GS trained hand surgeons are a rare breed.
I think only a dozen or so GS sit for the Hand board exam each year, maybe fewer.
The job prospects for GS trained hand surgeons is limited, because most groups looking for a hand surgeon will also be looking for a surgeon to take general ortho call.
There are a few dedicated 'hand centers' around the country, but most are controlled by orthopods, and tend to hire orthopods.
Perhaps you could convince an HMO to hire you to do both hand surgery and general surgery clinic and call.
The other thing to consider is the patient population you're dealing with. A lot of hand injuries occur in uninsured patients, or Medicare patients...blue collar folks with power saws etc. Reimbursement will be a problem, especially if you're in private practice.
I'd consider doing a vascular or onc fellowship instead.
Just my opinion.