Comparative Analysis of Isolated Nitinol Staple Fixation vs Staple Plus Screw Fixation In Midfoot and Hindfoot Arthrodesis.

Abstract

Nitinol staples are increasingly used in orthopaedic surgery for arthrodesis because of their superelasticity properties, which enable sustained dynamic compression. This study evaluates and compares outcomes of isolated nitinol staple fixation vs staple plus screw fixation in midfoot and hindfoot arthrodesis. This retrospective study analyzed 101 patients (103 joints) who underwent midfoot or hindfoot arthrodesis over 10 years, with an average follow-up of 2.2 years. Primary outcomes included fusion and revision rates. Patients without postoperative CT scans were excluded from fusion analysis but contributed to complication analysis. A musculoskeletal radiologist evaluated imaging for bony union. Fusion rates between constructs were compared using an omnibus test, followed by Fisher exact test for pairwise comparisons. Analysis of variance assessed demographic differences, with Tukey test for post hoc analysis. Overall joint fusion rates were identical across the staple and staple plus screw constructs (89.1% vs 89.5%, <i>P</i> > .99). There was no significant difference between the constructs in any region of the foot. Staple and screw fixation demonstrated significantly higher joint revision rates compared with staples alone, most often due to symptomatic hardware removal. In our series, nitinol staples used in isolation or alongside static screws resulted in nearly identical fusion rates across the foot. However, the addition of a static screw to a nitinol staple significantly increases the revision surgery rate and may not be recommended in younger, more active patients who may desire future hardware removal.