In patients with remote fractures there was a significantly lower rate of bone fusion (25%). Overall, complications related to hardware failure occurred in 14 patients (10%) and those unrelated to hardware in three patients (2%). There was one death (1%) related to surgery. Direct anterior screw fixation is an effective and safe method for treating recent odontoid fractures (<6 months postinjury). It confers immediate stability, preserves C1-2 rotatory motion, and achieves a fusion rate that compares favorably with alternative treatment methods. In contradistinction, in patients with remote fractures (> or = 18 months postinjury) a significantly lower rate of fusion is found when using this technique, and these patients are believed to be poor candidates for this procedure.

Direct anterior screw fixation for recent and remote odontoid fractures

Object The management of odontoid fractures remains controversial. Only direct anterior screw fixation provides immediate stabilization of the spine and may preserve normal C1–2 motion. To determine the indications, optimum timing, and results for direct anterior screw fixation of odontoid fractures, the authors reviewed the surgery-related outcome of patients who underwent this procedure at two institutions. Methods One hundred forty-seven consecutive patients (98 males and 49 females) who underwent direct anterior screw fixation for a recent fracture (&lt; 6 months postinjury [129 patients]) or remote (≥ 18 months postinjury [18 patients]) Type II (138 cases) or III (nine cases) odontoid fractures at the University of Utah (94 patients) and National Institute of Traumatology in Budapest, Hungary (53 patients) between 1986 and 1998 are included in this study (mean follow-up period 18.2 months). Data obtained from clinical examination, review of hospital charts, operative findings, and imaging studies were used to analyze the surgery-related results in these patients. In patients with recent fractures there was an overall bone fusion rate of 88%. The rate of anatomical bone fusion of recent fractures was significantly (p ≤ 0.05) higher in fractures oriented in the horizontal and posterior oblique direction (as compared with anterior oblique), but this finding was independent (p ≥ 0.05) of age, sex, number of screws placed (one or two), and the degree or the direction of odontoid displacement. In patients with remote fractures there was a significantly lower rate of bone fusion (25%). Overall, complications related to hardware failure occurred in 14 patients (10%) and unrelated to hardware in three patients (2%). There was one death (1%) related to surgery. Conclusions Direct anterior screw fixation is an effective and safe method for treating recent odontoid fractures (&lt; 6 months postinjury). It confers immediate stability, preserves C1–2 rotatory motion, and achieves a fusion rate that compares favorably with alternative treatment methods. In contradistinction, in patients with remote fractures (≥ 18 months postinjury) a significantly lower rate of fusion is found when using this technique, and these patients are believed to be poor candidates for this procedure.

Anterior screw fixation for odontoid fractures

The results of anterior screw fixation of odontoid fractures in 28 patients are presented. There were 27 type II- and 1 type III-injuries. Non-union with persistent instability had to be notified in one patient (3.6 %), secondary posterior C1/2 fusion had to be performed. Incorrect positioning of the screws in the odontoid with penetration of the postero-lateral cortex occurred in 3 patients (10.7 %). Malpositioning of the odontoid after screw fixation was documented in 5 cases (17.9 %). Cardiopulmonary complications had to be treated in 5 patients (17.9 %), 4 patients (14.3 %) died in the postoperative period. 17 patients could be followed up. Only 3 patients (17.8 %) were free of symptoms. A significant limitation in ROM of axial rotation was seen in 44 % of the patients. With anterior screw fixation of the odontoid high fusion rates can be achieved, however the procedure is technically demanding. Regarding the functional outcome, there is no significant difference to other established treatment methods.

Anterior screw fixation for odontoid fracture: clinical results in 45 cases

Clinical results of anterior screw fixation in 45 patients with odontoid fractures were reviewed retrospectively. The patients were 36 males and 9 females, with fractures classified as 35 type II and 10 type III. There were 34 fresh and 11 old fractures. Neurological complications were present in 16 patients and 18 had associated injuries. All patients underwent single screw fixation. Postoperative immobilization, external support, and surgical trauma were minimal. In one patient a screw extruded from the dens and immediate posterior fusion was necessary. The overall rate of fracture union was 93% (41 out of 44 fractures). Fracture resolution averaged 5.2 months. There were two delayed unions and three nonunions, the causes of which were preoperatively established nonunion, severe osteoporosis, and inaccurate screw placement. Out of 11 old cases, 8 went on to union. Ninety-six percent of the patients recovered neurologically. The overall complication rate, including a misplaced screw, a retropharyngeal wall injury, and three nonunions, was 11%. Head rotation was preserved in 90% of the patients with fracture union according to clinical measurements. Anterior screw fixation is an excellent treatment for fresh type II and cephalad type III odontoid fractures, carrying a high union rate, preservation of the C1-2 motion segment, and minimal surgical trauma; it can be applied even to some old cases. Precise patient selection in regard to patient age, bone density, and time elapsed since injury as well as preoperative anatomical reduction and meticulous surgical technique with fine fluoroscopy are essential to avoid complications and nonunions.

Screw Fixation of Odontoid Fractures and Nonunions

Surgical treatment of odontoid fractures has usually been carried out by C1-2 arthrodesis rather than by fracture fixation. An alternative treatment of compression screw fixation was used to treat selected acute odontoid fractures and nonunions. Ten patients were operated on. A variety of lag-screw types were used to compress and secure the fracture. Screw placement was considered excellent in five cases; in four, the screw tip protruded through the posterosuperior cortex of the dens by 1-3 mm. One patient died as a result of multiple injuries 2 days after surgery. In all other cases, including four cases of odontoid pseudarthroses, the fractures achieved solid union. It was concluded that screw fixation can be used for the successful treatment of selected odontoid fractures and nonunions.