【Abstract】 Objective To investigate the relationships between residual displacement of weight-bearing and non weight-bearing zones (gap displacement and step displacement) and hip function by analyzing the CT images after reconstruction of acetabular fractures. Methods The CT measures and clinical outcome were retrospectively analyzed from 48 patients with displaced acetabular fracture between June 2004 and June 2009. All patients were treated by open reduction and internal fixation, and were followed up 24 to 72 months (mean, 36 months); all fractures healed after operation. The residual displacement involved the weight-bearing zone in 30 cases (weight-bearing group), and involved the non weight-bearing zone in 18 cases (non weight-bearing group). The clinical outcomes were evaluated by Merle d’Aubigné-Postel criteria, and the reduction of articular surface by CT images, including the maximums of two indexes (gap displacement and step displacement). All the data were analyzed in accordance with the Spearman rank correlation coefficient analysis. Results There was b negative correlation between the hip function and the residual displacement values in weight-bearing group (rs= — 0.722, P=0.001). But there was no correlation between the hip function and the residual displacement values in non weight-bearing group (rs=0.481, P=0.059). The results of clinical follow-up were similar to the correlation analysis results. In weight-bearing group, the hip function had b negative correlation with step displacement (rs= — 0.825, P=0.002), but it had no correlation with gap displacement (rs=0.577, P=0.134). Conclusion In patients with acetabular fracture, the hip function has correlation not only with the extent of the residual displacement but also with the location of the residual displacement, so the residual displacement of weight-bearing zone is a key factor to affect the hip function. In patients with residual displacement in weight-bearing zone, the bigger the step displacement is, the worse the hip function is.
ObjectiveTo investigate the effect of different electrical stimulation waves on orientation and alignment of adipose derived mesenchymal stem cells (ADSCs).MethodsADSCs were isolated from 5-week-old Sprague Dawley rats (weight, 100-150 g) and cultivated. The cells at passages 3-5 were inoculated to prepare cell climbing slices, subsequently was exposed to direct-current electrical stimulations (ES) at electric field strengths of 1, 2, 3, 4, 5, and 6 V/cm on a homemade electric field bioreactor (groups A1, A2, A3, A4, A5, and A6); at electric field strength of 6 V/cm, at 50% duty cycle, and at frequency of 1 and 2 Hz (groups B1 and B2) of square wave ES; at electric field strength of 6 V/cm, at pulse width of 2 ms, and at frequency of 1 and 2 Hz (groups C1 and C2) of biphasic pulse wave ES; and no ES was given as a control (group D). The changes of cellular morphology affected by applied ES were evaluated by time-lapse micropho-tography via inverted microscope. The cell alignment was evaluated via average orientation factor (OF). The cytoske-leton of electric field treated ADSCs was characterized by rhodamine-phalloidin staining. The cell survival rates were assessed via cell live/dead staining and intracellular calcium activities were detected by calcium ion fluorescent staining.ResultsThe response of ADSCs to ES was related to the direct-current electric field intensity. The higher the direct-current electric field intensity was, the more cells aligned perpendicular to the direction of electric field. At each time point, there was no obvious cell alignment in groups B1, B2 and C1, C2. The average OF of groups A5 and A6 were significantly higher than that of group D (P<0.05), but no significant difference was found between other groups and group D (P>0.05). The cytoskeleton staining showed that the cells of groups A5 and A6 exhibited a compact fascicular structure of cytoskeleton, and tended to be perpendicular to the direction of the electric field vector. The cellular survival rate of groups A4, A5, and A6 were significantly lower than that of group D (P<0.05), but no significant difference was found between other groups and group D (P>0.05). Calcium fluorescence staining showed that the fluorescence intensity of calcium ions in groups A4, A5, and A6 was slightly higher than that in group D, and no significant difference was found between other groups and group D.ConclusionThe direct-current electric field stimulations with physiological electric field strength (5 V/cm and 6 V/cm) can induce the alignment of ADSCs, but no cell alignment is found under conditions of less than 5 V/cm direct-current electric field, square wave, and biphasic pulse wave stimulation. The cellular viability is negatively correlated with the electric field intensity.
Objective To observe the effectiveness of posterior approaches for the treatment of posterior coronal fractures of tibial plateau, and to analyze the fracture morphology, radiographic features, and the recognition of Schatzker classification. Methods Between June 2003 and June 2009, 23 patients with posterior coronal fractures of tibial plateau were treated surgically by posterior approaches. There were 15 males and 8 females with an average age of 38 years (range, 32-56 years). All patients had closed fractures. Fracture was caused by traffic accident in 15 cases, by sports in 3 cases, and by falling from height in 5 cases. According to Moore classification, there were 10 cases of type I, 9 cases of type II, and 4 cases of type IV. The X-ray films, CT scanning, and three-dimensional reconstruction were performed. The time from injury to operation was 3-14 days (mean, 6 days). Results After operation, 17 cases had anatomical reduction and 6 had normal reduction. Incisions healed by first intention. All cases were followed up 12 to 36 months (mean, 24 months). The average fracture healing time was 7.6 months (range, 6-9 months). No related complication occurred, such as nerve and vessel injuries, failure in internal fixation, ankylosis, traumatic osteoarthritis, and malunion. According to Rasmussen’s criteria for the function of the knee, the results were excellent in 14 cases, good in 7 cases, and fair in 2 cases with an excellent and good rate of 91.3%. Conclusion Posterior coronal fracture of tibial plateau is rare, which has distinctive morphological features, and Schatzker classification can not contain it totally. The advantages of posterior approach include reduction of articular surface under visualization, firm fixation, less complications, and earlier functional exercise, so it is an ideal surgical treatment plan.
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.
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。