Anterior Screw Fixation Of Type Research Articles

Type II Odontoid Fractures: Is the Anterior Screw a Good Solution for all Patients? A Case Series of 60 Consecutive Patients

Type II odontoid fracture is the most common fracture type, and its treatment remains challenging. The objective of this study was to evaluate the results of anterior screw fixation for type II odontoid fractures in patients aged over and below 60 years. A retrospective analysis of consecutive patients diagnosed with type II odontoid fractures who were surgically treated using the anterior approach by a single surgeon was conducted. Demographic characteristics, including age, sex, type of fracture, time from trauma to surgery, length of stay (LoS), fusion rate, complications, and reoperation, were evaluated. Surgical outcomes were compared between patients over and below 60 years of age. Sixty consecutive patients underwent odontoid anterior fixation during the analysis period. The mean age of patients was 49.58 ± 23.22 years. Twenty-three (38.3%) patients were aged over 60 years, and the minimum follow-up period was two years. Of the patients, 93.3% developed bone fusion, which was observed in 86.9% of patients over 60 years. Complications related to hardware failure occurred in six (10%) patients. Transient dysphagia was observed in 10% of the cases. Three (5%) patients required reoperation. Patients over 60 years had a significantly increased risk of dysphagia compared with those below 60 years (P= 0.0248). There was no significant difference between the groups regarding nonfusion rate, reoperation rate, or LoS. Anterior fixation of the odontoid showed high fusion rates with a low rate of complications. It is a technique to be considered for treating type II odontoid fractures in selected cases.

Anterior screw fixation for type II odontoid process fractures: A single-center experience with the double Herbert screw fixation technique (Retrospective cohort study)

BackgroundIn type II odontoid fractures with intact transverse ligament as classified by the Anderson and D'Alonzo system, anterior screw fixation offers the best anatomical and functional results. The goal of this study is to review the results of the double screw technique in anterior odontoid surgery using a headless 3.0-mm.-diameter cannulated Herbert screw on patients with odontoid process fractures. MethodsFrom January 2015 through March 2019, 12 cases of acute traumatic type II odontoid fractures were treated with double anterior screw fixation using 3.0-mm Herbert screws, slightly smaller than the standard size for Caucasian populations. The data collected included radiographic measurements, postoperative complications, union rate and clinical outcomes in follow-up examinations over an average of 24-months. ResultsThe age of the 12 patients, 8 males and 4 females, ranged from 17 to 68 years (mean, 38.42 ± 20.14). The fracture type was type IIa in 4 patients (33.33%) and type IIb in 8 patients (66.67%). The period of follow-up was 15–64 months (mean, 31.42 ± 17.37). All the patients had good clinical results after surgery with no postoperative complications. Eleven cases (92%) had achieved bone union with 1 case (8%) of nonunion. In the nonunion case, the patient was a chronic smoker who continued smoking both during treatment and follow-up. ConclusionsThis series of satisfactory clinical results demonstrates that double anterior screw fixation of type II odontoid process fractures using 3.0-mm screws is highly effective in the Thai population. Headless cannulated cancellous screws provide significant biomechanical strength which is not inferior to the traditional screws

Preliminary Biomechanical Proof of Concept for a Hybrid Locking Plate/Variable Pitch Screw Construct for Anterior Fixation of Type II Odontoid Fractures

A human cadaveric biomechanical proof-of-concept study. To test whether adding a locking plate to the anterior surface of C2 attaching directly to the interfragmentary screw may reduce potential for anterior screw cutout and improve construct strength. The most common mode of failure for screw fixation of dens fractures is via cutout at the anterior body of C2. A human, cadaveric model of type II dens fractures was created and fixed using either a headless, fully threaded variable pitch screw (FTVPS) or a screw with an attachable locking plate construct (LPC). Following quasistatic loading to failure, stiffness and load to failure were compared using t tests. Mode of failure was determined from radiographical and gross inspection. Load to failure was greater for the LPC than for the FTVPS alone (498 N vs. 362 N, P = 0.04). The LPC consistently failed via compression of cancellous bone posterior to the lag screw, whereas the FTVPS constructs failed via cutout of the screw from the anterior C2 body. Locking plate supplementation of anterior screw fixation of type II odontoid fractures improves construct strength and changes the failure mechanism from anterior screw cutout to posterior displacement of the screw. An attachable locking plate/interfragmentary screw construct may improve clinical outcomes for these fractures.

Analysis of Risk Factors Associated With Fusion Failure After Anterior Odontoid Screw Fixation

Retrospective study. To evaluate the incidence of fusion failure after anterior screw fixation of type II and rostral shallow type III fractures and to identify related risk factors. Although several studies have reported fusion rates after anterior odontoid screw fixation of type II and rostral shallow type III fractures, few reports have analyzed in detail the risk factors associated with fusion failure. Forty-one patients with a type II and rostral shallow type III odontoid fracture were treated using anterior screw fixation. The patients were 33 men and 8 women mean age = 46.6 years; age range = 15-79 years. Range of follow-up was 7 to 48 months. Anterior odontoid screw fixation resulted in solid bony union in 33 patients (80.5%), fibrous union in 3 (7.3%), and nonunion in 5 (12.2%). When surgery was delayed for more than 1 week, the incidence of fusion failure significantly increased (P = 0.0051). Furthermore, a fracture gap of 2 mm or more was found to be significantly associated with fusion failure (P = 0.0172). However, patient age and fracture displacement were not found to be significantly associated with fusion failure (P = 0.8236 and P = 0.5762, respectively). Our study of anterior odontoid screw fixation reveals that the risk of fusion failure is 37.5 times greater in patients with a delay of more than 1 week before operation, and 21 times greater in patients with a fracture gap of greater than 2 mm.

Clinical Evaluation of Anterior Screw Fixation for Elderly Patients With Type II Odontoid Fractures

A retrospective study of elderly patients who underwent anterior screw fixation for type II odontoid fractures between 2000 and 2009 was conducted. To evaluate the clinical outcome of anterior screw fixation for type II odontoid fractures in elderly people and to provide valuable information for spinal surgeon reference. Odontoid fractures are the most common fractures of the cervical spine in patients above 70 years of age, and patients above 80 years of age form the majority of spinal fractures. However, the optimum treatment of type II odontoid fractures in the geriatric population remains controversial. A retrospective analysis was performed in 43 patients (19 women; mean age, 80.6 y; range, 65 to 92 y) with type II odontoid fractures who were consecutively admitted to a single medical center between January 2000 and October 2009. Twenty-eight patients had posteriorly displaced odontoid fractures and the remaining 15 had anteriorly displaced odontoid fractures according to the radiographical presentation. Neurological symptoms were present in 4 patients including 3 Frankel D and 1 Frankel C and always occurred in patients with posteriorly displaced odontoid process. The medical records, plain x-rays, and computed tomographic scans of all patients were reviewed. After surgery, patients were discharged with rigid cervical immobilization and clinical follow-ups were between 18 and 24 months (average, 21.3 mo). The mean displacement of odontoid process revealed by preoperative radiologic evaluation was 4.9 mm (ranged from 1 to 10 mm). Anterior screw fixation was performed successfully in 42 cases except 1 in which posterior C1-C2 fusion had to be undertaken to replace the original operation scheme because of technical difficulty. According to postoperative radiologic evaluation, 36 of 42 type II odontoid fracture cases treated with anterior screw fixation achieved fusion within 6 months. The fusion rate was 85.7% (36 of 42). Thirty-four patients regained normal cervical movement, 5 patients had about 25%, and 3 had >25% limited cervical motion. Sixteen patients achieved clinically excellent outcomes, 24 good, and 2 fair outcomes. Anterior screw fixation can be performed safely in elderly patients with type II odontoid fracture, and the clinical outcomes of this procedure were satisfactory. High fusion rates, low postoperative complications, and maintenance of cervical motion were acquired. The anterior screw fixation can be a reliable and reasonable treatment for type II odontoid fractures in the elderly patients.

Avoiding pitfalls in anterior screw fixation for Type II odontoid fractures

Anterior screw fixation of Type II odontoid fractures provides immediate stabilization of the cervical spine while preserving C1-2 motion. This technique has a high fusion rate, but can be technically challenging. The authors identify key points that should be taken into account to maximize the chance for a favorable outcome. Keys to success include proper patient and fracture selection, identification of suitable screw entry point and correct screw trajectory, achieving bicortical purchase, and placing 2 screws when feasible and applicable. The authors review the operative technique and present guidance on appropriate patient selection and common pitfalls in anterior screw fixation, with strategies for avoiding complications.

Comparison of Percutaneous and Open Anterior Screw Fixation in the Treatment of Type II and Rostral Type III Odontoid Fractures

Prospective controlled study of the clinical and radiographic results of a group of 42 cases having undergone anterior screw fixation for type II and rostal type III odontoid fractures. The objective of this study is to determine the safety and efficacy of percutaneous anterior screw fixation as an alternative new technique in the management of type II and rostal type III odontoid fractures. Minimally invasive spinal techniques have only recently been developed. However, clinical and radiographic outcome of minimally invasive anterior screw fixation for odontoid fractures has been evaluated in very few studies. There have been no prospective clinical reports published on the comparison of percutaneous anterior screw fixation for type II and "shallow" type III odontoid fractures or a traditional open manner. Forty-two patients, 26 men and 16 women, with an average age of 47.1 years (32-65) were prospectively evaluated. All patients underwent percutaneous anterior screw fixation(n = 19) or open screw fixation (n = 23). The following data were compared between the two groups: operative time, blood loss, radiograph exposure time, the clinical and radiographic results, and complications. Radiologic examination of the cervical spine with plain radiographs was performed at 3, 6, and 12 months after surgery. In comparison with open fixation group, percutaneous fixation group had significantly less operating time and less blood loss. The radiation time and clinical outcome were basically identical in two groups. Radiographic evaluation showed satisfactory bony union and no evidence of abnormal movement at the fracture site in both percutaneous fixation group (18 of 19 cases) and open fixation group (22 of 23 cases). Two cases of postoperative dysphagia occurred in open screw fixation group. Percutaneous anterior screw fixation is a safe and reliable procedure for treatment of type II and rostral type III odontoid fractures with potential advantages.

Analysis of failure following anterior screw fixation of Type II odontoid fractures in geriatric patients

Anterior screw fixation of Type II odontoid fractures has been recommended. Only few publications analyse the mechanism of failure in geriatric patients. We reviewed 18 male and 15 female patients aged 65 and above for parameters that influence the development of postoperative loss of correction, delayed union or non-union. Patients were stratified in two groups: 21 cases in Group A (union) and 12 patients in Group B (loss of correction, delayed union, non-union, revision surgery). Statistically significant correlation (p<0.05) could be detected between failure to heal and: (1) degenerative changes in the atlanto-odontoid joint, (2) severity of osteoporosis in the odontoid process, (3) posterior oblique fracture type, (4) suboptimal fracture reduction, (5) suboptimal position of implant following demanding intraoperative conditions, (6) quality of fracture compression and (7) severity of fracture comminution. The overall morbidity and mortality rates were 29.0 and 8.6%, respectively. Our results indicate that these factors should be addressed regarding the selection of the operative treatment method in the geriatric patient.

Anterior Screw Fixation of Type II Odontoid Fractures in the Elderly

Optimal surgical treatment in elderly patients with type II odontoid fracture is still controversial. The purpose of this study is to investigate the surgical outcomes of anterior screw fixation of type II B odontoid fractures in the elderly. Fifteen patients who had type II B odontoid fracture were treated consecutively by anterior odontoid screw fixation between 2001 and 2005. The patient group comprised 11 men and 4 women. In all patients, 3-D CT reconstructions were checked for accurate diagnosis for type II odontoid fracture. The medical records, plain X-rays, and CT scans of all patients were reviewed and fusion rate, union time, incidence of perioperative complications, neurologic outcome, and mortality were studied. Radiologic and clinical follow-up were performed in all patients. All patients were treated with anterior odontoid screw fixation by use of one compression screw. Mean age was 68.9 years (range, 61-78) and mean follow-up was 18.3 months. The overall fusion rate was 77%. If follow-up studies revealed pseudarthrosis, additional dorsal fixation with transarticular C1-C2 screws or C1-C2 posterior screw-rod fixation with bone graft was performed. Mean union time was 17.1 week. The outcome of anterior odontoid screw fixation of type II B odontoid fractures in the elderly is satisfactory. We experienced satisfactory union rates and preserved cervical range of movement without the need of postoperative rigid neck immobilization. The morbidity associated with this procedure was low. We recommend anterior screw fixation as an effective method of treating type II B odontoid fractures in the elderly.

Treatment of odontoid fractures with single anterior screw fixation

We evaluate the efficacy and safety of single anterior screw fixation in the treatment of types II and III (Anderson and D’Alonzo classification) odontoid process fractures, and analyse our surgical results. From May 1996 to October 2003, 16 patients underwent single anterior screw fixation for type II ( n = 12) and III ( n = 4) odontoid process fractures and had at least 1 year follow-up. We analyzed sex, age, associated injuries, and complications. The radiographic findings, including union rate, union time, changes of fracture shape and metal migration, were evaluated and modified Robinson criteria were used for clinical assessment. Of 16 patients, 15 (94%) achieved bony union at an average of 13.8 weeks. One patient required a secondary posterior procedure after anterior screw fixation. A full range of cervical motion was maintained in 12 patients, a limitation of <25% in three, and of >25% in one. There were no major complications related to the operative technique, including neurologic deterioration or wound infection. We conclude that single anterior screw fixation is clinically and radiologically effective and safe for type II and III odontoid process fractures.

Anterior Screw Fixation of Odontoid Fractures Comparing Younger and Elderly Patients

A retrospective, comparative study. Anterior screw fixation has become an accomplished treatment option for the management of odontoid fractures. In younger patients, it has shown encouraging results with low complication rates; whereas in geriatric trauma victims, it remains the subject of controversy. The purpose of this study was to determine functional and radiographic results after anterior screw fixation of Type II odontoid fractures, with the particular interest to compare the outcome between younger and elderly patients. We reviewed clinical and radiographic records of 110 patients with an average age of 54 years at the time of surgery after anterior double screw fixation of their odontoid fractures between 1990 and 2004. To compare functional and radiographic results between nongeriatric and geriatric patients, they were divided by age into 2 groups: Group A included patients 65 years of age or younger and Group B contained patients older than 65 years. A total of 95 patients had returned to their preinjury activity level and were satisfied with their treatment. The Smiley-Webster scale showed an overall outcome score of 1.42 with similar results in both groups (Group A, 1.34; Group B, 1.50). Bony fusion was achieved in 102 patients, failures of reduction or fixation occurred in 12 patients. Comparing between the 2 groups, we had a nonunion rate of 4% in younger individuals and a significantly higher rate of 12% in geriatric patients. Reoperation due to nonunion or technical failures was necessary in 8 patients. We had encouraging results using anterior screw fixation for surgical treatment of odontoid fractures and favor this method as preferred management strategy for stabilization of these fractures. Comparing between age groups, we had similar results on cervical spine function. With regards to fracture healing as well as morbidity and mortality, younger patients had a superior outcome.

Treatment of O dontoid Fractures with Single Anterior Screw Fixation

Purpose : To evaluate the availability and safety of single anterior screw fixation in the treatment of type II and III odontoid process fractures through an analysis of the treatment outcomes. Materials and Methods : This study analyzed 16 patients who underwent surgery between May 1996 and Oct. 2003 by single anterior screw fixation for type II and III odontoid process fractures with at least a 1 year follow up. The radiographic findings such as the fusion rate, union time, changes in the fracture shape, and metal migration were evaluated. In addition, the Robinson modification criteria were used for the clinical assessment. Results : There were 12 and 4 patients with Anderson and D'Alonzo type II and type III fractures, respectively. Of the 16 patients, 15 (93%) achieved bony union after an average of 13.8 weeks. There were 2 cases of malunion with a normal range of cervical motion, and 1 case requiring posterior fusion as a result of nonunion. A full range of cervical motion was maintained in 11 cases. Three cases had a limitation of less than 25% and 2 cases had a limitation greater than 25%. Conclusion : Single anterior screw fixation is an effective treatment modality with a high fusion rate and low complication rates. However, precise preoperative planning and technical experience is essential for preventing unwanted complications.

Results of Long-Term Follow-Up in Patients Undergoing Anterior Screw Fixation for Type II and Rostral Type III Odontoid Fractures

Retrospective analysis of the fusion rate of a group of 38 patients having undergone anterior screw fixation for type II and "shallow" type III odontoid fractures. OBJECTIVE.: To determine primarily the long-term fusion rate after anterior screw fixation and to study the clinical characteristics of patients that have a statistically significant or nonsignificant influence on successful outcome. Long-term outcome of anterior screw fixation for odontoid fractures has been evaluated in very few studies. This information should be critical for further establishing this technique as a major therapeutic strategy for these cases. Thirty-eight patients, 25 males and 13 females (with mean age 48.4 +/- 0.4 years), with type II and rostral type III odontoid fractures, underwent anterior cannulated screw fixation during a 62-month period. Radiologic examination of the cervical spine with plain radiographs was performed at 6 weeks, and 2, 6, 12, and 24 months, while computerized tomography of the upper cervical spine (C1-C3) was obtained at 6 months after surgery. Follow-up was available for 31 patients, and the follow-up time ranged from 39 to 87 months (mean 58.4). Radiographic evaluation of the follow-up group showed satisfactory bony fusion and no evidence of abnormal movement at the fracture site in 27 (87.1%) patients. Pseudarthrosis developed in 4 (12.9%) patients; however, 3 (9.6%) of them without instability and 1 (3.2%) with instability. One (3.2%) patient had an instrumentation failure without instability. In our series, anterior odontoid screw fixation comprised a safe therapeutic modality with high stability and low mechanical failure rates during short-term and long-term follow-up.