Optimal Duration of Longitudinal Mechanical Traction in Displaced Radius Fractures: a Prospective Non-inferiority Study (DRF-LUKS)

Adults with an acute displaced distal radius fracture receive standard longitudinal mechanical traction, using finger traps on the thumb, index and middle fingers and a 5 kg counterweight. Standard wrist radiographs (PA and lateral) are taken before traction (T0) and after 10 minutes (T3). Two additional study radiographs (PA and lateral) are taken after 1 minute (T1) and 5 minutes (T2) of traction. Each participant serves as their own control. Closed reduction and casting then follow standard care.

Continuous longitudinal traction with standardized finger traps and a 5 kg weight over a pulley on the emergency department reduction frame, lasting 10 minutes. Wrist radiographs are taken at 1, 5 and 10 minutes of traction.

Volar or dorsal tilt of the distal radius (degrees), measured on the lateral wrist radiograph. The difference between time points is compared against a non-inferiority margin of 5 degrees.

Radial inclination (degrees), measured on the posteroanterior wrist radiograph. The difference between time points is compared against a non-inferiority margin of 5 degrees.

Radial height (mm), measured on the posteroanterior wrist radiograph. The difference between time points is compared against a non-inferiority margin of 2 mm.

Ulnar variance (mm), measured on the posteroanterior wrist radiograph. The difference between time points is compared against a non-inferiority margin of 2 mm.

Percentage of participants whose fracture meets acceptable alignment criteria for volar/dorsal tilt, radial inclination, radial height and ulnar variance at each traction time point.

The traction time point (1, 5 or 10 minutes) at which each of the four radiological parameters (volar/dorsal tilt, radial inclination, radial height, ulnar variance) reaches its maximal correction relative to baseline.

Association between fracture type (AO/OTA 23-A, 23-B, 23-C) and baseline displacement, and the change in the four radiological parameters over time. This is analysed with linear mixed-effects models.

Association between patient age and sex and the change in the four radiological parameters over time. This includes a sex × time interaction, analysed with linear mixed-effects models.

Association between BMI, forearm circumference (a proxy for muscle volume), time from injury to emergency department presentation and maximum pain during traction, and the change in volar/dorsal tilt, radial inclination, radial height and ulnar variance over time. Pain is scored on a Numeric Rating Scale (NRS) from 0 (no pain) to 10 (worst pain imaginable). This is analysed with linear mixed-effects models.