Surgical Outcomes of the Ossification of the Posterior Longitudinal Ligament According to the Involvement of the C2 Segment

Abstract

Objective: The complex structure around the upper cervical spine makes surgical treatment difficult. the present study aimed to analyze how patients with ossification of the longitudinal ligament (OPLL) involving the C2 were managed and to compare the surgical outcomes according to the C2 involvement.

Methods: Ninety-five patients with cervical OPLL who underwent surgical treatment were divided into C2 involvement (C2+ group, 40 patients) or none (C2- group, 55 patients). In the C2+ group, subanalysis was conducted to according to the C2 surgery (C2 surgery+ group, 14 patients).

Results: All patients had a minimum of 1 year of follow-up with a mean of 51.36 months. The most common location of the narrowest space available for the spinal cord was C2 and C5 in the C2+ and C2- groups, respectively. In the C2+ group, a longer OPLL with thickened diameter was radiographically demonstrated, but clinical outcomes were not different from the C2- group. In the C2 surgery+ group, the narrowest spinal cord was common in the C2 (50.0%), and an extension of the signal change of spinal cord to the C2 was observed in 4 patients, showing a statistical difference. C2 surgery was performed in all patients using the posterior approach and it did not result in different clinical outcomes or surgery-related complications. An anterior surgical approach was deemed risky given the chance of the development of complications.

Conclusions: Both of C2 involvement from OPLL and surgery including the C2 did not affect clinical outcomes. The posterior decompressive surgery is safer and more effective than the anterior approach regarding the development of surgery-related complications.

Keywords: C2; Decompressive surgery; Ossification of the posterior longitudinal ligament; Upper cervical spine.