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

Abstract

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.

Final class of evidence (CoE)—treatment	Yes
Study Design
RCT
Cohort	X
Case-control
Case series
Methods
Concealed allocation (RCT)
Intention to treat (RCT)
Blinded/independent evaluation of primary outcome
F/U ≥ 85%
Adequate sample size
Control for confounding
Overall class of evidence	III

Keywords

SRC - posterior wiring - Harms technique - atlantoaxial instability - C1 - C2 - fusion - screw rod construct

• References

• 1 Elliott RE, Tanweer O, Boah A , et al. Atlantoaxial Fusion with Screw-Rod Constructs: Meta-Analysis and Review of Literature. World Neurosurg 2012; 8750 (12) 412-417
• 2 Harms J, Melcher RP. Posterior C1-C2 fusion with polyaxial screw and rod fixation. Spine (Phila Pa 1976) 2001; 26 (22) 2467-2471
• 3 Sonntag VK. Atlantoaxial stabilization: a minimally invasive alternative. World Neurosurg 2013; 80 (3-4) 315-316
• 4 Mummaneni PV, Haid RW. Atlantoaxial fixation: overview of all techniques. Neurol India 2005; 53 (4) 408-415