Distraction Arthrodesis of the Atlantoaxial Facet Joint with Preservation of the C2 Root for the Management of Intractable Occipital Neuralgia Caused by C2 Root Compression

Abstract

IntroductionVertical collapse of the C1-C2 facet joint may cause narrowing of the C2 root foramen with root compression, resulting in severe occipital neuralgia. The purpose of this study was to evaluate the prospectively collected outcomes data of a distraction arthrodesis surgical group (Study group) in comparison to a Control group in a non-randomized design. Material and MethodsThe Study group underwent intraoperative skeletal traction, preservation of the C2 nerve roots, facet joint distraction and insertion of a bone block and cancellous bone into the joint along with posterior fusion, and segmental screw fixation using posterior C1 arch screws instead of lateral mass screws. The Control group had C2 root transection with C1-C2 segmental screw fixation and arthrodesis. Inclusion criteria for both groups were (1) occipital neuralgia caused by C2 root compression confirmed by clinical manifestation and imaging studies including radiographs, CT scan, and MRI, (2) intractable pain (VAS≥7) unresponsive to nonoperative treatment, and (3) follow-up period ≥12 months. We compared the preoperative and postoperative 10-point VAS scores for occipital neuralgia and neck pain; NDI; and JOA scores and recovery rates. ResultsThere were 15 patients in the Study group and 8 in the Control group. All had facet joint destruction and/or collapse caused by underlying disorders including rheumatoid arthritis (Study group: 5 ; Control group: 3), rheumatoid arthritis with odontoid nonunion (2, 0), odontoid nonunion (3, 1), unifacet spondylosis (3, 2), os odontoideum (2, 1), and cerebral palsy (0, 1). There was no significant difference in age (61 ± 6, 62 ± 9), gender (4 and 3 men, respectively), and the number of cases with accompanying myelopathy (5, 2) between the 2 groups. The follow-up period averaged 21 ± 12 versus 33 ± 25 months, respectively. There was no significant difference in the VAS score for the preoperative occipital neuralgia (8.2 ± 0.9, 7.9 ± 0.6, p = 0.39). However, it was significantly lower in the Study group at 1, 3, 6, and 12 months postoperatively (p = <0.01, respectively). At 12 months, the VAS was 0.4 ± 0.6 versus 2.5 ± 2.6 (p = 0.01). In the Study group, all patients had little or no pain (VAS ≤2) while 2 patients (25%) in the Control group were still on medication (Gabapentin) with moderate to severe pain (VAS 4 and 8 respectively). There was no significant difference in preoperative and postoperative VAS scores for neck pain, NDI, and JOA scores and recovery rate, since these values are minimally influenced by occipital neuralgia. ConclusionOur results suggest that our novel technique of distraction arthrodesis can be an effective option for the management of intractable occipital neuralgia caused by C2 root compression. Prospective randomized studies are required for better evaluation.