The Board has granted the Veteran's claim for service connection for a back disorder, finding that it is at least as likely as not related to his service-connected bilateral knee disability. The claims for an initial rating in excess of 10 percent for left knee disability and service connection for right foot disorder are also pending.

The Board denied service connection for multiple conditions, including bilateral hearing loss and various musculoskeletal issues, as well as an initial rating in excess of 0 percent for rhinitis. However, the Board granted a 70 percent rating for posttraumatic stress disorder (PTSD).

The Board remands the claims for service connection for various disabilities to the AOJ for further development and consideration of evidence not previously considered.

The Board granted service connection for right knee, right hip, and lumbar spine disabilities as secondary to the Veteran's service-connected left knee disability but denied a rating in excess of 30 percent for his left knee disability prior to April 25, 2019.

The Board granted service connection for multiple disabilities, including cervical spine and thoracolumbar spine disabilities, radiculopathies, a bladder disability, headaches, a left knee disability, an acquired psychiatric disorder, and bilateral conjunctivitis. The Board also granted entitlement to a total disability rating based on individual unemployability due to service-connected disability.