Time to Recovery of Radial Nerve Palsy After Surgically Treated Humeral Shaft Fractures

Purpose: The purpose of this study was to report a timeframe for neurologic recovery of complete radial nerve palsies in patients with humeral shaft fractures treated with internal fixation. Methods: We retrospectively analyzed the data of patients who underwent surgical treatment of a humeral shaft fracture between 2016 and 2021 at a level I trauma center. Patients with complete sensory and motor radial nerve palsy were identified. The time elapsed until detection of the first clinical signs of neurologic recovery, and then until full function (M5 according British Medical Research Council scale) was measured. Results: Of 32 radial nerve palsies in 471 surgically treated humeral shaft fractures (6.8%), 17 were recorded at the time of injury and 15 were noted after surgery. Median patient age was 31.5 years (range, 19–58 years). Thirty patients recovered full motor function at a median time of 36 weeks (range, 6–83 weeks). Kaplan-Meier analyses showed that 90.6% of patients presented the first signs of nerve recovery in the initial 6 months of observation. At 12 and 18 months of follow-up, 84.3% and 94% of patients, respectively, had recovered full function of the hand and wrist. Conclusions: Surgically treated humeral shaft fractures associated with radial nerve palsies are expected to show signs of neurologic recovery during the first 6 months and should recover completely after 12 months of follow-up in almost all cases. Type of study/level of evidence: Prognosis II.