Abstract
BACKGROUND: Several studies have been performed suggesting that a superolateral approach to cortisone injections for symptomatic osteoarthritis of the knee is more accurate than anteromedial or anterolateral approaches, but there are little data to correlate clinical outcomes with these results. Additionally, there are minimal data to evaluate the pain of such procedures, and this consideration may impact physician preferences for a preferred approach to knee injection. PURPOSE: To determine the comparative efficacy and tolerability (patient comfort) of landmark-guided cortisone injections at 3 commonly used portals into the arthritic knee without effusion. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Adult, English-speaking patients presenting to a sports medicine clinic with knee pain attributed to radiographically proven grades I through III knee osteoarthritis were randomized to receive a cortisone injection via superolateral, anteromedial, or anterolateral approaches. Patients used a visual analog scale (VAS) to self-report comfort with the procedure. Western Ontario and McMaster Universities Arthritis Index (WOMAC) 3.1 VAS scores were used to establish baseline pain and dysfunction prior to the injection and at 1 and 4 weeks follow-up via mail. RESULTS: A total of 55 knees from 53 patients were randomized for injection using a superolateral approach (17 knees), an anteromedial approach (20 knees), and an anterolateral approach (18 knees). The mean VAS scores for procedural discomfort showed no significant differences between groups (superolateral, 39.1 ± 28.5; anteromedial, 32.9 ± 31.5; anterolateral, 33.1 ± 26.6; P = .78). WOMAC scores at baseline were similar between groups as well (superolateral, 1051 ± 686; anteromedial, 1450 ± 573; anterolateral, 1378 ± 673; P = .18). The WOMAC scores decreased at 1 and 4 weeks for all groups, with no significant differences in reduction between the 3 groups. CONCLUSION: Other studies have shown that the superolateral portal is the most accurate. This study did not assess accuracy, but it showed that all 3 knee injection sites studied have similar overall clinical benefit at 4-week follow-up. Procedural pain was not significantly different between groups.