Object: The authors retrospectively analyzed a series of 108 patients in whom was diagnosed atlantoaxial instability due to degenerative osteoarthritis of the atlantoaxial joints. The management issues in such cases are discussed.
Methods: One hundred eight patients with osteoarthritis of the atlantoaxial joints and resultant craniovertebral instability-diagnosed on the basis of presenting clinical features, radiological imaging, and direct observation of the joint status during surgery-were retrospectively analyzed. Between 1990 and 2008, these patients were treated with a C1-2 lateral mass plate and screw method of atlantoaxial fixation and joint distraction using bone graft with or without the assistance of metal spacers.
Results: Patient ages ranged from 48 to 84 years (average 63 years). There was a history of mild to moderate head and/or neck trauma 2 months to 11 years prior to diagnosis in 40% of the cases. All patients had symptoms of neck pain, and 82% of the patients had progressive myelopathy. A reduction in the height of the atlantoaxial lateral mass complex (100%), mobile atlantoaxial dislocation (100%), basilar invagination (68%), and periodontoid degenerative tissue mass (90%) were the more frequently encountered radiological features. Two patients died in the immediate postoperative period. At an average follow-up of 64 months, all surviving patients remarkably improved to varying degrees in their neurological condition.
Conclusions: Atlantoaxial joint arthritis frequently leads to craniovertebral instability and cord compression. Treatment by joint distraction and lateral mass fixation can be an optimum form of treatment.