What a brilliant forum this is, I hope somebody will be able to help me with understanding my MRI results.

I've had lower back pain for approx 4 - 5 years, and it's really kicked in hard over the last 12 months. Walking for any length of time is difficilt along with the pain which radiates down my right leg, classic sciatica signs I'm told. My GP referred for Physiotherapy which over the course of 12 weeks didn't help much, if at all. Eventually I was sent for an MRI, the results of which are below:

• There is degenerative disc disease with marked height reduction at L5/S1. A prominent posterior disco-vertebral protrusion at this level which is mildly indenting on both S1 roots.

What this is saying is that you have degeneration of discs which is causing loss of height between the vertebrae and essentially squishing outwards toward either side of the vertebrae. This is causing the ‘indention’ or pressure on the S1 nerve roots. Degeneration is common and can be caused by the natural aging process, prior injuries, poor posture and even made worse by lack of exercise. Many people have degenerative disc disease and don’t even know it but because according to your MRI it is mildly pressing on the nerves this can cause pain.

• The other disc heights and vertebral alignment are maintained.
• Mild posterior degenerative disc bulge is seen at L4/5. Also at L4/5, there is a right-sided posterolateral disc protrusion with mild to moderate indentation of the right L4 root exiting canal.

This one indicates that the degenerative disc bulge is protruding more towards the backside of your spine (instead of outward or to the sides like above on S1) but, the disc height is not mentioned which indicates that as far as that is concerned there isn’t an issue. Then in goes on to say that actually the protrusion is posterolateral meaning backwards and to the side which is causing protrusion of the disc into the right side of the nerve root at L4. This along with your symptoms of right sided leg pain confirms that the pain is likely coming from the L4 nerve root.
From your description of symptoms down your leg it makes sense that you would have pain down the back and the side along with pin/needles/numbness on occasion. L4 is more likely your bigger pain trigger but, that isn’t to say that S1 doesn’t cause pain just that L4 is worse especially considering the S1 is bilateral (or both sides) but you are only commenting on the right which indicates that L4 is where one would focus first. An epidural steroid injection will likely be recommended as further confirmation that by releasing or temporarily medicating that nerve compression that your symptoms will improve or better yet disappear entirely. Some people get significant relief for many months with one or two injections, this is great because it will allow you to work diligently at improving posture, strengthen your back/core and start a regular walking (or other exercise program) daily before having surgery which will also improve your recovery time and give you the best chance of long term success with minimal surgical intervention.

My physio therapist suggests I should have surgery, as does my GP. I am being seen by a Neurologist in April, and have also been referred to a Neurosurgeon, still waiting for an appointment.
I am not a doctor but based on my own personal experience this would seem like a likely recommendation but, as always first try and exhaust all non-surgical interventions first and commit yourself to regular exercise to promote healing and less stress on the spine

Obviously, understanding what the MRI says will help me somewhat to understand what the situation is before I seen any of the specialists and can make an informed decision on what to do.
It does help to have a better understanding! I hope I was able to help you understand a little more. Wishing you a speedy recovery!!