Occipitocervical fusion combined with 3-dimensional navigation and 3-dimensional printing technology for the treatment of atlantoaxial dislocation with basilar invagination: A case report

Abstract

Introduction: Basilar invagination (BI) is a common deformity in the occipitocervical region. The traditional surgical method of BI is direct transoral decompression followed by posterior decompression and fixation. Posterior-only decompression and fixation have achieved good efficacy in the treatment of BI in recent years, but complications are common due to the operation in the upper cervical vertebra and the medulla oblongata region. Moreover, posterior-only occipitocervical fusion combined with an intraoperative 3-dimensional (3D) navigation system is relatively rare, and reports of this procedure combined with 3D printing technology have not been published. We present a case of BI treated with posterior-only occipitocervical fusion combined with 3D printing technology and 3D navigation system to reduce the risk of surgical complications.

Patient concerns: A 55-year-old patient with a history of neck pain and numbness of the extremities for 6 years developed a walking disorder for 1 year.

Diagnoses: Atlantoaxial dislocation with BI.

Interventions: The patient underwent posterior-only occipitocervical fusion combined with intraoperative 3D navigation system and 3D printing technology.

Outcomes: The patient's walking disorder was resolved and he was able to walk approximately 100 m by himself when he was allowed to get up and move around with the help of a neck brace. At 6 months postoperatively, the patient reported that the numbness of the limbs was reduced, and he could walk >500 m by himself.

Conclusion: Occipitocervical fusion is one of the established techniques for the treatment of BI. The biggest advantage of the 2 technologies was that it ensured precise implant placement. The advantages of intraoperative 3D navigation systems are as follows: real-time intraoperative monitoring of the angle and depth of implant placement; the best nailing point can be determined at the time of implantation, rather than according to the operator's previous experience; and the extent of screw insertion is visible to the naked eye, rather than being dependent on the "hand feel" of the surgeon. At the same time, the 3D printing technology can be applied to clarify the relationship between blood vessels and bone around the implant to minimize injury to important structures during implantation.

Figure 1

The atlantoaxial instability resulted in mild atlantoaxial dislocation, as observed on the preoperative X-ray (A) and CT scan (B). (C) MRI showed that the spinal cord was compressed by the posterior atlas arch. CT = computed tomography, MRI = magnetic resonance imaging.

Figure 2

(A) Preoperative cervical CTA to evaluate the relationship between the important blood vessels and bone in the cervical area. (B and C) 3D CT of the cervical was performed to evaluate the bony structure. (D) A 3D printing model of the patient's occipitocervical area was constructed using CTA and 3D-CT. 3D = 3-dimensional, CTA = computed tomography angiography.

Figure 3

(A) Intraoperative real-time monitoring the angle and depth of implant placement using a 3D-navigation system. (B) The pedicle screws (C2) and mass screws (C3-C4) were in the correct position with the guidance of the 3D-navigation system. (C) The blood supply of dural sac at C1 was well, indicating good decompression. 3D = 3-dimensional.

Figure 4

Intraoperative X-ray showing that the screws are in the correct position without displacement.

Figure 5

(A and C) After removal of the stitches, 3D-CT was performed and showed that the position of the pedicle screw was not significantly changed from that of the X-ray obtained 2 wk prior. 3D = 3-dimensional, CT = computed tomography.