Corticosteroid Meniscectomy Randomized Trial

The purpose of this intervention is to determine the use of extended release steroid knee injection (Zilretta) at the end of the surgery and its effects on your knee pain.In this study Zilretta will be injected intra-operatively for your arthroscopic partial meniscectomy (APM) surgery.Participants will have MRIs x-rays, and provide a sample of the synovial fluid from both knees at the beginning of surgery. This fluid is drained at the beginning of surgery and then usually discarded. Three samples each of blood and urine will be collected over the study period from each participant and sample of joint (synovial tissue) taken. Participants will be asked to answer questions about knee pain.