Introduction Indications Open reduction and internal fixation of distal humerus fractures (lateral condyle) Open treatment of lateral epicondylitis Anatomic Planes Internervous plane (none) Between the triceps (radial n.) and brachioradialis (radial n.) Positioning Anesthesia Position supine with arm lying across chest Tourniquet Approach Incision make a curved or straight incision over the lateral supracondylar ridge Superficial dissection incise the deep fascia in line with the skin incision identify the plane between the brachioradialis and triceps Cut in between these two muscles down to bone Reflect the triceps posteriorly and the brachioradialis anteriorly Deep dissection the common extensor origin can be released off the lateral humerus and the triceps can be similarly elevated posteriorly Extension proximal extension cannot be obtained due to the radial nerve crossing proximally in line with the incision distal extension can be obtained by extending into the interval between the anconeus (radial n.) and extensor carpi ulnaris (posterior interosseous n) this extension can only be carried to the radial head to avoid potential injury to the posterior interosseous nerve Dangers Radial nerve This nerve is at risk with proximal extension, as the nerve pierces the lateral septum in the distal third of the arm