Appellant served honorably in the United States Air Force from December 12, 1956, until January 15, 1959. R. at 17, 61, 114. The Veterans' Administration (now Department of Veterans Affairs) (VA) Chicago, Illinois, Regional Office (RO) granted service connection for appellant's disability resulting from postoperative residuals of a left medial meniscectomy with degenerative joint disease, and initially evaluated this disability as 0% disabling (noncompensable) from March 1, 1975. See R. at 17, 63. On February 2, 1984, after reviewing the results of a December 7, 1983, examination (not of record), which found that "anterior drawer and Lachman tests conducted on appellant's knee were mildly positive, [and] the pivot shift test is grade I/II and patella-femoral crepitus is clearly heard," the RO concluded that appellant's condition had reached a compensable degree of disability, and evaluated appellant's left knee condition as 10% disabling, effective September 22, 1983. R. at 17. A September 4, 1984, RO decision resulted in an increase in appellant's left knee disability rating to 20%, effective August 9, 1984. R. at 18. On January 1, 1986, the Board denied appellant's claims of entitlement to an effective date for a compensable rating earlier than September 22, 1983, and to a rating in excess of 20% for his left knee condition. R. at 19-25. On March 3, 1987, the Board again denied appellant's claim of entitlement to an increased (compensable) disability evaluation for his left knee condition prior to September 22, 1983. R. at 28-33.