While instances of trepanation have been documented in Neolithic Europe, proof of other types of surgical intervention, notably amputation, are extremely rare. They are, in fact, difficult to identify on ancient bones often in a poor state of conservation.  The man buried was oriented east-west, head to the east, facing south. Lying on his left side, flexed, with knees brought up, his position is also typical of this period. The left upper arm is slightly away from the upper body. No trace of the left forearm was found, and nothing can explain this absence.
As soon as the bones were found, anthropologists and archaeologists expressed the hypothesis of an amputation, based on morphological observations. A study shows today that the distal end of the humerus shows a clear cut whose origin is traumatic rather than a malformation.  Radiological and mictrotomographic examination resulted in a three-dimensional reconstruction of the bone. All the images show signs of healing of the bone. The cuts are located at a place where the bone was particularly robust, and difficult to cut, especially if using flint. It would have been much easier to cut on the diaphysis.  Whatever the reason of the traumatism (accident, etc.), the forearm was partially severed by breaking the bone. The surgical intervention was practised by cutting only what was still attached. Thus, it was not an accidental amputation but a true medical choice.  This operation can be reconstituted: the surgeon proceeded from the anterior towards the posterior side and the weight of the forearm, perhaps aided by the surgeon, caused the last few millimetres of cortical bone to break away, as when cutting a piËce of wood. The arm was probably slightly raised to allow the elbow to be extended. The fact that the bone healed shows that the patient survived. The absence of infection showed that the aseptic conditions were relatively good.
 
Amputation was extremely rare in Prehistory and until now only two cases dating from the Early Neolithic period in western Europe have been found: Sondershausen in the east of Germany and Vedrovice, in  Moravia (Czech Republic). Buthiers-Boulancourt is thus today the oldest case of amputation in France. This discovery had benefitted from the latest techniques of archaeological and of medical imaging.