Learning curves of two different techniques for the intra-articular injection of the knee joint under fluoroscopic guidance

Learning curves of two different techniques for the intra-articular injection of the knee joint under fluoroscopic guidance

La radiologia medica, January 2018

29292479

Paolo Simoni, Olivier Malaise, Mounia El Hachemi, Angelo Tromba, Grammatina Boitsios

The aim of the study was to compare the learning curves of three beginner operators using two different techniques of intra-articular injection of the knee under fluoroscopic guidance with a superolateral approach. In total, 177 consecutive patients (72 females (40.7%) and 105 males (59.3%), mean age 42.2 ± 15.0 years) scheduled for a computed tomography (CT) arthrography and without joint effusion on the lateral X-rays were enrolled. They underwent an intra-articular injection of the knee under fluoroscopic guidance with a superolateral approach. Patients were randomly assigned to three different operators, including a junior supervisor and two first-year residents in radiology who never performed an intra-articular injection of the knee before the present study. Procedures in lateral or supine position were randomly assigned to three operators. There was a higher rate of successful injections with the lateral position (92.1%) than with supine position (80.2%) (odds ratio (OR) 4.52, 95% confidence interval (CI) 1.46-14.0). A significant learning effect was observed for the supine position, while none was observed for the lateral position. Pain and time of fluoroscopy did not differ between the two procedures (p = 0.85 and p = 0.10, respectively). Junior supervisor had a higher rate of successful intra-articular injection compared with the other two operators (p = 0.0072). There was a statistically significant higher rate of extravasation with the supine position (66.3%) than with lateral position (19.7%) (p < 0.0001, OR 0.13, 95% CI 0.06-0.25). The intra-articular injection of the knee under fluoroscopic guidance with the patient in lateral position is an easy technique for operators in training with a low rate of extravasation. Lateral position does not require a supplementary irradiation and does not increase the procedural pain. Personal operator's skill is an independent factor in determining the success of the training.