PrEvention of posttraumatic contractuRes with Ketotifen 2 (PERK 2) - protocol for a multicenter randomized clinical trial. - Ademola, Ayoola; Hildebrand, Kevin A.; Schneider, Prism S.; Mohtadi, Nicholas G. H.; White, Neil J.; Bosse, Michael J.; Garven, Alexandra; Walker, Richard E. A.; Sajobi, Tolulope T. (BMC Musculoskeletal Disorders, 2020)