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.     

Structural Allograft Supporting a Trabecular Metal Cup Provides Durable Results in Complex Revision Arthroplasty

Background

Revision total hip arthroplasty (THA) is challenging specially in the presence of severe acetabular bone deficiency. We report the use of a highly porous revision shell augmented by structural allograft to provide structural support and coverage to the acetabular component.

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。     

Implant stability in revision total hip arthroplasty: Allograft bone packing following extended proximal femoral osteotomy

One method of revising the femoral component in revision total hip arthroplasty in the presence of compromised femoral bone stock is to pack the upper femur with particulate allograft and then to cement the femoral component into the allograft bed. This technique is being used clinically with encouraging results. Additionally, surgical exposure of the femoral canal during revision total hip arthroplasty can be greatly improved with an extended trochanteric osteotomy, which is subsequently repaired with wires or cables. To assess the feasibility of performing the allograft bone packing technique following an extended trochanteric osteotomy, the stability of this construct in a cadaver model was measured, using micromotion sensing instruments and loads applied on a materials testing machine. The stability of the cemented allograft impaction construct following extended trochanteric osteotomy was comparable to the stability of the control construct, which consisted of a similar impacted allograft construct without osteotomy. The stability of the osteotomized side was comparable to that of the control side. It is concluded that the initial in vitro stability of the allograft impaction technique following extended proximal femoral osteotomy is adequate to justify experimental in vivo use.     

Intramedullary step-cut osteotomy for revision total hip arthroplasty with allograft-host bone size mismatch

Eleven revision total hip arthroplasties were treated with proximal segmental femoral allograft reconstruction in which the diameter of the distal host bone was larger than the largest long-stem femoral component which could fit into the segmental allograft. A long, lateral step-cut osteotomy of the allograft was used with placement of the lateral cortical allograft inside the distal host bone. All allograft-host bone junctions healed. The average time to union was 6.7 months. The long step-cut osteotomy provides stability of the allograft-host bone junction when the diameter of the host bone is larger than the allograft. The osteotomy also provides a large surface area of contact between the allograft and host bone.     

Treatment options for chronic pelvic discontinuity

Chronic pelvic discontinuity is a distinct and unique challenge seen during revision total hip arthroplasty (THA) in which the superior ilium is separated from the inferior ischiopubic segment through the acetabulum, rendering the anterior and posterior columns discontinuous. The operative management of acetabular bone loss in revision THA is one of the most difficult challenges today. Common treatment options include cage reconstruction with bulk acetabular allograft, custom triflange acetabular component, a cup-cage construct, jumbo acetabular cup with porous metal augments, or acetabular distraction with a porous tantalum shell with or without modular porous augments.     

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.     

Constrained Acetabular Liners Cemented Into Cages During Total Hip Revision Arthroplasty

The combination of acetabular bone loss and hip instability is challenging. Sixteen patients underwent revision total hip arthroplasty using constrained acetabular liners cemented into cages. The average follow-up was 28 months (range, 24-60 months). Clinical evaluation was obtained using the Harris hip score along with radiographic data. At latest follow-up, 13 patients were available for evaluation. Although the average postoperative Harris hip score was 62 points, which was better than the preoperative score of 27 points, the overall radiographic failure rate was 23%. The combination of poor acetabular bone stock and altered stresses from the increased constraint likely led to the poor outcome. We would only recommend use of a cemented, constrained acetabular liner in combination with a protrusio cage as a bail out or salvage procedure.     

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。     

Revision Total Hip Arthroplasty Using the Kerboull Acetabular Reinforcement Device and Structural Allograft for Severe Defects of the Acetabulum

Background

The purpose of this study is to review our experience with Kerboull reinforcement device combined with bulk allograft for management of severe acetabular defects.

The jumbo cup: Easiest and safest solution

Jumbo cups can be used to address many acetabular revision cases with bone loss. The technique of implantation is relatively straight forward, and there is the potential to maximize bone-to-cup surface area, approximate the natural hip center, and to obtain a construct that allows immediate weight bearing. Experience from multiple sources has demonstrated survivorship up to 83% at 20 years, limited mostly by the wear of conventional polyethylene. A contraindication to this method is irradiated bone and a limitation is restoration of peripheral acetabular bone stock, which could compromise further revision surgery.     

二期翻修在人工髋关节置换术后感染治疗中的作用

[目的]探讨二期翻修手术在治疗人工髋关节置换术后感染的有效性、第二期翻修时假体的选择及异体骨植骨的可行性。[方法]运用二期翻修术治疗了24例(25髋)髋关节置换术后感染患者,9例采用灌注冲洗型占位器,16例采用抗生素骨水泥占位器。第二期重建时,16例采用生物固定髋臼,其中7例结合使用异体颗粒植骨;9例采用打压植骨技术。1例采用抗生素骨水泥固定假体;8例采用远端固定非骨水泥假体,其中4例结合使用异体支撑植骨;16例采用打压植骨技术。应用X线片及Harris评分进行评价。[结果]所有患者均获得随访,平均随访时间26.3个月(3~57个月),Harris评分从术前平均47.9分,提高到最后随访时的平均86.7分,患者满意率为92%。在最后随访时没有感染复发的病例。[结论]二期翻修手术是治疗人工髋关节置换术后感染的有效方法,临时占位器起到至关重要的作用,使用抗生素骨水泥占位器有控制感染效果好、术后抗生素使用时间短及术后不用灌注的优点。在第二期翻修重建时可以使用非骨水泥假体,并且可以同时进行异体骨植骨。     

Revision total hip arthroplasty without bone graft of high-grade acetabular defects

Mixed results have been reported with bulk and cancellous bone graft to fill defects during acetabular revision arthroplasty. Jumbo cups have been used to maximize host bone contact, and if adequate initial stability can be achieved, this approach may provide a superior long-term outcome. We retrospectively reviewed a consecutive series of 107 acetabular revisions performed using jumbo cups without bone graft. Bone defects were assessed using a validated radiographic classification system that yielded 64 hips with significant bone defects for inclusion. Mean change in American Academy of Orthopaedic Surgeons lower extremity core and pain scores and in Short Form-12 scores showed increases of 22.01, 37.52, and 17.08 points, respectively. Postoperative radiographs consistently demonstrated host bone ingrowth into the jumbo acetabular shells, except for 3 failures. Careful incremental reaming up to a size that optimizes host bone support and contact may eliminate the need for bone graft in most acetabular revision arthroplasties.     

Revision for Aseptic Loosening of Highly Porous Acetabular Components in Primary Total Hip Arthroplasty: An Analysis of 20,993 Total Hip Replacements

BackgroundHighly porous-coated titanium acetabular components have a high coefficient of friction and ultraporous surfaces to enhance bone ingrowth and osseointegration in total hip arthroplasty (THA). There have been concerns with the development of early radiolucent lines and aseptic loosening of highly porous acetabular components. It is unclear whether these concerns relate to a specific implant or the entire class. The aim of this study is to compare the revision rates for aseptic loosening of highly porous acetabular combinations in primary THA using data from a large joint replacement registry.MethodsData were retrieved from the Australian Orthopedic Association National Joint Replacement Registry for the study period September 1999 to December 2019. All primary THA procedures recorded and performed for osteoarthritis using the most common combinations for each highly porous acetabular component with highly cross-linked polyethylene and a 32-mm or 36-mm femoral head were included. The primary outcome measure was revision for aseptic loosening of the acetabular component. Results were adjusted for patient age and gender.ResultsThere were 20,993 primary THA procedures performed for osteoarthritis using a highly porous acetabular component across 6 combinations. Relative to the POLARSTEM/R3 (StikTite), the Exeter V40/Tritanium had a significantly higher risk of revision for aseptic loosening of the acetabular component (hazard ratio 0.21, 95% confidence interval 0.06-0.74, P = .014). There was no difference between any other highly porous acetabular component combination and no late revisions for aseptic loosening.ConclusionHighly porous-coated titanium acetabular components have low rates of aseptic loosening with long-term follow-up. A difference between components may exist.Level of EvidenceLevel III.     

髋臼加强环联合同种异体骨植骨重建髋臼在髋关节翻修中的应用

目的总结髋臼加强环(Cage)联合同种异体骨植骨重建髋臼在髋关节翻修术中的应用及疗效。方法 2006年2月-2010年8月,对14例(14髋)行人工全髋关节翻修术的重度髋臼骨缺损患者采用Cage联合同种异体骨植骨重建髋臼。男6例,女8例;年龄45～76岁,平均59.2岁。初次置换至此次翻修术时间为5～12年,平均7.2年。翻修原因:感染8例,骨溶解及假体松动6例。术前髋关节功能Harris评分为(37.7±5.3)分。髋臼骨缺损按照美国骨科医师协会(AAOS)分型标准:Ⅲ型8例,Ⅳ型6例。结果术后切口均Ⅰ期愈合,无坐骨神经损伤、下肢深静脉血栓形成等并发症发生。患者均获随访,随访时间14～62个月,平均44个月。患者疼痛症状均明显缓解或消失。末次随访时髋关节Harris评分为(89.7±3.2)分,与术前比较差异有统计学意义(t=—44.40,P=0.04)。X线片示髋臼假体均无松动,植骨未见明显吸收,并逐渐与宿主骨融合。结论在髋关节翻修时,采用Cage联合同种异体骨植骨能有效修复髋臼骨缺损并重建髋臼,近期疗效满意,远期疗效尚需进一步随访观察。     

Revision Total Hip Arthroplasty for a Vancouver Type B3 Periprosthetic Fracture Using an Allograft-Cemented Stem Composite by the Telescoping Technique

We describe a case of successful revision total hip arthroplasty for a Vancouver type B3 periprosthetic femoral fracture with extensive bone stock deficiency and osteoporotic diaphyseal bone. The femur was reconstructed with an allograft-cemented stem composite using a telescoping technique and a drainage hole for surplus cement. This procedure facilitated stable stem fixation to the host femur without cement interference and bony fusion between the allograft and host bone, as revealed by bone scintigraphy. This technique provides a surgical option for a severe periprosthetic femoral fracture in which the femoral diaphyseal bone is too osteoporotic to support the fixation of an allograft-cementless stem composite.     

The use of bulk allografts in revision knee arthroplasty

During the revision of a failed total knee implant, when large osseous defects are encountered, the surgeon has the following three options for managing severe bone loss: revision with a custom implant, revision with a rotating-hinge component, or reconstruction with an allograft and a long-stemmed revision component. An allograft reconstruction replaces the damaged bone, albeit with dead bone; whereas the other two options require additional bone to be removed. By using a bone defect classification system preoperatively, the surgeon estimates the extent of bone damage and orders the proper revision system and allograft material. A durable revision arthroplasty is achieved by using long-stemmed implants that provide axial stability, cementless stems that permit compressive loads, and step cuts that achieve rotational stability.     

Revision of the acetabular component without cement after a previous acetabular reconstruction with use of a bulk femoral head graft in patients who had congenital dislocation or dysplasia. A follow-up note

BACKGROUND: Revision of an acetabular component that has failed after a total hip arthroplasty in which a bulk femoral head autogenous graft or allograft was used as a structural graft for acetabular reconstruction is an uncommon but complex and challenging procedure. We previously reported the results for seventy hips at an average of 16.5 years after a total hip arthroplasty in which an acetabular reconstruction had been performed with a femoral head graft. In the present study, we evaluated a subset of nine hips from that series that had a subsequent revision of the acetabular component without cement. The purpose of the current study was to assess the usefulness of the bone graft in this revision. METHODS: The nine patients (nine hips) were followed clinically and radiographically for an average of seventy-six months (range, sixty-one to 114 months) after the index revision. In six hips the autogenous femoral head graft previously had been bolted to the lateral side of the ilium, and in one hip the femoral head allograft had been affixed in this manner. In the two remaining hips, the allograft had been placed within the acetabulum. The hips were classified according to the extent of acetabular bone loss, with use of criteria described previously. Three hips had stage-I bone loss; four, stage-II; and two, stage-IIB. A porous-coated hemispherical acetabular component was inserted without cement and fixed with screws in each hip. At least 70 percent of the porous coating was in contact with viable bone. RESULTS: At the time of the latest follow-up after the index revision, all nine acetabular components were functioning well without loosening or osteolysis and none had been revised. The average Harris hip score was 77 points (range, 61 to 98 points) compared with 49 points (range, 27 to 96 points) preoperatively. One hip had had revision of the femoral stem, and another had had exchange of the acetabular liner because of recurrent dislocations. There was no additional resorption of the residual bulk graft that was in contact with the metal shell in any hip. CONCLUSIONS: In this small series of complex acetabular revisions, the healed bulk graft provided valuable additional bone stock for the support of an acetabular component that was inserted without cement. Insertion of the acetabular component into the available bone, which consisted in major part of host bone and in minor part of united revascularized bulk graft, resulted in a well functioning hip after an intermediate duration of follow-up. In all except two hips, the enlarged bone stock allowed insertion of a larger acetabular component than had been used previously.     

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.     

One-Stage Revision Arthroplasty Using Cementless Stem for Infected Hip Arthroplasties

The objective of this retrospective study was to evaluate our results with one-stage revision using cementless femoral stem for infected hip arthroplasties. Twenty-four patients were included in the study. The acetabular component was cemented in 9 cases. In 2 patients a structured bone allograft was necessary to fill an acetabular defect. After a mean follow-up of 44.6 months, 23 patients showed no signs of infection (95.8%), the mean functional response according to the Merle d’Aubigné scale was 13.8 and the mean Harris Hip Score was 65.4. One-stage revision hip arthroplasty using cementless femoral stem was associated with a high success rate.