Anterior C1-C2 Screw Fixation and Bony Fusion Through an Anterior Retropharyngeal Approach

Abstract

We present a case that demonstrates an occasion where an alternative method of Cl -C2 fusion may be used when a posterior approach limited to the atlantoaxial level is not desirable. A 22-year-old man presented with a symptomatic nonunited Brooks posterior atlantoaxial fusion following a chronically displaced type Il odontoid fracture with a two-part fracture of the posterior arch of Cl . An anterior retropharyngeal approach was used to perform an anterior Cl - C2 fusion with screw fixation. The surgical technique, as well as the merits and indications of this infrequently used procedure, are discussed.

Percutaneous anterior transarticular screw fixation for atlantoaxial instability

“…This has been shown to achieve a similar degree of biomechanical stability as percutaneous transarticular screw fixation 7,8 and subsequent reports have shown a high rate of clinical success. [10][11][12][13][14][15] These open procedures require extensive dissection and care has to be taken to avoid injuring the adjacent nerves and blood vessels. The wounds also need to be drained post-operatively.…”

10 C1–C2 Cervical Transarticular Screw Fixation

“…In a certain subset of patients, when a posterior approach is not feasible the anterior C1-C2 transarticular technique described in this chapter by an anterior retropharyngeal approach or as performed and reported by Reindl et al, via a more familiar Smith-Robinson approach, appears to be relatively safe and straightforward. 8,11 This is accomplished with biplanar fluoroscopic guidance utilizing the Synframe retractor system via a Smith-Robinson approach. 8 The initial K-wires are placed 5 mm from the lateral aspect of the odontoid base and angled 25 degrees in a medial to lateral direction across the C1-C2 articulation.…”

“…8,9 More recently the approach has been described by Lu et al 10 in a cadaveric study, and used clinically by Vaccaro et al in a patient with a nonunited Brooks posterior atlantoaxial fusion following a chronically displaced type II odontoid fracture with a two-part fracture of the C1 posterior arch. 11 This infrequently used approach also utilizes a bilateral approach with little known about long-term outcomes and complications. The anterior retropharyngeal approach is technically more demanding than the other anterior or posterior methods.…”

11 C1–C2 Anterior Plate Fixation

“…These include anterior transarticular screw fixation discussed in another chapter and anterior C1-C2 plate application. 7,9,[12][13][14][15] Indications include certain fracture patterns involving the C1-C2 posterior elements, odontoid fracture nonunions, C1-C2 instability seen in rheumatoid arthritis with or without decompression, basilar impression, os odontoideum, and tumor resection involving the dens. Posterior transarticular screw placement requires a certain patient body habitus to place the acutely angled screws.…”

“…6,7 This approach has been described more recently by Vaccaro et al as an alternative salvage procedure in a patient with a nonunited C1-C2 posterior midline fusion with a displaced type II odontoid fracture and a two-part fracture involving the C1 posterior arch. 8,9 In this patient C1-C2 anterior transarticular screw fixation was performed instead of plating. The approach utilizes a posterior submandibular skin incision 2 cm lateral from the anterior midline curving around the mandibular angle toward the mastoid process ( Fig.…”