Chronic atlantoaxial rotatory fixation with neurofibromatosis type I: A case report

Abstract

Background: Atlantoaxial rotatory fixation (AARF) can be caused by infection, rheumatoid arthritis, surgery of head and neck, and congenital diseases. Type 1 neurofibromatosis (NF-1) is often associated with various musculoskeletal diseases, but few reports have described AARF with NF-1. Here, we report the success of a closed reduction and halo fixation utilized to treat chronic AARF with NF-1 in a 7-year-old female.

Case description: A 7-year-old female with NF-1 presented with a 2-month history of torticollis and neck pain. C2 facet deformity had previously been identified on computed tomography (CT) before the onset of neck pain. Cervical radiography and CT showed AARF classified Fielding's Type I and Ishii's Grade II. Following 2 weeks of cervical traction, a closed reduction was followed by halo fixation that was utilized for 2 months. The patient fully recovered cervical range of motion following halo vest removal 4 months later. Further, the follow-up CT documented a normal atlantoaxial joint despite residual C2 facet deformity. In addition, no recurrence was evident 2 years later.

Conclusion: Halo fixation for chronic AARF with NF-1 proved effective. C2 facet deformity associated with NF-1 might have contributed to the onset of AARF.

Keywords: Chronic atlantoaxial rotatory fixation; Halo fixation; Neurofibromatosis type I.

Figure 1:

Before the onset of neck pain, whole spine radiography (a) and anterior view three-dimensional computed tomography (CT) (b) show the left-sided convex scoliosis curve. Cervical spine three-dimensional CT in the axial view (c) and anterior view (d) shows C2 facet deformity (arrow).

Figure 2:

After the onset of neck pain, whole spine radiography shows lateral tilting of the cervical spine.

Figure 3:

After the onset of neck pain, three-dimensional computed tomography in the axial (a), anterior (b), and lateral (c) views reveals that the C1-C2 joint is locked with C1 rotated 32° to the left and C2 facet deformity (arrow).

Figure 4:

Photograph (a) and radiography (b) of the patient undergoing reduction treatment under general anesthesia.

Figure 5:

Two months after closed reduction and halo fixation, three-dimensional computed tomography in the axial (a) and anterior (b) views shows persistent C2 facet deformity (arrow), but cervical posture appears to have returned to a neutral position.

Figure 6:

Photograph (a) and radiography (b) at 1 month after removing halo fixation. Three-dimensional computed tomography images in the axial (c) and anterior (d) views at 4 months after removing the halo fixation show normal alignment of the atlantoaxial joint and C2 facet deformity (arrow).