抄録
Objective: Qvistgaard, et al. and Im, et al. reported the feasibility of guidance using ultrasound (US) for intra-articular hyaluronic acid (HA) injections for patients with knee osteoarthritis (OA) using lateral and medial patellar approaches, respectively. This study was designed to compare the accuracy rates and intensity of pain on injection between the lateral and medial approaches.
Methods: One hundred and sixteen patients with “dry” knee OA received injections using the lateral and medial approaches. Air (1 ml) was injected with simultaneous recording of US signals. Once intra-articular positioning of the needle was considered adequate, HA was injected and lateral radiographs were taken to confirm the accuracy from the air shadow. After each injection, participants reported the highest subjective pain level during injection using a visual analog scale (VAS).
Results: The accuracy rates when using the medial approach (110 out of 116, 94.8%) were significantly higher than those when using the lateral approach (96 out of 116, 82.6%), (P=0.003). However, the mean VAS pain level for injection via the lateral approach (31.2%±21.2%) was significantly lower than that for injection via the medial approach (38.4%±20.6%), (P=0.01).
Conclusions: In the lateral approach, the straight surface of the US probe does not match the curved surface of the thigh and the direction of the needle at the insert site was unclear. In the medial approach, the needle punctured through retinaculum tissue to reach the intra-articular space, and thus the VAS pain level during the injection was higher compared with that of the lateral approach.
