The efficacy of the Magerl technique combined with unilateral laminar clamp instrumentation for reducible atlantoaxial dislocation

English Keywords:Atlantoaxial dislocation  Internal fixators  Spinal fusion

English Abstract:

  【Abstract】 Objectives: To evaluate the early-middle stage clinical efficacy of posterior atlantoaxial facet screw(Magerl technique) combined with unilateral laminar clamp instrumentation for reducible atlantoaxial dislocation. Methods: From May 2004 to December 2010, 8 cases with reducible atlantoaxial dislocation underwent the combination of Magerl technique and unilateral laminar clamp instrumentation. There were 6 males and 2 females with an average age of 41.6 years old(range, 35 to 63 years). The pathogenesis included 2 acute traumatic dislocations, 3 old traumatic dislocations and 3 dislocations due to congenital deformity. The preoperative symptoms included occipital-cervical pain in 5 cases, torticollis in 4 cases and high level spinal cord compression in 5 cases. Preoperative spinal cord function evaluated by Frankel classifications was showed as following: Frankel D in 5 cases and Frankel E in 3 cases. 3 irreducible cases were subject to preoperative skull traction, and X-ray was taken every 2 days. 1 case achieved reduction after one-direction skull traction, while two cases underwent two-direction traction due to irresponsible to one-direction traction with maximal weight. The operations were performed after good reduction of C1-2. The UCSS screws by Margel technique were used in all cases together with Apofix and Vertex laminar clamps in 4 patients respectively. The perioperative and follow-up indexes included operation time, intraoperative blood loss, postoperative neurologic function and intra-/postoperative complications. Results: The average operation time was 106min(range, 75 to 160min). The average intraoperative blood loss was 200ml(range, 80 to 550ml). No cerebrospinal fluid leakage or neurological deficit was noted. Delayed healing of skin incision was noted in 1 case. All patients had neck pain and torticollis relieved after operation, and of 5 cases with preoperative Frankel D, 2 cases recovered to Frankel E while 3 cases remained unchanged. The average follow-up was 16.8 months(range, 10-35 months). Bone fusions were achieved in all patients with the average time of fusion of 5.6±0.5 months(range, 4-8 months). No instrument failure was noted during follow-up. Conclusions: For reducible C1-2 dislocation, Magerl technique combined with unilateral laminar clamp instrumentation is simple and reliable for early and middle stage.