JAAOS - 2026-07-02 - Journal Article
Surgical Fixation Versus Cast Immobilization for Adults With Bicortical Scaphoid Fractures: A Target Trial Emulation of the SWIFFT Trial.
Zhang W, Yi C, Wu P, Hu G, Shen Y, Lu S
Topics
Key Takeaway
Surgical fixation of bicortical scaphoid waist fractures halved nonunion risk (8.4% vs 17.5%) but increased complications sevenfold (14.1% vs 2.0%), with a DASH improvement of only -4.2 points at 52 weeks—below the 10-15 point MCID.
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Summary
This target trial emulation used a clone-censor-weight design applied to EHR data from three Chinese tertiary hospitals to replicate the SWIFFT trial protocol in a higher-risk population (81.6% male, 42.4% smokers, mean age 32.1 years). Surgery produced statistically significant DASH improvements at all time points, but the 52-week adjusted mean difference of -4.2 (95% CI -4.9 to -3.5) fell below the 10-15 point MCID. Subgroup analyses identified displaced fractures (DASH difference -8.5) and current smokers (-6.7) as groups with the largest surgical benefit, while 18.1% of cast-treated patients ultimately required surgery for nonunion.
Key Limitation
The sevenfold complication increase in the surgical group was driven predominantly by screw-related hardware issues, but the study does not disaggregate complication severity or report reoperation rates for complications, limiting interpretation of the true surgical morbidity burden.
Original Abstract
AIMS
The Scaphoid Waist Internal Fixation for Fractures Trial (SWIFFT) reported no notable difference in functional outcomes between surgical fixation and cast immobilization for minimally displaced scaphoid waist fractures in UK settings. We aimed to emulate SWIFFT using Chinese hospital electronic health record (EHR) data to evaluate whether similar treatment effects are observed in a population with different risk profiles and to identify subgroups that may benefit differentially from surgery.
METHODS
This target trial emulation used a clone-censor-weight design with inverse probability of treatment and censoring weighting. Deidentified EHR data were extracted from three Tertiary A teaching hospitals in China (July 2018 to August 2024). Adults aged 16 years or older with a bicortical scaphoid waist fracture (displacement ≤2 mm) presenting within 14 days of injury were eligible. Patients received either headless compression screw fixation (n = 2,544) or below-elbow cast immobilization (n = 4,225). The primary outcome was the Disabilities of the Arm, Shoulder, and Hand (DASH) score at 52 weeks.
RESULTS
Among 6,769 patients (mean age 32.1 years; 81.6% male; 42.4% current smokers), surgery produced statistically significant DASH improvements at all time points. At 52 weeks, the adjusted mean difference was -4.2 (95% CI, -4.9 to -3.5; P < 0.001), below commonly cited MCID estimates (10 to 15 points) but approaching lower proposed thresholds (7 to 10 points). Surgery halved nonunion risk (8.4% vs 17.5%; RR 0.48, 95% CI, 0.41 to 0.55) but increased complications sevenfold (14.1% vs 2.0%), predominantly screw-related. Subgroup analyses showed larger surgical benefits among patients with displaced fractures (-8.5) and current smokers (-6.7). Nearly one in five cast-treated patients (18.1%) ultimately required surgery for nonunion.
CONCLUSION
Surgery was associated with statistically significant but modest DASH improvements, halved nonunion risk, and a sevenfold increase in complications. Cast immobilization remains a reasonable initial strategy for undisplaced fractures, while surgery offers measurable advantages for displaced fractures or smokers.