Painboy

(also known as 'Mad Doks' or 'Doks') are a class of Ork Oddboy and are responsible for fixing injuries that the Ork physiology can't deal with, such as totally severed limbs and brain damage. They use "Stabby Bits" as their medical tools. An Ork will only go to a Painboy when he has no other choice, as these Oddboyz are infamous for trying out experimental procedures (such as the greatly feared squig brain transplant) on patients while they are under anesthesia (known as "concussion" to other races). Painboyz are responsible for attaching bioniks, although sometimes they aren't paying attention and replace the wrong part of the patient's body. High-ranking Painboyz are called Painbosses and are known to be accompanied by Cybork bodyguards. Orks are surprisingly resilient and have had arms, legs and even heads swapped around and the Ork in question has survived to tell the tale!

Sources

Codex: Orks (4th Edition)