Benito,
There is a third party utility that could be helpful here. Please refer to the following article:
https://support.ptc.com/appserver/cs/view/solution.jsp?n=CS104751
Technical support also has some tools in-house that can be used for data recovery. Please note that in all of these cases that the sid_*.wfcont or lid_*.wfcont files must also still exist in the cache in order to be able to recover the files.