Anterior screw fixation of posteriorly displaced type II odontoid fractures

Abstract

Posteriorly displaced Type II odontoid fractures (Type II-P) are difficult to stabilize in an anatomic position with accepted methods of posterior atlantoaxial arthrodesis. Nine patients with Type II-P odontoid fractures with 4 to 15 mm displacement were treated with anterior odontoid screw stabilization. Seven of these patients had associated fractures or defects of the posterior arch of the first cervical vertebra (C1). Atlantoaxial posterior arthrodesis in these patients would not have been possible initially because of the lack of structural integrity of the posterior arch of C1. Two patients, later in the study, had no injury to the ring of C1. The odontoid fractures were stabilized with two 4.0-mm cancellous screws inserted through an anterior approach to the neck under fluoroscopic control with the skin incision at the C5 level. Preoperative reduction of the displaced odontoid process and immediate operative stability of the atlantoaxial complex were obtained in each case. No neurological complications related to the procedure occurred. Two patients died of causes unrelated to their cervical fracture surgery. The 7 patients who survived were followed for a minimum of 6 months. Fracture union and cervical stability were demonstrated in each of the surviving patients, without evidence of screw loosening or loss of fixation. Normal range of motion of the neck was documented at follow-up in all surviving patients. Although this series represents a limited experience with this treatment technique, anterior odontoid screw fixation has significant advantages over accepted methods of cervical stabilization for Type II-P odontoid fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of Long-Term Follow-Up in Patients Undergoing Anterior Screw Fixation for Type II and Rostral Type III Odontoid Fractures

“…With these limitations in mind, we used strict radiographic criteria for defining fusion because this had been done in previously reported clinical series of anterior odontoid screw fixation. 30,37,38,45,48,53,56,57 In our series, the long-term fusion rate (87%) was comparable with the reported ones from other large but short-term clinical series. Aebi et al, 30 using rigid radiographic fusion criteria similar to ours, reported an 88% fusion rate in a large series of type II and "shallow" type III odontoid fractures; the same fusion rate was accomplished by Apfelbaum et al 48 In a large clinical series, Henry et al 57 reported a 92% radiographically proven fusion rate; although it is noteworthy that in their series, patients with only acute type II and type III odontoid fractures were included.…”

“…In a retrospective study, Subach et al 53 reported a 96% fusion rate in treating acute only, type II odontoid fractures. Similarly, in a limited series, Geisler et al, 38 and, in a short-term follow-up study, ElSaghir et al 56 reported a 100% fusion rate.…”

“…Detailed description of the surgical technique can be found in previously published technical reports. 30,37,38,48,[51][52][53] A specially designed instrument kit (SyntheSpine, Paoli, PA) was used in our cases. After insertion of the odontoid screw (Figures 1-3, available for viewing on ArticlePlus), meticulous hemostasis and vigorous antibiotic irrigation are used, and the surgical wound is closed in anatomic layers.…”

The Contemporary Treatment of Odontoid Injuries

“…Despite these contraindications, multiple clinical studies have documented odontoid fracture fusion rates that ranged from 83% to 100% following anterior screw placement for the appropriately selected patient. 24,25,43,65,73 Odontoid nonunion may also be successfully treated and salvaged with anterior odontoid screw fixation, but appropriate patient counseling should occur regarding the higher risk of treatment failure and persistent nonunion.…”

Management of acute odontoid fractures with single anterior screw fixation

“…[2][3][4][5][6][7] The high rate of non-union following non-surgical management has resulted in a gradual shift towards surgical treatment. [8][9][10][11][12][13] Presently, external immobilisation alone is generally reserved for patients with concomitant injuries or medical conditions that preclude surgery or are associated with unacceptable surgical risks. 14 Various internal fixation methods have been described to treat acute type II and rostral type III odontoid fractures.…”