Reduction of postoperative CT artifacts of pelvic fractures by use of titanium implants

The value of CT scanning for both preoperative and postoperative assessment of pelvic and acetabular fractures has been demonstrated. Previous attempts at our institution to obtain useful pelvic CT scans following internal fixation with stainless steel implants have been impaired by metal artifacts that degraded the transaxial CT images. Our use of titanium, instead of stainless steel implants, produced identical fixation and ultimate fracture healing, but yielded minimal artifacts. We recommend the use of titanium implants as substitutes for stainless steel implants in pelvic fixation to maximize the information obtained on subsequent CT exams.     

Titanium alloys for fracture fixation implants

This paper is intended to provide an overview of the composition, mechanical properties, biocompatibility, and clinical applications for titanium alloys that are used for fracture fixation implants. A new class of titanium implant alloys has emerged in recent years that exhibits a beta microstructure and a unique combination of mechanical properties. Important information regarding notch sensitivity testing and clinical significance is also discussed. Attributes such as stress corrosion cracking resistance, fatigue strength, and wear characteristics are also essential for specific clinical applications, but are beyond the scope of this presentation.     

Metallic Biomaterials in Skeletal Repair

Abstract Metallic biomaterials are becoming increasingly important in skeletal repair. The goal of this review article is to present an overview of metallic implant materials currently used in trauma and orthopedic surgery. Further, new research trends and future clinical concepts are described and discussed. Titanium, titanium alloys, stainless steels and CoCr alloys are used as bone implants in orthopedic and trauma surgery. Especially titanium and its alloys currently constitute the most highly favoured implant materials for joint replacement and osteosynthesis. In comparison to other metallic implant materials, titanium is characterized by a high biocompatibility, a good workability and corrosion resistance with suitable mechanical properties (low Young’s modulus—high strength). To improve orthopedic implants, there is a trend in current research towards the development of new titanium alloys with improved biological and biomechanical properties. To achieve a fast and safe bone fixation of the implants, optimized surface characteristics and surface structures are applied. Biomimetic coatings with and without the ability to release growth factors and cell coatings even including the development of stem-cell-coated titanium implants for the partial surface replacement of joints are under investigation.     

钛网在掌骨颈骨折治疗中的应用

目的：探讨采用钛网治疗掌骨颈骨折的临床效果。方法2011年6月-2011年12月，采用钛网、螺钉治疗掌骨颈部骨折8例。结果术后经5～12个月随访，骨折对位对线均优，全部愈合，掌指关节功能均恢复正常。结论采用钛网固定治疗掌骨颈骨折，手术操作简便，固定可靠，可早期功能锻炼，有利于手功能恢复，是掌骨颈骨折较好的治疗选择。     

An evaluation of the clinical application of three different biodegradable osteosynthesis materials for the fixation of zygomatic fractures.

OBJECTIVE: The aim of this prospective study was to compare the clinical handling of 3 different biodegradable osteosynthesis materials and to determine whether they can be used for the fixation of all types of zygomatic fractures. STUDY DESIGN: A total of 54 consecutive patients who presented with displaced fractures of the zygomatic bone between October 2001 and May 2003 were randomly allocated to 3 biodegradable material groups for the fixation of the fractures. A titanium fixation system was used as rescue osteosynthesis whenever biodegradable materials failed. RESULTS: Seventy-one (75.5%) of 94 fracture sites were fixed with biodegradable osteosynthesis; 23 (24.5%) had to be fixed with titanium plates and screws. No statistically significant difference was found between the 3 biodegradable materials with regard to their suitability for zygomatic fracture fixation (P = .16). Nonstable fixation (n = 7) or the need to fix small fragments (n = 16) were the reasons for using the titanium fixation system as rescue osteosynthesis at these sites. Biodegradable materials were most frequently unfeasible for use at the infraorbital rim and in the zygomaticomaxillary/anterior sinus wall area. CONCLUSIONS: It was possible to stabilize 3 of 4 zygomatic fractures with 1.5- or 1.7-mm biodegradable osteosynthesis. Insufficient fracture stabilization, especially at the infraorbital rim and the zygomaticomaxillary crest/anterior sinus wall, was the main reason to switch to titanium osteosynthesis. The biodegradable screw design is possibly too bulky for these particular bony structures.     

Custom titanium plating for failed nonunion or delayed internal fixation of femoral fractures

Eight patients with either failed internal fixation of nonunions of the femur (six) or delayed treatment of extensively comminuted femoral fractures (two) were treated with customized titanium plates for internal fixation. All eight patients had fixation problems that surpassed treatment by intramedullary nailing or standard plate osteosynthesis. Custom titanium plates were individually designed from roentgenograms and/or computed axial tomographic (CAT) scans. Plate dimensions were altered to increase strength, height, length, and placement of screw holes to enhance stabilization of the individual femoral anatomy. At an average follow-up period of 33 months, all fractures united; there were no complications, including fatigue or loosening of the custom implants. The implants were well tolerated and provided excellent fixation of difficult fracture problems.     

A new technique for cranioplasty with L-shaped titanium plates and combination ceramic implants composed of hydroxyapatite and tricalcium phosphate (Ceratite)

OBJECTIVE: The use of hydroxyapatite-based ceramics for cranioplasties has recently increased in Japan, because of the good cosmetic outcomes, biocompatibility, strength, osteoconductive properties, and lack of risk of disease transmission associated with these materials. However, miniplate fixation has not been possible for ceramic implants. We describe a new technique for miniplate fixation of ceramic implants. METHODS: Combination ceramic implants composed of hydroxyapatite and tricalcium phosphate (Ceratite; NGK Spark Plug Co., Aichi, Japan) were used for cranioplasties. A slot and a pair of holes were cut in each Ceratite implant, for use as a fixation unit. We have also developed a new L-shaped titanium plate (HOMS Engineering Inc., Nagano, Japan) that fits into the fixation unit. We first insert an L-shaped titanium plate through the slot from the back surface of the Ceratite implant. We then bend the plate outward at the front surface of the Ceratite implant and fix it to the cranium of the patient with titanium screws. The Ceratite implant is usually firmly fixed to the cranium of the patient with three L-shaped titanium plates. RESULTS: Using L-shaped titanium plates and Ceratite implants, we successfully performed cranioplasties for seven patients with cranial defects resulting from external decompression craniotomies. The Ceratite implant exactly fit the bone window for each patient. Surgical maneuvers were simple and easy for all patients, permitting shorter operating times. All Ceratite implants were firmly fixed, and no postoperative infections have occurred. CONCLUSION: Our new technique for cranioplasty is simple and allows rigid fixation of Ceratite implants.     

Treatment of proximal humeral fractures with Polarus nail fixation

A chart review of 20 patients who sustained acute proximal humeral fractures and who were treated by surgical stabilization with locked antegrade humeral intramedullary nails (Polarus nails) was undertaken. The clinical outcome measurements were fracture healing, infection, and neurologic injury. Radiologic outcome measurements included fracture alignment, loosening, fixation and hardware failure, and malunion and nonunion. Of 20 fractures, 11 healed without complications. The mean immediate postoperative and final radiographic valgus neck/shaft angulation measured 131 degrees. Of the 20 implants, 3 had proximal fixation screw loosening. Of the 20 implants, 2 underwent revision surgery for proximal fixation failure. With certain fracture types, the Polarus intramedullary humeral nail can be an effective implant. In fracture cases involving an unstable or comminuted lateral metaphyseal fracture, if the starting point extends into the greater tuberosity, fixation failure or fracture displacement may result.     

微型钛板固定整复陈旧性眶底、眶骨骨折伴邻近颅面骨骨折

目的 探讨陈旧性爆裂眶底、眶骨骨折伴邻近颅面骨骨折所致面部畸形，整复后应用微型钛板（microplate）固定的临床疗效。方法 对20例陈旧性眶底、眶骨骨折患者，根据CT扫描和三维成像诊断，重新截骨复位，用微型钛板根据骨折部位和形态，采用跨2～3个骨折线固定，或将钛板越过粉碎骨折部位，呈桥状两端固定。结果 无论眶底眶缘单纯骨折或粉碎性骨折错位愈合，在整复后微型钛板固定，完全修复了颜面畸形，并恢复了眼球运动和咀嚼功能。随访6个月至1年，无1例发生钛板排斥反应或断裂脱落等并发症。结论 微型钛板可以达到眶骨骨折复位后坚强内固定，是目前整复眶骨和颜面部骨折最有效的固定方法之一，并且使用方法简便，容易掌握。     

Effects of fibrin sealant on the fixation of porous titanium and pyrolytic carbon implants

The authors investigated the potential role the fibrin sealant system may portray in the fixation of osseous implants. The application of a layer of fibrin did not interfere with the fixation of osseous implants of either pyrolytic carbon or Biolite-coated porous titanium. A greater percentage of tissue ingrowth was observed in the porous titanium implants in the presence of the fibrin sealant system; however, no significant difference in the ultimate interfacial shear stress was observed.     

脊柱结核内固定的生物学基础

目的观察结核杆菌与不同内固定材料的粘附情况,以期初步探讨在脊柱结核病灶清除后植入内固定选择何种材料的问题。方法在结核杆菌的菌液分别加入四种不同的内固定材料（不锈钢、钛、钛合金、聚醚醚酮）,通过碘-125标记测量,比较细菌与材料之间的粘附情况。结果四种材料中,细菌在聚醚醚酮上的粘附最多,在纯钛上粘附最少,在不锈钢的粘附多于钛合金（P〈0.05）。结论在脊柱结核患者内固定材料的选择上,以纯钛为首选,钛合金次之,碳纤维材料慎用。     

Radiographic evaluation of osseointegration and loosening of titanium implants in the MCP and PIP joints

PURPOSE: Good to excellent clinical results have been shown in the initial studies on osseointegrated metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joint implants that consist of a flexible silicone spacer connected to osseointegrated titanium fixtures. A high fracture rate of the silicone spacer, however, has been reported, diminishing the value of this implant system. The purpose of this study was to evaluate the osseointegration of the titanium fixture itself in a large study group and compare patients with rheumatoid arthritis with those with osteoarthrosis as a base for further development of the implant concept. METHODS: Two hundred thirty-nine implants (27 PIP, 212 MCP) in 86 patients were retrospectively evaluated radiographically. Two hundred implants were in patients with rheumatoid arthritis. Radiographic evaluation included measuring the length and width of resorption zones around the titanium fixtures. A scoring system was used that grouped observations in 4 groups, from 0 (little or no change) to 3 (loosening). Status of the silicone spacer was also noted. RESULTS: At follow-up evaluation an average of 41 months (range, 12-103 months) after surgery, complete osseointegration was found in 450 of 478 fixtures (94%). Loosening was found in 10 proximal and 18 distal fixtures. The proximal fixtures showed loosening mainly during the first 3 years after surgery and the distal fixtures also had loosening. In the 31 MCP joint implants that were evaluated for more than 5 years, the osseointegration rate was 97%. CONCLUSIONS: Implant stem fixation with osseointegrated titanium fixtures is a valuable method that works well in rheumatoid arthritis patients. Further development will focus on a more durable constrained joint mechanism.     

侧方微型钛板内固定治疗近节指骨骨折

目的 报道应用侧方切开复位微型钛板内固定治疗近节指骨骨折的临床效果.方法 对14例16处近节指骨骨折行侧方切开复位微型钛板内固定治疗.术后2d进行手指功能锻炼.结果 术后随访10～36个月,平均13个月.所有患者于术后5～9周（平均6周）骨折均达到骨折临床愈合,无感染及畸形愈合的发生.按TAM法进行功能评定,优9例,良5例.结论 采用侧方切开复位微型钛板内固定治疗近节指骨骨折可减少对肌腱的刺激和关节僵硬的发生,手指功能恢复良好.     

The bone-implant interface: a dynamic surface.

This study quantifies and compares bone formation on and around roughened titanium implants with roughened cobalt chromium, polished solid implants, and titanium fibermetal implants. Cylindrical rods were implanted into the medullary canal of the distal femur of rabbits. The bone-implant interface was studied 3, 6, and 12 weeks after surgery using histomorphometric methods. Roughened surface implants demonstrated significantly more bone directly apposed to the surfaces when compared to the polished or fiber/metal implants at 6 and 12 weeks after surgery. New bone formation and remodeling of bone occurred directly on roughened surfaces as late as 12 weeks after implantation, but not on the unroughened implants. These results suggest that roughening of the surfaces of both titanium and cobalt chromium implants can enhance osseointegration and may be useful clinically for the fixation of prosthetic components.     

Complications after zygoma fracture fixation: is there a difference between biodegradable materials and how do they compare with titanium osteosynthesis?

OBJECTIVE: Biodegradable materials are particularly useful for the fixation of zygomatic fractures. Different systems are commercially available. The aim of this study was to compare the clinical outcome of zygomatic fracture fixation using 3 biodegradable systems and a titanium osteosynthesis system. STUDY DESIGN: Patients with displaced fractures of the zygomatic bone presenting at our department from October 2001 to May 2003 were randomly allocated to 1 of 3 treatment groups for fracture fixation (study group A: LactoSorb: n = 18; study group B: BioSorb: n = 18; study group C: Delta: n = 18). Treatment outcome and complication rates were compared with a historic patient group with zygomatic fractures fixed with titanium osteosynthesis (control group D: n = 15). RESULTS: A total of 64 patients (study groups A + B + C: n = 49; control group D: n = 15) were followed for at least 24 months (range: 24 to 44 months). Forty-nine patients in the biodegradable study groups (group A: n = 15; group B: n = 17; group C: n = 17) who had their fractures fixed with biodegradable plates and screws alone or in combination with titanium plates and screws were reviewed postoperatively. Uneventful healing occurred during the entire follow-up period in 39 (80%) out of 49 patients in the biodegradable groups (A + B + C) and in 12 (80%) out of 15 patients in group D. Ten patients in groups A + B + C developed postoperative complications (infection: n = 3; soft tissue dehiscence: n = 2; implant-related tissue reactions: n = 5), compared with 3 patients in group D (soft tissue dehiscence: n = 1; unspecific pain: n = 2) (P = .97). Complications occurred in 4 patients in group A and 3 patients each in groups B and C. Smokers developed significantly more postoperative complications than nonsmokers in groups A + B + C (P = .01). CONCLUSION: There was no significant difference between biodegradable osteosynthesis materials or between biodegradable materials and titanium fixation with respect to fracture healing and postoperative complications. Postoperative complications were of a minor nature and resolved spontaneously or after local therapy. Smoking habits may play a significant role in the incidence of complications with biodegradable materials.     

Effect of surface topography on removal of cortical bone screws in a novel sheep model

Difficulty in removing implants used in trauma patients can be a complication, and increased bone–implant adhesion likely is a major contributing factor. In vitro studies have shown that surface morphology of implant materials has the ability to influence cellular responses, with polished surfaces decreasing the potential for mineralization. This study examined the effect of polishing commercially pure titanium (cpTi) and the titanium alloy TAN on the removal torque and percentage bone–implant contact in cortical and cancellous bone of sheep. Polishing had a significant effect on both removal torque and percentage bone–implant contact, with the polished implants demonstrating a lower removal torque in both cortical and cancellous bone. Polished cpTi and stainless steel were similar in terms of surface roughness and removal torque. However, polished TAN, which was not as smooth as polished cpTi, did not show the same low level for reducing removal torque. Improved polishing of TAN should reduce the removal torque further. The results of the study show that polishing is promising in improving the ease of implant removal after fracture fixation and repair. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1377–1383, 2008     

青壮年股骨颈骨折手术治疗的回顾性分析

目的 探讨治疗青壮年股骨颈骨折的手术方法及临床疗效. 方法对2005年1月至2008年6月行手术治疗并获得随访的41例青壮年股骨颈骨折患者按照"难治性骨折的治疗研究随访表"进行随访,从骨折类型、手术时机、骨折复位质量、置入物类型、卧床时间以及髋关节功能等方面进行评估. 结果 41例患者获得10～52个月随访,平均30.5个月.37例(90.2%)患者在伤后2～5d内行手术治疗,平均3.6 d,Garden Ⅱ、Ⅲ型骨折采用闭合复位钛合金空心钉内固定术,Garden Ⅳ型及陈旧性骨折、病理性骨折采用切开复位钛合金空心钉内固定加髂骨瓣植骨术.术中复位评价平均4.83分,术后平均卧床时间3.5个月.髋关节功能按照Harris评分标准:优21例,良15例,可3例,差2例,优良率为87.8%.Garden Ⅳ型骨折优良率较Ⅱ、Ⅲ型骨折优良率低,但差异无统计学意义(χ2=1.35,P=0.25). 结论早期手术、解剖复位、多枚钛合金空心钉坚强内固定是青壮年股骨颈骨折手术治疗的关键,Garden Ⅳ型骨折髂骨瓣植骨、合理的早活动和晚负重是预防股骨头缺血坏死的有力保证.根据骨折的严重程度制定科学规范的治疗方案和合理的术后康复策略,对提高临床疗效具有极其重要的意义.     

应用微型钛板治疗掌指骨骨折

目的探讨应用微型钛板内固定治疗手部骨折及其临床疗效。方法2007年8月～2009年8月对手部掌指骨骨折75例（95处）采用切开复位,微型钛板内固定治疗。结果术后随访4～12个月,平均6个月,优良率为97％,骨折临床愈合时间4～12周（平均8周）。结论采用微型钛板治疗手部掌指骨骨折,获得稳定的骨折固定,缩短骨折愈合时间,疗效满意。     

Bioabsorbable magnesium versus standard titanium compression screws for fixation of distal metatarsal osteotomies – 3 year results of a randomized clinical trial

Background

For the treatment of hallux valgus commonly distal metatarsal osteotomies are performed. Persistent problems due to the hardware and the necessity of hardware removal has led to the development of absorbable implants. To overcome the limitations of formerly used materials for biodegradable implants, recently magnesium has been introduced as a novel implant material. This is the first study showing mid-term clinical and radiological (MRI) data after using magnesium implants for fixation of distal metatarsal osteotomies.

Management of distal humerus fractures with minifragment fixation

Minifragment implants provide several advantages for the stabilization of distal humerus fractures. Compared with small fragment implants, minifragment implants may provide enhanced fracture fixation because a greater number of screws can be placed into the distal fragments. In addition, minifragment plates are easier to contour and less prominent. We describe the surgical technique of minifragment fixation.