Ligamentum anulare variabile policis
Ligamentum anulare variabile policis
定义
当拇指的可变环形滑车存在时，它是一条薄而不恒定的纤维束，位于斜形滑车近端，靠近近节指骨基底部——介于斜形滑车与A1滑车之间。其走行方向与斜形滑车相似，由近端至远端、从尺侧至桡侧斜行，与斜形滑车平行排列。
拇指的可变环形滑车在运动过程中可能为拇长屈肌（FPL）肌腱提供额外的稳定作用，但并非在所有个体中均存在。
參考資料
Hirschmann, A., Sutter, R., Schweizer, A. and Pfirrmann, C.W., 2014. MRI of the thumb: anatomy and spectrum of findings in asymptomatic volunteers. American Journal of Roentgenology, 202(4), pp.819-827.
Hauger, O., Chung, C.B., Lektrakul, N., Botte, M.J., Trudell, D., Boutin, R.D. and Resnick, D., 2000. Pulley system in the fingers: normal anatomy and simulated lesions in cadavers at MR imaging, CT, and US with and without contrast material distention of the tendon sheath. Radiology, 217(1), pp.201-212.
