Comparison of infracondylar versus subsartorial approach to saphenous nerve block: A randomized controlled study.

BACKGROUND AND OBJECTIVES

Only a few different approaches are currently utilized for saphenous nerve block. Our study aimed to compare two different ultrasound (US)-guided saphenous nerve blocks and designed this study to test the hypothesis that the medial infracondylar approach has more success rate than the subsartorial approach applied in saphenous nerve blockage.

METHODS

The study included 76 patients (18-65 years old) with the American Society of Anesthesiologists physical status of I-III, who were scheduled for below-knee surgery by the orthopedics clinic. The patients who underwent US-guided saphenous nerve blockade were randomly divided into two groups: Group S (subsartorial approach) and Group M (medial infracondylar approach). For all patients who had a block procedure, the pinprick test was performed using a blunt needle on the saphenous nerve dermatome. Success rate, time of block performance (TBP), onset time of block (OTB), and duration of sensory blockade (DSB) were recorded using a patient follow-up form.

RESULTS

The US-guided saphenous nerve block success rate was similar (88% vs. 91%) or both techniques. The DSB values were 415.2 ± 65.3 min (95% confidence interval [CI]: 286.3-539.8) for Group S and 369.7 ± 52.2 min (95% CI: 265.6-467.8) for Group M ( = 0.04), and no significant differences in the TBP and OTB were observed between the groups.

CONCLUSION

Both of the different anatomical approaches have equally high success rates. Although the DSB was found to be significantly longer in the subsartorial approach, this is clinically unimportant, and the medial infracondylar approach is still a viable alternative technique during saphenous nerve blockage.