The Scandinavian Displaced Lateral Clavicle trial (ScanDiLaC): a study protocol for a randomized clinical trial

Abstract Background Evidence regarding the treatment of displaced, extraarticular lateral clavicle fractures is scarce. No study has shown clinically significant differences between surgical and nonsurgical treatment, but the sample sizes have been small, as it has been difficult to include enough patients with this relatively uncommon fracture type. Purpose This study aims to compare outcomes after surgical and nonsurgical treatment for displaced lateral clavicle fractures. Methods This is a pragmatic, noninferiority, preference-tolerant, randomized controlled trial (RCT). A total of 100 patients between the ages of 18 and 65 with displaced lateral clavicle fractures will be randomly allocated on a 1:1 ratio to surgical or nonsurgical treatment with the option of early crossover after 6 weeks. An observational cohort will comprise patients not willing to be randomized. This is a multicenter Scandinavian RCT including hospitals in Sweden, Norway, Denmark, and Finland. The primary outcome is the Disabilities of the Arm, Shoulder and Hand (DASH) score at 1 year. Follow-up points will be 6 weeks, 3 months, 6 months, and 1 year. The secondary outcomes are the DASH score, the EQ-5D-5L score, the University of California, Los Angeles (UCLA) activity score, the Nottingham Clavicle Score (NCS), a visual analog scale (VAS) for pain, and anchor questions in the form of the Patient Global Impression of Change (PGIC) collected at all timepoints during the study. All complications, radiographic healing, and return to work will be reported. Discussion The optimal treatment for displaced Neer type II and V lateral clavicle fractures remains a topic of debate. This RCT may provide a better understanding of the differences in outcomes of nonsurgical and surgical treatment while reflecting real-world clinical practice and guiding the development of a treatment algorithm for the orthopedic community. Trial registration ClinicalTrials.gov NCT06981065. Registered on 19 May 2025. https://clinicaltrials.gov/study/NCT06981065?term=Scandilac&rank=1