VALIDATION OF THE LIFT-OFF SCREW TECHNIQUE IN PATIENTS UNDERGOING CORRECTIVE OSTEOTOMY FOR MALUNITED DISTAL RADIUS FRACTURES

Malunion is a common complication of non-operative management of distal radius fractures and can lead to poor functional outcomes. Corrective osteotomy is an option to improve patient satisfaction. The Lift-Off Screw (LOS) technique described by Roebke et al. uses the equation Ls = [tan(Tc) * Lp + C] / [cos(⍬s)] to plan the sagittal plane deformity correction based on a calculated LOS length. We aim to clinically validate this technique for volar tilt correction (VTC) in patients undergoing corrective osteotomy for dorsally angulated distal radius fracture malunions. We hypothesized that the clinical VTC would be within 5 degrees of the calculated VTC, with a strong correlation between LOS length and clinical correction achieved (r > 0.7). We conducted a retrospective review of 23 consecutive patients with dorsally angulated distal radius fracture malunions treated with corrective osteotomy using the LOS technique. We compared the calculated VTC to the clinical VTC achieved, using paired t-test and Pearson correlation coefficient. Pre-operative volar tilt ranged from -6° to -50° (mean = -22.9° ± 10.6°), with an average desired correction of 32.5° ± 9.6°. The clinical VTC was 25.8° ± 9.3°. The difference between the clinical and calculated correction was -6.9°, with an average post-operative clinical volar tilt of 2.8° ± 5.7°, compared to a calculated volar tilt of 9.7° ± 4.4° (p The LOS technique is an easy and reproducible method to plan the amount of sagittal plane correction during corrective osteotomy surgery for dorsally angulated DRF malunions. We demonstrate that this technique under-estimates the clinical correction achieved by around 7°, which may be attributable to the effect of soft tissues and bone quality in a clinical setting. Under-correction of VTC during corrective osteotomy should be anticipated by surgeons, and considered in future implant and cutting guide designs.