One-year follow-up after treatment of proximal and/or middle one-third humeral shaft fractures with a helical plate: healing rates, complications and functional outcome measures

Background: Conventional plate osteosynthesis is a valuable treatment option in displaced proximal and/or middle one-third humeral shaft fractures. Nonetheless, this procedure can be complicated by a radial nerve palsy. To date, many surgical techniques have been developed in an attempt to minimize this high-impact complication. A helical plate has the potential to avoid an iatrogenic radial nerve palsy due to its design. This article aims to evaluate safety and functional outcomes of patients treated with a helical plate compared to conventional plate osteosynthesis. In particular healing rates, complications and functional outcome measures. Methods: We retrospectively included all patients with displaced proximal and/or middle one-third humeral shaft fractures who were treated with a helical plate from October 2016 until August 2018 at a single level-1 trauma center (AZ Groeninge, Kortrijk, Belgium). A self-molded long PHILOS plate (DePuy Synthes((R))) or a pre-contoured A.L.P.S proximal humeral plating system (Zimmer Biomet((R))) were used. Patient baseline characteristics and standard radiographs were obtained pre- and postoperatively. We retrospectively searched for complications. Patients were reassessed using the Disabilities of the Arm, Shoulder and Hand (DASH), Constant Murley (CMS) and EQ-5D-5L scores with a minimal follow-up of 1 year. Results: The humeral shaft fractures of all sixteen patients consolidated within 3 months and no iatrogenic radial nerve palsies were observed. One plate had to be removed after 1 year due to a late deep infection. With a minimum follow up of 1 year, the mean DASH score was 22 +/- 19 and the mean normalized CMS was 80 +/- 19. Conclusion: Operative treatment of proximal and/or middle one-third humeral shaft fractures with a helical plate is a safe procedure with good to excellent shoulder function at one-year follow-up. Contrary to conventional plate osteosynthesis, a helical plate has the potential to completely avoid a radial nerve palsy, while maintaining similar healing rates and functional outcomes.