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. 2009 Fall;17(3):e3-7.

Anatomical variations of the carpal tunnel structures

Ryan Mitchell  1 , Amy Chesney, Shane Seal, Leslie McKnight, Achilleas Thoma
Affiliations

Anatomical variations of the carpal tunnel structures

Ryan Mitchell et al. Can J Plast Surg. 2009 Fall.

Abstract
in English, French

There are many anatomical variations in and around the carpal tunnel that affect the nerves, tendons and arteries in this area. Awareness of these variations is important both during the clinical examination and during carpal tunnel release. The purpose of the present review is to highlight recognized anatomical variations within the carpal tunnel including variation in nerve anatomy, tendon anatomical variants, vascular anatomical variations and muscle anatomical variations.

L’anatomie des nerfs, des tendons et des artères situés dans le canal carpien ou autour de celui-ci connaît de nombreuses variations. Il est important de connaître l’existence de ces variations à l’examen clinique et durant la libération du nerf médian à la hauteur du canal carpien. Le présent article a pour but de faire ressortir des variations anatomiques reconnues des structures du canal carpien, notamment celles touchant les nerfs, les tendons, les vaisseaux sanguins et les muscles.

Keywords: Anatomical variations; Carpal tunnel; Carpal tunnel release; Median nerve; Ulnar nerve.

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Figures

Figure 1)
Figure 1)
A 23-year-old man with a bifid median nerve identified at time of carpal tunnel release. No other anomalies were noted
Figure 2)
Figure 2)
A 57-year-old woman with a bifid median nerve. The radial median nerve had its own compartment within the carpal tunnel that required separate release. The arrows show the two distinct branches
Figure 3)
Figure 3)
Variations in the takeoff of the median nerve motor branch. A Normal anatomy of the median nerve motor branch: extraligamentous and recurrent pattern. B Variation of the median nerve motor branch: subligamentous pattern. C Variation of the median nerve motor branch: transligmentous course. D Variation of the median nerve motor branch: ulnar takeoff. E Variation of the median nerve motor branch: superficial course. Reproduced from reference with permission
Figure 4)
Figure 4)
Linburg-Comstock syndrome: Anomalous tendon slips from the flexor pollicis longus to the flexor digitorum profundus resulting in an inability to actively flex the interphalangeal joint of the thumb without simultaneously flexing the distal interphalangeal joint of the index finger. Reproduced from reference with permission
Figure 5)
Figure 5)
An anomalous palmaris longus tendon was noted to pass through the carpal tunnel and insert into the palmar aponeurosis. It has been transected proximally and is held by a clamp
Figure 6)
Figure 6)
Superficial ulnar artery identified during forearm flap elevation, proximal to the carpal tunnel. The artery may be at risk in extended carpal tunnel release incisions or in repeat surgeries
Figure 7)
Figure 7)
An anomalous palmaris longus muscle belly identified within the carpal tunnel, likely representing an accessory palmaris muscle
See this image and copyright information in PMC

References

    1. Lindley SG, Jackson MS, Kleinert JM. Prevalence of anatomic variations encountered in elective tunnel release. J Hand Surg. 2003;28A:849–55. - PubMed
    1. Lanz U. Anatomic variations of the median nerve in the carpal tunnel. J Hand Surg. 1977;2A:44–53. - PubMed
    1. Amadio PC. Anatomic variations of the median nerve within the carpal tunnel. Clin Anat. 1988;1:23–31.
    1. Jeon IH, Kim PT, Park IH, Park BC, Ihn JC. High bifurcation of median nerve at the wrist causing common digital nerve injury in endoscopic carpal tunnel release. J Hand Surg. 2002;27B:580–2. - PubMed
    1. Gutowski KA, Oliver WA, Mehrara BJ, Friedman DW. Arteriovenous malformation of a persistent median artery with a bifurcated median nerve. Plast Reconstr Surg. 2000;106:1336–9. - PubMed

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