肘部管での尺骨神経圧迫因子の検討 <原著>

Factors of the Ulnar Nerve Entrapment in the Cubital Tunnel

宮島 良博

広島大学医学雑誌

Medical journal of Hiroshima Universtiy

[PISSN] 0018-2087

[NCID] AN00213202

変形性関節症を伴う肘部管症候群の病態を解明し, どのような治療が効果的かを検討するために, 系統解剖用26保存遺体, 50肘を用いて肘部管における尺骨神経圧迫因子の検討を行った。肘屈曲により, 肘部管容積が減少することがわかったが, 加齢とともに増加する尺骨神経溝底の骨隆起や骨棘などは骨性因子として肘部管容積をさらに減少させ, 神経圧迫の原因となることが推察された。肘部管近位縁の腱膜性構造物であるcubital tunnel retinaculum(滑車上肘靭帯)の形態が強靭な型では, これによる神経圧迫の関与も考えられ, 骨性因子とは別に腱膜性因子とした。また, 尺骨神経の肘関節枝の分枝の位置がおおむね, 肘部管の存在する位置に一致することから, 尺骨神経の絞扼部位における関節枝の圧迫や刺激が, 肘部管症候群での肘の疼痛の原因の一つと推察された。以上のことから, 変形性関節症を伴う肘部管症候群の発症には, 骨性圧迫因子が原因となり, さらに腱膜性因子の関与と, 尺骨神経関節枝の絞扼が関係するものと思われた。本症候群の治療には, 神経溝内の骨隆起や骨棘を切除して, 主因たる骨性圧迫因子を除去することが重要と考えられた。

The factors contributing to ulnar nerve entrapment in the cubital tunnel were studied to define the etiology of cubital tunnel syndrome (CTS) associated with osteoarthrosis (OA). In 50 cadaver elbows, the factors leading to osteal and tendinous nerve compression in the cubital tunnel were examined and the innervation of the elbow joint by articular branches of the ulnar nerve was studied. Reduction of cubital tunnel volume was found at the time of elbow flexion as a physiological mechanism. It was assumed that osteophytes in the ulnar groove further contributed to the narrowing of the cubital tunnel and could cause nerve compression with elbow flexion. If the cubital tunnel retinaculum (CTR), which forms the proximal edge of the roof of the cubital tunnel, was strongly tendinous, it could also cause dynamic nerve compression. As most of the articular branches of ulnar nerve were branched at the site where the cubital tunnel existed, their entrapment might be associated with the elbow pain reported by the patients with CTS. It was concluded in this study that osteophytes in the ulnar groove (osteal compression factor) were mainly responsible for the occurrence of CTS associated with OA. CTR (tendinous factor) and articular branch entrapment were also concerned with the pathogenesis of these conditions. It was considered necessary to remove the osteal factor for the treatment of CTS associated with OA.

肘部管

尺骨神経

解剖

Cubital tunnel

Ulnar nerve

Anatomy

医学 [ 490 ]

日本語

広島大学医学出版会

[作成日] 2006-03-21

[ISSN] 0018-2087

[NCID] AN00213202