Assessment of posterior, lateral, and medial techniques for ultrasound-guided popliteal nerve block: A randomized clinical study

Background: The popliteal block is frequently employed for analgesia and anaesthesia in below-knee surgical procedures. This study evaluates ultrasound-guided popliteal blocks using different approaches (posterior, lateral, and medial) to ascertain the optimal method concerning block performance time and patient satisfaction. Methods: This randomized trial included 120 ASA physical status I and II patients scheduled for below-knee surgery. Based on the ultrasound-guided popliteal block method, patients were randomly assigned to three equal groups: posterior (P), lateral (L), and medial (M). We recorded technical characteristics (number of attempts to locate the injection site and block performance time), positioning and needle insertion discomfort, and complications.Results: The mean block performance time was 9.5±2.15 minutes for P, 5.6±1.25 minutes for L, and 5.35±1.35 minutes for M groups. The block performance time was significantly greater in the (P) group (P1 < 0.001 and P2 < 0.001), while the (L) and (M) groups had comparable timings (P3 = 0.77). There was no significant difference in the total number of tries between the three methods for determining the injection site. The posterior technique had more positioning difficulty than the other two, although the lateral and medial approaches had higher needle insertion discomfort. None of the three methods had complications.Conclusions: The medial and lateral methods with ultrasound-guided popliteal blocks demonstrated reduced block performance time and little patient positioning changes compared to the posterior strategy. Nevertheless, the posterior procedure diminishes needle insertion discomfort while preserving patient satisfaction across all techniques.