Introduction Indications distal biceps avulsion neural compressions involving PIN syndrome Radial tunnel syndrome Superficial radial nerves total elbow replacements elbow joint I&D surgery of capitellum (ORIF, aseptic necrosis) excision of tumors Intermuscular plane Proximal between brachialis (musculocutaneous nerve) and brachioradialis (radial nerve) Distally between brachioradialis (radial nerve) and pronator teres (median nerve) Preparation Patient is supine on table with arm on radiolucent arm board Consider use of sterile tourniquet if dissection may proceed proximally Ensure fluoroscopic imaging can be obtained Approach Incision Make curved incision starting 5 cm proximal to flexion crease along the lateral border of the biceps Continue distally by following medial border of the brachioradialis Superficial dissection Identify lateral antebrachial cutaneous nerve (sensory branch of the musculocutaneous nerve which becomes superficial 2 inches proximal to the elbow crease, lateral to the biceps tendon) Incise the deep fascia along the medial border of the brachioradialis Identify radial nerve proximally at level of the elbow joint (between brachialis and brachioradialis) Follow the radial nerve distally until it divides into its three main branches: PIN (enters the supinator) sensory branch (travels deep to brachioradialis) motor branch to ECRB Develop brachiaradialis and PT interval distal to the division of the radial nerve. Ligate recurrent branches of the radial artery and muscular branches that enter the brachialis just below the elbow to allow better retraction Deep dissection Joint capsule incise the joint capsule between the radial nerve laterally and the brachialis muscle medially Proximal radius expose proximal radius by supinating the forearm to bring the supinator muscle anteriorly. Incise the muscle origin down to bone, lateral to the insertion of the biceps tendon Extension Proximal extends into the anterolateral approach to the arm developing the plane between the brachialis and the triceps muscles Distal extends to the anterior approach to the radius between the planes of the brachioradialis and pronator teres muscles proximally, and the brachioradialis and flexor carpi radialis (median nerve) muscles distally. Dangers Lateral antebrachial cutaneous nerve of the forearm must incise skin and subcutaneous tissues carefully Radial nerve PIN vulnerable as it winds around the neck of the radius within the substance of the supinator muscle. Incise the supinator muscle at its origin with forearm supinated to protect the nerve. Recurrent branch of the radial artery must be ligated to mobilize the brachioradialis