The annular pulleys (or ligaments) represent five areas where the fibrous flexor sheaths are reinforced by circular fibres. However the available literature only partially supports that view. Use the information in this article to help you with the answers. The annular pulleys are named A1 through A5 and the cruciate pulleys are named C1 through C3. 13 March 2017 | HAND, Vol. Tested Concept, Type in at least one full word to see suggestions list. From a biomechanical advantage point the A2 and A4 pulleys are considered the most important to prevent bowstringing. Annular Pulleys The fingers have 5 annular ligaments (A1–5) and 3 cruciate ligaments (C1–3) that hold the flexor tendons tightly close to the bones. Disruption of the finger flexor (annular) pulley system is a recognized injury in elite rock climbers. Trigger finger is the most common entrapment tendinopathy, with a lifetime risk of 2% to 3% for the general population and 10% for diabetic individuals. The pulley system is made up of thickened layers of the flexor tendon sheath, which holds the tendons to the bone known as annular and cruciate pulleys. 37, No. However, although rare, triggering of the flexor tendon can occur in other areas. 14 July 2017 | Journal of Ultrasound in Medicine, Vol. In this article, we shall look at the anatomy of the flexor pulley system – including the fibrous digital sheaths, annular ligaments and cruciate ligaments. Specifically, this protocol aims to address finger flexor tendon strains and annular pulley ligament sprains. The appearance in this patient is compatible with annular pulley partial tears. The aetiology of trigger finger explained on the basis of … Flexor pulley system consists of following 1. Miyamoto H, Miura T, Isayama H, Masuzaki R, Koike K, Ohe T. Stiffness of the first annular pulley in normal and trigger fingers. The name is due to the popping sound made by the affected finger when moved. The long flexor tendon of the thumb arises from the flexor pollicis longus (FPL). The variable annular pulley was present in 70 of 75 hands (93%) in 1 of 3 arrangements: transverse, oblique, or fused with the A1 pulley. Although the presence of the variable annular pulley is fairly consistent, the anatomic appearance of this pulley is somewhat variable. Abnormally thickened and hypoechoic 4th annular flexor pulley (A4) on the US transverse image. Along with the A1 pulley, the additional variable annular pulley might contribute to stenosis in trigger thumb. EG: A1 to A5 and C1 to C4. 2011 Sep. 36(9):1486-91. . 1 It is one of the most common and debilitating conditions of the hand, with a prevalence of nearly 3% in the population.