I have read up a little bit about this "terry thomas sign" or a form or indication of scapholunate instability due to a gap.
As far as I understand it it all boils down to the fact that surgery reduces pain and some motion problems, but it does not repair strength or pressure/strain capacity.
As that seems to be the case strength training would be unadvisable because the surgical repairs can become undone because of the stress and strain on the reapired areas. This can lead to a recurrance of the previous problem or it can mean that the stress on the repairs themselves cause a whole different, even worse, problem.
I think high-level strength training is out of the question.
BUT that does not necessarilly mean you can not do a lower volume workout.
I would ask your doctor and physiotherapist about ways you can still workout and if there are some tools with which you could move stress way from the wrist towards the upper forearm above the wrist.
Most of all...don't take advice without thinking about consequences and running it past a medical expert.
disclaimer:
I have no personal or secondhand experience with this...and I am not a doctor.. My advice or my suggestions are by no way an educated alternative or substitute for trained medical advice!