锁定加压钢板治疗人工关节假体周围骨折

目的　介绍一种采用锁定加压钢板螺钉 (L CP)固定人工关节周围骨折的方法。方法　为一例髋关节假体远端周围螺旋骨折 ,采用 12孔长锁定加压钢板于外侧固定。近折端 6孔 ,其中 5孔用锁定螺钉作单侧骨皮质固定 ,最末孔用 4 .5 m m螺钉固定 ;远折端 4孔 ,作双侧骨皮质固定 ,中间骨折区域 2孔空出 ,以免干扰骨折愈合。结果　术后 3天开始行髋膝关节功能锻炼 ,1周后下地站立锻炼 ,2周患肢部分负重训练。术后 X线片示骨折复位固定良好 ,假体柄周围无松动迹象。术后 3个月复查 X线片示骨折愈合无畸形 ,假体无松动 ;6个月随访 ,患肢无疼痛、肌萎缩 ,功能恢复正常。结论　 L CP用于处理关节假体周围骨折时方法简便 ,剥离范围小 ,对局部组织创伤小 ,有利于骨折的愈合 ,是一种良好选择     

Compression plating without bone grafts for delayed and non-union of humeral shaft fractures

Seventeen cases of delayed and non-union of the humeral shaft were treated with compression plates. Bone ends were excised in all but one in which the plate was applied directly over the fibrous union. Bone grafts were used only in the first 2 cases. Whenever compression and rigid fixation were effectively achieved and maintained, as in 14 cases (including the case in which the pseudarthrosis was not excised), primary bone union occurred within an average period of 8.5 weeks. When compression and fixation were not effectively achieved at operation or subsequently worked loose, as in 3 cases, union was slow to occur in 2 and failed in 1. If the bone is very porotic or the fracture line is a long spiral or if the non-union is just above the supracondylar region, the method is unsuitable and likely to fail.     

Influence of stable fixation on trabecular bone healing: a morphologic assessment in dogs

The healing patterns of trabecular bone are different from those of compact bone. In order to investigate further this observation, a histomorphometric assessment was undertaken. The influence of internal fixation devices on trabecular bone healing was also studied. Intercondylar osteotomies were produced in 19 dogs and fixed with screws. All dogs were killed between 1 and 14 weeks; eight of them had the screws removed 4 weeks after osteotomy and were killed 4 or 10 weeks later. The results of morphometry were compared to the histologic and radiologic pictures. Anatomic reduction with stable fixation led to contact healing characterized by a narrow endosteal bone formation at the osteotomy site that disappeared only after union was complete (4 weeks). In gap healing, the endosteal bone formation was greater. Internal fixation devices appeared to cause a diffuse osteopenia once union was complete. Their removal just after completion of union seems to prevent the bone loss. Screws induced bone formation around their threads; after they were removed, the reaction disappeared but the screw holes were not filled with normal trabeculae 10 weeks later. Union of fractures through trabecular bone can be assessed radiologically. A decrease of band-like bone density at the fracture site indicates completion of union. This is the optimal time for implant removal. It prevents the osteopenia observed in cases of continuous presence of screws.     

Comparison of stainless steel and composite plates in the healing of diaphyseal osteotomies of the dog radius: report on a short term study.

The rigid fixation of fractures is generally accepted as the best method to achieve union when open treatment of a fracture is undertaken. This has led to the development of plates that have a greater overall dimension and stiffness compared to earlier plate models, as exemplified by the Lane or Eggers type of plate. In our experience the more rigid plate generally leads to satisfactory union, but also carries with it the risk of refracture, either through a screw hole or across the original fracture after plate removal. Experiments by Uhtoff and Dubuc on experimental animals showed that plate induced osteopenia existed when a rigid plate was applied to an intact or osteomized canine femur. These results provide a possible explanation for the occurrence of late fracture. The study to be described is based on the hypothesis that a rigid plate applied to bone induced localized immobilization osteopenia, which ultimately weakens the bone and leads to the development of late fracture. The study was designed to compare a plate made of stainless steel, which exhibited mechanical stiffness comparable to that of devices presently in use, with a plate made of a composite material, which exhibited decreased stiffness by nearly one order of magnitude. It had been demonstrated by engineering analysis that the less stiff plate would allow the bone to experience normal loading, and it was thought that this loading would modulate the rate and pattern of bone remodeling, thereby resulting in bone of greater strength and size as compared to a more rigidly plated bone.     

Fracture repair during external fixation. Torsion tests of rabbit osteotomies

Bone repair was studied in the rabbit tibiofibular bone after a midshaft transverse osteotomy stabilized by external fixation and heavy compression. Both subendosteal and subperiosteal callus formation with concomitant contact healing were observed within 3 weeks, and were further succeeded by subendosteal resorption and increased porosis resulting in atrophy of the cortical bone. Subjected to the torsion test, the bones exhibited restoration of strength within 3 weeks, with maximal energy absorption and elasticity at 6 weeks. The failure of the osteotomy in the torsion test, with radiographic visibility of the osteotomy, characterized the soft-tissue type of behavior of the bones. Hard-tissue like behaviour of the bones with resistance to torsion at the osteotomy site and radiographic obliteration of the osteotomy line occurred by 12 weeks, indicating complete union of the osteotomy. Our experiments demonstrate that elastic external fixation is preferable to the rigid compression plate.     

Fracture repair during external fixation: Torsion tests of rabbit osteotomies

Bone repair was studied in the rabbit tibiofibular bone after a midshaft transverse osteotomy stabilized by external fixation and heavy compression. Both subendosteal and subperiosteal callus formation with concomitant contact healing were observed within 3 weeks, and were further succeeded by subendosteal resorption and increased porosis resulting in atrophy of the cortical bone. Subjected to the torsion test, the bones exhibited restoration of strength within 3 weeks, with maximal energy absorption and elasticity at 6 weeks. The failure of the osteotomy in the torsion test, with radiographic visibility of the osteotomy, characterized the soft-tissue type of behavior of the bones. Hard-tissue like behaviour of the bones with resistance to torsion at the osteotomy site and radiographic obliteration of the osteotomy line occurred by 12 weeks, indicating complete union of the osteotomy. Our experiments demonstrate that elastic external fixation is preferable to the rigid compression plate.     

Application of locking plate in long-bone atrophic nonunion following external fixation

The treatment of atrophic fracture nonunion continues to represent a therapeutic challenge. Large segmental osteopenia is often seen in patients who received uniplanar or hybrid external fixators as the definitive method of fixation for high-energy fractures, and this adds more difficulties to the treatment of fracture nonunion. This retrospective study was designed to assess the outcome of locking compression plating with autologous bone grafting in patients with long-bone atrophic nonunion following external fixation.From January 2004 to December 2009, a series of consecutive patients with atrophic nonunion of the long bone following external fixation were treated with this method in our institution. The clinical outcomes and complications of these patients were retrospectively analyzed. Twenty-seven patients with 28 fracture nonunions were involved in this study. Mean follow-up was 14.2±3.4 months. Bony union was achieved in all 27 patients within a mean 18.6±4.8 weeks after revision surgery. Two patients developed superficial wound infections. No deep infections were found, and no implant failure was seen. Three patients reported minor pain in the donor site of the bone graft, and no other donor site complications were found.Revision osteosynthesis of long-bone atrophic nonunion following external fixation by locking compression plating with autologous iliac crest bone grafting represents a safe and efficacious modality for the treatment of these challenging conditions.     

Stress shielding by rigid fixation studied in osteotomized rabbit tibiae

In 48 rabbits the bone-formation rates and strength in the tibial shaft, osteotomized and treated with rigid internal plate fixation, were compared with contralateral bones, which were treated with plate fixation without osteotomy. The plate fixation alone induced a 35 percent decrease in torsional strength after 12 weeks. The healing of the osteotomy counteracted the decrease in strength induced by stress protection of the rigid plate at 6 weeks, but this effect subsided within 12 weeks. The osteotomy also induced a 2-3-fold increase in the synthesis of bone matrix and mineral accretion of the bone underlying the plate at 6 and 9 weeks when compared with the contralateral side, which was plated but not osteotomized. The bone-formation levels returned to normal within 12 weeks; and the bone underlying the plate became subject to atrophy, resulting in decreased mechanical strength.     

异体骨板与钢板联合固定治疗萎缩性骨不连

目的 观察异体骨板与钢板联合固定治疗萎缩性骨不连的临床效果。方法 用新鲜冷冻异体长骨段,术中制备与钢板类似的长骨板,置于钢板对侧皮质骨表面联合固定骨折端。结果 治疗9例股骨和4例肱骨骨不连,获得良好的骨愈合。其中骨不连一次手术8例,二次手术5例。结论 通过异体骨板的骨强度,可提高螺钉对萎缩骨的骨把持力,同时利用异体骨的骨诱导作用,获得机械固定和生物学固定的双重效果,提高骨愈合率。     

Plate fixation of tibial fractures in the rabbit: Correlation of bone strength with duration of fixation

Bone healing after metal plate fixation of rabbit tibial osteotomies was studied in order to gain information as to the optimum time for plate removal. The fracture had regained almost normal biomechanical properties after 6 weeks. Significantly greater strength and stiffness of the healing tibiae were obtained at 12 weeks when the plate was removed after 4, 6 or 9 weeks and no further fixation was subsequently applied, compared to those plated for 12 weeks. The results indicate that a metal plate should be removed as soon as the fracture has regained normal biomechanical properties; i.e. before the stress-protecting effect has secondarily weakened the bone.

The findings suggest that metal plates should be removed at an earlier stage of the healing period than is usual in clinical practice.     

坚硬接骨板对板下皮质骨结构的影响——扫描电镜观察

为了对坚硬接骨板固定及取出后板下皮质骨结构变化进行观察，作者选用新西兰兔２８只，其中４只作对照；２４只在左胫骨作不锈钢接骨板固定，其中２０只于术后２个月取出接骨板，并分别在取钢板当时及取钢板后１、２、３和４个月各处死４只取材，另４只在内固定后６个月处死取材。用扫描电镜对各组板下皮质骨的结构变化进行观察。结果显示：坚硬接骨板内固定后，板下皮质骨不仅有大量骨丧失，而且骨的结构包括骨表面矿柱和骨内胶原纤维的结构排列也发生明显紊乱；接骨板取出后，骨量和骨结构可逐步恢复正常，但骨结构恢复有一延迟过程。作者认为，骨结构恢复延迟可能是接骨板取出后固定骨段再骨折的原因之一。     

肾硬接骨板对板下皮质骨结构的影响

为了对坚硬接骨板固定及取由后板下皮质骨结构变化进行观察,作者选用新西兰兔２８只,其中４只作对照;２４只在左胫骨作不钢接骨板固定,其中２０只于术后２个月取出接骨板,并分别在取钢板当时及取钢板及１、２、３和４个月各处死４只取材,另４只在内固定后６个月处死取材。用扫描电镜对各组板下皮质骨的结构变化进行观察。结果显示：坚硬投骨板内后,板下皮质骨不仅有大量骨丧失,而且骨的结构包括骨表面矿柱和骨内胶原纤维的结     

Plate fixation of tibial fractures in the rabbit: Correlation of bone strength with duration of fixation

Bone healing after metal plate fixation of rabbit tibial osteotomies was studied in order to gain information as to the optimum time for plate removal. The fracture had regained almost normal biomechanical properties after 6 weeks. Significantly greater strength and stiffness of the healing tibiae were obtained at 12 weeks when the plate was removed after 4, 6 or 9 weeks and no further fixation was subsequently applied, compared to those plated for 12 weeks. The results indicate that a metal plate should be removed as soon as the fracture has regained normal biomechanical properties; i.e. before the stress-protecting effect has secondarily weakened the bone.

The findings suggest that metal plates should be removed at an earlier stage of the healing period than is usual in clinical practice.     

Plate fixation of tibial fractures in the rabbit. Correlation of bone strength with duration of fixation

Bone healing after metal plate fixation of rabbit tibial osteotomies was studied in order to gain information as to the optimum time for plate removal. The fracture had regained almost normal biomechanical properties after 6 weeks. Significantly greater strength and stiffness of the healing tibiae were obtained at 12 weeks when the plate was removed after 4, 6 or 9 weeks and no further fixation was subsequently applied, compared to those plated for 12 weeks. The results indicate that a metal plate should be removed as soon as the fracture has regained normal biomechanical properties; i.e. before the stress-protecting effect has secondarily weakened the bone. The findings suggest that metal plates should be removed at an earlier stage of the healing period than is usual in clinical practice.     

Bodyloading on atrophied bone and bone mineral content. An experimental study in the rabbit

The quality of a cortical bone, as reflected in the bone mineral content, has been studied in rabbit tibiae during an experimental atrophy process, and following recovery and adaptation to increased loading. Atrophy of the bone was induced by a rigid internal fixation plate applied to the tibia for 12 weeks. During the process of recovery after the plate had been removed, the bone mineral content was studied by means of an ashing procedure. The bone mineral content per unit volume cortical bone remained unchanged both at maximum atrophy and during the subsequent process of recovery.     

The relationship between porosity, collagen fiber orientation and strength of plated bone after rigid plate fixation and removal

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An experimental study on various internal fixations in fracture of a long bone (author's transl)

In the operative treatment of a long bone fracture, the most important point is to secure the bone healing and to strengthen the bone after removal of internal fixation materials. In this regards, the author has analyzed the mechanical strength of various internal fixation methods (a plate, a medullary nail, screws and encircling wires) on the bone by using acrylics models. Experimental studies of their influences on the bone have also been performed especially investigating the decrease in the bone strength in rabbits. All of internal fixation materials are made of 316L stainless steel. Recently, there has been a tendency to use larger materials for internal fixations such as an AO compression plate or a Küntscher type medullary nail. However, it was found that the rigid plate fixation greatly affects the bone strength. A medullary nail produced less impairment to the bone. But this method is restricted in its application because of the weak fixability of the torsional load. On the other hand, the internal fixations with screws or encircling wires are weaker than the other methods especially against the bending load. Therefore the commencement of postoperative treatment will be delayed. But, these two methods have little influence on the bone during fixation.     

Treatment of periprosthetic femoral fracture after cementless total hip arthroplasty with Ilizarov external fixation

A 72-year-old woman with periprosthetic femoral fracture after cementless total hip arthroplasty (THA) underwent external fixation using the Ilizarov method. Although open reduction and internal fixation with a condylar plate system were initially attempted, deep infection with methicillin-resistant Staphylococcus aureus at the fracture site occurred 2 weeks postoperatively. Six weeks after removal of the plating system, the fracture was stabilized with external fixation using the Ilizarov method and went on to successful fusion at 3 months. To our knowledge, this is the first report in which Ilizarov external fixation has been used for periprosthetic femoral fracture after THA. Although this is a rare situation, where periprosthetic fracture and infection coexist, Ilizarov external fixation is a safe and reliable method for periprosthetic femoral fracture with infection.     

Plate stabilization with bone rivets: an alternative method for internal fixation of fractures

OBJECTIVES: Bone rivets were developed as an alternative method to fasten plates during internal fixation of fractures when screw anchorage may be inadequate. This study examined whether such rivets allow proper fracture healing without eliciting adverse bone remodelling and whether they can be removed safely. METHODS: A proximal diaphyseal fracture of the tibia was stabilized with a conventional plate (low-contact dynamic compression plate, Synthes) in 10 sheep. The distal fragment was anchored using bicortical screws, and the proximal fragment (1-2.5 mm thick cortex) with 3 rivets following screw stripping. Postoperative care included immediate weight bearing and biweekly radiographs. After 12 weeks, implants were removed from 6 sheep and the tibial strength measured. Tibiae with empty and filled rivet holes (at 12 and 24 weeks) were examined histologically. RESULTS: In all sheep, secondary bone healing was observed without length and angulation deformities. All fracture gaps were bridged and filled with new bone. The average torsional strength after 12 weeks was 75 +/- 11% of the intact tibia (mean +/- SD), and failure never occurred through an empty rivet hole. After 12 weeks, there was intensive cortical remodelling at the rivets correlating with slight to moderate nonprogressive periosteal radiolucency around 55% of the rivets. However, there was also endosteal appositional bone growth at 85% of the rivets. There was no observable macroscopic or microscopic osseous damage after implant removal. After 24 weeks, remodelling activity had decreased and was noted only sporadically. CONCLUSIONS: In this study, the efficacy of bone rivets for the internal fixation of a fracture with plates, where anchorage of screws may be difficult and/or insufficient, was demonstrated.     

坚硬接骨板固定后局部骨质疏松的骨组织形态计量学的实验研究

本实验通过骨组织形态计量学的方法，对家兔完整胫骨坚硬接骨板内固定后局部骨组织的变化进行了研究，实验家兔随机分为１、２、３、４组和空白对照组，固定时间为６．８．１０和１２周。对不脱钙骨组织切片在纵切面和横切面上进行普通光和莹光分析测量。结果发现：坚硬接骨板内固定后六周时固定段骨即出现骨质疏松，发生在哈佛氏系统的骨丢失，１０周后骨内膜表面出现骨吸收、骨髓腔增大，两个表面的骨重建单位的负平衡使固定段皮质骨疏松变薄，特别是在钢板下。