Anterior transcervical release with posterior atlantoaxial fixation for neglected malunited type II odontoid fractures

Abstract

Background: Type 2 odontoid fractures are associated with a high rate of nonunion without surgical treatment. If neglected, they may become fixed in an abnormal position, causing progressive myelopathy. Conventionally, odontoidectomy or transoral release is performed to relieve symptoms in such cases. Here, were report our experience with a transcervical approach for odontoid release (i.e., of a chronically fractured dens) followed by a posterior C1-C2 fusion.

Methods: The 11 patients (2017-2021) retrospectively included; in this study, all had a history of remote trauma and the radiological appearance of an old odontoid fracture that was displaced and could not be reduced with traction. There were eight males and three females who averaged 52.6 years of age.

Results: All 11 patients underwent anterior retropharyngeal release with a C4-C5 level incision followed by a posterior C1-C2 fusion. The mean Japanese orthopedic association on presentation was 9.9 ± 2.7 which improved to 13.8 ± 2.7 on final follow-up (P < 0.01). Patients were followed an average of 9.6 months ± 4.4 (mean ± SD) postoperatively during which time they all clinically improved.

Conclusion: Anterior release through a retropharyngeal approach coupled with posterior C1-C2 instrumentation proved to be an effective alternative to the traditional transoral approach to treat a chronic malunited odontoid fracture.

Keywords: Atlantoaxial instability; IAAD; Irreducible atlantoaxial dislocation; Irreducible dislocation; Odontoid fracture.

Figure 1:

(a) Intraoperative X-ray with patient in supine position. Anterior arch of atlas confirmed with lateral image. (b) Small curette inserted between C2 vertebral body and lower surface of fractured odontoid after release. The surfaces are being prepared for fusion. (c and d) Patient in prone position. C1 Lateral mass and C2 pedicle screws inserted.

Figure 2:

A 60-year-old male with a history of bike accident 7 year ago presented on a wheel chair with a history of progressive weakness and numbness in all four limbs for the past 6 months. (a and b) Preoperative CT and MRI shows old type 2 odontoid fracture with anterolisthesis of C1/odontoid complex on C2 body and some bony fusion with significant cord compression and signal changes. (c and d) Sagittal and coronal CT scan taken in the immediate postoperative period showing alignment of the released odontoid. (e and f) Sagittal and parasagittal CT cuts taken at 1-year postoperative show that the alignment is maintained.

Figure 3:

A 56-year-old man presented with clumsy hands, difficulty micturition, and gait disturbance for the past 1 year. The patient had a history of motor vehicle accident with neck injury 15 years ago. (a) Extension lateral radiograph, (b) midsagittal CT scan shows old odontoid type 2 fracture fixed in anterolisthesis and resultant spinal canal narrowing, (c) immediate postoperative X-ray to confirm alignment and screw position and (d and e) coronal and sagittal CT scan taken at 6 months follow-up showing the alignment is maintained.

Figure 4:

A 37-year-old male with a history of neck pain and clicking, which started after a fall at a construction site 3 years ago presented with progressive upper and lower limb weakness and impaired bowel bladder function. (a and b) Sagittal, parasagittal preoperative views with fixed anterolisthesis of odontoid over C2 body and resultant canal narrowing. (c) Sagittal MRI shows extreme cord compression. (d and e) Flexion and extension radiographs show irreducibility atlantoaxial dislocation. (f) Intraoperative image of posterior C1–C2 fixation being done in the patient following release of odontoid. (g) Postoperative CT showing reduction of the displaced odontoid.