Titanium fibermetal segmental replacement prostheses. A radiographic analysis and review of current status

Thirteen patients with titanium fibermetal segmental bone/joint prostheses at a minimum follow-up period of six months were reviewed. Detailed radiographic data were analyzed quantitatively in terms of stem/bone interface radiolucency and bone bridging over the segmental portion of the prosthesis at predefined zones. Although stem radiolucent lines were common in this series, only one case had clinical loosening and required reoperation. There were two cases of stem fracture; one achieved extracortical bone union without revision, and the other case required implant removal and revision. Analysis of the retrieved specimen revealed histologic evidence of bony ingrowth. The use of a long side plate for initial implant fixation might have been partially responsible for this complication because of inhibition of new bone formation over the porous-coated segment. Sequential study of radiograms at different follow-up time periods with the same zonal analysis criteria revealed that no progression of radiolucency occurred at the bone/prosthesis interface, and bone formation over the segmental portion either increased or stabilized with time. The patients' functional results and implant performance seemed to indicate that the porous-coated segmental prosthetic system was effective in bridging skeletal/joint defects. However, further improvements are needed in prosthetic design and implant quality control in order to minimize device-related complications.     

Endostale Reaktion im Schaftbereich einer zementfreien Prothese

Periprosthetic fractures are familiar complications after total hip arthroplasty and have often been reported in the literature. The most frequent localization of such fractures is the middle third of the shaft. In the case described here a minor trauma resulted in a periprosthetic fracture with fracture of the femur and of the femoral component of a Lord prosthesis. A radiograph taken prior to trauma showed an endosteal reaction at the level at which the fracture later occurred. This might have been an indication that the stem of the prosthesis was already broken; had this radiological sign been correctly interpreted, it is possible that the fracture could have been avoided.     

Massive metallosis after revision of a fractured ceramic head onto a metal head

We report a case in which metallosis occurred due to a ceramic head fracture after revision of a total hip prosthesis. In the primary revision, after retrieval of the head fragments, the firmly incorporated stem was left in place, the PE inlay was replaced, and a metal head was inserted. Subsequently, massive metallosis occurred, leading to loosening of the stem and necessitating a two-stage revision. Examinations of the explanted material showed that microparticles of the fractured ceramic head had come to rest in the new PE inlay, where they led to wear on the metal head. We conclude that the use of a metal/PE articular pairing is contraindicated after a ceramic head fracture and recommend the use of a ceramic/ceramic articular pairing in the event of revision. In the case of the stem remaining in situ, this procedure requires the use of a conical stem adapter in order to minimise the fracture risk of the new head.     

Results of operative therapy of periprosthetic femur shaft fractures in total hip endoprostheses

Periprosthetic femoral shaft fracture represents an uncommon but potentially devastating complication associated with total hip arthroplasty. The treatment should result in complete union of the fracture and at the same time guarantee stability of the implant. 15 patients treated between 1992 to 1998 were analysed. Clinical and radiographic follow-up averaged 30 months (6-79 months) in 13 cases. Two patients died regardless of the fracture. The method of treatment depended on the intraoperative stability of the prosthesis and in addition on the fracture type (Bethea). In 5 cases of intraoperative stability of the prosthesis plate fixation was performed. Plate fixation was complicated by fixation failure combined with a recurrent fracture in two cases leading to shift to a long stem prosthesis. Ten cases of fractures associated with loose stems were treated with a new prosthesis using a long stem system. In these cases an uncomplicated healing of the fracture was achieved with adequate stability in radiographic examinations. The average Harris score was 70 (26-93). For fractures near the femoral stem or in case of implant loosening we recommend the shift to a long stem prosthesis. Also in fractures distally from the femoral stem tip we prefer now long stem implants rather than plate fixation to avoid large exposure of the femoral shaft and resultant complications.     

交锁翻修柄在股骨侧假体翻修术的应用

目的 报道采用交锁翻修柄(Bicontact和Kent)进行在全髋关节股骨侧假体翻修手术的疗效。方法 12例股骨侧假体翻修手术(假体松动5例，假体周围骨折7例)均采用现代无骨水泥技术，Bictintact翻修柄8例，Kent翻修假体4例，结合金属网、钢丝线缆握紧系统器械和异体骨移植进行结构重建。结果 平均随访8．40个月，功能优良10例(83．34％)，可1例(8．33％)，差1例(8．33％)，后出现Bicontact假体柄断裂和股骨干骨折。结论 在老年患股骨侧假体翻修术中，运用交锁翻修柄(Bicontact和Kent)能使手术时间和创伤减少，股骨侧固定快且牢固，并允许患早期进行功能锻炼；在股骨近端广泛骨缺失而需要大块异体骨移植进行重建的情况下，交锁翻修柄解决了既往各种假体较难固定于异体植骨块和残留的受体股骨中的问题。     

Femoral prosthesis neck fracture following total hip arthroplasty: a case report

Fracture of the femoral prosthesis neck following total hip arthroplasty is not common. We report a case of femoral prosthesis neck fracture in an adult male patient following modular, uncemented total hip arthroplasty. This case report further emphasizes the importance of the potentially high loading situation in the prosthetic femoral neck. On the other hand, the occurrence of a femoral prosthesis neck fracture in a cementless system denotes a well fixed distal stem and calls for a difficult revision procedure usually requiring an extended trochanteric osteotomy for stem retrieval.     

Bilateral femoral component breakage in total hip replacement: a case report

Breakage of the femoral component of a total hip replacement prosthesis is an uncommon occurrence with modern prostheses. The authors report what appears to be the only case of bilateral prosthetic fracture. A 65-year-old man, who was physically active, suffered bilateral femoral stem fractures 3 and 5 years after total hip replacement. The bilateral cemented hip replacements remained asymptomatic until catastrophic failure of the femoral component occurred. Both the prostheses were titanium (Biomet; Warsaw, Ind.) with chrome cobalt modular femoral heads. The authors stress the importance of maintaining an adequate cement mantle in Gruen zones 1 and 7 because failure to do so may result in micromotion and subsequent stem fracture.     

Electra trapezio metacarpal prosthesis: results of the first 100 cases

The Elektra trapeziometacarpal prosthesis is a cementless, unconstrained prosthesis made by Fixano with titanium and chrome-cobalt steel. This paper examines the results of the first 100 prostheses used by the author for one indication only, viz. painful trapeziometacarpal osteoarthritis. The average follow-up period was 54 (range 36-78) months. Studies of pain, mobility and grip and pinch strength were carried out, the results of which were good in 83 cases. Seven dislocations occurred. Five of these were following severe trauma. The commonest complication was a lack of osteointegration of the trapezial part of the prosthesis, which occurred in 15 cases. Sinking into the metacarpal of the distal stem occurred early in the series in two cases. Some others complications were observed: allergy to the metal (one case), fracture after direct trauma of the thumb (one case) and very painful osteoarthritis of the scaphotrapeziotrapezoid joint (one case).     

Treatment of fractures adjacent to humeral prostheses

Fifteen patients with fractures adjacent to a humeral prosthesis were treated between 1986 and 2002. There were 10 females and 5 males. The average age was 58 years. The fractures were classified as to location relative to the prosthesis. Type I fractures (N = 3) occurred proximal to the tip of the prosthesis. Type II fractures (N = 7) occurred in which the fracture line extended from the proximal portion of the humeral shaft to beyond the distal tip of the prosthesis. Type III (N = 5) fractures occurred entirely distal to the tip of the prosthesis. Two type I and 3 type II fractures were managed with a fracture orthosis. The remainder of the fractures were treated surgically with a combination of cerclage wires and long stem prosthesis. All fractures progressed to union at an average of 11 weeks. Average forward elevation for the group was 124 degrees . No patient required a shoulder spica or bone grafting to obtain union. Treatment resulted in fracture union, prosthesis stability, and a paucity of complications.     

定制肿瘤型关节假体髓外柄断裂的有限翻修技术

 目的 介绍定制肿瘤型关节假体髓外柄断裂的有限翻修方法,并评价其临床应用效果。方法 3例患者行定制肿瘤型关节假体置换术后发生假体髓外柄断裂,男2例,女1例;年龄分别为25岁、51岁和52岁。原发肿瘤部位及病理组织学类型分别为股骨远端骨肉瘤、股骨远端复发性骨巨细胞瘤及股骨近端软骨肉瘤。假体髓外柄断裂分别发生于术后11个月、34个月和28个月,均无明显外伤史,为行走时发生假体断裂。假体断裂处位于股骨远端假体髓外柄结合部和股骨近端假体的股骨颈基底部。依据假体断裂后髓内柄固定牢固及髓外柄残留足够长度的情况,为避免常规翻修手术中较困难的原假体髓内柄及骨水泥取出,设计了股骨近端和远端翻修假体进行有限翻修,该翻修假体由套筒部和关节部组成,材质及关节部外形与原假体相同,翻修时保留原假体髓内柄,将翻修假体套接于残留的髓外柄,骨水泥及挤压螺钉固定,同时更换磨损的配件,从而完成有限翻修。术后常规功能锻炼,定期随访观察翻修假体稳定性及肢体功能恢复情况。结果 3例患者假体断裂原因为股骨远端假体髓外柄结合部、股骨近端假体股骨颈基底部疲劳断裂各1例,股骨远端假体髓外柄结合部松动、锁钉断裂1例。翻修术后分别随访1个月、103个月和110个月,1例骨巨细胞瘤患者发生软组织内肿瘤复发而再行肿瘤切除术。至末次随访时,3例患者翻修假体固定牢固、无松动。MSTS评分肢体功能评分分别为66.7%、86.7%和83.3%。结论 定制肿瘤型关节假体由于疲劳或结构失效可发生断裂,套接式翻修假体可保留固定牢固的原假体髓内柄而行有限翻修,降低了手术难度,有利于肢体功能的尽快恢复。     

A radiological study of fractures of acrylic cement in relation to the stem of a femoral head prosthesis.

The incidence and prognostic significance of fractures of acrylic cement related to the stem of a femoral head prosthesis in total hip replacement are examined. These fractures are demonstrated when the cement has been rendered radio-opaque by the addition of barium sulphate. One and a half percent of the radiographs of 6,649 patients showed these fractures, which were sometimes associated with subsidence of the prosthesis. Fracture of the cement was usually evident at the six-month post-operative review, if it occurred at all. This radiological complication was devoid of symptoms in the majority of cases and tended to occur in patients with excellent functional recovery. In a minority of patients pain in the thigh during the first six months seemed likely to be explained by this fracture. Slight subsidence of the prosthesis in the cement bed appeared to result in a new and final position of stability. The prognosis was very good; only when separation of the fracture exceeded about 4 millimetres was the prognosis doubtful, in which case a chronic deep infection might be suspected. Possible mechanical and structural causes of fracture of the cement are discussed.     

Schenkelhalsendoprothese nach medialer Schenkelhalsfraktur bei ipsilateraler langstieliger Knietumorendoprothese

Femoral neck fracture in the case of a previously implanted ipsilateral tumour knee-prosthesis represents a challenging situation because of the long proximal stem of the knee implant. Avoiding total femur replacement, we implanted a femoral neck prosthesis (Eska Cut 2000) in a 65 year old patient to preserve as much of the femur free of implant as possible, minimizing the risk of a periprosthetic or interprosthetic fracture. At 2.5 years postoperatively, there were no signs of loosening, migration or periprosthetic fracture with a good functional result.In our case, the femoral neck prosthesis avoided the implantation of a total femur replacement. Nevertheless, this prosthesis must be considered critically and cannot be recommended as the standard implant for femoral neck fracture in the case of an ipsilateral long stem-knee prosthesis.     

Resection of the knee reconstructed with a massive prosthesis. Results after a 5 to 9 years follow-up

Since ten years, with the progress of the adjuvant chemotherapy we treated conservatively 170 osteosarcomas. We try to review the functional and mechanical results of the knee prosthesis with 5 years of follow-up or more. There were 64 resections, 51 of the lower femur and 13 of the upper tibia. The early postoperative complications are few (less than 2%). The functional results are satisfying with 90% of excellent and good results. We observed 3 local recurrences (2 femur, 1 tibia). The survey is really increased by the adjuvant chemotherapy with a rate of 70% at 5 years. However for us the problem is the evolution of our reconstitution prosthesis. 3 kinds of mechanical failures occurred: a wear of the hinge, a fracture of the stem and a loosening of the massive component. The Guepar hinge was finally a good solution when it was metallic, but all the hinges with metal plastic. Articulation needed reinterventions because of quick wearing. For the tibial reconstitution prosthesis we did not observed any problem but for the femoral massive prosthesis, the failures were more frequent, perhaps because the mechanical situation is different. We observed 4 fractures of the stem, 5 loosening of femoral stem (bipolar loosening in one case). In all except one, the reintervention gave a good result. Finally, the result seems to be encouraging, the progress of the implant (Titanium stem, modular prosthesis, semi-constrained knee) may again decrease the rate of mechanical failures.     

非骨水泥长柄假体在髋关节翻修术中的应用

目的回顾性分析非骨水泥全涂层长柄假体在全髋关节翻修术中应用的临床疗效。方法对2006年1月至2011年1月四川大学华西医院收治的采用全涂层长柄假体全髋关节翻修术的53例患者（53髋）进行随访、分析。其中男26例,女27例;年龄49—78岁,平均62岁。股骨假体采用强生（Depuy）公司全涂层长度为165mm的直柄AML假体10例、全涂层165mm的Solution假体19例和203mm带弧度分左右侧的Solution假体24例。比较髋关节术前术后的Harris评分,x线片评价假体柄有无松动下沉及应力遮挡情况。结果53例患者均获随访,随访时间1．8～6．8年,平均4．7年。术前平均Harris评分为37分,最后随访时增加至86分。所有患者均在术后3个月后完全负重,原有髋关节疼痛缓解。在最后随访时,有45例股骨柄假体获得骨长人固定。并发症：术后脱位1例,手法复位后未再发生脱位,术后感染1例,假体柄明显下沉1例,后两例患者行再次翻修术,末次随访假体柄稳定。随访X线片显示多数患者骨质改建,密度增加,未发现假体周围有连续亮带及假体柄下沉的患者。结论复杂的股骨侧翻修手术,应尽可能选择非骨水泥长柄假体。特别是股骨干骺端骨质条件差,中段有骨缺损,近端不能获得牢固固定的病例。术中结合同种异体颗粒骨打压植骨处理股骨中上段中重度骨缺损,中期临床疗效良好,远期效果有待随访。     

人工全髋关节翻修术中股骨骨缺损的处理和股骨假体的选择

目的探讨人工全髋关节翻修时股骨侧骨缺损的处理和股骨假体的选择。方法2002年1月至2007年6月55例资料较完整的患者中，男16例，女39例；年龄30-89岁，平均73岁。翻修原因：假体松动35例；股骨侧假体下沉4例，断裂1例；髋臼磨透2例；股骨假体周围骨折3例；股骨假体末端穿通皮质3例；头臼不匹配2例；髋臼假体位置不良导致复发性脱位2例，髋臼局限性骨溶解3例；合并股骨骨缺损21例。按AAOS分类标准：Ⅰ型：节段性骨缺损5例；Ⅱ型：腔隙性骨缺损10例；Ⅲ型：混合型骨缺损6例。结果48例患者行全髋关节置换翻修术；7例保留较稳固的原股骨假体。5例股骨节段性骨缺损中，2例予自体大块髂骨移植＋选用远端稳定的加长生物型假体，1例予异体骨块和自体髂骨移植＋选用远端稳定的加长生物型假体，2例予自体大块髂骨移植＋选用加长骨水泥型假体；10例股骨腔隙性骨缺损中，2例应用骨水泥型假体，8例选用远端稳定加长生物型假体后，骨缺损部位予自体和异体骨混合植骨。6例混合型骨缺损，2例应用骨水泥型假体，4例选用远端稳定的加长生物型假体，骨缺损部位予自体和异体骨混合植骨。随访时间6-62个月，平均38个月。Harris评分由术前的平均49分，提高至随访时平均88分。结论股骨侧翻修的难点在于骨水泥假体的取出和骨缺损的修复，可采用截骨方法取出骨水泥假体；选用远端稳定的加长生物型股骨假体适用于多数的股骨翻修。     

Periprothetische Frakturen bei Hüfttotalendoprothese

Different operative techniques of stem revision for the treatment of periprosthetic fractures type Vancouver B2 and B3 are described. Our prospective study of 32 periprosthetic fractures (22?Vancouver type B2, 10?Vancouver type B3) with a follow-up period of at least 24?months showed that stem revision employing a transfemoral surgical approach and a modular, cementless, tapered and fluted revision stem led to reproducibly good results with respect to fracture healing, stability of the prosthesis stem, dislocation, intraoperative fracture, and clinical outcome. All fractures healed with a mean time of 14.5?±?5.2?weeks. No cases of subsidence of the stem were observed and, according to the classification of Engh et al. concerning the biological fixation of the stem, bony ingrowth fixation was observed in 28?cases and stable fibrous fixation was observed in 4?cases. One dislocation and one case of deep vein thrombosis occurred, and there were no cases of intraoperative fracture. The Harris Hip Score rose continually (3?months postoperation: 59.2?±?14.6 points; 24?months postoperation: 81.6?±?16.5?points). According to the classification of Beals and Tower, all results were rated as excellent.     

Analyses of Prosthesis Stem Failures in Noncemented Modular Hip Revision Prostheses

In recent years, hip prosthesis stem revision by means of modular revision systems has reached an essential role in revision prosthetics. It is an extremely successful technique. Reports about mechanical failure in nonmodular revision stems have already been published. This complication is rare, but feared. We report about mechanical failure of four non-cemented modular revision stems over a period of 28 months. All failures became clinically apparent because of severe inguinal or thigh pain and were confirmed by conventional x-ray imaging. All stem failures occurred just below the interface between prosthesis stem and neck, which is a biomechanically stressed area. Distal of the failure, all stems were still firmly fixed. In all cases, there was obvious evidence of loosening at the proximal component. Metallographic and energy-dispensive x-ray analysis of one stem showed a fatigue fracture due to dynamic stress. If new pain arises after revision surgery with modular non-cemented prosthesis systems, the possibility of an implant failure should be kept in mind. Patients should be informed accordingly about the risk of implant failure.     

Periprosthetic fractures of the hip. The role of revision arthroplasty

In periprosthetic fractures, an exchange of the prosthesis is necessary when the prosthesis is loose (Vancouver type B2 and B3 fractures). During revision, the prosthesis can be replaced by a cemented or by a cementless stem implant. The disadvantage of a cemented stem is that cement can be forced into the fracture site and so impede union and healing. Most cementless revision stems with distal fixation are preferred because the point of fixation lies outside the area of fracture, thus allowing the fracture itself to be bridged and to be osteosynthesised with cerclage wires or cables binding the fracture pieces to the prosthesis. The stems can be implanted in two different ways. The first technique involves initial reposition of the fragments and retention with cerclage wires and then the implantation of the stem. In the second procedure, first an opening of the proximal fragment is made using an extended trochanteric osteotomy to the tip of the fracture and separation of the proximal fragment, and then the fixation zone in the distal fragment is prepared with implantation of the stem and closure of the proximal fragment around the implanted stem with cerclages. In a prospective study, the last method for the treatment of Vancouver type B2 and B3 fractures leads to reproducibly very good results with respect to fixation of the prosthetic stem, and therefore subsidence, healing of the fracture and clinical outcome. The extension of the incision and division of the proximal fragment that is an integral part of the transfemoral approach does not impair healing of the fracture or the osteointegration of the stem. This technique enables the monitoring of the positioning of the stem fixation so that the surgeon can be certain that the stem or its distal component is firmly anchored distal to the fracture, by means of a press fit. Thus, we suggest that this technique is superior to the method involving repositioning of the fracture fragments and subsequent implantation of the prosthesis stem.     

Fracture of an Exeter 'cement in cement' revision stem: a case report

The 'cement in cement' technique for revision hip arthroplasty has become popular in recent years, particularly in relation to polished taper stems. Since 2006 a short Exeter stem with 44 mm offset has been available specifically for this purpose. We report a fracture of such a stem in the absence of trauma 5 years after the revision procedure. The patient had a BMI of 27.8 and the proximal cement mantle gave good support to the stem. The fracture initiated and propagated from the introducer hole on the shoulder of the prosthesis. Macroscopically there was no defect in this area. This may be an unusual case of fatigue failure.     

人工髋关节置换术并发股骨骨折临床分析

目的探讨人工髋关节置换术并发股骨骨折的病因、治疗及预防。方法总结本院１９７２年４月～１９９６年６月行人工髋关节置换术９４５例，其中人工髋关节翻修术１４２例，初次人工髋关节置换术４９３例，人工股骨头置换３１０例。结果术中共发生股骨骨折２５例，总发生率为２．６％，其中人工髋关节翻修术８例，初次人工髋关节置换术１２例，人工股骨头置换５例。结论骨质疏松、医源性、先天性的股骨解剖结构改变以及软组织松解不彻底是发生术中骨折的主要原因。以下措施可有效地预防术中骨折的发生：（１）术前测量髓腔的大小，选择合适的假体；（２）彻底松解髋周软组织，脱位或复位时避免暴力；（３）用长假体应充分扩大髓腔；（４）假体置入时如遇有阻力，应避免强力打入，如突然有突破感，应考虑可能有骨折，应术中透视或照像。