Posterior atlantoaxial fixation: A cadaveric and fluoroscopic step-by-step technical guide

C1-C2 Pedicle Screw Fixation for Pediatric Atlantoaxial Dislocation: Initial Results and Long-term Follow-up

BACKGROUND

There are few studies reporting the use of atlantoaxial pedicle screws and the long-term effects of C1-C2 posterior fusion in children. Our study is to investigate the initial results of C1-C2 pedicle screw fixation for pediatric atlantoaxial dislocation (AAD) and assessed spontaneous change of postoperative radiography after a long-term follow-up period.

METHODS

Posterior pedicle screw fixations were performed in 21 pediatric patients with AAD. All the patients underwent implant removal 1 year after their initial surgery and had regular follow-up with an average duration of 76.4 months (range, 52 to 117 mo). Clinical and radiographic data were then collected and compared.

RESULTS

Frankel Grade was significantly improved at 3 months follow-up compared with pretreatment values. All patients had good bony fusion at a mean of 4.2±0.9 months (range, 3 to 6 mo) after treatment. None of the patients experienced worsening neurological symptoms or injury to the vertebral artery. However, 2 cases experienced minor complications. Following removal of the implants, no spinal deformities or subaxial instabilities were found. The mean angle of sagittal curvature increased from 12.1±2.4 degrees (range, 0 to 22 degrees) immediately postoperatively to 19.1±2.7 degrees (range, 6 to 31 degrees) at the final follow-up (P>0.05).

CONCLUSIONS

The results demonstrated that C1-C2 pedicle screw fixation could achieve satisfactory initial results for the management of the pediatric AAD. Moreover, removal of the metal implant after bony fusion did not increase the risk of spinal deformity or subaxial instability at long-term follow-up.

Management of Combined Atlas Fracture with Type II Odontoid Fracture: A Review of 21 Cases

PURPOSE

To evaluate the therapeutic effects of combined atlas fracture with type II (C₁-type II) odontoid fractures and to outline a management strategy for it.

PATIENTS AND METHODS

Twenty three patients with C₁-type II odontoid fractures were treated according to our management strategy. Nonoperative external immobilization in the form of cervical collar and halo vest was used in 13 patients with stable atlantoaxial joint. Surgical treatment was early performed in 10 patients whose fractures with traumatic transverse atlantal ligament disruption or atlantoaxial instability. The visual analog scale (VAS), neck disability index (NDI) scale, and American Spinal Injury Association (ASIA) scale at each stage of followup were then collected and compared.

RESULTS

Compared to pretreatment, the VAS score, NDI score, and ASIA scale were improved among both groups at followup evaluation after treatment. However, in the nonsurgical group, one patient (1/11) developed nonunion which required surgical treatment in later stage and one patient (1/13) with halo vest immobilization had happened pin site infection. Two patients of the surgical group (2/11) had appeared minor complications: occipital cervical pain in one case and cerebrospinal fluid leakage in one case. Two patients (2/23) were excluded from nonsurgical treatment group because their followup period was less than 12 months. Twenty one patients were followed up regularly with an average of 23.9 months (range 15-45 months).

CONCLUSIONS

We outlined our concluding management principle for the treatment of C₁-type II odontoid fractures based on the nature of C₁ fracture and atlantoaxial stability. The treatment principle can obtain satisfactory results for the management of C₁-type II odontoid fractures.

Prognostic factors in traumatic atlanto-occipital dislocation

Traumatic atlanto-occipital dislocation (AOD) is an ominous injury with high mortality and morbidity in trauma patients. Improved survival has been observed with advancements in pre-hospital and hospital care. Furthermore, high quality imaging studies are accessible at most trauma centers; these are crucial for prompt diagnosis of AOD. The objective of this study is to perform a comprehensive literature review of traumatic AOD, with specific emphasis on identifying prognostic factors for survival. A review of the literature was performed using the Medline database for all traumatic atlanto-occipital articles published between March 1959 and June 2015; 141 patients from 60 total studies met eligibility criteria for study inclusion. A binary logistic regression model was utilized to identify prognostic factors. The analysis assessed age, sex, spinal cord injury (SCI), traumatic brain injury (TBI), polytrauma injury (PI), and Traynelis AOD Classification. Only TBI was statistically significantly associated with death (OR 8.05 p<0.05); SCI did not reach statistical significance for predicting mortality in AOD patients (OR 1.25 p>0.05). Age, sex, PI, and Traynelis AOD Classification did not meet significance to predict mortality in AOD patients. We found that patients with TBI are eight times more likely to die than patients without TBI. A high degree of suspicion for AOD during pre-hospital care, as well as, prompt diagnosis and management in the trauma center play a key role in the treatment of this devastating injury. The relationship between survival and factors such as TBI and SCI should be further explored.

C1 fractures: a review of diagnoses, management options, and outcomes

The atlas is subject to fracture under axial load, often due to traumatic injuries such as shallow dives and automobile accidents. These fractures account for 2-13 % of injuries to the cervical spine [Marcon RM et al. Clinics (Sao Paulo) 68(11):1455-61, 2013]. Fractures of the C1 vertebra are often difficult to diagnose, as there is often no neurological deficit or easily identifiable findings on radiographs. However, injuries to the atlas can be associated with vertebral artery injury and atlantoaxial or atlanto-occipital instability, making prompt and accurate diagnosis imperative. A detailed understanding of the anatomy, inherent stability, and common injury patterns is essential for any surgeon treating spinal trauma. This chapter explores the diagnosis and management of C1 fractures, as well as outcomes after treatment.

Management of combined atlas-axis fractures: a review of forty one cases

PURPOSE

To outline a management principle for the combined atlas (C1)-axis (C2) fractures and assess its therapeutic effects.

METHODS

Forty-one patients with combined C1-C2 fractures were treated according to their C2 fracture types. Non-operative external immobilization in the form of a cervical collar or halo vest was used in 22 patients. Early posterior pedicle screw fixations were performed in 19 patients whose fractures had a combination of any of the three conditions: an atlantodens interval (ADI) ≥ 5 mm, lateral mass displacement (LMD) > 7 mm, and/or C2-C3 angulation > 11°. Thirty-nine patients were followed up regularly with an average of 19.3 months (range, 12 to 45 months). Clinical and radiographic data were then collected and compared.

RESULTS

At three months following treatment, patients' visual analog scale (VAS), Neck Disability Index (NDI), American Spinal Injury Association (ASIA) scale, and Frankel grades were all significantly improved when compared to pretreatment. These results indicated that the cervical collar, halo vest, and posterior pedicle screw fixation approaches were all able to effectively treat cases of combined C1-C2 fractures. One patient in the non-surgical group developed nonunion which required late surgical treatment and one patient had pin site infection in the non-surgical group (2/22), while there were three minor complications in the surgical group.

CONCLUSION

We propose a management principle that bases the treatment of a combined C1-C2 fracture on the nature of the C2 fracture. This treatment strategy has yielded promising results as a satisfactory means for the management of combined C1-C2 fractures.