• Five ulnar shortening osteotomy techniques all maintained stable osteotomy ends under axial compression, pronation, and supination loads, with no significant biomechanical differences among them.
• The internal fixation plate in ulnar metaphyseal transverse osteotomy showed fracture risk under pronation and deformation risk under supination, indicating potential mechanical safety concerns.
• Distal ulnar V-shaped osteotomy demonstrated superior stress distribution and displacement control, with the most stable internal fixation across all simulated loading conditions.
• Finite element analysis provides a valuable tool for comparing biomechanical outcomes of different osteotomy techniques, aiding clinical decision-making in ulnar impaction syndrome treatment.