頸部脊椎症における頸椎のレ線学的研究—とくにChrispin氏法の適応について

RADIOLOGICAL STUDY OF THE CERVICAL SPINE IN CERVICAL SPONDYLOSIS WITH SPECIAL REFERENCE TO THE APPLICATION OF CHRISPIN'S METHOD

I．はじめに

　Cervical spondylosis （以下C．S．と略す）は，古くから病理学的ないしレ線学的に用いられてきた名称で，頸椎の椎間板傷害に基づく慢性変性変化を意味するものである。レ線上認められるこのC．S．は，高年者になるにつれてその頻度は増加を示すことはすでに報告されている^2）。しかしながらC．S．を示す者が必ずしも神経症状を呈するものではなく，そのなかの一部のものにすぎないと推定されており，神経症状の発生機転に関しては，なお未解決な問題が残されている。

　頸椎の椎体と頸椎管の相互関係を検討することは，神経症状の成因を追求する一つのアプローチであり，Boilsen^1）およびPayne^5）らによつてすでに検討され，いずれも頸椎符の狭少が神経症状発現者において正常者よりも高度に認められると述べている。

In 1963, Chrispin, et al., described a new method of measuring the cervical spine. The principle used is that of tracing the radiographic outlines of spinal canal and vertebral bodies on x-ray film and weighing the cut-out tracings. The size of the spinal canal is compared with that of the vertebral bodies and a ratio (C/B) was calculated. Such ratios were obtained in symptomatic cervical spondylosis (cervical spondylosis with neurological signs; S.C.S.) 57 cases, asympto-matic cervical spondylosis (A.C.S.) 20 cases, cervical intervertebral disc hernia 20 cases, and normal control 60 cases which were seen at our Institute during the period from June 1964 to May 1965. The purpose of this paper is to report the results of our statistically analyzed values C/B in those conditions. This com-munication presents also the clinical application of this method.

(1) The mean values of C/B were as follows; normal control 98.0±6.7%. A.C.S. 94.3±3. 5%, Cervical disc hernia 93.3±12.3%, and S.C.S. 81.3±9.7%. Each decrease of ratios of S.C.S., cervical disc hernia, and A.C.S. was significant in compared with that of normal control (P<0.05).

(2) In S.C.S., and cervical disc hernia, the mean values of C/B in the cases with so-called pyramidal tract signs was not significantly lower than that of the cases without pyramidal tract signs (P>0.05). However, when value of C/B of S.C.S. was compared in both groups higher and lower from the level of 90(%), significant difference was found in cases with and without long tract signs (P<0.01).

(3) Radiological severity of cervical spine was found in S.C.S. and A.C.S., however, significant difference in values of C/B was found in both conditions. (P<0.01).

(4) In regard to the clinical application of the Chrispin's method, the following points are useful in differentiation between S.C.S., A.C.S., and normal groups.

1) when the value shows over 97.3%, S.C.S. is ruled out.

2) when the value shows belows 83%, A.C.S. and normal groups are ruled out.