<s>[INST] I am 52, about 195 lbs and 6 3.I have had two ACL replacements and a third surgery on left knee, found out I no longer have an ACL. I have been expierencing what seems like a deadness in my knee after prolongedwalking. I work for a major railroad and am constantly walking on uneven surfaces,It seems my knees goes dead,then my hip gets really sore, I feel myself walking differently then my lower back starts aching badly. I guess my question is what can I do? I amnow toldi have a bulging disc in the l5 s1 area. [/INST] Hi, As you mentioned that you have two ACL reconstructions previously but still you don't have ACL in your left knee, so whether the left ACL failed again or it is the right knee for which ACL reconstruction done twice. Whatever the case if you are involved in tasks that involve walking frequently and on uneven surfaces you need to have ACL reconstruction on the left side. Secondly, for disc herniation at L5-S1 level, further line of management depends on the amount of herniation as well as on the severity of symptoms and their response to conservative treatment. Usually, we do surgery for disc herniation in case when conservative management fails over a period of 3 weeks, or there is acute and progressive neurological deficit or there is severe uncontrolled pain. Take care. Hope I have answered your question. Let me know if I can assist you further.  </s>