Free Functional Muscle Transfer for Thumb Opposition

Abstract

Summary:Traumatic injuries and other conditions resulting in thenar loss and loss of opposition function can cause significant functional limitations. There are limited options available to restore function and bulk to the thenar musculature. A 26-year-old man had an unfortunate accident at work with a machine mixer creating a crush injury to his left hand. This required several debridements due to the tissue injury and resulted in loss of the thenar muscles and ability to oppose the thumb. He recovered well from the initial injury, however, was left with difficulty with grasp and holding objects due to the loss of thenar motion and strength. His function was also affected by the loss of bulk. He successfully underwent a free functional muscle reconstruction with his serratus anterior. This case report is a description of his reconstruction and a review of the literature. The patient had an excellent outcome. He obtained active opposition and improved grip strength, improving his activities of daily living and vocational life. The serratus anterior muscle can successfully be used for thumb opposition reconstruction. This case report demonstrates good outcomes for both motion and bulk restoration.

Functional Thenar Reconstruction

“…Harvest of the gracilis muscle is also well described in the literature 21 . Although it is more widely used as a workhorse flap for elbow flexion in brachial plexus injury, 12 its shape, flexibility in size, and donor site location also make it an ideal option for functional thumb reconstruction. Because of the relatively small size of thenar defects, partial harvest of the gracilis muscle will suffice for reconstruction.…”

“…One series reported muscle activation at 6 months with recovered opposition at 18 months after surgery 12 . Two patients underwent combined toe-to-thumb transfer with a serratus anterior flap for functional thumb reconstruction 14 .…”

“…The serratus anterior muscle flap is a versatile flap that can be used for coverage of a wide variety of defects 12,22,23 . Three series have described use of the serratus anterior muscle as an FFMT for thumb reconstruction 12–14 . A total of 5 patients underwent thenar reconstruction with a serratus anterior FFMT alone, and 2 underwent concomitant toe-to-thumb transfer at the time of reconstruction.…”

Single incision thenar muscle reconstruction using the free functional pronator quadratus flap

“…No impairment in forearm pronation was observed, due to intact pronator teres-function. Other FFMT found in the literature used the serratus flap or a gracilis flap for functional thenar reconstruction [ 3 , 4 ]. Hereby, the donor site morbidity should be considered higher as with the PQ flap due to the need of a second incision on a different donor site on the body and potential intraoperative relocation of the patient.…”

“…With the improvement of microsurgery, reconstructive approaches such as nerve transfers and free functional muscle transfers (FFMT) have become a viable option for functional reconstruction. Hereby, several case reports exist, describing FFMT for thenar reconstruction, including the gracilis flap, the serratus flap or the minor pectoral muscle flap [ 3 , 4 ]. These flaps are all viable yet bulky options, but also come with the burden of a certain donor site morbidity.…”