The arm is composed of anterior and posterior compartments.

At the midpoint of the humeral shaft, the profunda brachii artery and radial nerve are located within the spiral groove of the humerus.

The profunda brachii divides into two main branches within the spiral groove: the radial collateral artery (RCA) and middle collateral artery (MCA).

The RCA accompanies the radial nerve and branches into the anterior and posterior radial collateral arteries (ARCA and PRCA) (FIG 1).

The posterior antebrachial cutaneous nerve (PACN) branches from the radial nerve and accompanies the PRCA.

Assess for prior trauma or surgery at the potential donor site.

Ensure adequate recipient site debridement.

Doppler sonography can be used to ensure intact vascular pedicle and perforators in cases with prior trauma/surgery, but we generally avoid this flap in this situation.

Lateral arm flap is indicated for coverage of small to mediumsized defects of the volar and dorsal wrist and hand.

Maximum skin island size is 8 × 25 cm, as the flap can be extended distal to the lateral epicondyle along the lateral forearm. Primary donor-site closure is dependent on body habitus, but generally 6 cm width can be closed primarily.

Obese patients will have a bulky lateral arm flap that may be cosmetically unappealing in the hand and wrist.

The PRCA pedicle is generally limited to 6 cm in length.

For extremity reconstruction with bone defect, a vascularized segment of distal humerus may be included in the flap.²

Doppler examination is used to center the skin paddle over the vascular pedicle.

The patient is placed supine with the hand on a hand table.