Does Injection Site Matter? A Randomized Controlled Trial to Evaluate Efficacy of Knee Intraarticular Injections on Improval of Patient Reported Outcomes.

Knee osteoarthritis is one of the most prevalent orthopedic conditions worldwide. With the aging population, a 40% patient increase is expected to present at clinics with complaints of primary osteoarthritis by 2025. Multiple studies have attempted to establish non-surgical criteria for knee arthritis and usage of resources to avoid major surgery. It has long been accepted as a treatment option for patients who have failed to respond to NSAIDs and other non-surgical therapies to receive intra-articular injections of steroid and anesthesia mixtures to hold off disease progression.

Various studies have compared different sites of injection and the accuracy rate of the injection being within the joint. Recent studies report a 66% accuracy on palpation-guided injection on the anterolateral knee, 93% accuracy on palpation-guided injection on the superolateral portal of the knee, and new studies show an improvement of up to 98% with use of ultrasound guiding software. However, in a health care system with limited resources, providing patients with US-guided injections represented an increased cost of $178.35 per patient as per 2010 Medicare reports.

Therefore, assuming these accuracy rates, we will compare the anterolateral and superolateral portals for knee injection and their clinical effect to monitor if in fact there is a difference in patient reported outcomes. As a secondary analysis, if no difference is found, a strong case for palpation-guided injections versus ultrasound-guided injections can be made.

In this study we will prospectively enroll 60 patients to be divided into two 30 patient groups with primary knee osteoarthritis. Patients that qualify as subjects will be treated with an intraarticular knee injection through an anterolateral portal or a suprapatellar portal as per group in which they are placed. Scores will be given for pain of the injection and of the baseline illness and compared on a subsequent visit to assess self-reported functional outcomes.