The Veteran's claims for increased ratings and TDIU prior to April 1, 2017 were denied. The decision also noted that the Veteran's right knee replacement rating is at its maximum under DC 5055.

The Veteran's low back strain with pain and sacroiliitis with degenerative joint disease is currently rated at 20 percent, but the evidence does not meet the criteria for a higher rating.

The Veteran's claims for increased ratings and SMC were denied. The left knee disability, including instability with DJD and painful motion, was rated at 30 percent since 1946. A separate 10 percent rating was granted for painful motion of the left knee. Prior to December 30, 2019, a noncompensable rating was assigned for left knee scarring; from that date onwards, a 10 percent rating was granted.

The Veteran's claims for higher ratings for his right knee disabilities from August 10, 2010 to January 22, 2013 were denied as the evidence did not support a rating in excess of 10 percent for right knee laxity or osteoarthritis with limitation of flexion. A separate 20 percent rating was granted for limited extension.

The Board granted a 40% disability rating for the Veteran's lumbar disability from April 18, 2013 to July 22, 2015. The rating was denied in excess of 40% for the period from April 18, 2013 to February 14, 2017 and granted a 50% disability rating starting from February 15, 2017.