Anatomic Association of the Proximal Fingernail Matrix to the Extensor Pollicis Longus Tendon: A Morphological and Histological Study

Accessory extensor pollicis longus tendon in emergency surgery

Background

A true accessory extensor tendon of the thumb seems to be rare. We found a variation of the accessory extensor pollicis longus (EPL) tendon while performing an emergency surgical procedure. Identification of this accessory tendon during emergency surgery has not been previously reported.

Case presentation: A 43-year-old man presented to our hospital after sustaining a work-related injury involving a saw. During the operation, the tendons of the EPL, accessory EPL, and extensor pollicis brevis were severed. The lacerated tendon and tendon sheath were repaired, and the wrist and thumb were positioned in extension. The patient’s postoperative activity returned to normal without the need for a second tendon release operation.

Conclusions

Surgeons should be aware of this anatomic anomaly of the EPL tendon. Presentation of our case increases clinicians’ chances of preoperatively detecting this anomaly, which can improve surgical outcomes.

Anatomic and Histological Features of the Extensor Digitorum Longus Tendon Insertion in the Proximal Nail Matrix of the Second Toe

Background: Anatomic and histological landmarks of the extensor digitorum longus (EDL) tendon insertion in the proximal nail matrix may be key aspects during surgery exposure in order to avoid permanent nail deformities. Objective: The main purpose was to determine the anatomic and histological features of the EDL’s insertion to the proximal nail matrix of the second toe. Methods: A sample of fifty second toes from fresh-frozen human cadavers was included in this study. Using X25-magnification, the proximal nail matrix limits and distal EDL tendon bony insertions were anatomically and histologically detailed. Results: The second toes’ EDLs were deeply located with respect to the nail matrix and extended superficially and dorsally to the distal phalanx in all human cadavers. The second toe distal nail matrix was not attached to the dorsal part of the distal phalanx base periosteum. Conclusions: The EDL is located plantar and directly underneath to the proximal nail matrix as well as dorsally to the bone. The proximal edge of the nail matrix and bed in human cadaver second toes are placed dorsally and overlap the distal EDL insertion. These anatomic and histological features should be used as reference landmarks during digital surgery and invasive procedures.