I can t get my legs to straighten out when standing or sitting. I walk with both knees bent which is now causing low back pain. I experience pain in thighs when standing. I recently had blood tests showing I have a high level of ammonia in blood. I had bone marrow biopsy which was negative three months ago. I had CT Abd/Pelvis which shows enlarged spleen and scarring of liver. I do not drink alcohol but have had Crohn s disease for 40 years. I had total left knee replacement done Jan. 2014 and results have not been good. I got second opinion on left knee and xrays showed build-up of scar tissue.