Introduction: Multiple methods for C1-2 arthrodesis have been described. The use of a polyaxial screw and rod construct was popularized by Harms and Melcher in 2001. However, the placement of C1 lateral mass screws increases the risk of venous blood loss and injury to the C2 nerve root. The authors describe a technique for placement of C1 lateral mass screws using a Steinmann pin as a guide. The drill is inserted over the pins with a smooth protected guide canula over the drill bit minimizing dissection and providing atlantoaxial stabilization during arthrodesis.
Methods: In our technique, a non-threaded 1.6mm spade-tip Steinmann pin is placed into the lateral mass of C1 to serve as a guide over which a powered drill is used for screw insertion. Perioperative data were collected for 93 consecutive patients who underwent a C1-2 arthrodesis that involved the modified technique between March 2010 and July 2016. Data included blood loss, operative times, and C2 nerve root injury.
Results: The data for 93 patients were reviewed. Most (91.4%) patients presented with a fracture from an acute trauma. A mean of 1.97 levels was fused in these patients with a mean blood loss of 76 ml and a mean operative time of 144 minutes. The overall morbidity and mortality rate was 10.7%. The morbidity rate of 7.5% included 30 day postoperative respiratory failure and dysphasia. There were no postoperative vertebral artery injuries, hardware failures, or instances of occipital neuralgia.
Conclusions: The use of Steinmann pins to guide the placement of C1 lateral mass screws is safe and effective in C1-2 arthrodesis. Limiting dissection minimizes blood loss and injury, maintains efficient operative time, and assists in accurate placement of the screws. With less manipulation and retraction of the C2 nerve root, postoperative occipital neuralgia and the need for C2 root transection are avoided.
Patient Care: This research will be able to expand the options available for safe and effective placement of C1 lateral mass screws. By minimizing blood loss, operative time, injury to the soft tissues, and C2 nerve root retractions patients can experience safe and effective C1-2 arthrodesis.
Learning Objectives: By the conclusion of this session, participants should be able to 1. Describe the method of C1 lateral mass screw placement using Steinmann pins. 2. Discuss the perioperative complications associated with its use 3. Discuss the intraoperative advantages including operative time, blood loss, and C2 root injury.
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