Locking plate fixation provides superior fixation of humerus split type greater tuberosity fractures than tension bands and double row suture bridges

• Published in: Clinical biomechanics (Bristol) Vol. 29; no. 9; pp. 1003 - 1008
• Main Authors: Gaudelli, Cinzia, Ménard, Jérémie, Mutch, Jennifer, Laflamme, G-Yves, Petit, Yvan, Rouleau, Dominique M
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2014
• Subjects: Animals; Biomechanical Phenomena; Biomechanics; Bone Plates; Bone Screws; Bone Wires; Disease Models, Animal; Double-row suture-bridge fixation; Equipment Failure Analysis; Female; Fracture Fixation, Internal - instrumentation; Fracture Fixation, Internal - methods; Greater tuberosity fracture; Humans; Humerus - surgery; Locking plate; Osteotomy - methods; Physical Medicine and Rehabilitation; Rotator Cuff - surgery; Shoulder Fractures - surgery; Stress, Mechanical; Suture Anchors; Suture Techniques; Swine; Tension band; Biomechanics; Locking plate; Greater tuberosity fracture; Tension band; Double-row suture-bridge fixation
• ISSN: 0268-0033; 1879-1271
• DOI: 10.1016/j.clinbiomech.2014.08.013

Abstract Background This paper aims to determine the strongest fixation method for split type greater tuberosity fractures of the proximal humerus by testing and comparing three fixation methods: a tension band with No. 2 wire suture, a double-row suture bridge with suture anchors, and a manually contoured calcaneal locking plate. Methods Each method was tested on eight porcine humeri. A osteotomy of the greater tuberosity was performed 50° to the humeral shaft and then fixed according to one of three methods. The humeri were then placed in a testing apparatus and tension was applied along the supraspinatus tendon using a thermoelectric cooling clamp. The load required to produce 3 mm and 5 mm of displacement, as well as complete failure, was recorded using an axial load cell. Findings The average load required to produce 3 mm and 5 mm of displacement was 658 N and 1112 N for the locking plate, 199 N and 247 N for the double row, and 75 N and 105 N for the tension band. The difference between the three groups was significant ( P < 0.01). The average load to failure of the locking plate (810 N) was significantly stronger than double row (456 N) and tension band (279 N) ( P < 0.05). The stiffness of the locking plate (404 N/mm) was significantly greater than double row (71 N/mm) and tension band (33 N/mm) ( P < 0.01). Interpretation Locking plate fixation provides the strongest and stiffest biomechanical fixation for split type greater tuberosity fractures.