Staples can be used in the foot for a number of problems, though often to fuse arthritic joints.
It is also unclear where "90% damage" comes from. Is that from nerve conduction velocities? Is that from intra-operative findings of a 90% severed nerve?
Nerve injuries fall into 3 main categories:
1. Neurapraxias--these are stretch/bruise/compression
injuries where the nerve is not disrupted. It usually takes around 3 months for the nerve to recover and these tend to do well. Nerve pain
can be an issue while the nerve recovers.
2. Axonotmesis--these injuries involve disruption of some of the nerve fibers (axons), but not the outer structure of the nerve. These can recover by regrowing the axon
. The nerve rests for about a month, then sprouts new axons which grow at a rate of about 1mm/day. Depending on the distance from the nerve injury
to the target tissue (muscles or skin), the functional recovery can be quite good. However, after about 1 year, the muscles lose their ability to recognize nerve signals and cannot recover.
3. Neurotmesis--these injuries involve disruption of the nerve structure and may be partial or complete. In this case, the nerve will still try to grow new axons, but they may not find the other end of the nerve and may ball up into a painful nodule
called a neuroma
. These injuries have the worst outcomes.
So, depending on the location and nature of the nerve injury, it may or may not recover. Often a waiting period of 3 months is used to allow injuries that will recover to do so. After that, surgery may be helpful, but has to be worth the anticipated benefits and recovery time.