Navigated Osteosynthesis for Unstable Atlas Fractures: Technical Note and Case Series

Area of Science:

• Orthopedic surgery
• Neurosurgery
• Trauma surgery

Background:

• Atlas fractures require assessment of transverse ligament integrity to determine stability.
• Unstable atlas fractures with ligament disruption often necessitate surgical intervention, traditionally atlantoaxial fusion.
• Atlas osteosynthesis presents a motion-preserving alternative to fusion for treating unstable atlas fractures.

Purpose of the Study:

• To evaluate the efficacy and safety of navigated posterior atlas osteosynthesis for unstable C1 fractures.
• To assess outcomes including fracture healing, alignment, and the need for revision surgery.

Main Methods:

• Retrospective review of eight patients with unstable atlas fractures treated with navigated posterior atlas osteosynthesis.
• Assessment of clinical presentation, surgical technique, and postoperative outcomes via serial radiographs and CT scans.

Main Results:

• All eight patients had transverse ligament injuries (Dickman type I or II).
• Postoperative radiographs showed preserved alignment with no significant change in the atlantodental interval.
• CT scans confirmed osseous union in six patients, with no hardware complications or need for fusion.

Conclusions:

• Navigated atlas osteosynthesis is an effective motion-preserving treatment for unstable atlas fractures, including those with Dickman type I and II transverse ligament injuries.
• This technique avoids the morbidity associated with atlantoaxial fusion.
• Intraoperative navigation is beneficial for precise screw placement in complex, distorted anatomy.