Soft tissue dissection
Blunt dissection of the soft tissues and the use of small Langenbeck retractors will prevent damage to muscular, vascular and neurological structures.
Prepare a channel for insertion of the pin, using a blunt clamp down to the bone. If there is any doubt an incision should be made big enough to prove that the drill sleeve (for the humerus a must) will have direct contact with the bone.
Be especially careful of the radial nerve, which spirals around the humeral shaft and, in the distal third, it intersects the lateral intermuscular septum.