抄録
In order to understand the pathomechanism of cervical subaxial subluxation (SAS) in rheumatoid arthritis, the authors analysed the radiological findings of 31 cases operated on for atlanto- axial subluxation (AAS), vertical subluxation (VS) and subaxial lesion (SAL) .
SAS (≥2mm) was found in 90% of the patients. The distance of anterolisthesis (AL) was 4.5 ± 2.1 mm, whereas that of posterolisthesis (PL) was 2.6 ±1.1 mm (p<0.01) . AL was found most frequently in C4/5, while PL occurred most often in C3/4. PL was accompanied with AAS in 85% of the cases. There was less mobility of the lower cervical spine (at least four levels were spontaneously fused) in 88% of the AL cases. Postoperative anterolisthesis occurred at the next lower disc level in 2 of 13 cases which had received posterior fusion for SAL. Destruction of the posterior spinal column due to RA granulation was found in 73 % of the AL cases during surgery. Also, there was postoperative AL in all of the laminectomized SAL cases.
The destruction of the posterior spinal column due to RA and the decreased mobility due to spontaneous fusion may play an important role in producing AL in SAS. AAS may have a tendency to cause PL in relation to the kyphotic change of the closed lower cervical spine.
