不同范围的骨膜剥离对兔股骨血供的影响

为了解不同范围的骨膜剥离对长骨血供的影响,我们采用放射性核素显像的方法观察了兔股骨不同范围的骨膜剥离后血供的变化情况。结果显示:骨膜完全剥离后当天血供下降(0.78,t=6.90,P〈0.01),第4、8天高于健侧;骨膜1/3剥离后当天血供无明显变化(0.95,t=0.91,P〉0.05),第4、8天均高于健侧。结果表明骨膜剥离的范围增大对血供的损伤加重,但小范围的骨膜剥离并不造成骨血供的明显下降。     

Mechanical effects of reaming and implantation of acrylic cement into the medullary cavity of bones

Changes in the mechanical properties of the rat femur caused by intramedullary application of bone cement were studied. In one group of animals reaming of the medullary cavity was performed, and bone cement was injected. In a control group only reaming was performed. At various intervals from day 0 to day 180 following operation the mechanical characteristics of the bone were evaluated. Reaming of the medullary cavity provoked a temporarily reduced bending moment of the femur at 40 days after operation. Intramedullary bone cement caused no significant changes in the bending moment of the femora until day 180 after operation. At this time, the bending moment of the cemented femora was significantly greater than that of the contralateral bones. This may be attributed to more periosteal bone being deposited, as implantation of bone cement induced a significant increase in periosteal reaction. The elastic stiffness of the bone was not altered either by reaming or the implantation of bone cement. It is concluded that reaming and implantation of bone cement into the medullary cavity do not impair the mechanical properties of the femur in the young rat.     

Effects of two epiphyseal—stimulating procedures on local growth of long bones in rabbits

Objective:To study the effects of two epiphyseal stimulating procedures on local growth of long bone in rabbits.Methods:Osteotomy was performed in the metakphysis near the proximal tibial epiphyseal plate and hemicircumferential periosteal excision was made on the proximal tibial epiphysis.Tibia roentgenography,tetracycline labelling,histological method and electron microscopy were used.Results:The local stimulating effect following the hemicircumferential periosteal excision was more remarkable than the osteotomy.Conclusions:Periosteal excision is a better treatment for children‘s knee deformity.     

Die Reaktion der Epiphysenfuge auf fugenkreuzende Bohrdrahtosteosynthesen

In young rabbits of five to six weeks of age we revealed bony bridging as constant reaction of the epiphyseal cartilage on drilling with a 2 mm diameter trephine into the distal femur growth plate. Gross growth disturbancies will be the consequence of such partial closures. For this present study we inserted one 2 mm Kirschnerwire across the epiphyseal plate of the distal femur. The drilling was directed distally. During longitudinal growth the epiphysis moves away from the wire, that remains 8 weeks after the operation completely within the metaphyseal cancellous bone. Four, 8, 12 and 16 weeks postoperatively one group of the rabbits were sacrified. After radiological examination of the explanted femurs fixation and embedding in methylmetacrylate for morphological examination was performed. Our histological results reveal, that the crossing Kirschner-wire does not irritate the growth plate, even the physiological structure of the epiphyseal cartilage in the direct contact to the metal implant is not altered. The defect within the epiphyseal plate left after the relative retraction of the wire caused by growth activity fills with cancellous bone. Its trabecular structure is markedly thinner than the spongy bone within the metaphysis and shows longitudinal orientation. These trabeculae undergo segmental disruption by the growth pressure of the surrounding epiphyseal plate. In consequence there is no bone bridging and growth alterations by the Kirschner-wire crossing of the epiphyseal plate. This proves experimentally the clinical experienced therapeutic value of Kirschner-wires for internal fixation of dislocated joint injuries.     

Femoral bone blood flow after reaming and intramedullary canal preparation: a canine study using laser Doppler flowmetry

This study was conducted to determine the effect of intramedullary reaming and canal preparation on bone blood flow in the proximal femur. Thirty-five adult dogs were randomly assigned to have their intramedullary canals prepared after reaming in the following manner: group 1, ream only; group 2, lavage; group 3, methylmethacrylate cement introduction; group 4, cement pressurization after placing a cement restrictor; group 5, lavage then cement introduction; and group 6, lavage then cement pressurization. Bone blood flow was measured at both metaphyseal and diaphyseal sites by using laser Doppler flowmetry before reaming, after reaming, after lavage, after cementing, and at 6 weeks after the procedure just before euthanasia. Reaming significantly decreased bone blood flow in the diaphysis (P = .046) but not in the metaphysis. Cement introduction and cement pressurization both significantly decreased bone blood flow in the metaphysis (P = .035, P = .004) and diaphysis (P = .007, P = .029). Pressurization of cement had a significantly greater relative effect than cement introduction alone in the diaphysis (P = .006) but not in the metaphysis. Lavage had no effect on bone perfusion. Bone blood flow was significantly increased at 6 weeks after the initial procedure in both the metaphysis (P = .049) and the diaphysis (P = .004). The results suggest that reaming decreases diaphyseal cortical but not metaphyseal bone blood flow significantly, whereas lavage has no effect. Cement introduction with or without pressurization has a significant detrimental effect on metaphyseal and diaphyseal blood flow. These findings have implications for intramedullary nailing and for canal preparation when performing arthroplasty.     

实验性骨折愈合的血运重建

本实验对骨折愈合局部血液循环的重建进行了研究.8只山羊分为两组:正常组.用于观察骨微血管;实验组,观察骨折血运重建,线锯造成胫骨中段横骨折,6周后处死.两组动物均在股动脉插管,注射中国墨汁,连续切片观察.结果表明;(1)滋养动脉供应骨干骨髓,骺——干骺动脉供应骺、干骺端骨髓;皮质深层2/3由滋养动脉分支供应,而皮质浅层1/3由骨膜动脉供应;(2)当骨折损伤滋养动脉,干骺部血管、骨膜血管扩张,增多.提示这些动脉在骨折愈合血运重建中起重要作用.     

A quantitative study of the routes of blood flow to the tibial diaphysis after an osteotomy

Techniques of tissue exclusion have been used previously in qualitative investigations of the vascularity of long bones, after experimental fracture; we quantified their effects on bone blood flow in rabbits. Thirty-six adult rabbits were divided into three groups in which flow was measured, with the microsphere technique, 1 and 2 weeks after osteotomy. In Group 1, osteotomy of the tibial shaft only was done; in Group 2, osteotomy was done with exclusion of the periosteum and muscle by a silicone rubber sheath; and in Group 3, osteotomy was done with exclusion of the marrow by reaming and insertion of an intramedullary nail. All involved limbs were immobilized in a cast. In Group 1, cortical flow increased but marrow flow did not change, which suggests that the changes in cortical flow were mediated by a supply paralleling that of the marrow. In Group 2, the changes in cortical flow were abolished, which implies that this parallel supply is from the periosteum and extraosseous tissues. In Group 3, cortical flow was not significantly reduced, which demonstrates reeruitment of this periosteal and extraosseous supply. These results lend support to the hypothesis that the blood supply to the healing diaphysis is principally from the periosteum and extraosseous tissues during the early peak period of blood flow.     

Long-term effects of plate osteosynthesis: comparison of four different plates

Various phenomena have been observed subsequent to plate osteosynthesis, for example, refracture after plate removal. Experimental research has shown that changes in the cortex occur within the first three months after plating and again several months later. These changes are independent of the fracture and take the form of porosis under the plate and excessive bone growth around the plate. Porosis under the plate was regarded until recently as being due to unloading of the bone by the plate, also known as stress shielding. Investigations of the relationship between bone porosis and the changes in periosteal blood supply due to its compression by the plate, however, have been neglected. In this study, the effect of plate properties such as structural stiffness ('unloading'), implant material, and plate contact surface (altered periosteal blood supply) on bone after osteosynthesis were investigated. This was done by comparative histomorphometry of the altered bone in sheep after application of four plates differing in the above-mentioned properties. After plating the sheep tibia with a trapezoid plate with narrow contact surface, significantly larger bone cross sections were observed one year after the operation and considerable bone growth around the plate. The area of early temporary porosis in the cortex under the plate as observed in the first nine weeks and after one year was not significantly different for any particular plate, all of which were applied subperiosteally. The trapezoid plates were easier to remove, thus causing less damage to the bone lamellae along the sides of the plate. The marked increase in bone cross section after one year and the larger areas of bone growth around the trapezoid plates with smaller contact surface can be attributed to the larger grooves cut along the sides of the plates. Cortical porosis was mainly the result of impaired periosteal blood supply which was of equal size in all groups as a result of careful periosteal stripping and subperiosteal plate insertion. It was assumed that applying the plate onto the periosteum would be associated with effects on periosteal blood supply directly related to the plate and consequently cortical porosis. Plate related stress shielding and the implant material had no significant effect on the extent of cortical porosis.     

Effect of periosteal stripping on cortical bone perfusion: A laser doppler study in sheep

The goals of internal fixation are an accurate reduction and stable fixation in the presence of adequate bony vascularity. This can be achieved by a variety of means including plate fixation. A certain amount of periosteal stripping is necessary for proper open reduction of a fracture and for proper plate application. With displaced diaphyseal fractures, cortical bone perfusion (CBP) is already compromised. Further damage, in terms of periosteal stripping for plate fixation, may not be acceptable. Little information is available as to what extent the periosteum contributes to cortical bone perfusion. The purpose of this study was to determine the acute effects of periosteal stripping on cortical bone perfusion in a sheep tibia model. Twenty-three sheep were operated on and had the medial aspect of their right tibia exposed. Cortical bone perfusion measurements were obtained using laser Doppler flowmetry prior to periosteal stripping and after periosteal stripping. The results of this study show that the cortical bone perfusion significantly decreased by 20% after periosteal stripping over the entire length of the tibia. We therefore conclude that the periosteum contributes to diaphyseal bone perfusion and that it is important to preserve this source with fractures where blood supply is already significantly compromised.     

两种骨骺刺激术影响长骨局部生长的实验研究

目的 比较截骨和骨膜切除两种常用骨骺刺激术对兔胫骨局部骨生长的影响。方法 将４０只兔分为胫骨上端骨骺远端２ｍｍ处截骨和上端骨骺线上下１ｍｍ以内骨膜切除两组，经大体骨标本测量。Ｘ线摄片，四环素荧光标记，组织学及电镜观察，进行比较研究，结果 骨膜切除术对骨骺生长的刺激作用大于截骨术。结论 骨膜切除术可作为治疗儿童膝关节畸形的良好方法。     

Induction of osteochondromas by periosteal resection.

Forty immature and 40 mature rabbits which received periosteal resection from the proximal metaphyses or diaphyses of tibiae were evaluated for the occurrence of osteochondromas at the sites of periosteal defects. Thirteen of 20 immature tibiae with the periosteal defects at their proximal metaphyses showed osteochondromas covered by hyaline cartilage caps. We assume that the occurrence of osteochondroma at the metaphyseal region of growing long bone, where the periosteal defects were made, is due primarily to a decrease in the power of the periosteum to control the circumferential growth of the metaphysis, and is due secondarily to an abnormal proliferation of cartilage progenitors located in Ranvier's groove.     

骨髓腔内微血管在骨折愈合中的形态变化

为探讨骨折造成滋养动脉损伤对骨干皮质深层２／３和髓腔内组织的缺血坏死及骨折愈合的影响，采用墨汁灌注法，观察４只兔骨髓内微血管；另２０只兔制备骨折模型，于术后３，８，１８，２８及４２ｄ处死动物，观察骨折后髓内微血管变化情况。结果表明：在骨折损伤滋养动脉时，髓内及皮质深层２／３供血阻断，髓内微血管增多、扩张，在整个骨折愈合时期（３～４２ｄ），髓内微血管密度高于正常。认为，骨骺与干骺端之间丰富的微血管吻合，在骨折愈后侧支循环的建立中，具有非常重要的作用。     

An unusual early complication of fracture. Separation of the distal humeral epiphysis

Summary A fracture separation of the distal humeral epiphysis, a rare injury can result in an extensive periosteal new bone formation around the humeral metaphysis due to extensive periosteal stripping, if an early and appropriate diagnosis is not established. A case with a rapid bone formation after such an injury is presented.     

Biomechanical effects of intramedullary reaming and nailing on intact femora in rats

In order to study the effects of intramedullary reaming and nailing on bone mechanics, the left femur of male Wistar rats was reamed after circular periosteal stripping of the middle part as if for osteotomy. Osteotomy was, however, not performed. The rats were allocated into three groups: the first group had no nailing, the second group received flexible intramedullary polyacetal nails, and the third group was nailed with solid stainless-steel nails. Ten animals from the first group were sacrificed on the day of surgery. At four, eight, 16, and 24 weeks after operation, ten animals from each of the three groups were sacrificed. Both femora were tested mechanically and examined histologically. Intramedullary reaming resulted in the following immediate reductions in mechanical properties compared to the unoperated right femur: strength, 15%; stiffness, 20%; toughness, 7%; and resilience, 15%. From four weeks on, strength and energy absorption values were always lowest in the group with steel nails. The differences between groups were significant at four, 16, and 24 weeks. The lower values for mechanical properties of the femora with steel nails is interpreted as a result of stress shielding by the rigid nails. Flexible nails did not interfere with the ultimate restoration of mechanical properties of bones initially weakened by reaming.     

Periosteal microvascular reorganization after tibial reaming and intramedullary nailing in rats

BackgroundIntramedullary reaming and nailing of long bones impairs the endosteal circulation, often causing necrosis of the inner region of the bone cortex. We hypothesized that compensatory hypertrophy of the periosteal microcirculation may develop in response to mechanical destruction of the endosteum, and that this may affect bone survival in these circumstances. In these studies, nailing was performed with materials that affect regeneration of the endosteum differently, and the effects on the tibial periosteal microvasculatory organization were examined.MethodsIn male Wistar rats, the right tibia was reamed and implanted with an inert titanium nail or a less osseointegrative polyethylene nail; the contralateral tibial endosteum was destroyed by reaming. Reaming without nailing or sham operation was performed on both extremities in two other groups of rats. Twelve weeks later, the anteromedial and anterolateral surfaces of the tibias were exposed by a microsurgical technique. The structural characteristics of the periosteal microcirculation (vessel density and distribution of vessel diameters) were determined by intravital videomicroscopy and computer-assisted analysis. The stability of the implants was assessed on the basis of grades 0–2 on a qualitative scale.ResultsTibial reaming alone caused significant increases in overall blood vessel and capillary densities in the periosteum compared with those of the intact tibias. Implantation with a titanium nail resulted in firm embedding of the nail and caused changes in the periosteal vasculature similar to those after reaming alone. In contrast, implantation of a polyethylene nail was followed by the development of marked instability of the endomedullary implant and significant increases in the percentage of capillaries and the vessel density in the periosteum.ConclusionsDestruction of the endosteal microcirculation per se brings about an increase in periosteal vascular density, which is further augmented if implantation is performed with a material which delays regeneration of the endosteal circulation.     

Bone formation from periosteal grafts and investigation on the possible effect of calcitonin

Autotransplantation of free periosteal grafts from the tibia to leg muscles and to the mandibular arches was performed in young rabbits, for the creation of new bone. The development of bone was followed up by serial radiographic examinations and by histological examination after sacrificing the animals. Calcitonin, which may increase bone mass by inhibiting bone resorption, was administered postoperatively to four rabbits.Bone formation was achieved in all rabbits. No effect of administration of calcitonin on bone mass could be demonstrated.Clinical applications of free periosteal grafts are suggested.     

不同程度的髓腔扩大对长骨血供影响的实验研究

为了解不同程度的髓腔扩大对长骨血供的影响，采用放射性核素显像的方法观察了兔股骨不同程度的髓腔扩大后血供的变化情况。结果显示：轻度扩大后第１天血供稍有下降，第４天超过健侧，此后进一步升高；重度扩大后第 １天血供明显下降，第 ４天后逐渐恢复，但直到第 １２天仍未达到健侧水平。结果表明：髓放扩大越重，血供下降趋多；扩大的轻，血供下降少。     

Haemodynamics in acute arthritis of the knee in puppies

In order to study the haemodynamic changes of the juvenile knee in acute arthritis, an experimental model was developed in puppies by unilateral intra-articular injections of Carragheenin solution into the knee. Tissue blood flow was studied by the tracer microsphere technique in eight dogs and simultaneous intra-articular and intraosseous pressure recordings were performed in seven other dogs. The intra-articular pressure was elevated in all arthritic knees. Hyperaemia was found in the knee-joint capsule and distal femoral metaphysis, whereas juxta-articular epiphyseal blood flow rates were not significantly changed. A decrease of femoral muscle blood flow was encountered. Intraosseous pressure recordings during venous tamponade of the knee-joint capsules suggested a qualitative change of bone vasculature in acute arthritis. The juxta-articular bone blood flow in arthritis appears to be influenced by synovial hyperaemia, synovial effusion pressure, an "inflammatory resistance factor" and the anatomical relationship of the epiphyseal vessels to the knee-joint capsule.     

Differentiation of periosteal cells in muscle. An experimental study using the diffusion chamber method

The osteo-chondrogenic capacity of the undifferentiated mesenchymal cells of the periosteum has been made use of in clinical reconstructive surgery. In the present investigation we studied the osteo-chondrogenic potency of free periosteal transplants in muscle using the diffusion chamber method. A total of 42 experimental and seven control rabbits aged four to six weeks were operated on. Periosteum was obtained from the anterior aspect of the left tibial bone by stripping. The grafts were placed in Nucleopore diffusion chambers with a pore size of 0.4 micron. The chambers were implanted in the anterior tibial and paraspinal muscles of the rabbit. Osteogenesis began after the second postoperative week and increased up to the 5-6 week interval when a plateau phase was reached. Chondrogenesis, which also began after the second postoperative week, reached two plateau phases; the first observed at 4-8 weeks and the second at 12-16 weeks. Neither bone nor cartilage formation could be observed outside the chambers. In the semi-open control chambers with only one end sealed, bone formed within the chamber as early as two weeks after transplantation and grew out into the adjacent connective tissue of muscle. It is noteworthy that the periosteal transplant retained its osteochondrogenic properties even when isolated in the diffusion chamber. The young age of the donor animals might have contributed to our findings.     

The relative contribution of individual osseous circulations to diaphyseal cortical blood supply

The potential contributions of periosteal, nutrient (medullary), and epiphyseo-metaphyseal circulations, respectively, to cortical blood supply have been investigated by isolating each using a diaphyseal segment model. The periosteal circulation was isolated by creating and nailing a 2-cm segment of the adult rabbit tibial diaphysis. The medullary circulation was isolated by external application of a silastic sheath to a diaphyseal segment. The epiphyseo-metaphyseal circulation was isolated by combining both techniques. The residual potential routes of blood supply to each isolated segment were studied by arterial radiography and by histology in a postmortem study and in a survival study at various times up to 4 weeks after the isolation procedure. Both centrifugal and centripetal arterial supply were observed in the postmortem study. In the survival study, cortical arterial perfusion was observed up to 4 weeks following isolation of the periosteal circulation but only up to 2 weeks following isolation of the nutrient (medullary) circulation. At 4 weeks, the segment was not perfused when supplied only by the epiphyseo-metaphyseal system. It would appear, therefore, that the periosteal circulation provides a potential source of arterial supply to the diaphyseal cortex. Furthermore, an intact periosteal circulation seems to be necessary if an isolated segment of cortical bone is to continue to be adequately perfused with blood.