Significance of corrective growth of opposite physes in the surgical correction of deformity following epiphyseal injury around the knee joint

Deformation due to growth disturbance after epiphyseal fractures around the knee may involve more than the primarily injured epiphysis, as spontaneous corrective growth of the opposite epiphyseal plate can take place in an attempt to maintain overall alignment of the leg. As a result, there will be an inclination in the knee joint line if corrective osteotomy is only performed for the primary angulation. We report two cases of this complex deformity in which corrective osteotomies of both the distal femur and the proximal tibia were performed, resulting in correct alignment of the overall leg axis and knee joint axis. Received: 25 May 1996 Accepted: 20 November 1996     

应力松弛接骨板对骨几何形态和力学性能影响的实验观察

作者采用粘弹性材料制成垫圈置于接骨板螺孔与螺丝钉之间，构成应力松弛接骨板系统。实验证实，有垫与无垫接骨板在固定早期对模拟骨的应力遮挡作用相同，固定８周后垫圈出现明显变形和破坏，使有垫接骨板的应力遮挡率从第１０周起明显低于无垫接骨板。有垫接骨板固定的胫骨骨质疏松明显轻于无垫组，固定２０周后，有垫组的胫骨髓腔径明显小于无垫组，骨皮质厚度和胫骨抗弯强度均明显大于无垫组（Ｐ＜０．０５～０．０１）。说明应力松弛接骨板系统早期具有与坚强接骨板相同的固定作用，后期其应力遮挡效应可逐渐减小，避免严重的骨质疏松和骨力学性能下降。     

The Domain of Hypertrophic Chondrocytes in Growth Plates Growing at Different Rates

In this study, we tested the hypotheses that (a) both the domain volume (volume of the cell and the matrix it has formed) and matrix volume of juxtametaphyseal hypertrophic chondrocytes in the growth plate is tightly controlled, and that (b) the domain volume of juxtametaphyseal hypertrophic chondrocytes is a strong determinant of the rate of bone length growth. We analyzed the rate of bone length growth (oxytetracycline labeling techniques) and nine stereologic and kinetic parameters related to the juxtametaphyseal chondrocytic domain in the proximal and distal radial and tibial growth plates of 21- and 35-day-old rats. The domain volume increased with increasing growth rates, independent of the location of the growth plate and the age of the animal. Within age groups, the matrix volume per cell increased with increasing growth rates, but an identical growth plate had the same matrix volume per cell in 21- and 35-day-old rats. The most suitable regression model (R ²= 0.992) to describe the rate of bone length growth included the mean volume of juxtametaphyseal hypertrophic chondrocytes and the mean rate of cell loss/cell proliferation. This relationship was independent of the location of the growth plate and the age of the animal. The data suggest that the domain volume of juxtametaphyseal hypertrophic chondrocytes, as well as the matrix volume produced per cell, may be tightly regulated. In addition, the volume of juxtametaphyseal hypertrophic chondrocytes and the rate of cell loss/rate of cell proliferation may play the most important role in the determination of the rate of bone length growth. Received: 2 December 1996 / Accepted: 24 March 1997     

肩锁钩板治疗不稳定性锁骨外侧段骨折的临床研究

目的：比较肩锁钩板和传统克氏针内固定治疗不稳定性锁骨外侧段骨折的疗效。方法：54例不稳定性锁骨外侧段骨折的患者接受了手术治疗，内固定分别是锁骨钩板或克氏针，根据国外的锁骨外侧段骨折肩部功能评价标准进行6－12个月的术后随访，随访结果运用统计学方法进行分析处理，结果：克氏针内固定组的手术优良率为77．3％，并发症发生率为27．3％，骨折愈合率为81．8％；锁骨钩板内固定组的手术优良率为100％，并发症发生率为3．1％，骨折愈合率100％。两组数据统计学差异有显著性，结论：在不稳定性锁骨外侧段骨折的手术治疗中，锁骨钩板较传统克氏针内固定有较高的手术优良率和骨折愈合率，且并发症的发生率较低，因此，它是一种疗效满意的内固定方法。     

In Vitro Evaluation of Platelet/Biomaterial Interactions in an Epifluorescent Video Microscopy Combined with a Parallel Plate Flow Cell

Abstract: Suitable evaluation systems are critical for ranking various biomaterials in order to develop a method to design and synthesize nonthrombogenic biomaterials. We have recently developed an in vitro test system to evaluate platelet/biomaterial interactions in whole blood. The system consists of a parallel plate flow cell and epifluorescent video microscopy (EVM). A glass coverslip coated with a polymer was incorporated into the flow cell, and blood was perfused using a syringe pump via a polymer–coated PVC tubing connected to the flow cell. Whole human blood was anticoagulated with heparin (2 U/ml), and the platelets were labeled with the fluorescent dye mepacrine (5 μM). This system permitted real–time and dynamic observations of platelet/biomaterial interactions in whole blood under a defined flow condition. In order to evaluate the feasibility of this system, two different segmented polyether–polyurethanes (SPEUs), PU–PTMG(650) and PU–PTMG(2000), were chosen as test polymers. Surface characteristics verified with electron spectroscopy for chemical analysis (ESCA) and contact angle measurements showed similar results in both SPEUs. Blood was perfused at a wall shear rate of 200 s^–1 for 20 min. Excitation light was applied for 2 s at 1 min intervals. The real–time image was then analyzed at each time point for the percentage of surface area of platelet coverage. Plasma β–thromboglobulin (β–TG) levels were also measured before and after each run. PU–PTMG(650) showed a significantly higher number of adhered platelets than PU–PTMG(2000) at each time point. β–TG levels of PU–PTMG(650) were also higher than those of PU–PTMG(2000), which is comparable to the results of EVM. Thus, this EVM system has been proven to be an excellent and highly sensitive in vitro analytical method for evaluating platelet/biomaterial interactions.     

骺板软骨细胞复合三维支架体外构建组织工程软骨的研究

目的探讨将骺板软骨细胞复合三维支架经体外培养,构建组织工程软骨的效果及其生物学特点. 方法将3周龄幼兔第1代骺板软骨细胞与液态的生物凝胶混合,接种于聚磷酸钙纤维/L-聚乳酸(CPPF/PLLA)三维支架材料,构建组织工程软骨组织块,连续培养4周.行大体、倒置显微镜及组织学、Ⅰ型和Ⅱ型胶原免疫组织化学光镜观察,定量检测硫酸糖胺多糖(GAG)含量. 结果构建的组织工程软骨块在培养过程中能保持其初始外形,种子细胞呈稳定的三维均相分布,外观逐渐呈乳白色、半透明,硬度亦不断增加.培养1周有软骨细胞陷窝形成,2周后形成富含Ⅱ型胶原和蛋白聚糖、具有典型软骨组织结构的工程化软骨,且Ⅰ型胶原逐渐转为阴性.4周时构建软骨的组织结构与天然骺板软骨相类似,硫酸GAG含量平均为天然骺板软骨的34%以上. 结论骺板软骨细胞复合三维支架体外培养可生成典型软骨,且可形成类似天然骺板软骨的组织结构,能满足修复骺板缺损的基本要求.体外培养1～2周可能是植入体内修复骺板缺损的较佳时机.     

改良上颌平面导板矫正青少年深覆颌的临床观察

目的观察改良上颌平面导致矫正青少年深覆颌的效果。方法制作上颌平面导板,下颌双侧尖牙与其接触,后牙抬高3.0 mm。分为昼夜戴用导板及仅夜间戴用导板两组,观察疗效。结果深覆颌总矫正率72.2%,昼夜戴用该改良上颌平面导板组的深覆颌矫正率100%。结论改良上颌平面导板制作简单,戴用方便,效果明显。     

旋入式髓内钉与加压钢板治疗股骨骨折的临床研究

目的观察用旋入式髓内钉和加压钢板治疗股骨骨折的疗效,探求一种更好的治疗方法。方法2001年1月至2002年6月间对18例股骨中段新鲜骨折及骨折不愈合行旋入式髓内钉治疗。与20例采用加压钢板治疗股骨骨折的疗效进行对比、分析。结果旋入式自锁髓内钉固定术后骨折全部临床愈合,愈合时间5～10个月,平均8个月,髋、膝关节伸屈功能及行走正常,未发生感染、无延迟和不愈合,无髓内钉断裂及再骨折发生。用加压钢板内固定术后,出现骨折不愈合1例,内固定松动拔钉1例,钢板断裂1例。两种方法对比,差异有统计学意义(P<0.05)。结论旋入式自锁髓内钉具有轴向加压、抗分离和抗旋转的功能,手术操作简便,不损伤骨外膜,疗效可靠,是治疗股骨中段骨折一种有效的手段。     

髓内植骨加压钢板固定治疗下肢骨折不愈合

本文报告采用自体半侧腓骨髓内植骨、髂骨充填骨缺损区、梯型加压钢板固定的术式治疗21例下肢骨不愈合.随访6～49个月,疗效满意.通过动物实验证明,长节段自体皮质骨髓腔内移植后,6～12周血运恢复,12～24周与宿主骨愈合并被新骨取代.其固定作用由最初的单纯机械固定逐渐自然转变为生物性固定.     

The extracellular matrix of cartilage in the growth plate before and during calcification: Changes in composition and degradation of type II collagen

Summary Calcification occurs in the extracellular matrix of the hypertrophic zone of the growth plate when the extra-cellular matrix volume is reduced to a minimum and alkaline phosphatase content is maximal. The present study shows that significant quantitative and qualitative changes occur in the composition and structure of macromolecules in the extracellular matrix before and during calcification in the proximal tibial growth plate of the bovine fetus. These were detected in part by using microchemical and microimmuno-chemical analyses of sequential transverse frozen sections at chemical analyses of sequential transverse frozen sections at defined sites throughout the growth plate. Concentrations of matrix molecules in the extracellular matrix have not previously been determined biochemically. They were measured per unit matrix volume by using combined immunochemical/chemical-histomorphometric analyses. The concentrations within the extracellular matrix of the C-propeptide of type II collagen, aggregating proteoglycan (aggrecan), and hyaluronic acid all progressively increased in the maturing and hypertrophic zones, being maximal (or near maximal) at the time of initiation of mineralization. These results for proteoglycan are contrary to some earlier reports of a loss of proteoglycan prior to mineralization which measured the tissue content of proteoglycan rather than that present in the extracellular matrix, the volume of which is progressively reduced as the growth plate matures. The C-propeptide data provides a quantitative confirmation of previous immunohistochemical studies. Total collagen concentration (measured as hydroxyproline) in the extracellular matrix initially increased through the proliferating and maturing zones but then rapidly decreased in the hypertrophic zone. Immunohistochemical studies revealed that this is associated with the unwinding of the triple helix of type II collagen (previously shown to result from cleavage) which starts in pericellular sites in the zone of maturation (when type X collagen is first synthesized) and then extends throughout the hypertrophic zone. The significance of these matrix changes in the development and mineralization of the growth plate is discussed.