2 years post op fusion l3-l4 diagnosed with seroma been in pain the whole time after surgery is this something serious back, hip, leg pain. how treated?

See your surgeon : For something this serious, please contact your treating surgeon. If you no longer see than surgeon, ask your pcp for spine or ortho spine surgeon.

Maybe: A collection of fluid may be seroma or a pseudomeningocele. The latter is a spinal fluid leak that has collected but not enlarged or communicated with the skin. Sure, this could cause pain if there is a nerve trapped. I would suggest that maybe the fusion has not become solid (pseudoarthrosis) or there is a problem adjacent to the previous surgery from progressive arthritis. See your spine surgeon.