I had a lumbar spinal fusion of l4/l5 in may of 2012. i wasdiagnosed with nerve compression and stenosis. i am currently having leg weakness and back pain. could arthritis be involved?

See surgeon: Arthritis is usually involved in stenosis requiring fusion. If your leg weakness is new then this could be an urgent problem. It's possible that you could have herniated a segment above or below your fusion. You should speak to your surgeon asap if you have true neurological weakness in your legs.

Adjacent level: Question is are these symptoms new, or old symptoms pre op that are slowly getting better? I tell my patients expect a recovery period from 6 to 12 months with good days and bad days. If the weakness is new, a fusion can put stress on the level above and below. It's a little early for that but your spine surgeon may want to investigate first with x-rays and eventually with a myelogram or mri.

LBP: Depending upon your exam finding a follow-up mei of the lumbar spine is necessary.

Weakness 1 yr postop: Weakness that is new now 1 year postop is likely another problem. Pain and/or weakness that never really improved suggests a problem that was incompletely treated by surgery (missed a problem, unable to safely remove all pressure, etc). It is possible that adjacent segment has worn causing pressure now above or below your fusion. Disc herniation or other pressure could also be present. Get checkup.