As odontoid process fractures become increasingly common in the aging population, a technical understanding of treatment approaches is critical.
Establishing a clear treatment paradigm for octogenarians with odontoid fracture type II in hampered by a literature replete with level III articles.
Anterior odontoid screw fixation was first reported by Nakanishi 1) and Bohler 2). This procedure provides immediate spinal stability, preserves the normal rotation between C1-2, allows the best anatomical and functional outcome for type II odontoid fracture, and is associated with rapid patient mobilization, minimal postoperative pain and a short hospital stay. Acute odontoid fractures treated by anterior screw fixation have a fusion rate of approximately 90 percent 3).
Posterior approach for stabilization of odontoid fracture is indicated in the cases of odontoid fracture that are not amenable to anterior screw fixation. Commonly used procedures involve wedging a bone graft between posterior arch of C1 and the C2 lamina with sublaminar wiring. The well-described different methods for this C1- 2 posterior fusion procedure are the Gallie, Brooks, Sonntag techniques. These procedures have a satisfactory fusion rate of about 74 percent. The demerit of this procedure is that it causes elimination of the normal C1-2 rotatory motion ( which accounts for more than 50% of all cervical spine rotatory movements) and reduced cervical spine flexion– extension by 10 percent.
Another excellent alternative technique for odontoid fracture is the posterior C1-2 transarticular screw fixation (Magerl’s procedure) using unilateral or bilateral screws. This provides an excellent spinal rotational spinal stability. This is an indirect method of stabilizing the fracture (in which the normal anatomical configuration is disrupted). Preoperative CT evaluation is mandatory to avoid vertebral artery injury in this procedure. This technique can be supplemented with metal plate for occipito-cervical stabilization. Alternatively, Jain’s technique of occipitocervical fusion, Goel’s plate and screw lateral mass fixation, or a Ransford’s contoured rod technique31 may be utilized.
In the study by Graffeo et al., the authors evaluated 111 patients over the age of 79 (average age: 87) with type II odontoid fractures undergoing nonoperative (94 patients) vs. operative intervention (17 total; 15 posterior and 2 anterior). They studied multiple variables and utilized several scales [abbreviated injury scale (AIS), injury severity score (ISS), and the Glasgow coma scale (GCS)] to determine the outcomes of nonoperative vs. operative management.
Graffeo et al. concluded that there were no significant differences between nonoperative and operative management for type II odontoid fractures in octogenarians. They found similar frequencies of additional cervical fractures, mechanisms of injury, GCS of 8 or under, AIS/ISS scores, and disposition to “nonhome” facilities. Furthermore, both appeared to have increased mortality rates at 1-year post injury; 13% during hospitalization, 26% within the first post-injury month, and 41% at 1 year.
In the editorial by Falavigna, his major criticism of Graffeo’s article was the marked disparity in the number of patients in the operative (17 patients) vs. the nonoperative group (94 patients), making it difficult to accept any conclusions as “significant”. He further noted that few prior studies provided level I evidence, and that most, like this one, were level III analyses that did not “significantly” advance our knowledge as to whether to treat octogenarians with type II odontoid fractures operatively vs. nonoperatively 4).
Pisapia et al., 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.
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.
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).
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 5).
Twenty-one of 22 patients who underwent posterior C1-C2 temporary fixation of an odontoid fracture achieved fracture healing and regained motion of the atlantoaxial joint. The functional outcomes of these 21 patients were compared with that of a control group, which consisted of 21 randomly enrolled cases with posterior C1-C2 fixation and fusion. The differences between the 2 groups in the visual analog scale score for neck pain, neck stiffness, Neck Disability Index, 36-Item Short Form Health Survey, and time to fracture healing were analyzed.
Significantly better outcomes were observed in the temporary-fixation group for visual analog scale score for neck pain, Neck Disability Index, and neck stiffness. The outcomes in the temporary-fixation group was superior to those in the fusion group in all dimensions of the 36-Item Short Form Health Survey. There were no significant differences in fracture healing rate and time to fracture healing between the 2 techniques.
Functional outcomes were significantly better after posterior C1-C2 temporary fixation than after fusion. Temporary fixation can be used as a salvage treatment for an odontoid fracture with an intact transverse ligament in cases of failure of, or contraindication to, anterior screw fixation 6).
Data of twenty patients who underwent posterior temporary-fixation due to Anderson-D’Alonzo type II odontoid fractures with intact transverse ligament were retrospectively reviewed. Another twenty patients undergoing anterior screw fixation were randomly selected as the control group. The range of motion (ROM) in rotation of C1-C2 measured on functional computed tomography (CT) scan and outcomes evaluated by the visual analog scale (VAS) for neck pain, neck stiffness, patient satisfaction, and neck disability index (NDI) were compared between two groups at the final follow-up.
At the final follow-up, 19 cases in each groups achieved facture healing. Total C1-C2 ROM in rotation on both sides in the posterior temporary-fixation group was 32.4 ± 12.5°, smaller than 40.0 ± 13.0 in the anterior fixation group. However, there was no statistical difference between two groups. And there was no significant difference between two groups in functional outcomes evaluated by VAS for neck pain, neck stiffness, patient satisfaction and NDI.
Posterior temporary-fixation can spare the motion of C1-C2 and achieve same good clinical outcomes as anterior screw fixation in the treatment of Anderson-D’Alonzo type II odontoid fractures. It was an ideal alternative strategy to anterior screw fixation 7).
The treatment of type II odontoid fractures in elderly patients is controversial.
Anterior screw fixation is a well-recognized technique that is used to stabilize Type IIB fractures of the odontoid process in the elderly. However, advanced age and osteoporosis are 2 risk factors for pseudarthrosis. Kyphoplasty has been described in the treatment of lytic lesions in C-2. Terraux et al. decided to combine these 2 techniques in the treatment of unstable fractures of the odontoid.
Two approximately 90-year-old patients were treated for this type of fracture. Instability was demonstrated on dynamic radiography in one patient, and the fracture was seen on static radiography in the other.
Clinical parameters, pain, range of motion, 36-Item Short Form Health Survey (SF-36) score (for the first patient), and radiological examinations (CT scans and dynamic radiographs) were studied both before and after surgery. After inflating the balloon both above and below the fracture line, the authors applied a high-viscosity polymethylmethacrylate cement. Some minor leakage of cement was noted in both cases but proved to be harmless. The screws were correctly positioned. The clinical result was excellent, both in terms of pain relief and in the fact that there was no reduction in the SF-36 score. The range of motion remained the same. A follow-up CT scan obtained 1 year later in one of the patients showed no evidence of change in the materials used, and the dynamic radiographs showed no instability. This combination of kyphoplasty and anterior screw fixation of the odontoid seems to be an interesting technique in osteoporotic Type IIB fractures of the odontoid process in the elderly, with good results both clinically and radiologically 8).