Im not an orthopedic surgeon, however, if I recall correctly from my internship years...reattaching a torn tendon is relatively straightforward and can be done years later, unfortunately, the strength and pliability of the tendon suffers. Torn muscles basically are reattached by oversewing, and the cosmetic result is not ideal to say the least (see DY for example).
Repairing nerve damage such as Colemans or Cutlers, w Hemiatrophy of the entire body is not as easy. Depends if the damage is second to a herniated disc, which can be repaired (discectomy, etc...) or higher up in the CNS (stroke).
