I have bilateral pars defect in c5, what does this mean?

C5 pars defect. Are you sure it is c5? L5 (lower back) is much more common... Just checking. If it is indeed c5, there is neck pain and possible instability that may need to be addressed surgically. Please check with a good local ortho spine surgeon to get a good understanding of what you have and make an eductated decision after that. Best of luck!