Treatment of Post Traumatic Knee Osteoarthritis With Extracorporeal Shockwave Therapy

Inclusion Criteria: * Previous ACL reconstruction using an autograft or allograft in the knee with PTOA * Minimum of one year following ACL reconstruction surgery * Between ages of 18 and 55 * No clear contraindication to complete protocol including mechanical symptoms which would limit ability to complete the study * Score on KOOS for 2 of 4 domains (pain, symptoms, activities of daily living (ADL), quality of life (QOL)) of 85 or lower * Primary pain is coming from the knee * Diagnosis of PTOA based on clinical diagnosis and confirmation with radiographic evidence by a medical professional prior to study enrollment. If individuals have suspected OA based on impairments such as pain, they must have a score on KOOS for 2 of 4 domains (pain, symptoms, activities of daily living (ADL), quality of life (QOL)) of 85 or lower to participate in the study. Exclusion Criteria: * Have previously received injections to the knee joint within the past 3 months * Women who are pregnant or those who are planning to become pregnant. This is due to the fact that pregnancy will reduce participants activity after the treatment and the safety concerns related to shockwave treatment. - Participants with neuropathy affecting sensation to pain * Participants with a known underlying cardiac disease that could be affected by shockwave therapy * Chronic rheumatological conditions, immunodeficiency, severe asthma, connective tissue disorder (i.e. Ehlers-Danlos Syndrome), or other medical conditions (ex. active malignancy, severe asthma) outside of PTOA that are known to impact inflammatory state or requiring chronic use of oral or intravenous immune modulatory medications. Asthma requiring use of inhalers only is not an exclusion criteria * Neuropathy diagnosis that can affect response to pain * No active use of oral steroids or anti-inflammatories at the time of enrollment * Have bilateral ACL injury or reconstruction surgery, or have had ACL revision surgery * No active malignancy and at least five years in remission * Previous ESWT treatment using study treatment devices for management of knee osteoarthritis * Have a pacemaker, bone screws, or any other metal implants that would prohibit participation in an MRI scan or EWST * Non-English speaking individuals