Scientific Publications Database

Article Title: Fixation of Anteromedial Coronoid Facet Fractures: A Biomechanical Evaluation of Plated Versus Screw Constructs
Authors: Morellato, John; Louati, Hakim; Desloges, William; Papp, Steven; Pollock, J. Whitcomb
Journal: JOURNAL OF ORTHOPAEDIC TRAUMA Volume 32 Issue 11
Date of Publication:2018
Abstract:
Objective: To examine the stability of plate (locking and non-) versus screw constructs in the fixation of these fractures.Methods: An anteromedial coronoid facet fracture (OTA/AO type 21-B1, O'Driscoll type 2, subtype 3) was simulated in 24 synthetic ulna bones that were then assigned to 3 fracture fixation groups: non-locking plate, locking plate (LP), or screw fixation. Each construct was first cycled in tension (through a simulated medial collateral ligament) and then in compression. They were then loaded to failure (displacement >2 mu m). Fracture fragment displacement was recorded with an optical tracking system.Results: During tension testing, a mean maximum fragment displacement of 12 +/- 13 and 14 +/- 9 mu m was seen in the locking and non-locking constructs, respectively. There was no difference in fragment motion between the plated constructs. All screw-only fixed constructs failed during the tension protocol. During compression testing, the mean maximum fragment displacement for the screw-only construct (64 +/- 79 mu m) was significantly greater than locking (9 +/- 5 mu m) and non-locking constructs (10 +/- 9 mu m). During load to failure testing, the maximum load to failure in the screw-only group (316 +/- 83 N) was significantly lower than locking (650.4 +/- 107 N) and non-locking constructs (550 +/- 76 N). There was no difference in load to failure between the plated groups.Conclusion: Fixation of anteromedial coronoid fractures (type 2, subtype 3) is best achieved with a plating technique. Although LPs had greater stiffness, they did not offer any advantage over conventional non-LPs with respect to fracture fragment displacement in this study.Clinical Relevance: Isolated screw fixation showed inferior stability when compared with plate constructs for these fractures. This could result in loss of fracture reduction leading to instability and posttraumatic arthrosis.