股骨远端套接式翻修假体的生物力学研究及临床应用

[目的]为定制肿瘤型股骨远端假体断裂提供一种简单有效的翻修方法,即SPRS(socket-type prosthetic revision system,SPRS)假体。评价其套接部分的生物力学稳定性,初步确定适用范围,回顾性分析临床应用效果。[方法]制作SPRS假体套接部分实验标本共6套,按固定长度分成6组;用骨水泥及挤压螺钉将其重复套接、固定3次,微机控制电子万能实验机分别进行测试,比较各方向位移及角度变化,初步确定其最短有效固定长度;回顾性分析临床上应用该假体行翻修手术的病例,评价其应用效果。[结果]SPRS假体不同长度的套接部分(10、20、30、40、50、70 mm)平均拉伸(压缩)刚度组间比较差异有统计学意义(P<0.05);平均扭转刚度组间比较差异有统计学意义(P<0.05)。固定长度为30 mm的标本,完成疲劳实验后未发生松动及破坏,30 mm及以上的固定长度满足实验要求。应用该假体行有限翻修手术的病例术后分别随访26、128个月,影像学检查发现均固定牢固、无松动,至末次随访MSTS肢体功能评分分别为63.3%、83.7%。[结论]对于股骨远端定制肿瘤假体自髓外柄断裂、髓内柄固定牢固的病例可应用SPRS假体行有限翻修手术,生物力学测试发现该假体要求残留髓外柄固定长度应不少于30mm。虽然临床应用例数较少,最长近11年的随访证实了该假体的可靠性。     

髋关节置换术后骨水泥股骨假体断裂原因分析及处理

目的 探讨骨水泥股骨假体断裂的原因和处理方法.方法 自2003年3月至2009年3月,共收治8例国产骨水泥股骨假体断裂患者,男6例,女2例.断裂距初次关节置换手术时间为36～98个月,平均72个月;体重60～88 kg,平均75 kg.均无明确外伤史.分析断裂前、后X线片,观察原假体安放位置、断裂部位、骨水泥固定情况及有无假体周围骨折;对术中假体表面骨水泥覆盖情况及断裂假体取出要点进行同顾性分析.5例行股骨假体翻修手术,采用生物碰股骨假体同定.3例转诊.翻修术后3个月、6个月、1年定期复查,行X线及Harris评估.结果 4例初次置换假体内翻,1例外翻;5例假体偏小.断裂均位于假体中点至中、远1/3交界处,远端崮定牢固.4例断裂前X线片可见近端假体周围细透光线,1例假体周围骨折.近端假体取出容易,远端假体取出困难.4例行股骨开窗,1例行转子延展截骨.翻修病例随访12～80个月,平均48个月.开窗或截骨部化平均愈合时间3.5个月.无假体松动、下沉及感染.末次随访时Harris评分85～97分,平均92分.结论 骨水泥股骨假体断裂可能与骨水泥假体近、远端固定质量不一致有关.对假体断裂者应及早行翻修术,术中股骨开窗安全有效.     

大转子延长截骨在股骨柄翻修术中的应用

目的 报道大转子延长截骨在股骨柄翻修术中的应用及其疗效。方法 从 1998年 1月～ 2000年 1月,采用大转子延长截骨术取出股骨柄、骨水泥,行翻修术 11例。男 7例,女 4例。年龄 53～ 69岁,平均 65.4岁。翻修原因 :股骨柄断裂 2例,人工股骨头置换术后髋臼骨关节炎 8例,假体位置异常 1例。结果 11例患者术后第 2 d均在助行器辅助下下床行走,术后 3个月大转子延长截骨处临床愈合后,改扶单拐行走, 6个月后弃拐行走。术后随访 6～ 30个月,大转子延长截骨处骨性愈合, Harris评分平均为 89.6分。结论 大转子延长截骨术多用于翻修术中取出固定牢固的骨水泥或非骨水泥假体柄。其适应证包括 :(1)股骨柄近端断裂,远端仍牢固固定者; (2)人工股骨头置换术后发生髋臼骨关节炎伴髋关节强直,股骨柄固定牢固,需行全髋翻修者; (3)股骨柄安放位置错误,但骨水泥固定良好者; (4)不伴有假体松动的早期严重感染需行翻修者。该方法显露充分,术后恢复快,是一种较好的股骨柄固定牢固的翻修方法。主要并发症有截骨处不愈合、移位及截骨片骨折。     

髓内打压植骨结合广泛多孔涂层长柄假体在股骨侧严重骨缺损（PaproskymA型）翻修术中的应用

目的 探讨股骨侧严重骨缺损（Paprosky ⅢA型）翻修中应用髓内打压植骨结合广泛多孔涂层长柄假体的临床疗效.方法 2006年3月～2010年9月,对38例（38髋）Paprosky ⅢA型股骨骨缺损患者行翻修重建,其中男24例,女14例,平均年龄62岁.翻修原因：骨溶解、无菌性松动29例,全髋关节置换术（THA）术后感染二期翻修6例,假体周围骨折3例（Vancouver B3型）.股骨侧干骺端骨缺损采用同种异体颗粒骨髓腔内打压植骨进行修复,股骨柄采用全涂层长柄假体（7～10英寸）.术后定期随访,髋关节功能评价采用Harris评分,影像学采用X线片及CT观察：假体柄有无松动下沉、股骨近端应力遮挡情况、植入的异体颗粒骨与宿主骨整合情况.结果 38例均获得随访,平均随访53.4个月（23～62个月）,Harris评分由术前平均42分（32～47分）,提高至末次随访时平均86分（69～95分）.无患者发生脱位、假体周围骨折.1例术后感染,行再次二期翻修;1例假体柄在术后6个月内下沉4.24 cm,再次翻修时选择更粗的假体柄,末次随访时假体柄稳定;其余所有患者假体柄均牢固固定.3例出现轻-中度应力遮挡.15例近端皮质骨密度及厚度有增加,厚度平均增加约1.8 mm（0.7～3.5 mm）,植入骨与宿主骨逐渐整合并增加了骨缺损区的骨质储备.结论严重骨缺损（Paprosky ⅢA型）的股骨翻修中,采用髓内颗粒骨打压植骨可以很好的修复股骨中上段骨缺损,重建股骨干骺端.依靠广泛多孔涂层长柄假体在远端的牢固压配固定,结合股骨干骺端髓内紧密打压植骨,使假体柄在股骨中上段及远端均能获得较好的初始稳定性,近期临床和影像学结果满意,远期疗效有待观察.     

股骨皮质骨开窗技术在髋关节翻修术中的应用

目的 探讨股骨前外侧皮质骨开窗技术在髋关节翻修术中取出股骨远端稳定固定骨水泥的价值.方法 2005年5月至2009年6月,共14例(14髋)因各种原因致髋关节置换术后失败患者接受全髋关节翻修手术.其中男性10例,女性4例,年龄54～75岁,平均66岁.翻修原因为股骨头置换术后髋臼磨损5例、全髋关节置换术后假体周围骨溶解并松动6例、骨水泥柄股骨近端骨溶解柄断裂1例、髋臼骨溶解假体松动翻修同时行股骨柄翻修1例,感染后二期翻修时远端骨水泥取出困难1例.14例(14髋)股骨柄均为骨水泥同定.术中按术前计划开窗部位、开窗范围于股骨皮质骨开一长方形骨窗.通过骨窗直视下彻底清除髓腔内稳定固定的骨水泥,修整股骨髓腔.植入翻修柄后将皮质骨开窗骨瓣原位回植,双股钢丝捆绑固定.术后定期随访拍摄x线片.观察皮质骨开窗骨瓣与周围骨愈合情况、骨瓣有无移位、股骨柄有无下沉以及有无捆绑钢丝断裂等.结果 10例患者术后获得随访,平均随访时间24.6个月.股骨皮质骨开窗长度2.5～6.0 cm,平均3.4 cm,宽度0.8～1.4 cm,平均1.2 cm.股骨开窗远端以远部分发生纵形劈裂骨折1例.无术中皮质骨穿孔及股骨干骨折.向远段扩大开窗1例,扩大长度1.5 cm.开窗部位皮质骨骨瓣原位回植选择2～3道双股钢丝固定,平均2.3道.随访期间2例发牛假体柄下沉(平均2.5 mm),无皮质骨瓣移位以及捆绑钢丝断裂,术后3～5个月皮质骨瓣已于周围骨纤维愈合.随访期间无一例因各种原因致再次翻修.结论 股骨皮质骨开窗技术在髋关节翻修术中有助于直视下彻底取出股骨髓腔远端稳定固定的骨水泥,同时不会造成股骨骨丢失、不影响翻修柄植入后的稳定固定.     

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。     

组配式假体在Paprosky Ⅲ型股骨近端骨缺损翻修中的应用

[目的]报道应用组配式远端固定生物型假体翻修Paprosky Ⅲ型股骨近端骨缺损的手术要点及疗效. [方法]2003年5月～2006年10月应用MP、ZMR组配式股骨假体翻修Paprosky Ⅲ型股骨近端骨缺损9例,男5例,女4例,年龄39～65岁,平均57岁,术后随防时间8～34个月,平均19个月.翻修原因:7例为骨水泥固定假体松动、骨溶解,2例为珊瑚面假体无菌性松动.原手术到翻修时间最短4年,最长12年.依据Papresky分型,ⅢA型5例,ⅢB型4例. [结果]Harris评分:术前平均35分(28～54分),术后85分(70～90分).7例弃拐行走,2例存在大腿疼痛,其中1例轻度疼痛伴下肢短缩2.5 cm,需扶手杖行走,1例中度疼痛,扶单拐行走、跛行.本组随访过程中均无再松动、感染征象,1例发生假体下沉12 mm,股骨柄远端无骨溶解现象. [结论]组配式远端固定生物型假体可较好完成Paprosky Ⅲ型股骨骨缺损的翻修,能达到初期及后期稳定.由于假体的假体柄与假体近端部分分开,使其植入变得容易,多部件组配可方便解决各种可能问题,如偏心距、前倾角、肢体长度等,明显简化了手术,且手术安全性好,是较理想的股骨翻修假体.     

应用假体翻修大段异体骨保肢失败后的功能重建

目的探讨应用组合式假体翻修大段异体骨感染或骨折的疗效。方法回顾性研究了美国迈阿密大学医学院和中山大学附属第一医院骨肿瘤科共22例肩关节或膝关节周围肿瘤的患者,大段异体骨保肢失败后,应用肿瘤型假体重建肢体功能。最初诊断包括骨肉瘤11例、软骨肉瘤4例、恶性纤维组织细胞瘤3例、骨巨细胞瘤2例、恶性血管内皮瘤1例和鼻咽癌转移瘤1例。发病部位包括股骨远端15例、肱骨近端3例和胫骨近端4例。结果异体骨失败原因包括:骨折14例、感染6例、持久不愈合1例、合并骨折和感染1例。异体骨移植后平均随访154.2(63～293)个月,假体翻修后平均随访73.4(24～234)个月。90.9%(20/22)的患者最终肢体功能良好,MSTS功能评分为76.5%(60%～93.3%)。81.8%(18/22)的患者假体翻修手术成功,在翻修失败的患者中,1例肱骨近端肿瘤患者为了改善功能经历了多次翻修手术,另1例股骨远端的患者,异体骨移植失败假体翻修后,由于假体近端松动而进行二次翻修——全股骨置换术,另外2例股骨远端的患者翻修后合并感染和骨折而截肢。结论异体骨重建因骨折或感染失败后,再次行假体翻修重建肢体功能是可靠的,并发症较低。翻修技术会影响重建肢体的功能。对于异体骨感染的患者,建议分期翻修重建肢体功能。     

解剖髓腔交锁假体对Ⅱ型股骨骨缺损翻修的应用

全髋关节置换术（THA）术后股骨假体松动常造成股骨近端骨缺损，对失败股骨假体翻修的方法很多。最初，普遍采用骨水泥技术进行翻修，据报道骨水泥假体翻修失败率较高。主要原因是髓腔内多为硬化、光滑菲薄的骨面，难以获得骨一骨水泥之间的微交锁，所植入的新假体因而难以获得长期稳定。使用非骨水泥假体进行股骨假体翻修的技术，除骨量丢失较少的患者，以近端微孔涂层假体翻修的结果并不满意”。当近端骨量中度或者重度丢失时，需要某种形式的远端固定才能获得成功重建。1997年至2000年我们对60例患者采用解剖髓腔交锁假体（anatomic medullary locking，AML）进行翻修，现报告如下。     

远端固定生物型假体在股骨翻修术中的应用

目的探讨远端固定生物型假体结合干燥同种异体骨植骨在近端骨缺损股骨翻修术中的应用疗效。方法自1999年7月至2004年1月,对16例（17髋）非感染性股骨假体松动患者进行翻修手术,其中2例为再次翻修,采用远端固定生物型股骨假体结合干燥同种异体骨植骨。男7例,女9例,年龄58～77岁,平均63岁,术后平均随访时间为35个月（18～56个月）。翻修前人工股骨头置换5例,全髋关节置换12例,从初次关节置换到翻修手术的间隔时间最短7年,最长16年,平均13．5年。股骨骨缺损根据Paprosky分型,Ⅰ型8髋,Ⅱ型6髋,ⅢA型3髋。翻修用假体：MP（Link）1髋,AML（DePuy）9髋,Full—coated（Zimmer）5髋,Enchelon（Smith—Nephew）股骨距替代型假体2髋。结果Harris评分从术前平均37分改善至术后平均88分,无患者发生再次松动。术后X线片显示植入骨愈合良好,假体部位骨皮质密度和厚度明显增加。结论远端固定生物型假体可以在股骨远端髓腔内获得可靠的轴向及抗旋转初始稳定性,干燥异体骨植骨能有效修复骨缺损,恢复骨量,骨愈合率高,两者结合运用于伴有近端骨缺损的股骨翻修术中,中短期疗效满意,远期疗效尚待进一步随访。     

Intramedullary strut substitution and impaction allografting cemented revision for the treatment of a periprosthetic fracture in a severely compromised femur

Revision for the treatment of a B3 periprosthetic femoral fracture often requires proximal femoral allograft arthroplasty in physiologically young or tumor prostheses in elderly patients. Extramedullary strut allograft augmentation can only be used when the host femur is structurally adequate for the insertion of the revision stem (periprosthetic femoral fractures type B2) and appears to be an attractive biological concept as early incorporation to the host bone results in a sound biomechanical construct. We report here the simultaneous use of whole femur intramedullary strut substitution along with an extramedullary strut graft placement, with impaction allografting revision to a long cemented femoral prosthesis, to augment the deficient metadiaphyseal bone stock (Paprosky type IV) for the treatment of a complex type B3 periprosthetic femoral fracture.     

Use of a long distally fixed intramedullary stem to treat a periprosthetic femoral fracture following total hip arthroplasty using a thrust plate hip prosthesis: A case report

IntroductionThe thrust plate hip prosthesis (TPP; Zimmer, Winterthur, Switzerland) is a hip prosthesis that is no longer in production. Few reports have focused on periprosthetic fractures following total hip arthroplasty (THA) with the use of a TPP.Presentation of caseWe report a 57-year-old woman with a periprosthetic femoral fracture 13 years after THA with the use of a TPP. A plain radiograph showed a displaced subtrochanteric fracture of the right femur just below the distal tip of the lateral plate without implant loosening. She underwent revision surgery with a long distally fixed intramedullary stem in conjunction with a plate and cable system. Three months after surgery, bone union was confirmed using radiography and the patient was clinically asymptomatic.DiscussionWe encountered three major problems while planning surgical treatment, these being, discontinuation of the TPP system, loss of proximal femoral cancellous bone, and difficulties with the type of subtrochanteric fracture. After considering these problems, we planned revision surgery using a long distally fixed intramedullary stem in conjunction with a plate and cable system.ConclusionThis case shows that sufficient implant preparation based on precise preoperative planning is necessary to obtain good clinical results for the surgical treatment of periprosthetic femoral fractures following THA with the use of a TPP.     

Intraoperative modular stem lengthening to treat periprosthetic femur fracture

Fracture of the femur around a femoral prosthesis can be a difficult problem to manage. Treatment options consist of traction, allograft struts, or plating with cerclage fixation, and revision arthroplasty. Intramedullary stabilization is usually preferable to plating for treatment of diaphyseal femur fractures; however, for a fracture around a cementless stem, disruption of the biologically fixed proximal area of the implant and revision to a long-stem component are generally required to permit intramedullary fixation of the fracture. Many modular femoral stems are currently available. Some of these have both proximal and distal modular options. Distal modularity provides the surgeon treating a fracture around a femoral component with a unique opportunity to lengthen the stem during surgery by adding an attachment to the distal stem through the fracture site.     

Einfluss des Prothesendesigns auf die intramedulläre Druckentwicklung bei der Femurschaftimplantation von zementierten Hüftendoprothesen

The increase of intramedullary femoral pressure can lead to the intravasation of bone marrow and fat cells into the blood stream of the femoral vein and consequently into the pulmonary circulation. This effect is the same in intramedullary nailing and in the implantation of femoral stem prostheses. In a prospective study we evaluated the intraoperative, intramedullary pressure in the distal femur during the implantation of femoral stem prostheses with two different designs. In eight patients we implanted Müller straight stems and in another eight we implanted stem type Option 3000. Intramedullary pressure was recorded continuously by the implantation of a microtip pressure probe (piezoresistive principle, 50 Hz) in the distal femur. We found markedly higher pressure in Müller straight stem prostheses: range: 590-2,570 mmHg (median = 1,293, SD = 627 mmHg). Intramedullary pressure in stem prosthesis type Option 3000 was much lower: range: 59-574 mmHg (median = 289, SD = 219 mmHg). The differences were statistically significant (p = 0.0008). By changing the designs of femoral stem prostheses, the intramedullary pressure can be markedly reduced. In the case of elderly patients or those with pulmonary illness we recommend femoral stem prosthesis designs, which induce little increase in the intramedullary pressure, in order to reduce cardiopulmonary complications.     

Femoral shaft fracture after hip arthroplasty

Femoral shaft fractures after hip arthroplasties were treated in 74 noncemented hemiarthroplasties and 65 cemented arthroplasties. In loose prostheses the best clinical results and the least number of operations were achieved with revision arthroplasty with a long-stem prosthesis, combined with simple internal fixation methods when applicable. In firmly fixed prostheses the results of revision arthroplasty and traction treatment were similar. Cemented revision arthroplasty did not interfere with fracture union. Internal fixation with the prosthesis in situ cannot be recommended because of a large number of secondary revision arthroplasties and nonunions. Removal of the femoral stem prosthesis and internal fixation nearly always require a secondary revision and cannot be recommended.     

Distal femoral replacement with allograft/prosthetic reconstruction for treatment of supracondylar fractures in patients with total knee arthroplasty.

Large-segment distal femoral allografts were used in conjunction with non-linked total knee prostheses to reconstruct bone deficits following supracondylar fracture of the femur in seven patients with previous total knee arthroplasties. Three patients with multiple medical problems died of unrelated causes prior to a minimum 2 year follow-up. Indications for surgery were previously failed attempts at osteosynthesis and significant fracture comminution, osteopenia, and intercondylar extension or femoral component loosening. Specifics of the surgical technique included subperiosteal excision of the involved distal femur with retention of a soft tissue sleeve containing the collateral ligaments and reconstruction with a large-segment allograft and a stemmed, semiconstrained total knee prosthesis. Cement fixation using pressurized technique with intramedullary plugging of the tibial and femoral canal was routinely used to secure the prosthesis/allograft construct to the host bone. Postoperative complications included one dislocation, which was successfully treated closed, and one popliteal artery injury, which was successfully repaired. There were no postoperative infections. Two patients, however, had some degree of persistent instability, warranting bracing at the time of last follow-up. Using the Knee Society rating system, the average knee score for these patients was 71, and the average pain score and function score were 33 and 49, respectively. Range of motion averaged 96 degrees. All of the femoral components were well fixed at last follow-up. Results of this study indicate that large-segment distal femoral allografts used in conjunction with nonlinked knee prostheses can be an acceptable method of treatment of these difficult reconstructive problems.     

Design and first clinical results with the ZMR taper revision prosthesis

AIM: The purpose of this study was to survey and to evaluate the first clinical and radiological results with the cementless ZMR taper hip prosthesis. METHOD: The modular distal-tapered stem was designed with a roughened titanium surface and sharp splines to achieve secure distal fixation and rotational stability. 90 ZMR taper hip prostheses were implanted between October 1999 and July 2002. Out of these, 4 interventions were primary and 86 were revision procedures. In 43 cases a complete hip prosthesis revision and in 43 cases a stem revision was necessary. The mean age of the 90 patients (42 males, 48 females) was 67.1 years. The mean follow-up period was 7.6 months (3 to 25 months). RESULTS: The stem displayed an excellent distal fixation. The mean subsidence could be measured with 4.3 mm. Furthermore, most cases showed a particularly favourable remodelling of the proximal femoral bone stock. Complications associated with revision included intraoperatively 4 femur fractures, 3 femur fissures, 5 femur perforations, 2 trochanter fractures and postoperatively 19 dislocations, 5 superficial wound infections, 2 transient palsies, 1 pulmonary embolism, 1 stem rotation and 4 wound healing failures. Considering these complications 15 re-revisions were necessary and the ZMR taper hip prosthesis had to be exchanged in 3 cases. CONCLUSION: On the one hand the ZMR taper hip prosthesis proved its value, particularly with regard to the stem modularity, the excellent distal fixation in conjunction with the possibility of partial body weight bearing and the rapid bone remodelling of the femur. On the other hand an increased number of postoperative complications and re-revisions occurred. Further long-term studies seem to be essential.     

Femoral shaft fracture after hip arthroplasty

Femoral shaft fractures after hip arthroplasties were treated in 74 noncemented hemiarthroplasties and 65 cemented arthroplasties.

In loose prostheses the best clinical results and the least number of operations were achieved with revision arthroplasty with a long-stem prosthesis, combined with simple internal fixation methods when applicable. In firmly fixed prostheses the results of revision arthroplasty and traction treatment were similar. Cemented revision arthroplasty did not interfere with fracture union. Internal fixation with the prosthesis in situ cannot be recommended because of a large number of secondary revision arthroplasties and nonunions. Removal of the femoral stem prosthesis and internal fixation nearly always require a secondary revision and cannot be recommended.     

骨肿瘤初次保肢手术后生物性重建失败的肿瘤假体翻修术

目的评估骨肿瘤初次保肢手术后生物性重建失败的肿瘤假体翻修的疗效。方法2004至2006年，13例骨肉瘤和3例骨巨细胞瘤患者在香港威尔斯亲王医院接受手术治疗。15例患者应用同种异体骨重建，另1例患者应用带血管腓骨移植重建骨缺损。应用肿瘤型假体进行翻修手术的重建。翻修术后患者膝关节活动范围良好时，订制的可延长假体接受延长手术。结果患者平均年龄23．2岁（13～43岁），平均随诊26．4个月（6～47个月）。翻修手术的原因包括：7例患者出现同种异体骨骨折或软骨下骨塌陷，5例患者骨不愈合，3例患者异体骨感染，1例患者膝关节僵硬。翻修手术的假体包括10例患者应用订制型假体，其他患者应用组合式假体。翻修手术的部位包括9例股骨远端假体，6例胫骨近端假体和1例股骨中段假体。订制假体中6例是可延长假体，假体的延长方式中5例是微创延长、1例无创延长。翻修手术后，膝关节活动改善，平均从18．1&#176;（0&#176;-90&#176;）至91．9&#176;（50&#176;-120&#176;）。下肢缩短不等长畸形从平均5cm（2-11．5cm）纠正至平均1．5cm（0-4cm）。翻修术后患肢功能MSTS评分从34．6％改善到89．2％。翻修术后2例患者出现部分皮肤坏死，1例患者出现腓总神经麻痹，以后部分恢复，1例患者出现胫骨裂纹骨折；没有感染和植入物失败。结论保肢手术后生物学重建失败所引起下肢缩短和僵硬，应用人工假体翻修是可行的，早期效果令人鼓舞。膝关节僵硬患者可获得良好的关节活动度。严重的下肢缩短畸形通过可伸长假体逐渐获得纠正。     

Revision of failed knee replacements using fixed-axis hinges

Forty failed hinged arthroplasties of the knee were revised by the insertion of another hinged implant. In 14 cases the prosthesis used at the revision operation was similar to the primary implant; in 26, a hinge with an elongated femoral stem was used, usually replacing part of the femoral shaft. In seven of these knees an elongated tibial stem was also required, though the tibial shaft was replaced in only two of them. There were many complications. Fracture of the femur at the tip of the femoral stem was the most frequent. Sixteen first revisions failed and were revised a second time; 12 required replacement of the distal femoral shaft and three required replacement of the proximal tibia. The incidence of complications in knees requiring a second revision was even higher. Four required a third revision after an average interval of three years. Failure of a hinged prosthesis results in bone loss mainly in the femur. Revision of a failed hinged prosthesis with another of the same design is unlikely to be successful and may cause fracture of the femur.