Acetabular revision using a total acetabular allograft

The most challenging aspect of an acetabular revision is the management of severe bone loss, which compromises implant fixation and stability. We present a case of failed acetabular revision with extensive bone loss (Paprosky Type 3b) in a 50-year-old woman with rheumatoid arthritis, which was treated using total acetabular allograft. At a follow-up of 1 year and 3 months, the allograft had united with the host bone. This is the first report of the use of a total acetabular allograft for revision total hip arthroplasty in India. The total acetabular allograft allows the placement of the component closer to the normal hip center, provides initial stability for the acetabular component, and restores bone stock to the host pelvis.     

Azetabuläre Defektrekonstruktion in der Revisionschirurgie der Hüfte

The treatment of periprosthetic bone defects of the acetabulum is a therapeutic challenge in hip revision surgery. The aims are the biological reconstruction of osseous acetabular defects and the restoration of a load-bearing acetabular bone stock as well as restoring the physiological joint biomechanics and achieving primary and load-stable fixation of the revision graft in the vital pelvic bone. The biological reconstruction of the acetabular bone stock should include what is referred to as “down-grading” of the acetabular defect situation in case a repeat revision procedure becomes necessary. Nowadays, a large variety of grafts and reconstruction procedures are available for the reconstruction of acetabular defects. The choice of suitable materials (osseous or metallic) for the restoration of a load-bearing acetabular bone stock is currently the subject of controversial discussion. This article reviews the various options for the reconstruction of acetabular bone defects taking into consideration the current findings in the scientific literature.     

Modification of the Explant System for the Removal of Well Fixed Hip Resurfacing Sockets

A major concern during revision hip arthroplasty is acetabular bone loss during the extraction of well-fixed acetabular components. Despite the good early survivorship of resurfacing prostheses, revision surgery may be necessary. We recommend the use of the Explant acetabular extraction system (Zimmer, Warsaw, Ind) with a trial liner to preserve acetabular bone stock. We present 2 cases of revised resurfacings using this technique, demonstrating minimal interference to the remaining acetabular bone.     

Revision total hip: a novel modular cementless acetabular system for reconstruction of severe acetabular bone loss

Severe acetabular bone loss remains a challenge at the time of revision hip arthroplasty. A novel modular system is available to aid in the reconstruction of these challenging cases. This technique can provide support for an uncemented acetabular shell. By using the augments in combination with the revision acetabular component, the following goals of revision surgery on the acetabular side can be achieved at the time of surgery: initial stable fixation, restoration of the center of rotation, and maximization of host bone contact.     

颗粒骨打压植骨结合多孔非骨水泥臼杯在AAOSⅢ型髋臼大面积骨缺损翻修中的应用

背景：颗粒骨打压植骨是修复髋臼骨缺损的重要方法,对大面积髋臼骨缺损采用打压植骨结合非骨水泥臼杯重建仍然存在争议。目的：探讨同种异体颗粒骨打压植骨结合多孔非骨水泥臼杯髋臼重建术修复AAOSⅢ型髋臼大面积骨缺损的方法及近期疗效。方法：随访2005年6月至2010年4月收治的28例（28髋）AA0SⅢ型髋臼大面积骨缺损患者。男18例,女10例,年龄34-74岁,平均53．8岁。髋关节置换术后感染醐翻修9例,骨溶解及髋臼假体松动翻修19例。本组AAOSⅢ型髋臼骨缺损面积大,术中见髋臼骨缺损超过髋臼关节面的50％。全部采用同种异体颗粒骨打压植骨结合多孔非骨水泥臼杯髋臼重建术。术后定期随访,观察臼杯有无松动、植入骨与宿主骨整合情况,髋关节功能评分采用Harris评分。结果：28例均获得随访,术后随访时间为13-70个月,平均43个月。Harris评分由术前32-48分,平均41分,提高至末次随访时86-95分,平均90分。28例髋臼假体均固定牢固无松动征象,植入骨逐渐与宿主骨整合,无感染及坐骨神经损伤。结论：在获得臼杯初始稳定固定的情况下,大面积颗粒骨打压植骨（臼杯与宿主骨接触面积〈50％）结合多孔非骨水泥臼杯髋臼重建术修复AAOSⅢ型髋臼大面积骨缺损近期疗效较好,远期疗效尚待进一步随访。     

髋臼加强杯在髋臼翻修术中的应用

目的 观察髋臼加强杯在髋臼翻修手术中巨大髋臼骨缺损修复中的应用疗效.方法 2003年2月至2008年10月对12例在翻修术中存在严重髋臼骨缺损的患者采用植骨与髋臼加强杯重建髋臼骨缺损后固定假体.手术前、后情况进行临床评估及影像学评估.术前骨缺损分类按Paprosky分型:ⅡB型2例,ⅢA型6例,ⅢB型4例.术前Harris评分平均为35.2分.结果 术后所有患者均获随访,平均随访时间37个月(9～71个月);术后第一次随访时Harris评分平均为80.9分,末次随访时平均84.6分.术后假体无松动或断裂.有1例患者翻修术后6个月于髋臼Delee&Chamley Ⅲ区出现轻度放射线透亮带,但继续随访未进展.未出现假体失败而需要再次翻修病例.结论 采用髋臼加强杯联合植骨技术可有效修复髋臼骨缺损,重建髋臼结构稳定性,中短期随访疗效可靠.     

Evaluation of a porous tantalum uncemented acetabular cup in revision total hip arthroplasty: clinical and radiological results of 60 hips

Long-term survival of the acetabular component in revision total hip arthroplasty (THA) is determined by initial implant stability and bone ingrowth. Highly porous Trabecular Metal (TM, Zimmer, Inc, Warsaw, Ind) facilitates ingrowth and may be an ideal material for revision THA. The outcome and survivorship of a TM, nonmodular, uncemented acetabular cup were assessed in 60 consecutive patients undergoing revision THA (mean follow-up, 42 months; range, 14-68 months). Most (55/60) acetabular cups were implanted without screw fixation. Mean Harris Hips Scores improved from 74.8 preoperatively to 94.4 at last follow-up. Serial radiographs demonstrated excellent bone apposition and bone graft incorporation. Complications were limited to 7 cases of dislocation and 1 revision for aseptic loosening. The TM acetabular cup appears suitable for use in revision THA and warrants further study.     

Cemented cup revisions

Among the several treatment techniques for acetabular reconstruction after total hip arthroplasty is cemented acetabular revision. Use of isolated cemented cup revision is not frequently chosen for acetabular revision, however, because outcomes with this technique are poor despite improved cementing techniques. Most cemented cup revisions are performed for severe bone loss when biologic fixation near the normal hip center is unlikely and are often supplemented with bone grafting and metal reinforcement devices cases. Advantages of using this technique are the ability to incorporate antibiotics into the cement and the ability to customize the cement mantle to host bone.     

髋关节翻修术中髋臼骨缺损的处理与重建

目的探讨髋关节翻修术中髋臼骨质缺损的处理和重建方法。方法对28例髋关节置换术后髋臼骨缺损的患者进行翻修,观察术后随访X线片上的髋臼假体及周围骨质变化情况,并对髋关节行Harris功能评定。结果 28例均获随访,随访时间12～184个月,平均61.6个月。1例术后出现脱位,2例术后出现骨溶解并伴患髋疼痛。7例术后随访的X线片上出现髋臼的骨溶解,但髋臼假体无松动表现,患髋无疼痛,患髋功能不受影响。至末次随访为止,25例髋（89%）获得良好的稳定性。术前Harris评分平均31.8分（14～57分）,末次随访时平均85.2分（46～99分）。两组数据具有显著性差异。结论充分的术前准备是手术顺利进行并获得良好效果的一个重要前提,植骨的方式和翻修假体的选择还需结合术中对骨缺损的评价。髋臼假体表面被自体骨覆盖超过50%,可考虑行植骨加非骨水泥型髋臼假体置换;自体骨覆盖不足50%,宜行骨水泥型髋臼假体置换。如骨缺损面积较大,可行加强环等翻修。从随访中可见,颗粒骨打压植骨是治疗髋臼骨缺损可靠的方法。     

Cementless acetabular revision for aseptic failure of cemented hip arthroplasty

This study is a 5- to 11-year retrospective followup of 40 hips in 33 patients with cementless acetabular revision for aseptic failure of a cemented total hip arthroplasty. A porous coated, Harris-Galante acetabular component was used in all revisions. Thirty-eight of the 40 hips received acetabular bone grafting at revision. The mean Harris Hip Score improved from 51 points just before the index cementless revision to 87 points at the most recent followup. Twenty-nine of 40 (73%) hips were classified as having a good or excellent result. Radiolucencies were observed in seven of the 40 (18%) hips at the most recent followup, but none of these radiolucencies were complete or progressive. Five of the 40 (13%) hips were rated as failures and required repeat revision. Two (5%) of these failures were caused by aseptic loosening, with both hips having severe acetabular bone damage at the time of the index revision. This failure rate for aseptic loosening was less than that reported for cemented acetabular revision, thereby confirming the efficacy of cementless acetabular components in revision hip surgery in the intermediate term.     

全髋关节翻修术中髋臼骨缺损的处理方法

目的探讨全髋关节翻修术中对于髋臼骨缺损重建的方法及其术后疗效。方法回顾性分析自2007-03—2011-12的75例（76髋）全髋关节翻修术,髋臼骨缺损根据Paprosky分型：Ⅰ型9髋,ⅡA型21髋,ⅡB型18髋,ⅡC型11髋,ⅢA型10髋,ⅢB型7髋。髋臼骨缺损采用不同方式修复,术后定期随访。采用髋关节功能Harris评分评估髋关节功能,根据X线片判断假体是否松动、植骨是否融合。结果 75例（76髋）均获得平均36（16~73）个月随访。术后12个月不同类型骨缺损患者髋关节功能Harris评分较术前明显提高,差异有统计学意义（P〈0.05）。术后症状和关节功能明显改善,未出现髋臼骨折、感染、下肢深静脉血栓形成、坐骨神经损伤等严重并发症。X线片可见移植骨与宿主骨质交界处有连续性骨小梁通过,假体未见松动迹象。结论髋臼假体无菌性松动及骨溶解是需要进行全髋关节翻修的主要原因,而髋臼骨缺损Paprosky分型法对髋臼翻修重建方法有指导意义,正确选择假体类型及合理选择植骨方式是全髋关节翻修术后取得满意疗效的保证。     

Porous metal revision shells for management of contained acetabular bone defects at a mean follow-up of six years: a comparison between up to 50% bleeding host bone contact and more than 50% contact

We report the use of porous metal acetabular revision shells in the treatment of contained bone loss. The outcomes of 53 patients with ≤ 50% acetabular bleeding host bone contact were compared with a control group of 49 patients with > 50% to 85% bleeding host bone contact. All patients were treated with the same type of trabecular metal acetabular revision shell. The mean age at revision was 62.4 years (42 to 80) and the mean follow-up of both groups was 72.4 months (60 to 102). Clinical, radiological and functional outcomes were assessed. There were four (7.5%) mechanical failures in the ≤ 50% host bone contact group and no failures in the > 50% host bone contact group (p = 0.068). Out of both groups combined there were four infections (3.9%) and five recurrent dislocations (4.9%) with a stable acetabular component construct that were revised to a constrained liner. Given the complexity of the reconstructive challenge, porous metal revision acetabular shells show acceptable failure rates at five to ten years' follow-up in the setting of significant contained bone defects. This favourable outcome might be due to the improved initial stability achieved by a high coefficient of friction between the acetabular implant and the host bone, and the high porosity, which affords good bone ingrowth.     

3D Printed Acetabular Components for Complex Revision Arthroplasty

Recent studies have shown high early failure rates with Cup Cage constructs in complex revision surgery for Paprosky 3B acetabular defects. As a result, the use of 3D printed custom-made acetabular components has become more common. In this case series, we present two cases that demonstrate the latest advancement in 3D printed implants for severe acetabular bone loss. The follow up was 3 and 7 years. Neither patient has undergone revision surgery of the acetabular component to date. One patient sustained a femoral peri-prosthetic fracture requiring plate fixation. This case study demonstrates that 3D printed implants have excellent intraoperative and immediate postoperative outcomes in revision surgery for severe acetabular bone defects.     

The incorporation of morselized bone grafts in cementless acetabular revisions

The treatment of large osteolytic lesions is a challenge during acetabular revisions. Periprosthetic bone loss can compromise the stability of new implants. The purpose of this study was to evaluate the 5- to 10-year clinical and radiographic results of morselized bone grafting for acetabular osteolysis during cementless acetabular revisions. Ninety-nine patients (108 hips) who had an acetabular revision hip arthroplasty for osteolysis were retrospectively reviewed. There were 44 men and 55 women who had a mean age of 66 years. At the index revision, the acetabular defects were debrided of granulomatous tissue and packed tightly with morselized cancellous femoral head allograft. All the revision acetabular components were implanted using cementless fixation. At a mean followup of 85 months (range, 60-118 months), the results of 103 of 108 hips (95%) were clinically and radiographically successful. The mean preoperative Harris hip score was 37 points, which improved to a mean of 91 points at the last followup. All cavitary defects had complete radiographic incorporation of the bone grafts except for two lesions. The results of this study indicate that morselized bone graft incorporates into cementless acetabular revisions. This treatment method provided a stable reconstruction in 98% of patients at a mean of 7 years followup.     

Cancellous allograft in revision total hip arthroplasty. A clinical review

There are numerous indications for the use of cancellous allograft bone in the context of revision hip arthroplasty. These indications range from the well-documented use of morselized bone chips to fill cavitary defects during cementless acetabular reconstructions--in which complete or near-complete graft remodeling is expected--to the use of particulate allografting with bipolar hemiarthroplasty for acetabular revision, which largely has been abandoned because of frequent component migration, graft resorption, and clinical failure. Most other indications, including femoral and acetabular impaction allografting techniques, curettage of osteolytic defects with component retention, and complex reconstructions using acetabular reconstruction rings or cages with cancellous donor bone, are controversial but are supported by published clinical series. The current study reviews the literature on cancellous allografting in revision total hip arthroplasty.     

Trabecular metal used for major bone loss in acetabular hip revision

The purpose of this study was to evaluate the outcome of trabecular metal (TM) acetabular components used in revision hip arthroplasty with major bone deficiency. We retrospectively reviewed the records of 46 patients undergoing revision hip arthroplasty with severe acetabular bone loss. Clinical outcomes were assessed using Harris Hip Score, Western Ontario and McMaster Universities, and Short-Form 12. Mean follow-up was 50 months. All patients had Paprosky type IIc or III acetabular bone deficiency. Major complications included 1 infection, 2 dislocations, and 1 arterial bleeding. Average Harris Hip Score was 78.2. Short-Form 12 scores were within population-based age-matched averages. Western Ontario and McMaster Universities scores were mainly in the 2 lowest disability categories. Porous tantalum shows promising results in revision arthroplasty with severe acetabular bone loss.     

Acetabular revision using grafts and cages

Principles of acetabular revision include stable bone coverage that can support the new acetabular component, restoration of the anatomy and bone stock for future revisions, and equalization of leg length. Achieving these goals depends on the severity of the pelvic defect. Classification of these acetabular defects is critical to optimal treatment choice. A classification formulated by the authors of this paper and based on proven Severity Instrument methodology has been applied effectively at their institutions after meeting reliability and validation criteria. Approaches to acetabular revision based on this classification have resulted in good outcomes.     

Extra-large uncemented hemispherical acetabular components for revision total hip arthroplasty

BACKGROUND: Extra-large uncemented components provide several advantages for acetabular revision, but limited information is available on the results of their use. The purpose of this study was to evaluate, at a minimum of five years, the results associated with the use of an extra-large uncemented porous-coated component for acetabular revision in the presence of bone loss. METHODS: Eighty-nine extra-large uncemented hemispherical acetabular components were used for revision after aseptic failure of a total hip arthroplasty in forty-six men and forty-three women (mean age at revision, fifty-nine years; range, thirty to eighty-three years). The revision implant (a Harris-Galante-I or II cup fixed with screws) had an outside diameter of > or = 66 mm in men and > or = 62 mm in women. Seventy-nine patients had a segmental or combined segmental and cavitary acetabular bone deficiency before the revision. Particulate bone graft was used in fifty-four hips and bulk bone graft, in nine. RESULTS: One patient died with the acetabular component intact and two patients were lost to follow-up within five years after the operation. At the time of the last follow--up, four acetabular components had been removed or revised again (two for aseptic loosening). All of the remaining patients were followed clinically for at least five years (mean, 7.2 years; range, 5.0 to 11.3 years). In the hips that were not revised again, only two sockets had definite radiographic evidence of loosening. All four of the sockets that loosened were in hips that had had combined cavitary and segmental bone loss preoperatively. In the hips that were not revised again, the mean modified Harris hip score increased from 56 points preoperatively to 83 points at the time of the most recent follow-up. The most frequent complication, dislocation of the hip, occurred in eleven patients. The probability of survival of the acetabular component at eight years was 93% (95% confidence interval, 85% to 100%) with removal for any reason as the end point, 98% (95% confidence interval, 92% to 100%) with revision for aseptic loosening as the end point, and 95% (95% confidence interval, 88% to 100%) with radiographic evidence of loosening or revision for aseptic loosening as the end point. CONCLUSIONS: This study demonstrates that extra-large uncemented components used for acetabular revision in the presence of bone loss perform very well and have a low rate of aseptic loosening at the time of intermediate-term follow-up.     

Trabecular metal acetabular revision system (cup-cage construct) to address the massive acetabular defects in revision arthroplasty

The increasing number of total hip replacements in the younger clique has added to the demand for revision procedures. Revision situations are often encountered with infection, loss of bone stock and bone defects. There are various methods of reconstruction of acetabular defects. The management options of type 3B Paprosky acetabular defects are limited with allograft and conventional cages. Trabecular metal technology has evolved to address these bone defects. Trabecular metal acetabular revision system (TMARS) cup-cage construct is a new technique to address massive acetabular defects. We describe a case of failed hip reconstruction done for a Giant cell tumour of proximal femur managed by a two stage procedure, initial debridement and second stage reconstruction of acetabulum with TMARS cup-cage construct and femur with allograft prosthesis composite.     

全髋关节翻修术中髋臼假体的选择和髋臼骨缺损的处理

目的探讨全髋关节翻修术中髋臼假体的选择和髋臼骨缺损的处理。方法2002年1月至2007年6月收治资料较完整的全髋关节翻修术患者共55例，其中行髋臼假体翻修术的患者有36例，男8例，女28例；年龄52～86岁，平均73岁。左髋13例，右髋23例。髋臼翻修原因：髋臼假体松动20例，髋臼和股骨假体均有明显松动12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。髋臼骨缺损21例，按照美国矫形外科学会（AAOS）分类标准：Ⅰ型：节段性骨缺损6例；Ⅱ型：腔隙性骨缺损9例；Ⅲ型：混合型骨缺损6例。结果36例中，4例仅翻修髋臼侧假体，保留原股骨假体；3例更换了磨损严重的聚乙烯内衬，未予更换金属假体，其余29例均行全髋关节置换翻修术。髋臼骨缺损21例中，6例使用颗粒骨打压植骨＋骨水泥假体，2例为结构性和颗粒性打压植骨＋骨水泥假体，9例为结构性植骨＋颗粒打压植骨后，使用金属加强环＋骨水泥假体，1例为结构性植骨后，使用常规髋臼假体，3例仅对局部骨缺损部位进行植骨未予更换稳定的金属假体。随访时间6～68个月，平均39个月。Harris评分由术前的平均48分，提高至随访时平均89分。结论机械性磨损是人工髋关节松动翻修的主要原因；翻修时，假体的选择和骨缺损的处理要根据患者个体情况差异和术中具体情况综合考虑；周密的术前计划、准备多种类型髋臼假体供术中选择、充分自体和异体植骨是保证手术顺利进行的根本。