Scaphoid Waist Internal Fixation for Fractures Trial (SWIFFT) Cast treatment versus surgical fixation of fractures of the Scaphoid waist in adults: –a Multi-centre Randomised Controlled Trial

Design: A multi-centre randomised trial of surgical fixation vs initial cast immobilisation of acute scaphoid fractures followed by fixation of the 10-12% that fail to unite, including an economic evaluation and a nested qualitative study to explore patients’ experience of the fracture and its treatment. Setting: 17 NHS hand surgery units have agreed to participate, ensuring wide surgeon involvement. The pragmatic design will make findings generalisable. Health technologies being assessed: Surgical treatment is open or percutaneous surgical fixation with headless compression screws, which are standard and avoid the effects of the screw head. These are unlikely to change in the next 5 years. Control treatment: immobilisation in a below elbow plaster cast for 6-10 weeks, followed by surgical fixation of the 10-12% that fail to unite reflecting current clinical practice. Target population: All skeletally mature patients aged 16 years old or above and presenting with a bicortical fracture of the scaphoid waist within 2 weeks of injury. We will include minimally displaced fractures with less than or equal to 2mm step or gap on radiographs as greater displacement would challenge surgeon equipoise. We will exclude fractures with displacement >2mm, fractures in the proximal pole (proximal 20%), patients with a trans-scaphoid perilunate dislocation, other injuries in the same limb or previous injury or disease in the same wrist, patients not resident in the trauma centre catchment area and patients who lack mental capacity to understand the trial or instructions for treatment. Measurement of outcomes and costs: The primary patient reported outcome is the Patient Rated Wrist Evaluation at 52 weeks, the primary time-point. The secondary outcome will include bone union on a CT scan at 52 weeks, SF-12, time to return to work and leisure, complications e.g. malunion, nerve injury, arthritis, osteonecrosis, implant problems and infection. Prospective data on NHS and indirect (employment) costs will be collected with EQ-5D to provide health utility data. For the qualitative study, by interview in the first 6 weeks and repeated at 52 weeks, randomly selected participants will be asked open ended questions about previous experience of fractures and their treatment, how they feel about being in a trial of different treatments and the advantages and drawbacks of their treatment. Data analysis will use the constant comparative method based on grounded theory. We will also recruit patients who did not consent to the main study to note their views. Sample size: We judge a 6 point improvement in the PRWE in the surgery group (compared to the controls) should be a minimally clinical important difference. We cautiously estimate the standard deviation to be 20, which gives an effect size of 0.3 and at 80% power using a 2-sided 5% significance level we need 350 participants. Allowing for 20% attrition we need to recruit and randomise 438 participants (219 surgery and 219 controls). Sampling to the nested qualitative study will be purposive intending to include men and women from different trial sites, of different ages, occupations and leisure/ sporting activities, and those with scaphoid fractures on their dominant and non-dominant sides. We are unlikely to need more than 40 participants to reach theoretical saturation. Project timetables: We envisage a 4.5 year main study: the first 6 months for training and completion of research governance arrangements at trial centres. The recruitment period will be for 30 (24+6 for slower recruitment) months and will include an internal pilot study to test recruitment assumptions. Patients will be followed up at 6, 12, 26 and 52 weeks. A further 6 months will allow complete data collection, analyses and write up of the main study. We have extended the study to include a 5 year review. The recruitment rate, analysis plan and 5 year review are discussed under “Additional Information”.