Posterior C1-C2 fusion for atlantoaxial rotatory fixation after posterior fossa craniotomy in a 4-year old: a case report

INTRODUCTION

This study aimed to highlight that atlantoaxial rotatory fixation (AARF) can be related to neurosurgery procedures in children, with an afterward demonstration of good results after halo-gravity traction and C1-C2 stabilization using the Harms technique.

CASE DESCRIPTION

To the best of our knowledge, this is the first case to report a 4-year-old boy who presented with AARF after a posterior fossa craniotomy to treat a cerebellar astrocytoma. At our medical facility, AARF was diagnosed using plain radiography and computed tomography imaging. The patient was treated with continuous cranial traction for 14 days. Initially, we detected that the patient had no C1 posterior arch or C2 spinous process; therefore, the best option was to perform the Harms technique. Postoperatively, the patient was placed in a cervical collar for 4 weeks. At the 4-year postoperative follow-up, the patient was doing well and had not developed any complications.

CONCLUSION

Herein, we report a case in which AARF can be developed after neurosurgical procedure. Surgical techniques used for atlantoaxial subluxation should be carefully selected. In our case, the Harms technique after cranial traction was an excellent option for correcting and stabilizing the abnormal neck position. However, further studies are required to determine the best technique to use in the pediatric population.

Nuance in Craniovertebral Junction Surgical Approach for Posterior C1-C2 Harms Stabilization: "Window Transposition" of the External Vertebral Venous Plexus for Bloodless C1 Lateral Mass Screw Insertion: Anatomical Aspects and Technical Notes

Atlas and axis instrumentation may be necessary in cases of several craniocervical junction pathologies. According to the Harms technique, C1-C2 polyaxial screws are inserted respectively in the C1 lateral masses and in C2 pedicles. C1 lateral mass screw insertion requires the careful subperiosteal dissection of the posterior elements of C1, the identification of the screw entry point by the downward distraction of C2 nerve root, and the cautious sparing of the overlying posterior external vertebral venous plexus (peVVP), whose bleeding, obstructing the surgical field, is sometimes barely controlled by hemostatic agents and swabbing. The authors describe in detail the anatomical aspects of an alternative surgical technique developed for the microsurgical transposition of the C1-C2 interposed external vertebral venous plexus in the case of Harms C1-C2 screw stabilization. The longitudinal median incision of the atlantoaxial membrane, followed by bilateral subperiosteal dissection and microsurgical section respectively at the inferior borders of the C1 laminae and at the superior borders of the C2 laminae, allows, as a "window opening," the symmetrical mediolateral transposition of the peVVP. This procedure provides a faster and cleaner anatomical exposition of the posterior surface of the C1 lateral mass and the C2 isthmus, preventing troublesome intraoperative venous bleeding that hinders C1 lateral mass screw insertion.

Trends in the surgical management of odontoid fractures in patients above 75 years of age: Retrospective study of 70 cases

BACKGROUND

Odontoid fractures are the most common upper cervical spine fracture in adults over 70 years of age. Hence, treatment of these fractures has public health implications.

OBJECTIVES

Evaluate the early complications, bone healing and mortality in patients above 75 years of age who undergo surgical treatment of an odontoid fracture. Compare the results between patients operated with the Harms technique or anterior screw fixation.

METHODS

This was a retrospective study of 70 patients with an odontoid fracture who were treated surgically between 2000 and 2015 at the Hôpital de la Timone in France. The age at the time of diagnosis, comorbidities, ASA score and autonomy were evaluated. Bone healing was determined using computed tomography.

RESULTS

In the cohort, 22 patients underwent anterior screw fixation, 38 were treated using the Harms technique and 10 with other procedures. The average age was 85.1 years. Fifty-four percent of patients had an ASA score above 3. The average follow-up was 23.4 months. An Anderson type II fracture was present in 80.6% of patients. In the anterior screw fixation group, the operative time was significantly shorter than in the Harms group and no blood transfusions were needed. However, 13.6% of these patients had to be re-operated because the initial construct was unstable; no patients in the Harms group underwent revision surgery. There were more complications in the anterior screw fixation group than in the Harms group: 41% versus 13.2% (P<0.02). The fractures had healed in all patients reviewed after 1 year. The 3-month survival in the anterior screw fixation group was 64.7% and it was 81.3% in the Harms group. These rates were stable at 1 year with no statistical differences between groups.

CONCLUSION

Surgical treatment of odontoid fractures in the elderly results in an excellent union rate. The mortality rate is stable after 3 months. In our experience, the Harms technique has a lower risk of complications and better mechanical stability than anterior screw fixation. Despite the steep learning curve, we believe the Harms technique is probably the best choice for treating odontoid fractures in the elderly.

LEVEL OF EVIDENCE

IV.

Comparison between C1-2 Fixation with and without Supplemental Posterior Wiring

Study Design Retrospective analysis. Clinical Question Is there a difference between the screw-rod construct (SRC) procedure without wiring and the SRC procedure with wiring with respect to fusion, implant failure, reoperation, donor-site morbidity, and complication rates? Patients and Methods We performed a retrospective analysis of 26 patients who underwent C1-2 fixation between 2004 and 2012 (SRC with wiring and structural bone graft, 13 patients; SRC with autograft but without wiring, 13 patients). Fusion was assessed using dynamic X-rays in all patients and computed tomographic scans in selected cases. Pseudoarthrosis was confirmed during reoperation. Results The mean follow-up time was 2 years and 5 months for the SRC without wiring group and 2 years and 1 month for the SRC with wiring group. Patients with less than 1-year follow-up time were excluded. The fusion rate, implant failure rate, and reoperation rates for the SRC without wiring group were 92, 8, and 8%, respectively. The fusion, implant failure, and reoperation rates for the SRC with wiring group were 100, 0, and 0%, respectively. There were no donor-site morbidities or complications in either group (both 0%). There were no differences in parameters we examined between the two groups (p > 0.05 for each rate, Fisher exact test). Conclusions The results suggest that supplementing the SRC procedure with wiring may increase fusion rate, but this difference is not statistically significant. Although the sample size was small, there was not a significant discrepancy in outcomes between the two groups at an average follow-up of 2 years. [Table: see text].

Rod migration into the posterior fossa after harms operation : case report and review of literatures

C1 lateral mass and C2 pedicle (C1LM-C2P) fixation is a relatively new technique for atlantoaxial stabilization. Complications from C1LM-C2P fixation have been rarely reported. The authors report unilateral rod migration into the posterior fossa as a rare complication after this posterior C1-C2 stabilization technique. A 23-year-old man suffered severe head trauma and cervical spine injury after vehicle accident. He was unconscious for 2 months and regained consciousness. He underwent C1LM-C2P fixation for stabilization of type II odontoid process fracture described by Harms. The patient recovered without a major complication. Twenty months after operation, brain computed tomogram performed at psychology department for disability evaluation showed rod migration into the right cerebellar hemisphere. The patient had mild occipital headache and dizziness only regarding the misplaced rod. He refused further operation for rod removal. To our knowledge, this complication is the first report regarding rod migration after Harms method. We should be kept in mind the possibility of rod migration, and C1LM-C2P fixation should be performed with meticulous technique and long-term follow-up.