Robot-assisted double screw fixation of minimally displaced scaphoid waist fracture nonunions or delayed unions without bone graft.

We retrospectively reviewed 12 minimally displaced fractures of the scaphoid waist in 12 patients who developed delayed or nonunions with or without conservative treatment. Mean time between injury and surgery was 6 months (range 3-12). The fractures were stabilized with double screws, which were percutaneously inserted with robot assistance, and without bone grafting. All fractures united at a mean of 8 weeks (range 6-10) after surgery. The patients were followed-up at 6 months and 1 year. The patients recovered good wrist function. No major postoperative complications were reported, and the patients returned to their usual level of activity. Robot assistance gave a high degree of accuracy when placing the cannulated screws since only two attempts were needed for correct placement of the guide wires. We explain the high union incidence by patient selection, good stabilization and not disturbing the vascular supply.Level of evidence: IV.