Effectiveness of ultrasonographic evaluation under general anesthesia for radial nerve palsy associated with humeral fractures during the first operation

Purpose To evaluate the effectiveness of sonographic evaluation of the radial nerve at the first operation for closed humeral fracture cases. Methods Seventeen cases of closed humeral fractures were included in this study. These cases were categorized into two groups: Group P, consisting of seven cases with complete radial nerve palsy after the injuries; and Group C, consisting of ten cases without radial nerve palsy after the injuries. Sonographic evaluation of the condition of the radial nerve was performed before or after open or closed reduction and internal fixation (ORIF or CRIF) during the first operation. Results Five of seven Query ID="Q2" Text=" As keywords are mandatory for this journal, please provide 3-6 keywords." cases in Group P showed entrapment or compression of the radial nerve at fracture sites with sonography. Simultaneous radial nerve exploration (SRNE) confirmed sonographic findings in these five cases. The other two cases showed no abnormal sonographic findings except swelling of the radial nerve. CLIF without SRNE was selected and additional sonographic reevaluation of the nerve after CRIF confirmed there were no iatrogenic nerve injuries in these two cases. All of the ten cases in Group C showed no abnormal sonographic findings of the radial nerve. Five of these ten cases selected ORIF, exposed the nerve at the time of approaching the fracture site, and matched sonographic findings. The other five cases without exposure of the nerve confirmed no iatrogenic radial nerve injuries with additional sonographic reevaluation after ORIF or CRIF. All cases in Group P had complete resolution of radial nerve palsy within 4 months postoperatively, and no case in Group C had postoperative iatrogenic radial nerve palsy. Conclusions Sonographic evaluation of the radial nerve at the first operation was a useful method to detect conditions of the nerve which can prevent compression or entrapment of the nerve and the need for secondary nerve exploration.