Approach to Knee Injections: A Review of the Literature

Abstract

Many factors should be considered when managing a joint injection for an osteoarthritic knee. Along with the type of needle, medication to be injected, and how often the injections need to be done, the actual step-by-step procedure should be carefully considered. Studies have shown variability between medial vs. lateral approaches, and guidance by ultrasound or anatomical landmarks. The lateral midpatellar site was found to have a 93% accuracy compared to the anteromedial and anterolateral with only 75% and 71% accuracy, respectively (Strength-ofrecommendation - SOR B)[8]. Ultrasound has been shown to increase accuracy rates as well, providing 95.8% injection accuracy for the knee joint compared to only 77.8% without using any imaging (p < 0.001)(SOR C)[8]. Cost effectiveness is another issue and revolves around whether the increased benefits outweigh the cost of ultrasound in knee injections. Studies show they do in the hospital setting, with spending at 58% less on overall procedures ($224) compared to conventional (anatomically guided) methods (p < 0.0001)(SOR B)[10]. The aim of this literature review is to discuss the most up-to-date material on knee injections and the approaches which: 1) have the most efficacy, 2) produce the least side effects, 3) have the easiest inter-physician reliability, and 4) are most cost effective.