Radial nerve trapped posterior to the proximal fracture end after closed reduction of supracondylar humerus fracture in children: A case report

INTRODUCTION AND IMPORTANCE: Radial nerve injury is very common in supracondylar humerus fractures, but radial nerve entrapment between the fracture ends after closed reduction is very rare, and we report a case of radial nerve entrapment after closed reduction. CASE PRESENTATION: A 7-year-old boy was admitted to the Department of Pediatric Orthopedics 24 days after closed reduction of a supracondylar fracture of the humerus with radial nerve injury. Preoperative ultrasound showed radial nerve entrapment between the fracture ends, which was confirmed by surgery. After nerve release surgery, the radial nerve recovered well. CLINICAL DISCUSSION: How to treat supracondylar humerus fractures in case of nerve damage remains controversial. We presented a rare case with radial nerve injury after supracondylar humerus fracture caused complete motor palsy in which the main trunk of the radial nerve above the right elbow traveled posterior to the fracture site. Awareness of the status of the nerve before and after surgery can help in the clinical decision to perform a concomitant nerve exploration, and in the context of this, ultrasound may be more helpful. CONCLUSION: We recommend identifying the radial nerve using ultrasound during the closed reduction. If the nerve is entrapped between the fracture ends, exploration is recommended. For cases without entrapment, closed reduction with Kirschner wire fixation can be performed first, and the nerve should be re-examined with ultrasound.