title: Application of Additional Medial Plate in Treatment of Proximal Humeral Fractures With Unstable Medial Column: A Finite Element Study and Clinical Practice.
abstract: The purpose of this study was to use finite element analysis to compare the biomechanical characteristics after lateral locking plate (LLP) or LLP with a medial anatomical locking plate (LLP-MLP) fixation of proximal humeral fractures with an unstable medial column.First, a 3-dimensional, finite element analysis model was developed. Next, LLP and LLP-MLP implants were instrumented into the proximal humeral fracture models. Compressive and rotational loads were then applied to the humerus model to determine the biomechanical characteristics. Both normal and osteoporotic proximal humerus fractures were simulated using 2 internal fixation methods each under 7 loading conditions. To assess the biomechanical characteristics, the construct stiffness, fracture micromotion, and stress distribution on the implants were recorded and compared.The LLP-MLP method provided both lateral and medial support that reduced the stress on the LLP and the amount of displacement in the fracture region. In contrast, the LLP method resulted in more instability in the medial column and larger magnitudes of stress. In osteoporotic bone, the LLP was more inclined to fail than LLP-MLP.The LLP-MLP method provides a strong support for the medial column and increases the stability of the region surrounding the fracture.
authors.affiliation: From the Department of Orthopedic Surgery, Shandong Provincial Hospital Affiliated to Shandong University (YH, JH, FW, DZ, BW, SX); and Department of Medical Laboratory Diagnosis Center, Jinan Central Hospital, Ji'nan, Shandong, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: He
authors.forename: Jiliang
authors.initials: J
authors.lastname: He
authors.forename: Fu
authors.initials: F
authors.lastname: Wang
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Zhou
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Bomin
authors.initials: B
authors.lastname: Wang
authors.forename: Shihong
authors.initials: S
authors.lastname: Xu
mesh_terms: D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D055119:Elastic Modulus; D020342:Finite Element Analysis; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D006810:Humeral Fractures / Q000601:surgery*; D011183:Postoperative Complications; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome