Originally Posted by Excargodog

Typically a 0% disability is a placeholder for something expected to deteriorate in the future. An example would be a serious knee joint injury. Right now the guy/gal has good strength and full range of motion, but them eventually getting degenerative arthritis is a virtual certainty and at some time in the future maybe even a knee joint replacement. A 0% establishes the service-connectedness of the condition, particularly important to those who separate before retirement and don't have access to Tricare or Uniformed Services care.