The extensor carpi radialis intermedius tendon.

I examined 312 arms from 156 cadavers in the anatomy laboratory of Loma Linda University to find the incidence of the extensor carpi radialis intermedius tendon. I found 29 bodies (12%) that had a good extensor carpi radialis intermedius. In 17 of these 29 bodies, an extra tendon was found bilaterally. Thirty-two extensor carpi radialis intermedius tendons were suitable for transfer operations, and seven were unacceptable. One must be careful to differentiate between a true extensor carpi radialis intermedius tendon and accessory tendinous bands. The relatively high incidence rate and percentage of tendons suitable for transfer operations make this tendon potentially valuable in treating severe quadriplegia with tendon transfers. It can be used successfully for thumb opposition, to motor the flexor pollicis longus, or as a motor for the extensor pollicis longus of the thumb.