Simultaneous reconstruction of the forearm extensor compartment tendon, soft tissue, and skin

Abstract

Malignant peripheral nerve sheath tumor (MPNST) is a very rare type of sarcoma, with an incidence of 0.001%. MPNST has a 5-year survival rate near 80%, so successful reconstruction techniques are important to ensure the patient's quality of life. Sarcoma of the forearm is known for its poor prognosis, which leads to wider excision, making reconstruction even more challenging due to the unique anatomical structure and delicate function of the forearm. A 44-year-old male presented with a large mass that had two aspects, measuring 9×6 cm and 7×5 cm, on the dorsal aspect of the right forearm. The extensor compartment muscles (EDM, EDC, EIP, EPB, EPL, ECRB, ECRL, APL) and invaded radius were resected with the mass. Tendon transfer of the entire extensor compartment with skin defect coverage using a 24×8 cm anterolateral thigh (ALT) perforator free flap was performed. The patient was discharged after 18 days without wound complications, and has not complained of discomfort during supination, pronation, or wrist extension/flexion through 3 years of follow-up. To our knowledge, this is the first report of successful reconstruction of the entire forearm extensor compartment with ALT free flap coverage after resection of MPNST.

Keywords: Forearm; Neoplasms; Surgical flaps.

Fig. 1.. Preoperative design of resection and tendon transfer

An anterolateral thigh perforator flap was planned for coverage of the predicted skin defect.

Fig. 2.. Immediate postoperatve photograph

An anterolateral thigh perforator flap measuring 24×8 cm was used for skin coverage.

Fig. 3.. Pathologic imaging of resected tumor

Pathologic imgaging of the resected tumor reveals spindle cells with irregular contours, marked mitotic activity (30 per high-power field), and entrapped nerve fibers (×100 magnification with hematoxylin and eosin stain).

Fig. 4.. Pinching motion at postoperative 22 months

Pinching with the thumb and little finger could be performed. Thumb abduction was preserved (35°).

Fig. 5.. Fist motion at postoperative 22 months

A full fist was made performed with full flexion of all five fingers.

Fig. 6.. Thumb hyperextension at postoperative 22 months

Thumb metacarpophalageal joint hyperextension was preserved (10°). All five fingers were extended.

Fig. 7.. Wrist extension at postoperative 22 months

Wrist extension up to 65° was performed.

Fig. 8.. Radial abduction of thumb at postoperative 22 months

Radial abduction of the thumb (up to 45°) was performed.