Gillespie Robert J, Ramachandran Vimala, Lea Ethan S, Vallier Heather A
Department of Orthopedic Surgery, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, OH 44106, USA.
Orthopedics. 2009 Nov;32(11):816. doi: 10.3928/01477447-20090922-06.
Proximal humerus fractures occur frequently, and treatment remains controversial. This study compares stiffness in axial loading for 3 methods of fixation (locking compression plate, standard (nonlocking) proximal humerus plate, and blade plate) in a 3-part proximal humerus fracture model. Twelve paired proximal humeri were obtained from embalmed human cadavers and separated into 3 groups. Osteotomies of the surgical neck and greater tuberosity were created to simulate a 3-part proximal humerus fracture. After fixation, constructs were axially loaded in 20 degrees of abduction for 200 cycles in an Instron materials testing machine (Norwood, Massachusetts). The blade plate (mean, 146.87+/-28.9 N/mm) demonstrated 29% more mean stiffness than the standard plate (mean, 113.0+/-22.3 N/mm; P=.19). The locking compression plate (mean, 130.71+/-39.2 N/mm) exhibited 15% greater stiffness compared to the standard plate in our 3-part model (P=.58). The blade plate demonstrated 12% greater stiffness than the locking compression plate (P=.64). There was no significant difference in mean stiffness between the fixed-angle devices and the standard plate. Future in vitro and clinical studies of plate devices for proximal humerus fractures would be worthwhile to determine the benefits and limitations of various implants for specific types of fractures, including clinical performance and cost of care.
肱骨近端骨折很常见，其治疗方法仍存在争议。本研究在三部分肱骨近端骨折模型中比较了三种固定方法（锁定加压钢板、标准（非锁定）肱骨近端钢板和接骨板）在轴向加载时的刚度。从防腐处理的人体尸体上获取了12对肱骨近端，并将其分为3组。在外科颈和大结节处进行截骨，以模拟三部分肱骨近端骨折。固定后，在Instron材料试验机（马萨诸塞州诺伍德）中，将构建体在20度外展位轴向加载200个循环。接骨板（平均值为146.87±28.9 N/mm）的平均刚度比标准钢板（平均值为113.0±22.3 N/mm；P = 0.19）高29%。在我们的三部分模型中，锁定加压钢板（平均值为130.71±39.2 N/mm）的刚度比标准钢板高15%（P = 0.58）。接骨板的刚度比锁定加压钢板高12%（P = 0.64）。角度固定装置和标准钢板之间的平均刚度没有显著差异。未来对肱骨近端骨折钢板装置进行体外和临床研究，以确定各种植入物对特定类型骨折的益处和局限性，包括临床性能和护理成本，将是很有价值的。
