Unilateral lag-screw technique for an isolated anterior 1/4 atlas fracture

Abstract

Study Design:Fractures of the atlas are classified based on the fracture location and associated ligamentous injury. Among patients with atlas fractures treated using external immobilization, nonunion of the fracture could be seen.Objective:Ideally, treatment strategy for an unstable atlas fracture would involve limited fixation to maintain the fracture fragments in a reduced position without restricting the range of motion (ROM) of the atlantoaxial and atlantooccipital joints.Summary of Background Data:Such a result can be established using either transoral limited internal fixation or limited posterior lateral mass fixation. However, due to high infection risk and technical difficulty, posterior approaches are preferred but none of these techniques can fully address anterior 1/4 atlas fractures such as in this case.Materials and Methods:A novel open and direct technique in which a unilateral lag screw was placed to reduce and stabilize a progressively widening isolated right-sided anterior 1/4 single fracture of C1 that was initially treated with a rigid cervical collar is described.Results:Radiological studies made after the surgery showed no implant failure, good cervical alignment, and good reduction with fusion of C1.Conclusions:It is suggested that isolated C1 fractures can be surgically reduced and immobilized using a lateral compression screw to allow union and maintain both C1-0 and C1-2 motions, and in our knowledge this is the first description of the use of a lag screw to achieve reduction of distracted anterior 1/4 fracture fragments of the C1 from a posterior approach. This technique has the potential to become a valuable adjunct to the surgeon's armamentarium, in our opinion, only for fractures with distracted or comminuted fragments whose alignment would not be expected to significantly change with classical lateral mass screw reduction.

Epidemiology and management of atlas fractures

“…The literature mainly recommends conservative treatment for isolated fractures of the lateral masses [10]. However, recent studies observed frequently a lateral displacement of the lateral mass fragments associated with subluxation of the occipital condyle resulting in neck pain, head malposition and impaired head rotation [17]. Hence, some guidelines advocate for surgery in Gehweiler 4 fractures with joint incongruency [9,18].…”

Treatment of Atlas Fractures: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU)

“…As an alternative, a unilateral lag screw osteosynthesis has been described in oblique fracture patterns without comminution. 22 In temporary occipito-cervical stabilizations the implants should be removed after bony healing of the atlas fracture to allow for regaining motion. In case of an inadequate healing and an occipito-atlantal or atlanto-axial joint incongruity under halo-traction resulting in a symptomatic nonunion, fusion of the affected motion segments is recommended to prevent the patient from persistent pain caused by posttraumatic arthritis.…”

Lag-Screw Osteosynthesis in Thoracolumbar Pincer Fractures

“…The lag-screw principle in combination with anti-rotational plates is common in long-bone fractures, as lag-screws reduce the threat of a non-union. However, besides case reports dealing with cervical spine fractures, 26 this principle has no relevance in spine surgery so far. Obviously, a lag-screw osteosynthesis is out of the question in most vertebral fractures; however, keeping in mind the fracture-morphology both split and pincer fractures could benefit from this treatment.…”