Ali Ahmad M, Saleh Michael, Eastell Richard, Wigderowitz Carlos A, Rigby Alan S, Yang Lang
Department of Orthopaedic and Traumatology, Oldchurch Hospital, Waterloo Road, Romford, Essex RM7 0BE, and Orthopaedic and Traumatic Surgery Research Group, Division of Clinical Sciences (North), University of Sheffield, United Kingdom.
J Orthop Res. 2006 Nov;24(11):2080-6. doi: 10.1002/jor.20270.
We studied the influence of different parameters of bone quality on the fixation strength of bicondylar tibial plateau fractures and examined the relationship between these parameters. Bone quality was measured in the plateau of 16 cadaveric tibias using three modalities: dual-energy X-ray absorptiometry (DXA), peripheral quantitative computer tomography (pQCT), and spectral analysis of digitized radiographs (SADR). The tibias were divided into two groups by the median bone mineral density (BMD) and randomized to receive either dual plating or external fixator for the stabilization of a standardized bicondylar tibial fracture. The fixed fractures were subjected to axial compression until failure. DXA BMD correlated most significantly with the failure load (r>or=0.79, p<0.001), followed by the pQCT parameters of cancellous bone (0.52>or=r>or=0.73, p<0.01). Similar strong correlations were also evident in both fixation methods. For parameters derived from SADR, only those including both longitudinal and transverse trabecular orientations had modest correlation with the fixation strength (0.53>or=r>or=0.71, p<0.01). The failure loads of the two fixation techniques were not significantly different (mean+/-SD=3522+/-1386 N and 3710+/-1356 N, respectively, p=0.78). However, BMD in the dual-plating group influenced the failure load significantly (p=0.03), whereas in the external fixation group this was less evident (p=0.100). The majority of bone quality parameters that correlated with fixation strength were also strongly correlated with each other, particularly the BMDs measured by DXA and pQCT. This is the first study that relates fixation strength of bicondylar tibial plateau fractures to bone quality assessed at the same anatomical site. BMD around the fracture site had the best correlation with the failure load regardless of the fixation technique. The two fixation methods tested performed equally well, and the choice between them depends on the soft tissue condition and surgeon preference.
我们研究了不同骨质量参数对双髁胫骨平台骨折固定强度的影响，并探讨了这些参数之间的关系。采用双能X线吸收法（DXA）、外周定量计算机断层扫描（pQCT）和数字化X线片光谱分析（SADR）三种方式，对16具尸体胫骨平台的骨质量进行测量。根据骨密度（BMD）中位数将胫骨分为两组，并随机分组接受双钢板固定或外固定架固定，以稳定标准化双髁胫骨骨折。对固定后的骨折进行轴向压缩直至失效。DXA测量的BMD与失效载荷的相关性最为显著（r≥0.79，p<0.001），其次是松质骨的pQCT参数（0.52≥r≥0.73，p<0.01）。两种固定方法中均存在类似的强相关性。对于SADR得出的参数，只有那些包含纵向和横向小梁方向的参数与固定强度有中等程度的相关性（0.53≥r≥0.71，p<0.01）。两种固定技术的失效载荷无显著差异（平均值±标准差分别为3522±1386 N和3710±1356 N，p=0.78）。然而，双钢板固定组的BMD对失效载荷有显著影响（p=0.03），而在外固定组中这种影响不太明显（p=0.100）。大多数与固定强度相关的骨质量参数之间也存在强相关性，尤其是DXA和pQCT测量的BMD。这是第一项将双髁胫骨平台骨折固定强度与同一解剖部位评估的骨质量相关联的研究。无论采用何种固定技术，骨折部位周围的BMD与失效载荷的相关性最佳。所测试的两种固定方法效果相当，两者之间的选择取决于软组织状况和外科医生的偏好。
