High tibial osteotomy (HTO) fixation can be achieved using various plate designs. Compared with nonlocking plates, the stability of locking plates allows patients to return to weight-bearing and work sooner and may also decrease postoperative complications, introducing the potential for overall cost savings. However, material costs for locking plates are higher, and the plate bulkiness may lead to additional surgery to remove the plate. We conducted a retrospective study to evaluate the cost-effectiveness of a locking versus a nonlocking plate in HTO from both the health care payer and societal perspectives up to 12 months postoperative. We observed that from a health care payer perspective, the locking plate was not cost-effective. However, the locking plate was cost-effective from the societal perspective (addition of indirect costs, such as time off work). These findings highlight the importance of considering costing perspective in economic evaluations for chronic conditions, particularly in publicly funded health care systems.