Variations in extensor carpi radialis longus and brevis A cadaveric study

Abstract

Objectives : The Extensor Carpi Radialis Longus (ECRL) and Extensor Carpi Radialis Brevis (ECRB) are two of the superficial muscles of extensor compartment of forearm. The extensor carpi radialis brevis is involved in tennis elbow. The surgeons performing Z shaped tenotomy on tennis elbow to lengthen the tendon of ECRB must be aware of the variation in order to avoid unwanted complications. Recently, ECRB has also gained importance for use in free functional muscle transfer. In cases of variation of extensor muscles like fusion of muscle bellies or splitting of tendon and in cases of absent ECRB, the entrapment neuropathy of Radial nerve or Posterior interosseous nerve should also be kept in mind. In this study, we have described some variations of ECRL and ECRB which were different from what has already been reported as they are clinically important. Methods: 30 upper limbs from 15 formalin fixed adult human cadavers were dissected to study the ECRL and ECRB. Results: Out of 15, 4 cadavers showed variations. ECRL showed a split of its tendon into two in 3 limbs belonging to 2 cadavers in which one cadaver showed bilateral split. ECRB showed a similar split of tendon in two limbs. One of the limbs showed complete absence of ECRB. Bellies of ECRL and ECRB fused to form a single mass in 3 limbs. Conclusions: The additional tendons noted in the present study could be utilized effectively and reliably in tendon transfers and in surgical rehabilitation in patients with paralytic disorders.