Treatment can be conservative or surgical. Conservative management is more likely to be recommended when clinical signs are mild, or surgical treatment is not possible due to other medical conditions of your pet. Pets are managed with strict cage rest and a neck brace for several weeks. Steroids and pain medications may also be used, and your pet will need to be protected indefinitely from trauma. Complete recoveries have been reported, even for dogs with severe signs, but dogs can also either remain unchanged or deteriorate. With continued instability, there is a risk for suddenly dislocating the spine, with acute paralysis and death. Potential complications include:
- continued instability
- inadequate stabilization by the brace
- chronic spinal cord compression
- failure to heal fractures of the dens or body of the axis
- bandage sores and eye ulcers related to the splint/neck brace are frequently seen
Surgery is usually recommended over conservative treatment because of the possibility of recurrence and further spinal cord damage. Goals of surgery are to relieve pressure on the spinal cord, and permanently stabilize the joint. Pressure is usually relieved by reducing the vertebrae into a normal position. If the dens are malformed and is deviated towards the cord, occasionally it will need to be removed to relieve the compression. The joint can be stabilized with many different techniques. It can be stabilized from the top (dorsal) or from the bottom (ventral). Most surgeons will now use a ventral technique, as approaches from the dorsal side do not usually result in fusion of the two bones, and long-term stability relies on scar tissue and lasting strength of the implants.
Ventral techniques are currently preferred, as they allow removal of the joint cartilage to enable fusion, and placement of bone graft to stimulate this bony healing. This approach facilitates correct alignment and reduction, and removal of the dens if necessary. Ventral techniques include cross-pinning, trans-articular screws, a combination of pins or screws and bone cement, or bone plates (Figures 3a and 3b, 4a and 4b). The choice of repair is often dependent on surgeon preference, as well as size of the dog. Potential complications of surgery:
- Death due to sudden respiratory arrest with injury to the spinal cord during surgery.
- Breakdown of the repair with migration or breakage of the implants.
- Inadequate reduction or mal-alignment of the spine. Implants can be positioned incorrectly causing chronic pain or impingement of the spinal cord, and requiring removal. Improper positioning can be a problem due to the small amount of bone available to engage the pins or screws, and a very small target area in small dogs to avoid the spinal canal.