Stability of Unicortical versus Bicortical Metacarpal Fracture Internal Fixation Trial (SUBMIT): study protocol for a randomized controlled trial

Background Metacarpal fractures are common, accounting for 40 % of all hand injuries. The use of plates for the fixation of these fractures allows early aggressive hand therapy post-operatively, reducing post-operative stiffness. Traditionally, bicortical fixation is the standard practice, where both dorsal and palmar cortices of the metacarpal are drilled through, with screws engaging both cortices. Recent biomechanical studies have shown that unicortical fixation, where only the near cortex is drilled and engaged by the screw, results in no difference in stiffness, load to failure or failure mechanism, when compared with bicortical fixation. This trial aims to compare fracture union, complication rate and functional outcomes between unicortical and bicortical fixation for adults with displaced metacarpal fractures. Methods/Design All adults with displaced diaphyseal metacarpal fracture requiring plate fixation are potentially eligible to take part in this study. A total of 315 consenting patients will be randomly allocated to either unicortical or bicortical plate and screw fixation. The surgery will be performed in specialist hand trauma units across the UK. Data regarding fracture healing, hand function, quality of life, and complications will be collected at 2 weeks, 6 weeks and 6 months following surgery. Discussion This pragmatic, prospective, multi-centre, randomized controlled trial is expected to deliver results in 2018. Trial registration ISRCTN 18006607. Registered on 19 Nov 2015.