Intra-articular knee injections.Lateral or medial approach?

Abstract

Objectives: The purpose of the present study was to identify whether the medial or the lateral mid-patellar approach is the most reliable for intra-articular knee injections. Materials and Methods: By magnetic resonance imaging (MRI) the medial and lateral joint openings were measured in 76 knees. There were 38 knees with post-traumatic effusion and 38 knees without effusion. The medial joint opening was calculated on a T1-weighted transverse image by measuring the anatomic angle between the femur and the patella. The lateral joint opening was calculated in a similar way. Results: In both groups of patients statistically significant differences were detected between the medial and lateral patellofemoral angles with the medial patellofemoral angle being higher than the lateral. Conclusion: This study supports that the medial patellofemoral angle is significantly higher than the lateral both in healthy knees and knees with effusion. Therefore, the intra-articular knee injection is more accurate via the medial approach since the medial joint opening is larger than the lateral. DOI: 10.3944/AOTT.2015.14.0142 This abstract belongs to the un-edited version of the article and is only for informative purposes. Published version may differ from the current version.