(4) physical and mental restoration services, including, but not limited to, (A) corrective surgery or
therapeutic treatment
necessary to correct or substantially modify a physical or mental
condition which is stable or slowly progressive and constitutes a substantial handicap to employment, but is of such nature that such correction or modification may reasonably be expected to eliminate or substantially reduce the handicap within a reasonable length of time, (B)
necessary hospitalization in connection with surgery or treatment.