Iatrogenic Nerve Injuries in the Treatment of Supracondylar Humerus Fractures: Are We Really Just Missing Nerve Injuries on Preoperative Examination?

BACKGROUND:Recent studies report the rate of iatrogenic nerve injury in operatively treated supracondylar humerus (SCH) fractures is 3% to 4%. A reliable neurological examination can be difficult to obtain in a young child in pain. We hypothesized that nerve injuries may be missed preoperatively, later noted postoperatively in a more compliant patient, and then falsely considered an iatrogenic injury. METHODS:A prospective study was conducted on patients who presented between April 2011 and April 2013 with an extension-type SCH fracture that was managed surgically. A neurological examination was performed preoperatively, postoperatively, and at follow-up visits by a fellowship-trained attending pediatric orthopaedic surgeon. Only patients in whom the attending surgeon felt a reliable neurovascular examination was obtained were included in this study. RESULTS:Of the 100 patients, 16% had a nerve injury recognized on preoperative examination and 3% had a new nerve injury on postoperative examination (1 anterior interosseous, 1 median sensory, and 1 radial motor). The Gartland type (P=0.421), type of reduction (open vs. closed; P=0.720), and number of lateral-entry (P=0.898) or medial-entry (P=0.938) pins used were not associated with patients who had a new nerve injury found postoperatively. A trend was seen between fracture severity and rate of a preoperative nerve injurytype II 7% (2/28), type III 19% (9/58), and type IV 36% (5/14) (P=0.058). Preoperatively, nerve injuries were noted at the following ratesmedian 12% (12/100) (including 8 anterior interosseous nerve injuries), radial 8% (8/100), ulnar 3% (3/100). CONCLUSIONS:In this prospective study, in patients who were able to comply with a preoperative neurological examination done by an attending pediatric orthopaedic surgeon, the rate of iatrogenic nerve injury after operative treatment of SCH fractures is 3%. We conclude that this finding is true, and not a result of inadequate preoperative neurological examinations. LEVEL OF EVIDENCE:Level I prognostic study.