Nitinol Staples for Olecranon Osteotomy Fixation, Juxtacortical Versus Inset, Effect on Biomechanical Stability

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Materials Science

Background:

• Hardware prominence is a challenge in olecranon osteotomy fixation.
• Nitinol staples offer low-profile fixation in other orthopedic applications.
• Subcutaneous prominence of non-inset staples is a concern.

Purpose of the Study:

• To evaluate the fixation strength of inset nitinol staples in olecranon osteotomies.
• To determine if inset nitinol staples provide sufficient stability for daily activities.
• To compare the prominence of inset versus non-inset nitinol staples.

Main Methods:

• Olecranon osteotomies were created in 8 cadaver arms and fixed with nitinol staples.
• Displacement was measured under increasing loads (0 N, 15 N, 150 N) for inset and non-inset staples.
• Elbows underwent cyclic flexion testing (0°-90°) at each load to assess osteotomy compression loss.

Main Results:

• At 150 N, average displacement was 0.05 mm for inset staples and 0.09 mm for non-inset staples.
• No statistically significant differences in displacement (loss of compression) were found between inset and non-inset staples (P = .323).
• The fixation strength of inset nitinol staples was comparable to non-inset staples.

Conclusions:

• Inset nitinol staples do not compromise osteotomy fixation strength.
• Nitinol staples, when inset, may offer a low-profile, efficient fixation alternative for olecranon osteotomies.
• Further research comparing staples with plate constructs is warranted.