77 Pa. Stat. § 1023
Nothing in this act shall affect or impair any right of action which shall have accrued before this act shall take effect, except that, because litigation is now pending as to the constitutionality of the compensation schedules contained in the amendment of this act, approved the fourth day of June, one thousand nine hundred and thirty-seven (Pamphlet Laws, one thousand five hundred fifty-two), the department is hereby authorized to approve agreements or supplemental agreements, and the board and referees are hereby authorized to make awards effectuating agreements, compromising disputes between employers and employes or their dependents, as to the amount of compensation payable in cases arising out of injuries occurring between January first, one thousand nine hundred and thirty-eight and the effective date of this reenactment of this act, if such agreements or supplemental agreements provide for, or the parties to cases pending before the board or referees have agreed to, the payment of compensation at the rates and for the periods specified in this reenactment of this act.
77 P.S. § 1023