We analyzed the cases of 73 patients who were managed over a 20-year period for rheumatoid involvement of the cervical spine and were followed for a minimum of 2 years, with an average follow-up of 7 years. A neurological deficit did not develop in 31 patients (Ranawat et al. Class I) and paralysis developed in the remaining 42 patients: Class II in 11 and Class III in 31. Of the 42 patients in whom paralysis developed, 35 had operative stabilization. 7 patients were managed with a soft cervical collar because they refused or were medically unable to have the operation; all of the had an increase in the severity of the paralysis. The posterior atlanto-odontoid interval and the diameter of the subaxial sagittal canal measured on the cervical radiographs demonstrated statistically significant correlations with the presence and severity of paralysis. All of the patients who had a Class-III neurological deficit had a posterior atlanto-odontoid interval or diameter of the subaxial canal that was less than 14 millimeters. In contrast, the anterior atlanto-odontoid interval, which has traditionally been reported, did not correlate with paralysis. The prognosis for neurological recovery following the operation was not affected by the duration of the paralysis but was influenced by the severity of the paralysis at the time of the operation. The most important predictor of the potential for neurological recovery after the operation was the preoperative posterior atlanto-odontoid interval. In patients who had paralysis due to atlanto-axial subluxation, no recovery occurred if the posterior atlanto-odontoid interval was less than 10 millimeters, whereas recovery of at least one neurological class always occurred when the posterior atlanto-odontoid interval was at least 10 millimeters. If basilar invagination was superimposed, clinically important neurological recovery occurred only when the posterior atlanto-odontoid interval was at least 13 millimeters. All patients who had paralysis and a posterior atlanto-odontoid interval or diameter of the subaxial canal of 14 millimeters had complete motor recovery after the operation. In this series, although only patients who had a neurological deficit were operated on, we observed the range of the posterior atlanto-odontoid interval that was associated with poor or no recovery after the operation, and we identified the safe range on the basis of the patients in whom paralysis did not develop.(ABSTRACT TRUNCATED AT 400 WORDS)
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We analyzed the cases of 73 patients who were managed over a 20-year period for rheumatoid involvement of the cervical spine and were followed for a minimum of 2 years, with an average follow-up of 7 years. A neurological deficit did not develop in 31 patients (Ranawat et al. Class I) and paralysis developed in the remaining 42 patients: Class II in 11 and Class III in 31. Of the 42 patients in whom paralysis developed, 35 had operative stabilization. 7 patients were managed with a soft cervical collar because they refused or were medically unable to have the operation; all of the had an increase in the severity of the paralysis. The posterior atlanto-odontoid interval and the diameter of the subaxial sagittal canal measured on the cervical radiographs demonstrated statistically significant correlations with the presence and severity of paralysis. All of the patients who had a Class-III neurological deficit had a posterior atlanto-odontoid interval or diameter of the subaxial canal that was less than 14 millimeters. In contrast, the anterior atlanto-odontoid interval, which has traditionally been reported, did not correlate with paralysis. The prognosis for neurological recovery following the operation was not affected by the duration of the paralysis but was influenced by the severity of the paralysis at the time of the operation. The most important predictor of the potential for neurological recovery after the operation was the preoperative posterior atlanto-odontoid interval. In patients who had paralysis due to atlanto-axial subluxation, no recovery occurred if the posterior atlanto-odontoid interval was less than 10 millimeters, whereas recovery of at least one neurological class always occurred when the posterior atlanto-odontoid interval was at least 10 millimeters. If basilar invagination was superimposed, clinically important neurological recovery occurred only when the posterior atlanto-odontoid interval was at least 13 millimeters. All patients who had paralysis and a posterior atlanto-odontoid interval or diameter of the subaxial canal of 14 millimeters had complete motor recovery after the operation. In this series, although only patients who had a neurological deficit were operated on, we observed the range of the posterior atlanto-odontoid interval that was associated with poor or no recovery after the operation, and we identified the safe range on the basis of the patients in whom paralysis did not develop.(ABSTRACT TRUNCATED AT 400 WORDS)
Copyright remains with the authors and publisher.