Marcellin-Little Denis J, Cansizoglu Omer, Harrysson Ola L A, Roe Simon C
Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
Am J Vet Res. 2010 Sep;71(9):1089-95. doi: 10.2460/ajvr.71.9.1089.
To compare an electron beam melting-processed (EBMP) low-modulus titanium alloy mesh stem with a commercial cobalt-chromium (CC) stem in a canine cadaver model.
9 pairs of cadaver femora.
EBMP stems of 3 sizes were placed in randomly chosen sides of femora (left or right) and CC stems in opposite sides. Stem impaction distances were recorded. Five strain gauges were attached to the femoral surface to record transverse tensile (hoop) strains in the femur during axial loading. Constructs were axially loaded 4 times to 800 N and 4 times to 1,600 N in a materials testing machine. Axial stiffness of constructs and bone surface strains were compared between EBMP and CC constructs.
Stems were impacted without creating femoral fissures or fractures. Stem impaction distances were larger for EBMP stems than for CC stems. Mean axial stiffness of EBMP constructs was lower than mean axial stiffness of CC constructs. Subsidence did not differ between groups. Bone strains varied among strain gauge positions and were largest at the distal aspect of the stems. At a load of 1,600 N, bones strains were higher in CC constructs than in EBMP constructs for 2 of 4 medial strain gauges.
EBMP stems were successfully impacted and stable and led to a focal decrease in bone strain; this may represent an acceptable option for conventional or custom joint replacement.
在犬类尸体模型中，比较电子束熔融加工（EBMP）的低模量钛合金网状柄与商用钴铬（CC）柄。
9对尸体股骨。
将3种尺寸的EBMP柄置于随机选择的股骨侧（左侧或右侧），CC柄置于对侧。记录柄的压入距离。在股骨表面粘贴5个应变片，以记录轴向加载过程中股骨的横向拉伸（环向）应变。在材料试验机中，对构建体进行4次轴向加载至800 N，4次轴向加载至1600 N。比较EBMP和CC构建体的构建体轴向刚度和骨表面应变。
柄压入时未造成股骨裂缝或骨折。EBMP柄的柄压入距离大于CC柄。EBMP构建体的平均轴向刚度低于CC构建体的平均轴向刚度。两组之间的下沉情况无差异。骨应变在应变片位置之间有所不同，且在柄的远端最大。在1600 N的载荷下，4个内侧应变片中的2个，CC构建体中的骨应变高于EBMP构建体。
EBMP柄成功压入且稳定，并导致骨应变局部降低；这可能是传统或定制关节置换的一个可接受选择。
