The axis is an important element of the musculoskeletal complex in the upper cervical spine
. It is surrounded by a number of delicate neurological and vascular structures and controls a wide range of movements [1
]. Thus, a pathological C2 fracture is a threatening condition. Multiple myeloma (MM) and osteolytic metastases are the most frequent malignant lesions affecting the spine [2
]. Severe neck and back pain and reduced mobility are the most common symptoms in patients with vertebral metastases and MM. The treatment is basically conservative, with analgesics, cytostatic, radiotherapy, reinforced corset and/or neck brace. However, the cervical spine, especially the C1 and C2 region, seems to be involved less often. Pathologic fractures involving the C2 vertebral body and odontoid process pose a unique dilemma, as the surgical approaches for direct odontoid process screw fixation have several limitations. There have been a small number of transoral approach C2 vertebroplasties or kyphoplasties reported in the literature. Previous attempts at accessing the C2 vertebral body and/or odontoid process were performed utilizing fluoroscopy or CT guidance. The proximity to the spinal cord and adjacent vascular structures increases the difficulty of this procedure. Lateral, poster lateral, and anterior approaches have been described in prior reports for surgery, biopsy, and/or bone cement placement. The anterior transoral approach for accessing the cervical spine appears to best avoid the adjacent neurovascular structures.
Otolaryngologists and neurosurgeons have extensively used the transoral approach to access the upper cervical spine. This is a well-established access route in the otolaryngological and neurosurgical
] a thin layer of fascia and muscles separates the upper cervical spine from the oral mucosa. One of the potential downsides of the transoral cervical spine surgical approach is a reported risk of wound infection up to 2% and a risk of meningitis up to 4.5%. Extension of infection into facial planes can cause a retropharyngeal abscess and invasion of the meningeal layers leading to meningitis and encephalitis. The rate of infection has dropped significantly in recent years, due to the improvement in aseptic techniques, perioperative antibiotics, and thorough cleansing of the surgical bed prior to the procedure.
Percutaneous vertebroplasty (PVP) of the axis is a challenging procedure which may be performed by a percutaneous or a transoral approach [5
]. There are few reports of PVP at the C2 level. Transoral vertebroplasty
is postulated to have a lower risk of infection given the minimal tissue disruption by the needle. The addition of peri-operative intravenous antibiotics, antibiotics within the PMMA mixture, and post-procedural antibiotics should further reduce the infection risk.
Severe neck and back pain and reduced mobility are the most common symptoms in patients with vertebral metastases. The treatment is basically conservative, with analgesics, cytostatic, radiotherapy, reinforced corset and/or neck brace.
In patients with osteolytic lesions in the cervical spine and refractory pain, with or without fracture dislocations, different types of surgical stabilization methods have traditionally been used. The least invasive method consists of the halo-vest treatment, which can safely be performed concurrently with the medical treatment. This form of treatment may lead to bone reconstitution and stability. Posterior osteosynthesis with or without decompression involves permanent fixation from occipital bone to C4 with restriction of flexion, extension, bending and rotation. The procedure has a low risk of complications, provides immediate stabilization of the C2 lesion and allows safe mobilization of the patient with a neck brace.
During recent years an increasing number of patients with C2 metastases have been treated with PVP. This has offered rapid and long-lasting pain relief in up to 85% of cases [7
Vertebroplasty is a well-established procedure for pain control and stabilization of vertebral pathology including metastasis, hemangioma
, and multiple myeloma.
The PVP procedure allows the option of preserving the mobility of the upper cervical spine. On the other hand, posterior stabilization leads to fixation from the occipital bone to the C4 vertebra, resulting in a considerable decrease in mobility. If sufficient stabilization is not achieved with PVP, the surgical option is still available.
We think that PVP is a less aggressive procedure than any surgical stabilizing procedure in the upper cervical spine and does not restrict the mobility of the occipito-cervical junction [8
]. The patient can usually walk a couple of hours after treatment, and can be discharged from hospital within 24 h of the procedure. Considering the higher risk of complications of PVP in this region, it is highly recommended that the treatment be performed by an experienced specialist at a centre where many PVP procedures are carried out and which has excellent radiological equipment.