In Hopkins v. Industrial Commission, 176 Ariz. 173, 859 P.2d 796 (App. 1993), the claimant received an award of scheduled permanent partial disability benefits for a 1986 knee injury and continued working. Id. at 174-75, 859 P.2d at 797-98. By 1991, his knee injury had deteriorated and he could no longer work. Id. He petitioned in 1991 to reopen his claim to seek additional disability benefits pursuant to either Dutra v. Industrial Commission, 135 Ariz. 59, 659 P.2d 18 (1983) or a 1987 amendment to A.R.S. 23-1044(B)(21) (Supp. 1992) that increased benefits for an employee unable to return to his pre-injury work. Id. at 176, 859 P.2d at 799. The ICA denied the petition to reopen. The Court set aside the award, finding that the claimant had established that he was entitled to reopen to have the ICA consider his inability to perform his pre-injury employment under Dutra. Id. at 177, 859 P.2d at 800. The Hopkins court decided, however, that the 1987 statutory amendment was not applicable. The court stated: "Statutes in effect on the date of injury govern a claimant's substantive rights. Because A.R.S. section 23-1044(B)(21) was amended in 1987 and Claimant's injury occurred in 1986, this statute is not applicable to this case." Id. at 176-77, 859 P.2d at 799-800.