The lasso technique for posterior C1-C2 fusion

Area of Science:

• Neurosurgery
• Orthopedic Surgery
• Spinal Fusion Techniques

Background:

• Posterior atlantoaxial arthrodesis necessitates a prepared bony environment for successful bone graft fusion.
• Existing techniques for posterior atlantoaxial arthrodesis typically require an intact posterior arch of the first cervical vertebra (C1).
• Patients with congenital, iatrogenic, or traumatic defects of the C1 posterior arch face challenges in achieving atlantoaxial fusion.

Purpose of the Study:

• To introduce and describe the "lasso technique" for posterior atlantoaxial arthrodesis.
• To present a method for securing bone grafts in patients with absent or incompetent C1 posterior arches.
• To evaluate the efficacy of the lasso technique in achieving C1-C2 fusion.

Main Methods:

• A retrospective review of patients who underwent the lasso technique was performed.
• The study recorded clinical and radiographic history, perioperative course, and time to fusion.
• The detailed surgical procedure of the lasso technique was described.

Main Results:

• The lasso technique was successfully employed in nine patients (five female, four male) over 13 years.
• Indications for the technique included congenital defects (1), prior surgery (4), and fractures from failed fusions (4).
• All patients achieved successful bony fusion, with an average fusion time of 6.8 months.

Conclusions:

• The lasso technique offers a viable solution for bone graft fixation in atlantoaxial instability when the C1 lamina is compromised.
• This method utilizes the remaining posterior atlantal arch to secure an interpositional C1-C2 graft.
• Despite infrequent use, the lasso technique has proven valuable and effective for achieving atlantoaxial fusion in challenging cases.