Hi there and thanks for your post on the Forum. It's interesting that you mention the shower and heat causes numbness. This might be a cause of the area being hypersensitive following the initial injury. It could also suggest that you might have a referred sensitivity that could be neural origin, e.g that when you had the incident you tweaked the back or even the proximal Tib/fib joint at the side of the knee. Unless the swelling is significant I would not focus on that too much if as you suggest your current scans are not picking up anything. Of course there are other investigations but they could be another option later if required (e.g. a bone scan).

So as a first step I would get the physio to take another look to see if the surface is hypersensitive (a superficial nerve trauma might take 18 months to heal). Also check the lumbar spine and tib/fib joint for any referral. Ideally we want to see if some mobilisation can reduce the walking discomfort during the same PT session. Although I am not a keen recommending pull-on type knee braces, it can sometimes be useful to use an elasticated type pull on sleeve to give some general compression and proprioception to the joint, and as they are inexpensive it might be worth giving one a try too.

Let us know how you get on and we can provide some more input.

Also if you have a copy of the MRI and Arthrogram reports do share them with us.

regards