Comparative study on treatment of midshaft tibial fracture with expandable and interlocking intramedullary nails

Objective ： To evaluate the clinical results of treatment of midshaft tibial fracture with expandable intramedullary nails compared with interlocking intramednilary nails. Methods： From June 2003 to August 2005, 46 patients （27 males and 19 females, aged 20-74 years, mean =38.4 years ） with midshaft tibial fracture were treated surgically in our department. The causes of fractures were traffic injury in 21 patients, fall injury in 6, tumbling injury in 11 and crushing injury in 8. According to AO/ ASIF classification, Type A fracture was found in 16 patients, Type B in 11, Type C1 in 5, and Type C2 in 2. Open fractures were found in 12 patients, according to Gustilo classification, Type Ⅰ in 9 patients and Type Ⅱin 3 patients. Based on the patients＇consent, 24 patients were treated with expandable intramedullary nails （Group A ） and 22 with interlocking intramedullary nails （Group B ）. The operation time, blood loss during operation, X-ray fluoroscopic times, hospitalization time, weight bearing time after operation, healing time of fracture and complications of all the patients were recorded. The clinical effects of all the cases were evaluated according to the criteria of Johner-Wruhs. Results： All the patients were followed up for 12,34 months （ mean = 16.2 months）. The time of operation, the blood loss, X-ray fluoroscopic times, hospitalization time and healing time of fracture of Group A significantly decreased （P 〈 0.05 ） compared with those of Group B, but the time for weight bearing after operation, the Johner- Wruhs degree of clinical effects and complications had no significant difference between Group A and Group B （P〉0.05）. Conclusions： Expandable intramedullary nail can shorten operation time, decrease blood loss and reduce invasion, which is a safe and effective treatment method for tibial midshaft fracture.     

Regulation of vascular endothelial growth factor on the expression of fracture healing,related factors

Objective ： To study the effect of vascular endothelial growth factor （VEGF）and anti-VEGF on the expression of fracture healing-related factors and observe pathological changes at fractured sites. Methods： Fracture models were established in 105 New Zealand white rabbits and they were randomly divided into control group, VEGF group and anti-VEGF group. The relevant factors expression at fractured sites was assayed and pathological changes were observed in decalcified samples at 8, 24, 72 hours and 1,3,5,8 weeks after fracture. Results： After application of VGEF, the expression of BMP appeared earlier and expression time lasted longer. On the contrary, anti-VEGF completely inhibited the expression of BMP. The fractured sites were filled with fibrous callus, cartilaginous callus and bony callus at the 3rd week and woven bone was constructed at the 5th week. Fracture healing was accomplished at the 8th week in VEGF group. In anti-VEGF polyclonal antibody group, cellular necrosis increased at early period. Continuous focal necrosis was seen in the fractured sites from the 1st week to 5th week. Vascularization reduced obviously at the 3rd week. Conclusions： Fracture healing is a result of mutual regulation and coordination among many factors. VEGF may be an important factor in fracture healing.     

Trauma and pulmonary thromboembolism： an experimental study on their correlation

Objective： To investigate the correlation between trauma and pulmonary thromboembolism. Methods： Comminuted fractures and extensive soft- tissue contusion at both hind limbs were made by a falling weight from a height in 16 rabbits. Lung perfnsion scanning was performed to obtain the radioactivity counts before trauma, at 1 h, 48 h and 96 h after trauma. All the data were divided into 4 groups based on the above 4 time points. The rabbits were sacrificed when positive findings on the pulmonary perfnsion scanning appeared. Their lungs were harvested to be paraffln-embedded and stained with hematoxylin-erosin method for histological examination of thrombocmbolism. The randomized block design ANOVA and the method of least significant difference （LSD） were used for statistical analysis of the radioactivity counts. Results： The histological findings showed that pulmonary embolism developed in 6 of the 16 rabbits （37.5%）. Five of the 6 pulmonary embolism rabbits presented neither clinical symptoms nor positive pulmonary embolism manifestations in the lung perfnsion scanning. A significant difference was found in lung perfusion radioactivity between the pre-traumatic, post-traumatic lh groups and post-traumatic 48 b and 96 b groups （P 〈 0. 05）. Conclusions ： Fractures of the bind limbs accompanied with extensive soft-tissue contusion may cause pulmonary micro-embolism that is not sensitive to lung perfnsion scanning and tends to have no clinical symptoms. Pulmonary embofism development may take more than two days after trauma.     

Can low doses of simvastatin enhance fracture healing? An experimental study in rabbits

Several observational and experimental studies have investigated the potential anabolic effects of statins on undisturbed bone but only a few recent studies have examined the effect of statins on skeletal repair. The goal of the study is to investigate any potential early anabolic effect of the systemic administration of simvastatin in low doses (based on earlier safety and efficacy studies on undisturbed bone) on fracture healing. Fifty-four skeletally mature male New Zealand White rabbits were used for the study. The rabbits were assigned to one of three experimental groups: a control group, and two groups that were orally administrated a diet with 10 and 30 mg/kg/day of simvastatin, respectively. A complete biochemical blood count was performed to exclude drug-induced complications. Half of the animals of each group were sacrificed at 15 days and the other half at 30 days after surgery at which time intervals healing quality was assessed. The bones were subjected to biomechanical testing, histomorphometric analysis and peripheral quantitative computed tomography. In animals received simvastatin of 30 mg/kg/day a significant reduction of BMD, stiffness, and energy absorbed to failure were observed. At 15 days, the amount of cartilaginous callus formation was reduced, and the void space was significantly increased, in the animals of both groups that received simvastatin when compared to the control group (p < .05). Our results suggest that simvastatin doses of 30 mg/kg/day may have a negative anabolic effect on callus formation in rabbits, whereas doses of 10 mg/kg/day seem not to produce a significant positive or a negative effect, especially at the early stages of fracture remodeling.     

Role of dual energy X-ray absorptiometry in monitoring fracture healing in a rat femoral fracture model

Earlymobilizationandweightbearingplayimportantrolesinminimizingtheamountofbonelosstoachievegoodhealingafterbonefracture.1Areliableandnoninvasivemethodforevaluatingfracturehealingcannotonlyhelpdecidewhentostarweightbearing, butalsohelpdetecttheimpairedboneunionearlytopreventdelayedunionsornonunions.However, objectivequantitativemethodsforearlyevaluationoffracturehealinghavenotbeendevelopedyet. DualenergyX rayabsorptiometry(DEXA)isoneofthemostaccuratemethodsformeasuringbonemassinvivo. Itismain…     

Computer-assisted auto-frame navigation system for distal locking of tibial intramedullary nails： a preliminary report on clinical application

Objective: To evaluate the clinical feasibility and effect of the computer-assisted auto-frame navigation system for distal locking of tibial intramedullary nails. Methods: The hardware components of the system included a PC computer with a monitor, auto mechanical stereotactical locating cubic frame, foot holder and localization operative apparatus. Special navigation software can be used for registration of X-ray fluoroscopic images and real-tune controlling navigation of tools. Twenty-one cases of close tibial and fibular fractures were treated with closed intramedullary nailing, 6 of which involved in middle third, 12 in middle and lower third, 3 in lower third. C-arm alignment and registration time, fluoroscopic time and drilling time involved in the locking procedure were recorded. The size of unreamed or reamed tibial nails ranged from 8/300-11/330. Results: All distal holes except 1 were locked successfuUy. In 9 of 41 locked holes (21.95%), the drill bit touched the canal of locking hole without damage of the nail and clinical consequences. The fluoroscopy time per pair of screws was 2.23 s±0.31 s . Conclusions: The computer-assisted auto-frame navigation system for distal locking is well designed, easy to operate and do not need additional instruments during the procedure. The developed system enables the physician to precisely navigate surgical instruments throughout the anatomy using just a few computer-calibrated radiographic images. The total time of x-ray exposure per procedure can be significantly reduced.     

Effect of Wnt/β-catenin signals on the fracture healing in transgenic mice

Objective To evaluate the effect of Wnt/β-catenin signals on the fracture healing in transgenic mice. Methods Col2al-ICAT transgenic mice were generated by the gene targeting technology with the ICAT transgene specifically expressed in chondrocytes as a competitive inhibitor to block Wnt/ β-catenin signals. The 8-week-old Col2al-ICAT mice were used in the experimental group and the wild type (WT) littermates with the same age served as the control group. A transverse osteotomy was performed at the middle of the tibia and the fracture healing was evaluated on the 7th, 9th, 14th, 21th and 28th days re-spectively after fracture. Roentgenogyaphy and histology observations were performed to evaluate the fracture healing pattern and the histomorphometric analysis was used to quantitate the cartilage callus volume / total callus volume (CV/TV) or bony callus volume / total callus volume (BV/TV). Results X-ray exam-ination revealed that on the 21st day after fracture, callus appeared at the fracture gap to form a bony bridge in WT mice while a radiolucent zone was apparent in the fracture gap in the Col2al-ICAT transgenic mice. Histology observation revealed that compared with WT mice, the formation of cartilage callus and endochondral ossification were delayed in Col2al-ICAT transgenic mice. Histomorphometric analysis indicated that the peak value of CV/TV arrived later in Col2al-ICAT transgenie mice than in WT mice. The BV/TV in Col2al-ICAT transgenic mice was significantly less than that in WT mice on 14th and 21st days after fracture (P<0.05). Conclusion The Wnt/β-catenin signals cause delayed fracture healing in Col2al-ICAT transgenic mice by affecting the cartilage callus formation and endochondral ossification.     

带锁髓内钉治疗胫骨多段骨折

胫骨多段骨折是小腿严重骨折中的一种特殊类型,具有软组织损伤严重、手术治疗难度大、游离骨折段容易出现缺血性坏死及骨不连接等特点。本文回顾1998年6月-2005年5月采用带锁髓内钉治疗胫骨多段骨折23例,总结如下。1临床资料23例中男15例,女8例;年龄:21～68岁,平均46岁。左侧10     

An intramedullary nail with multifunctional interlocking for all types of fracture in both femurs

Objective: A femoral compound interlocking intramedullary nail (FCIIN) was designed to treat all types of fractures between the trochanter and epicondyle of both femurs. It could substitute for femoral interlocking intramedullary nails (FIIN) at five points. Methods: According to the morphological characteristics of the femoral medullary canal, the nail is designed to accommodate a 1250 mm radius of radian and a 135° neck‐shaft angle. Three interlocking holes of 6.5 mm diameter are located at the proximal end of the FCIIN, making crossing of the screws possible. The hole is designed to be vertical (90°) or oblique (45° upper or lower). At the tip of the proximal interlocking screws, whose root diameter gradually increases from 3.5 mm to 6.5 mm, a self‐tapping cancellous screw is placed. There are two types of distal interlocking screws. One is a fine thread and the other a bolt screw. Two interlocking holes and a recess 4.5 mm in diameter are located at the distal end of the FCIIN. Under biomechanical destructive testing, the proximal interlocking screw device has satisfactory strength and reasonable structure. A total of 47 patients (31 males and 16 females, with an average age of 39.83 years) with femoral fractures were assessed in this study. Fourteen cases were diagnosed as intertrochanteric, 7 as subtrochanteric, 18 as femoral shaft, and 8 as supracondylar fractures. All 47 patients were treated with the FCIIN. Results: Of the 47 patients, anatomic reduction was achieved in 34, good reduction in 11, and forced line reduction in 2 cases. Reduction was excellent or good in 95.87% of the fractures. The removal time of the FCIIN was 12 to 21 months (average, 16.9 months). One patient with an intertrochanteric fracture who had a fixation failure combined with non‐union achieved healing with an external fixator at 18 months. Failure to insert the distal interlocking screws occurred in 5 patients but did not affect bone healing. Conclusion: The FCIIN is a useful device in the treatment of a variety of femoral fractures.     

两端膨胀自锁髓内钉治疗股骨骨折的生物力学评价

目的 对一种新型无需传统锁钉的两端膨胀自锁髓内钉进行生物力学性能测试和评价. 方法将6对新鲜人股骨尸体标本分为两组,均制备股骨中段横行骨折模型,分别用两端膨胀自锁髓内钉和国产传统交锁髓内钉内固定,并使断端间保留1.5 cm的裂隙.分别对其进行轴向压缩载荷、水平扭转及三点弯曲等生物力学测试,并对相关实验数据进行统计学分析. 结果两端膨胀自锁髓内钉的抗短缩刚度、抗旋转刚度及抗弯曲刚度均略小于传统交锁髓内钉,差异无统计学意义(P>0.05). 结论两端膨胀自锁髓内钉与交锁髓内钉固定效果相当,具有较强抗压、抗弯、抗旋性能,符合生物学固定的要求,有较好的临床推广应用前景.     

Internal fixation of shaft humerus fractures by dynamic compression plate or interlocking intramedullary nail: a prospective,randomised study

Compare the results of internal fixation of shaft of humerus fractures using dynamic compression plating (DCP) or antegrade interlocking intramedullary nail (IMN). Fifty patients with diaphyseal fracture of the shaft of the humerus and fulfilling the inclusion criterion were randomly assigned to one of the two groups. Twenty-five patients were managed with closed antegrade interlocking intramedullary nail, and 25 underwent open reduction and internal fixation using dynamic compression plating. The mean age of patients with IMN fixation was 37.28 years (SD 12.26) and 37.72 years (SD 12.70) for those who underwent plating. Road traffic accident was the most common mode of injury in both groups. There was a statistically significant difference between the two groups with respect to duration of hospital stay, operative time and blood loss. There was no significant difference between the two groups in terms of union or complications. The functional assessment at the end of 1 year between the two groups did not show any significant difference in outcome. Antegrade interlocking IMN and DCP fixation are comparable when managing diaphyseal shaft of humerus fractures with respect to union rates and complications. Although shoulder related complications are more in the IMN group, however, it is associated with shorter hospital stay, lesser operative time and less blood loss. This makes interlocking IMN an effective option in managing these fractures.     

逆行交锁髓内钉与钢板治疗股骨髁部骨折的疗效比较

目的:评价逆行交锁髓内钉与钢板治疗股骨髁部骨折的疗效.方法:回顾分析应用逆行交锁髓内钉治疗股骨髁部骨折31例,钢板治疗股骨髁部骨折45例的恢复情况.结果:经过6～18个月的随访,逆行交锁髓内钉治疗组骨折愈合率100%,骨折平均愈合时间4个月,感染率为3.2%.钢板治疗组骨折愈合率91.1%,感染率11.1%,2例钢板外露,骨折平均愈合时间5.5个月.结论:逆行交锁髓内钉治疗股骨髁部骨折,操作简单,固定坚强,对骨折局部血供破坏小,是一种疗效满意的方法.治疗结果优于钢板,但其应用有一定局限性.     

骨折愈合的应力适应性研究──功能活动时兔胫骨断端应力状态的动态观察

设计了生物适应性很强的力学控制装置──滑动机械加载控制器，对骨折断端没有应力遮挡，把肌肉动力与肢体负重力作为执行力学加载的源动力，通过压力传感器、多导传感放大器动态记录生理活动状态下断端受力情况及愈合过程中断端的应力状态。结果表明，同一时期内骨折断端压力随肌肉收缩及步态发生变化，不同愈合时间断端压力均值随时间的增加而逐渐增加，而滑动机械加载控制器上承载由术后当日平均２．４ｋｇ逐渐变小至术后五周平均０．７８ｋｇ。同时，通过解剖显微镜进行断端骨痂显微观察，显示断端完全由外骨痂包绕，从而认为骨折断端压力变化是肢体功能恢复，断端骨痂承受载荷的表现，提示临床骨折固定后应适时地进行功能锻炼，肌肉收缩、患肢负重可为断端提供最好的力学环境──生理应力状态。     

骨折愈合的应力适应性研究

设计了生物适应性很强的力学控制装置──滑动机械加载控制器,对骨折断端没有应力遮挡,把肌肉动力与肢体负重力作为执行力学加载的源动力,通过压力传感器、多导传感放大器动态记录生理活动状态下断端受力情况及愈合过程中断端的应力状态。结果表明,同一时期内骨折断端压力随肌肉收缩及步态发生变化,不同愈合时间断端压力均值随时间的增加而逐渐增加,而滑动机械加载控制器上承载由术后当日平均2.4kg逐渐变小至术后五周平均0.78kg.同时,通过解剖显微镜进行断端骨痂显微观察,显示断端完全由外骨痂包绕,从而认为骨折断端压力变化是肢体功能恢复,断端骨痂承受载荷的表现,提示临床骨折固定后应适时地进行功能锻炼,肌肉收缩、患肢负重可为断端提供最好的力学环境──生理应力状态。     

逆行交锁髓内钉治疗股骨髁上骨折

目的 探索治疗股骨髁上骨折的理想方法。方法 从1996年12月至今，采用交锁髓内钉经膝由踝间窝逆行闭合穿针治疗股骨上骨折共24例。结果 24例经平均22.5个月的随访，23例骨折愈合，膝关节功能按Kolment评定标准，优良率87.4%。结论 逆行交锁髓内钉治疗股骨髁上骨折，内固定坚强，创伤小，骨折愈合快，可有效防止膝关节内外翻畸形。术后能早期膝关节活动，有利膝关节功能恢复。     

股骨近端带锁髓内钉治疗股骨转子部骨折

股骨转子部骨折是临床常见的骨折,好发于老年人,目前治疗方法很多,我院2000年10月-2004年12月,用股骨近端髓内针（PFN）治疗股骨转子部骨折32例,取得良好疗效。1临床资料本组患者32例,男21例,女11例;年龄47⁷3岁,平均60岁;受伤距手术时间2¹7d,平均8d。按AO分类A1型7例,A2型17例,A3型8例。其中1例合并胫腓骨骨折,2例合并脑挫伤,1例合并肋骨骨折并血气胸。手术使用骨科牵引床,C形臂X线机下复位锁定,手术时间约60²10min。2方法2·1治疗方法采用硬膜外麻醉,置骨科牵引床上,将C形臂放于髋部以便取得良好的X线透视效果。自大转子顶点向近端行切口并从顶点插     

股骨近端带锁髓内钉治疗股骨转子部骨折

股骨转子部骨折是临床常见的骨折,好发于老年人,目前治疗方法很多,我院2000年10月-2004年12月,用股骨近端髓内针(PFN)治疗股骨转子部骨折32例,取得良好疗效。1临床资料本组患者32例,男21例,女11例;年龄47~73岁,平均60岁;受伤距手术时间2~17d,平均8d。按AO分类A1型7例,A2型17例,