ObjectiveTo evaluate the biomechanical effect of a nickel-titanium (Ni-Ti) three-dimensional memory alloy mesh in treating a canine tibial plateau collapse fracture model and to lay a foundation for further experiments in vivo.MethodsSixteen tibial plateau specimens of 8 adult Beagle dogs were harvested. Twelve specimens were taken to prepare canine tibial plateau collapse fracture models (Schatzker type Ⅲ) and randomly divided into groups A, B, and C, with 4 specimens in each group. Four normal tibia specimens were used as blank control group (group D). In groups A and B, the bone defects were repaired with Ni-Ti three-dimensional shape memory alloy mesh combined with autologous bone and simple autologous bone respectively, and fixed with the lateral plate and screw. In group C, the bone defect was directly fixed with the lateral plate and screw. By using a biomechanical tester, a progressive load (0-1 700 N) was loaded vertically above the femoral condyle. The maximum failure load was recorded and the stiffness was calculated according to the load-displacement curve.ResultsThe maximum failure loads in groups A, B, C, and D were (1 624.72±7.02), (1 506.57±3.37), (1 102.00±1.83), and (1 767.64±24.56) N, respectively; and the stiffnesses were (129.72±20.83), (96.54±27.05), (74.96±17.70), and (169.01±35.62) N/mm, respectively. The maximum failure load and stiffness in group A were significantly higher than those in groups B and C, but which were significantly lower than those in group D (P<0.05).ConclusionNi-Ti three-dimensional memory alloy mesh combined with autologous bone can repair the Schatzker type Ⅲ tibial plateau collapse fracture, which has better biomechanical properties than simple autologous bone grafting.
ObjectiveTo evaluate the effect of nickel-titanium three-dimensional memory alloy mesh combined with autologous bone for living model of canine tibial plateau collapse fracture by biomechanical testing. MethodsSixteen healthy 12-month-old Beagle dogs were randomly divided into 4 group, 4 dogs in each group. The dogs were used to establish the tibial plateau collapse fracture model in groups A, B, and C. Then, the nickel-titanium three-dimensional memory alloy mesh combined with autologous bone (the fibula cortical bone particles), the artificial bone (nano-hydroxyapatite), and autologous fibula cortical bone particles were implanted to repair the bone defects within 4 hours after modeling in groups A, B, and C, respectively; and the plate and screws were fixed outside the bone defects. The dogs were not treated in group D, as normal control. At 5 months after operation, all animals were sacrificed and the tibial specimens were harvested and observed visually. The destructive axial compression experiments were carried out by the biomechanical testing machine. The displacement and the maximum failure load were recorded and the axial stiffness was calculated. ResultsAll animals stayed alive after operation, and all incisions healed. After 1-3 days of operation, the animals could stand and move, and no obvious limb deformity was found. The articular surfaces of the tibial plateau specimens were completely smooth at 5 months after operation. No obvious articular surface collapse was observed. The displacement and maximum failure load of specimens in groups A and D were significantly higher than those in groups B and C (P<0.05). But no significant difference was found between groups A and D and between groups B and C (P>0.05). ConclusionThe nickel-titanium three-dimensional memory alloy mesh combined with autologous bone for subarticular bone defect of tibial plateau in dogs has good biomechanical properties at 5 months after operation, and has better axial stiffness when compared with the artificial bone and autologous bone graft.
目的 评价股骨近端防旋髓内钉（PFNA）、动力髋螺钉（DHS）、伽马钉治疗股骨转子间骨折的有效性和安全性。 方法 计算机检索Cochrane图书馆（2011年第12期），PubMed （1966年－2011年12月），EMBASE（1974年－2011年12月），web of science（1958年－2011年12月），万方数据库（1992年－2011年12月），维普资讯网（1989年－2011年12月），中国期刊全文数据库（1994年－2011年12月），中国生物医学文献数据库（1978年－2011年12月），纳入PFNA、DHS、伽马钉治疗股骨转子间骨折的随机前瞻性研究，采取修订后的Jadad评分量表对纳入研究进行质量评价。用RevMan 5.1软件进行Meta分析。 结果 共纳入12个研究（1 477例患者）。Meta分析结果显示PFNA治疗股骨转子间骨折的手术时间[MD=−32.19，95%CI（−49.69，−14.69），P=0.000 3；MD=−4.52，95%CI（−5.24，−3.80），P＜0.000 01］，出血量[MD=−183.06，95%CI（−277.37，−88.74），P=0.000 1；MD=−49.49，95%CI（−84.15，−14.83），P=0.005]少于DHS组和伽马钉组，但是三者在总有效率、住院时间和术后并发症等方面差异无统计学意义。DHS组与伽马钉组在所有指标差异均无统计学意义。 结论 与DHS、伽马钉相比，PFNA可明显缩短手术时间、降低术中出血量，但并不能提高总有效率、缩短住院时间以及减少术后并发症；而DHS与伽马钉治疗股骨转子间骨折的疗效无明显差异。