Transverse ligament of the elbow joint: an anatomic study of cadavers

Background The medial collateral ligament of the elbow joint consists of the anterior oblique ligament (AOL), posterior oblique ligament (POL), and transverse ligament (TL). This study aimed to clarify the structure of the TL, with a focus on the continuity between the TL and AOL. Methods A total of 42 cadavers (18 males, 24 females) were dissected at Aichi Medical University between 2016 and 2018. Cases of elbow deformity or atrophy were excluded, and 60 elbows (15 males, 15 females) were dissected to assess the fibers of both the TL and AOL using a stereomicroscope. Results The TL could be detected in all elbows and always continued to the AOL. The TL was classified into 2 types. The TLs continuing to the distal half of the AOL (type I) were observed in 44 elbows (73.3%), whereas the TLs continuing to the entire AOL (type II) were found in 16 elbows (26.7%). Type II TLs were significantly more frequently observed in the elbows of females than in those of males ( P = .041). Stereomicroscopic observation revealed that the TL fibers entered perpendicularly to the distal half of the AOL in both types. Conclusions The TL frequently continues to the distal half of the AOL, but rarely continues to the entire AOL. The TLs continuing to the entire AOL were more frequently detected in the elbows of females than in those of males. The TL possibly contributes to medial elbow stability via its continuity to the AOL.