Background: Biomechanical studies have shown a higher compressive force and higher torsional stiffness for fixation with three screws compared to two screws. However, clinical data to compare these fixation techniques is still lacking.
Methods: A retrospective analysis of 113 patients was performed, who underwent isolated subtalar fusion between January 2006 and April 2018.
Results: Revision arthrodesis was required in 8% (n=6/36) for 3-screw-fixation and 38% (n=35/77) for 2-screw-fixation. For 3-screw-fixation, non-union, was observed in 14% (n=5/36) compared to 35% (n=27/77) in 2-screw fixation. Non-union (p=.025) and revision arthrodesis (p=.034) were significantly more frequent in patients with 2 screws. A body mass index ≥30kg/m2 (p=.04, OR=2.6,95%CI:1.1-6.3), prior ankle-fusion (p=.017,OR=4.4,95%CI:1.3-14.5) and diabetes mellitus (p=.04,OR=4.9,95%CI:1.1-17.8) were associated with a higher rate of revision arthrodesis.
Conclusions: Our findings suggest that successful subtalar fusion is more reliably achieved with use of three screws. However, future prospective studies will be necessary to further specify this recommendation.
Keywords: Arthrodesis; Fusion; Revision; Screws; Subtalar.
Copyright © 2019 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.