A 54-year-old German dairy farmer became the only person in the world to receive a full arm transplant in July. Now, more than two months later, Karl Merk said he is extremely happy with the transplant.

"The feeling is indescribable," Merk said as he showed off the new limbs, which are supported by a special "corset" while the healing continues. "Every day I gain more mobility."

Merk lost both arms in a farming accident six years ago. Two attempts to attach artificial protheses failed, leaving Merk completely reliant on others to care for him.

No signs of rejection

In desperation, Merk turned to doctors at the Technical University in the southern German city of Munich for advice. Doctors at the university's Rechts der Isar Clinic decided Merk would be a good candidate for the experimental surgery.

Five teams of doctors performed the gruelling procedure over two days in July. One team removed the arms from a doner who had died only hours before while the other team prepared Merk for the transplant.

Hand and lower arm transplants are extremely rare and a double transplant which included the elbow joint and upper arm had never been attempted. It posed a great challenge for both the immune and circulatory systems, the doctors involved said.

There is "no sign" that Merk's body was rejecting the foreign tissue, as was feared before the procedure, according to doctors.