Brian, may be you should ask of your doctor if the changes to your lumbar sacral junction (L5-S1) are the result of the fall or if it is likely there has been some deterioration of this joint over a long period of time - the phrase "mild subacute to chronic degenerative spondylosis of the lumbar spine" may suggest that the deterioration has not happened overnight. If this is the case then you could then ask of your doctor why these changes are taking place, may be there is something in your posture / lifestyle / work that is causing undue wear and tear on your lower back - Seriously you do need to get some good professional advice, long term lower back problems need to be avoided like the plague.