Final answer:
The Sean retractor is used in hand surgery to retract skin and tissues, providing better surgical visibility especially involving the extensor and flexor retinacula, which play a significant role in the structure and function of the hand.
Step-by-step explanation:
The Sean retractor is a surgical instrument commonly used in hand surgery for exposing and retracting skin and deeper structures to improve visibility and access for the surgeon. It is particularly useful in procedures involving the extensor retinaculum, a band of connective tissue that extends over the dorsal surface of the hand, and the flexor retinaculum, which lies on the palm side of the hand encompassing the carpal tunnel along with the carpal bones such as the trapezium. Understanding the composition and function of these structures, including the flexor retinaculum's attachment to the lateral base of the proximal phalanx of the thumb and its relationship to the trapezium, is important in a range of surgical interventions in hand surgery.