Surgery of the upper cervical spine in rheumatoid arthritis. Indications and results apropos of 28 cases

PURPOSE OF THE STUDY: The goal of this study was to precise indications and surgical techniques for stabilisation with or without decompression of the upper cervical spine instability in rheumatoid arthritis. MATERIAL AND METHODS: 28 patients presenting upper cervical spine disease have been reviewed (mean age 57 years). These patients had been suffering from severe diffuse arthritis during an average of 14.5 years. The anterior atlanto-axial dislocation was most frequent (25 times), 1 posterior dislocation and 2 vertical dislocations. Odontoid lysis was noted 19 times. A subluxation of the lower cervical spine was present in 12 patients. SURGICAL TECHNIQUE: C1-C2 arthrodesis was performed 12 times (9 times with a loop wire and 3 isthmo-pedicular screws C2-C1), occipito-cervical arthrodesis with plates 16 times. Operative traction was necessary 5 times. The associated surgical gestures included 3 times a laminectomy, 2 times an enlargement of the occipital foramen, 1 section of the Arnold nerve. In 2 patients was associated a fixation of the lower cervical spine. RESULTS: With an average of 27 months follow-up, functional results (classified according to Ranawat's criteria) were satisfactory in 14 patients, improved in 7 patients, unchanged in 4 and bad in 3. The reduction of the anterior displacement in 25 patients was complete 11 times, partial 17 times and null 3 times. The reduction of the vertical displacement was complete once, partial 3 times. Arthrodesis fusion was obtained in 19 cases, 5 times it was a fibrous union and 4 pseudarthrosis occurred, all with C1-C2 loop wire. The rate of complications was high: 2 infections on bone site grafting requiring reoperation, 2 infections with secondary septicemia after lack of reduction. DISCUSSION AND CONCLUSION: Occipito-cervical arthrodesis is necessary as soon as the patient presents neurological signs. When there is an anterior dislocation associated with vertical dislocation, if there is posterior dislocation in case of osteoporosis of the posterior C1-C2 arc, or destabilisation of the lower cervical spine. C1-C2 arthrodesis is suggested when there is no important neurological signs, when displacement is limited to a pure anterior dislocation and in young patient with good bone quality.