Accuracy of blind versus ultrasound-guided suprapatellar bursal injection.

PURPOSE: To compare the accuracy rates between ultrasound (US)-guided and blind knee intra-articular injection via the suprapatellar bursa.

METHODS: Ninety-nine patients with radiographically confirmed knee osteoarthritis (Kellgren/Lawrence grade 2 or 3) without effusion were included. Fifty patients were assigned to the US-guided injection group and 49 to the blind injection group. After a US-guided or blind injection of hyaluronic acid (HA) and contrast dye through the suprapatellar bursa into the knee joint, a radiographic image was obtained in each case to ascertain whether all injected material had reached the intra-articular space.

RESULTS: US-guided HA injection exhibited a significantly greater accuracy (48 of 50 knees, 96.0%) than blind injection (41 of 49 knees, 83.7%).

CONCLUSIONS: Intra-articular injections through the suprapatellar bursa under US guidance increased the accuracy of knee joint injections.