From the Research
Intraarticular knee injections should be performed lateral to the patellar tendon, as this approach has been shown to have a higher accuracy rate and is generally preferred. When performing a knee injection, the most common technique is to access the joint from the lateral side of the patellar tendon with the knee flexed at 90 degrees. This lateral approach is favored because it typically provides easier access to the joint space and avoids the infrapatellar branch of the saphenous nerve, which runs medially. The lateral approach also tends to be less painful for patients. To perform the injection, the clinician would identify the space between the patella and femoral condyle on the lateral side, clean the area with antiseptic, and insert the needle horizontally or slightly upward into the joint space.
Some key points to consider when performing an intraarticular knee injection include:
- The lateral approach has been shown to have a higher accuracy rate, with a study published in the Journal of the Medical Association of Thailand finding an accuracy rate of 77.3% using the lateral mid-patellar approach 1.
- The choice between approaches may sometimes be influenced by individual patient anatomy, presence of effusion, or clinician preference.
- While the medial approach is also anatomically feasible, it's generally considered a secondary option due to the increased risk of nerve injury and often more challenging anatomical access.
- A study published in Acta orthopaedica et traumatologica turcica found that the medial patellofemoral angle was significantly higher than the lateral patellofemoral angle, suggesting that the medial approach may be more accurate in some cases 2. However, this study was published in 2015 and has been superseded by more recent research.
Overall, the lateral approach is generally preferred for intraarticular knee injections due to its higher accuracy rate and ease of access to the joint space.