Introduction Overview allows exposure of the radial head, coronoid and anterolateral distal humerus should only be done by experienced surgeons familiar with anatomy in this region given significant risk of injury to PIN Indications radial head fractures capitellum fractures PIN decompression lateral humeral condyle fractures proximal radius tumors irrigation and drainage of septic elbow Surgical plane Intermuscular ECRB (radial n. or PIN) and EDC (PIN) ECRB has variable innervation cadaveric study: 50% PIN, 35% superficial sensory, 15% radial nerve proper Preparation Anesthesia general regional supraclavicular block risks: pneumothorax, phrenic nerve paresis Position supine abducted arm on hand table "sloppy lateral" - bump under ipsilateral scapula, arm draped over chest Tourniquet sterile vs. nonsterile sterile best if proximal extension anticipated Approach Incision proximal landmark: lateral epicondyle distal landmark: Lister's tubercle make 4cm longitudinal incision from tip of lateral epicondyle distally towards Lister's tubercle Superficial dissection identify ECRB / EDC interval and bluntly develop plane retract ECRB radial and EDC ulnar to expose supinator deep pronate the forearm to protect PIN detach humeral and ulnar heads of the supinator to visualize annular ligament and capsule deep Deep dissection incise lateral annular ligament + capsule anterior to LUCL along the equator of the radiocapitellar joint to expose the radial head Extension proximal same as proximal extension of Kocher approach intermuscular: triceps (radial n.) and brachioradialis/ECRL (radial n.) distal: posterolateral approach to the forearm (Thompson) extend skin incision distally, still aiming towards Lister's tubercle develop ECRB / EDC interval to visualize distal extent of supinator identify PIN and protect can palpate as bulge in muscle belly or make small nick in the muscle and dissect to find the nerve supinate arm to bring supinator insertion into surgical field incise supinator along radial insertion and elevate subperiosteally to expose the radial shaft Dangers Posterior interosseous nerve (PIN) more anterior, greater risk than Kocher approach pronation of forearm moves PIN ~1cm further from the radiocapitellar joint; supination moves PIN ~1cm closer to radiocapitellar joint Radial nerve Lateral antebrachial cutaneous nerve travels within subcutaneous fat at the distal aspect of the incision Radial recurrent artery (recurrent leash of Henry) injury can result in post-op hematoma Lateral collateral ligament repair more anterior approach avoids injury to LCL complex, but if LCL is traumatically disrupted it is difficult to access and repair via the Kaplan approach necessitates release of EDC to visualize LCL complex