I am a 49 year old competitive runner with left L5-S1 facet arthritis.
The facet joint on the affected side has an abnormal angle (more sagittal) compared with the unaffected right side. About 8mos ago I developed severe pain while training. Initially it was dx'd as disc herniation (no imaging done) although pain was atypical as it did not radiate below the buttocks, and maneuvers that often produce discogenic pain were negative.
MRI eventually done showed normal discs but facet arthritis as mentioned. Subsequent CT scan showed arthritis with hypertrophied joint capsule, osteophytes, probable ostephyte fx as a cause for sudden pain, and abnormal sagittal joint orientation. I had no pain for the previous 49 years here. I have no pain at rest or while walking. Can run up the stairs with no pain. I obviously want to return to running but am weighing the risk of worsening the problem against refraining from my passion and being miserable. Life is short. Anyone with similar history have a successful return to running .