Indications Access provides exposure to extensor tendons passing over wrist dorsal wrist joint dorsal carpus dorsal surface of proximal ends of metacarpals Indications synovectomy and repair of extensor tendons wrist fusion posterior interossesous nerve (PIN) neurectomy excision of lower end of radius proximal row carpectomy proximal pole scaphoid fx ORIF of distal radius fx (displaced intra-articular dorsal lip fxs) ORIF of carpal fx and dislocations Internervous Plane No true intermuscular plane dissection carried out between the third and fourth extensor compartments Relevant anatomy radial styloid ulnar styloid Lister's tubercle extensor tendon compartments Preparation Anesthesia regional blocks general sedation Position place supine on table pronate arm and place on armboard Tourniquet optional exsanguinate arm Approach Incision make ~ 8 cm incision midline (halfway between radial and ulnar styloid) can extend proximally or distally as needed Superficial dissection incise subcutaneous fat inline with skin incision expose extensor retinaculum Deep dissection incise extensor retinaculum over the extensor digitorum communis and extensor indicis proprius (fourth compartment) mobilize tendons radially and ulnarly to expose the underlying radius and joint capsule incise the joint capsule longitudinally on the dorsal radius and carpus continue dissection below the capsule (dorsal radiocarpal ligament) toward the radial and ulnar sides of the radius to expose the entire distal radius and carpal bones Dangers Radial nerve (superficial radial nerve) emerges from beneath brachioradialis tendon just above the wrist joint before traveling to dorsum of the hand distal extent of approach at base of 3rd metacarpal Dorsal cutaneous branches supplied by both radial and ulnar nerves lie in subcutaneous fat injury may lead to painful neuromas Radial artery crosses wrist joint laterally avoid by maintaining dissection below the periosteum Interosseous ligaments can destabilize carpus avoid by raising flaps Scaphoid devascularization avoid by not detaching capsular attachment on dorsal ridge of scaphoid