What is the anatomy of the wrist relevant to carpal tunnel steroid injection?

Updated: May 31, 2018
  • Author: Samir Shah, MD; Chief Editor: Meda Raghavendra (Raghu), MD  more...
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The wrist is a complex joint consisting of the distal portion of the radius and ulna articulating with eight carpal bones which in turn articulate with the proximal aspects of five metacarpal bones. Together, these bones are responsible for flexing and extending, pronating and supinating as well as ulnar and radial deviation.

The carpal tunnel is defined ventrally by the flexor retinaculum, attached radially to the scaphoid and trapezium, and the pisiform and hamate on the ulnar side. The carpal bones define the dorsal border of the carpal tunnel. The carpal tunnel contains four tendons of the flexor digitorum profundus, four tendons of the flexor digitorum superficialis as well as the flexor pollicis longus tendon. Just deep to the flexor retinaculum is where the median nerve traverses the carpal tunnel. This branch of the median nerve supplies the sensory innervation of the first three digits and the radial half of the fourth digit.

For more information about the relevant anatomy, see Wrist Joint Anatomy.

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