Supernumerary Tendons of the Abductor pollicis

Abstract

During a study of variants of the tendon of the abductor pollicis longus (APL) muscle, in 1 of 110 upper extremities prepared, we recorded the rare finding of a division of the APL muscle tendon into 7 sections in the first tunnel. Whereas the actual main tendon inserted at the base of the first metacarpal bone, as depicted in the textbooks, the supernumerary tendons attached to the fascia of the opponens pollicis muscle, to the radial edge of the abductor pollicis brevis muscle and to the dorsoradial third of the base of the first metacarpal bone. All accessory tendons were arranged in a radial formation around the main tendon within the same synovial sheath, but the main tendon occupied a separate compartment. In 80% of the upper extremities prepared for this study, the classical description of the abductor tendon did not apply. The classical representation of a single abductor tendon applied to only 20% of the upper extremities examined. In about one third of the wrists prepared, the first tunnel was clearly divided by a septum, so that 2 or more osteofibrous tunnels were present within the main tunnel. The number, thickness and length of such accessory tendons have a functional significance in the development of de Quervain’s stenosing tendovaginitis and possibly also have a practical significance, as they may be regarded as a source of transplant material for plastic reconstructions.

Variant Abductor Pollicis Longus Muscle: a Case Report

“…A varying number of tendon slips ranging from three to seven have been reported. (2,3,9,10,11). From the above facts it is clear that APL exhibits more than one tendon, hence the clinical importance of the anomalous divisions of APL cannot be neglected.…”

“…The anomalies of the APL are important to understand the etiology and subsequent surgical decompression of De Quervains Syndrome (7,8,14). During surgeries the unawareness of the multiple tendons in separate compartments may result in improper recognition of the tendons (9). There are more chances of injury during surgeries, if there is the lateral position of the supernumerary tendon (12).…”

A Case of Three Tendon Insertion of Bilateral Abductor Pollicis Longus Muscle

“…Ancak tendon parçalarının farklı yerlerde sonlanması, tendonun yangısından değil de kasın ve çevre dokuların gelişim evrelerindeki bir anormallikten kaynaklanabileceği ifade edilmektedir. [1][2][3][4][5][6][7][8] Vollala 50 adet kadavrada MAPL tendonunun %30'unda tek, %50'sinde çift ve %20'sinde ise multipl olduğunu, tek tendon olan vakaların tümünde tendonun os metacarpale I'in tabanına, aksesuar tendonların MAPB, os trapezium, m.opponens pollicis ve facia thenaris'e tutunduğunu bildirmiştir. 7 Baba aksesuar tendonların %98 sıklıkla bulunduğunu, 6 Melling ve ark.…”

“…ise MAPL tendonlarının 7 parçalı olarak da bulunabildiğini bildirmişlerdir. 5 Fazla tendonların ekstensor bölgede m.extensor carpi radialis longus ve m.extensor carpi radialis brevis tendonlarını çaprazladığı yerde ve ayrıca retinaculum extensorum'un altından geçerken osseofibröz kanallarda daralmaya yol açabileceği ve başparmak hareketleriyle birlikte artan ağrılara neden olabileceği bildirilmiştir. 7,8 Aydınlıoğlu ve ark., MAPL tendonundaki varyasyonlarda, iki veya daha fazla sayıdaki bantların muhtelif yerlere insersiyon yaptığını, bunlardan bir tendonun genel olarak os metacarpale I'in proksimal ucunun dorsal veya lateral tarafına, diğer tendonların ise os trapezium, volar ligamentler, MAPB, m. opponens pollicis, m. flexor pollicis brevis veya bunların fasyalarına insersiyon yaptığını bildirmişlerdir.…”

Unusual Topography of Posterior Antebrachial Musculature in the First Osseofibrous Compartment of Wrist: Clinicomorphological Appraisal

“…The variations in the anatomy of the first extensor compartment have been associated with De Quervain's disease (Gonzalez et al, 1995). Number, thickness and length of accessory tendons of APL and EPB might have an important function in the development of this disease (Melling et al, 1996;Ippolito et al, 1985).This disease is caused by stenosing tenosynovitis of the first dorsal compartment of the wrist, which includes tendon of APL and EPB.…”