Thank you for your question to HCM.
You had pain while waking up and getting out of bed. This can not be from fracture
as you have not done anything that can cause a fracture. As you have described that you had fusion in back it is always a possibility that the disc at the next level might have herniated which is at increased risk.
What I would suggest to my patients with similar symptoms is if it has happened only once there is not much to worry about. Over the counter ibuprofen
will suffice to control pain. Local heat will alleviate pain as well. If the symptoms are recurrent over a long period of time and start happening frequently you will need to see a spine surgeon
for Xray and MRI of lumbar spine
to explore the possibility of disc problems as described above.
Hope this is helpful. If you have any questions I will be happy to help.