Splinting of the upper extremity may be preferable over external fixation especially for isolated injuries. Upper extremity external fixators can be complicated by the proximity of neurovascular structures. Familiarity with upper extremity anatomy and careful dissection before pin placement can lessen the chance of injury.

Humerus: External fixation of the humerus can be particularly risky due to the intimate relationship with the neurovascular structures. External fixation should be reserved for instances of severe soft-tissue destruction or when associated vascular injury requires shunting or repair. In general, the lateral and anterior surfaces are safer for half pin insertion. Over-penetration of the medial cortex places the neurovascular bundle at risk for injury. For fixation around the elbow, half pins are placed proximal to the lateral epicondyle through an open approach. The incision should be of sufficient length to positively identify the radial nerve as it traverses anteriorly between the biceps and brachioradialis about 10-14 cm proximal to the lateral epicondyle. After pin placement, the incision is closed around the pins.

Ulna: The dorsal surface of the ulna is easily palpable along its entire length. The ulnar nerve is located radial and volar to the bone making the palpable surface an ideal site for pin placement. 5mm pin diameters can be too large based on the diameter of the bone, and 3-4mm pins should be used instead.

Radius: At the proximal third of the radius, the dorsal surface is obscured by the variable course of the posterior interosseous nerve. Accordingly, pin placement should be limited to the radial surface of the more palpable middle and distal third of the radius to avoid injuring the radial nerve motor branches. An incision allowing sufficient dissection to expose and retract the branches of the superficial branch of the radial nerve and underlying tendons is necessary to avoid entrapment or damage of these structures. As with the ulna, 3-4mm diameter pins are often more appropriate due to the size of the radius at the location the pins are being placed.