Background: Symptomatic hardware is a commonly reported complication after surgical fixation of an unstable meso-type os acromiale. This study compared the biomechanical properties of a cannulated screw tension band construct using a metal wire tension band vs. a suture tension band, considering that the suture construct could allow for decreased hardware burden in the clinical setting.
Methods: A meso-type os acromiale was created in 16 cadaveric shoulders. Two cannulated 4-mm screws were placed in each specimen. Tension band augmentation was accomplished with a 1-mm stainless steel wire (wire group) or a #5 braided polyethylene suture (suture group), with 8 specimens in each group. An inferiorly directed force was applied to the anterior acromion at 1 mm/s on a materials testing machine. Stiffness and ultimate failure load were recorded and analyzed.
Results: No significant difference (P = .22) was observed in the ultimate failure load between the wire (228 ± 85 N; range, 114-397 N) and the suture (275 ± 139 N; range, 112-530 N). No significant difference (P = .17) was observed in the stiffness between the wire (28 ± 12 N/mm; range, 18-53 N/mm) and the suture (38 ± 25 N/mm; range, 10-83 N/mm).
Conclusions: Stainless steel wire and polyethylene suture have similar biomechanical strength in the cannulated screw tension band fixation of meso-type os acromiale at time zero.
Keywords: Biomechanics; Os acromiale; Polyethylene suture; Stainless steel wire; Suture tension band; Tension band.
Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.