Treatment of Dens Fractures with Anterior Screw Fixation.

INTRODUCTION: Direct anterior screw fixation of the dens preserves C1-C2 rotation, and the reported fusion rates range from 88% to 100%. STEP 1 POSITIONING OF THE PATIENT: Exact positioning of the patient and use of image intensifiers are mandatory to obtain perfect anteroposterior and lateral views of the axis. STEP 2 SURGICAL APPROACH: The surgical approach is standardized, and the pretracheal layer can be exposed without violating any essential anatomic structures. STEP 3 ENTRY POINT OF THE SCREW: The perfect entry point is directly anterior-inferior at the base of C2; therefore, the anterior rim of the C2-C3 intervertebral disc must be penetrated. STEP 4 SCREW INSERTION: We use a single cannulated screw in most cases: insert the screw in the center of the dens with its tip perforating the cranial, cortical bone of the dens just posterior to the apex. STEP 5 WOUND CLOSURE: Precise and anatomic closure of the platysma determines the quality of the scar that will be visible after the operation. STEP 6 FOLLOW-UP: The patient wears a rigid collar for six weeks, removing it for body care; radiographic evaluations should be performed regularly. RESULTS: In a study of sixty-nine patients with a fracture of the dens, three of the thirteen patients who underwent direct anterior screw fixation had persistent instability and nonunion of the dens four months after surgery. Indications Contraindications Pitfalls & Challenges.

Treatment of Dens Fractures with Posterior Transarticular Fixation.

INTRODUCTION: Treatment of unstable dens fractures with posterior transarticular C1-C2 arthrodesis provides a biomechanically stable construct, even when poor bone quality is present, and a low rate of complications even in elderly patients; however, when this method of fixation is performed, cervical spine rotation is substantially reduced as compared with that associated with alternative fixation techniques. STEP 1 POSITIONING: Exact positioning of the patient and use of image intensifiers are mandatory to obtain appropriate anteroposterior and lateral views of C1 and C2. STEP 2 SURGICAL APPROACH: Use the modified technique of Magerl and Seemann, as it allows a less extensive approach to C1 and C2, and the drill can enter through two incisions at the level of T1. STEP 3 INSERTION OF SCREWS: Use smooth 2.0-mm Kirschner wires to prepare the canal for the screws, and subsequently replace them with 3.0-mm self-tapping screws. STEP 4 GALLIE FUSION: Perform a modified Gallie fusion, in addition to the transarticular screw fixation, to increase stability and osseous fusion between C1 and C2. STEP 5 WOUND CLOSURE: Perform meticulous closure of the wound to avoid wound-healing complications. RESULTS: In our original study, we treated twenty-five patients with posterior transarticular fixation.IndicationsContraindicationsPitfalls & Challenges.

Treatment algorithm for dens fractures: non-halo immobilization, anterior screw fixation, or posterior transarticular C1-C2 fixation.

BACKGROUND: The appropriate treatment of dens fractures is unclear. We established a staged treatment protocol for dens fractures and conducted a prospective study to evaluate the outcome of treatment based on this protocol. METHODS: We prospectively evaluated sixty-nine consecutive patients who presented to our institution with a dens fracture. The mean duration of follow-up was 9.7 months (range, six to fifty-eight months). Fractures were categorized as stable or unstable. Stable fractures were treated by immobilization in a rigid collar. Patients seventy-five years or older with unstable fractures, patients with a neurological deficit, and patients with Anderson and D'Alonzo type-III fractures underwent posterior transarticular C1-C2 stabilization. Unstable fractures in patients younger than seventy-five years were stabilized with direct anterior screw fixation. Thirty-one patients were treated with a Philadelphia collar, twenty-five with posterior transarticular fixation, and thirteen with direct anterior screw fixation. RESULTS: Fracture-healing or solid fusion of C1-C2 was documented in sixty-eight of sixty-nine treated patients at final follow-up. The remaining patient had a stable nonunion of the dens. Secondary procedures were performed in five patients. CONCLUSIONS: Our treatment algorithm based on dens fracture type, fracture stability, and patient age was associated with a high success rate. Evaluating fracture stability is crucial when considering nonoperative treatment. External stabilization with a rigid cervical collar was adequate for stable fractures of the dens and was associated with a high healing rate. Posterior transarticular screw fixation of C1-C2 was associated with a high success rate, including in elderly patients. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Mini-open percutaneous transarticular screw fixation for acute and late atlantoaxial instability.

The treatment of atlantoaxial instability by means of posterior transarticular screw fixation combined with a Gallie fusion is an established method when direct anterior odontoid screw fixation is not indicated or has failed. In this retrospective study, the results of a modified percutaneous mini-open transarticular C1-C2 screw fixation are presented. Between February 1998 and March 2006, 47 patients with acute or late (after failed conservative treatment) atlantoaxial instability were treated with the modified technique. Their average age was 74.9 years. There were no intraoperative injuries to neural structures or blood vessels; 96.8% of the screws were placed correctly. A revision operation was necessary in one patient because of infection at the graft donor site. No patient experienced a neurological complication. Three patients died during hospitalisation, 6 others later on; 6 could not be traced, leaving thirty-two patients or 68% available for follow-up. The average clinical follow-up was 42 months (range: 12 to 91). The results with respect to the pain and activity status were good or excellent in more than 90% of cases. The radiographic follow-up averaged 25 months (range: 12 to 75). Bony fusion was documented in all cases. The modified technique of transarticular screw fixation presented here is a safe and functionally satisfactory method of achieving stabilisation of the atlantoaxial complex. Special cannulated instruments are not required. This mini-open transcutaneous technique is an alternative to the conventional open procedure, and reduces operation time as well as blood loss.