Removal of well-fixed, cementless, acetabular components in revision hip arthroplasty

Removal of well-fixed, cementless, acetabular components during revision arthroplasty remains a challenging problem. Further damage to host bone may limit options for reconstruction and compromise the long-term result of the revision operation. We report the results of 31 hips with well-fixed, cementless sockets which were removed using a new cup extraction system. In all hips the socket was removed without difficulty and with minimal further bone loss.     

Component removal in revision total hip arthroplasty.

One of the primary steps in revision hip arthroplasty is the extraction of retained components before surgical reconstruction. In revision arthroplasty, the removal of well-fixed components and cement can be extremely demanding, time consuming, and damaging to the remaining host bone. The aims of the current study were to examine the numerous operative techniques used during extraction of acetabular and femoral components and review the results of revision hip arthroplasty after cementless component removal. A review of 157 acetabular components and 113 femoral components removed from 219 patients during hip revision arthroplasty between 1985 and 2000 was done. The average age of the patients was 64.3 years. The average followup was 5 years (range, 0.7-12.5 years). An extended proximal femoral osteotomy was done in 37 (33%) of the femoral revisions. There were 14 (5%) acetabular failures for which the patients required reoperation. There were no femoral rerevisions. Complications included dislocation (6% after acetabular revision and 9% after femoral revision), infection (6%), femoral fracture (6%), hematoma (3.5%), acetabular fixation failure (2.5%), and femoral osteolysis (1%). The removal of cemented and well-fixed porous-coated implants can be done with adequate preoperative planning and a thorough knowledge of numerous implant removal techniques.     

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.     

6 years follow-up of hip revision surgery

Revision total hip arthroplasty often presents surgeons with difficult bone loss problems. The purpose of this study was to evaluate the results of hip revision surgery according to bone stock We evaluated, in a retrospective study, 148 hip revision surgeries during 2004 to 2010. The Harris Hip Score (HHS), the acetabular cementation, the AAOS classification, the SOFCOT 99 bone loss grading and Barrack classification were used for clinical and radiological assessment. It can be observed significant improvement of HHS from a mean value of 45 preoperatively to 77.2 points postoperatively. Grade B acetabular cementation was observed in a significantly higher rate for situations that needed acetabular allograft reconstruction and where it cannot be performed because of allografts lack. Barrack grades C and D cementation were associated with 70% of SOFCOT 99 stage III and IV cases and only 5% of SOFCOT 99 stage 0-II cases.Using bone graft seems to be a reliable solution for restoring bone stock and stabilizing the cup in revision total hip arthroplasty with type II-IV acetabular defect according to the AAOS classification. Because SOFCOT 99 stages III-IV are often associated with poor cementation we prefer using uncemented distally fixed with screws revision stems for these cases.     

A simple polyethylene liner extraction method in hip arthroplasty revision surgery

Avoiding or diminishing bone stock loss in hip revision surgery is one of the main concerns of a surgeon. The surgical procedure must be safe, non-traumatic, reproducible, reliable, and if possible with the lowest or minimum cost. We present an easy technique of polyethylene liner extraction in hip revision surgery, reviewing other common extraction methods. The method depicted here has been used by the authors for years in many occasions where the liner is to be removed while preserving the acetabular shell.     

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.     

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。     

Dissociation of modular total hip arthroplasty at the femoral head-neck interface after loosening of the acetabular shell following hip dislocation

Modular component dissociation is a potential problem of current modular total hip arthroplasty (THA) systems. We describe a case of dissociation of the modular THA at the femoral head-neck interface after loosening of the acetabular shell during closed reduction for posterior dislocation of THA. The causes of this dissociation and acetabular shell loosening are discussed. Successful treatment was provided with surgical revision of the acetabular and the femoral head components. The present case serves as a graphic reminder that the acetabular shell overhanging the acetabular bone must be avoided when implanting modular THA components.     

Revision of well-fixed infected Birmingham hip resurfacing using the Explant system and cement mould: an useful technique

Deep infections do occur during hip resurfacing despite all precautions. We present the method and use of the acetabular bone stock preserving Explant system in the removal of infected well-fixed cementless acetabular components and the technique of using an antibiotic impregnated cement spacer to provide a functional joint, enabling the patient to mobilise with minimal discomfort between two staged revision procedures.     

Graft incorporation after acetabular and femoral impaction grafting with washed irradiated allograft and autologous marrow

Rates of around 40% incorporation have been described when chips of irradiated cancellous allograft with retained fat were impacted with the Exeter technique. We report the results of acetabular and femoral impaction bone grafting during revision hip arthroplasty using washed irradiated allograft with autologous marrow. Eighty-five consecutive patients underwent acetabular and or femoral revision arthroplasty. Evidence of graft cortication and trabeculation was recorded on successive postoperative radiographs, over a mean period of 44 months. Ninety-six percent (49/51) and 90% (53/59) of patients showed incorporation in acetabular and femoral grafts, respectively. This was usually apparent by 6 months postoperatively. We conclude that the addition of autologous marrow to irradiated bone allograft during impaction grafting is a cheap and highly effective way of achieving graft incorporation.     

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.     

Pelvic discontinuity: Where are we today?

Pelvic discontinuities in revision total hip arthroplasty remain a challenging problem with an evolving set of treatment options. Discontinuities occur when bone loss of the acetabulum and subsequent unstable movement of the acetabular component result in a fracture between the anterior and posterior columns. These resemble chronic nonunions by the time of revision arthroplasty and are managed differently from the acute fracture type occurring during primary or revision acetabular reconstruction in a previously stable pelvis. We review the treatment options and describe our preferred method of treatment using surgical distraction.     

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.     

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.     

The fate of stable cemented acetabular components retained during revision of a femoral component of a total hip arthroplasty

BACKGROUND: The decision as to whether to revise or retain a well fixed cemented acetabular component during revision of a femoral component is especially difficult; the rate of loosening of cemented acetabular components is high, whereas that of porous-coated acetabular components inserted during revision is low. However, removal of a well fixed cemented acetabular component can result in increased operative morbidity and cost and in loss of acetabular bone. Data that can be used to predict the long-term survival of retained well fixed cemented acetabular components are therefore needed. METHODS: We studied the five to thirteen-year clinical and radiographic results in a group of twenty-six consecutive patients in whom a well fixed cemented acetabular component had been retained during revision of a femoral component. Typical demographic data on the patients and information about the components were recorded, and the cemented acetabular components were graded as A through F, according to the system of Ranawat et al., at the time of the femoral revision. The average duration of follow-up was 8.4 years (range, 5.0 to 12.7 years). No patient was lost to follow-up. RESULTS: Four acetabular components (15 percent) had progressive radiolucency (at forty-eight, forty-eight, fifty-nine, and seventy-five months after the femoral revision) and were considered radiographically loose despite not being associated with symptoms. All four components were graded as either E or F at the time that they were retained during the femoral revision; radiographic loosening was significantly related to these two grades (p < 0.01). No acetabular component with a grade of A, B, C, or D loosened. The components that loosened had been in vivo for a relatively shorter, as opposed to longer, duration before the femoral revision compared with the components that did not loosen (p < 0.05). CONCLUSIONS: Retention of the well fixed cemented acetabular components was associated with good clinical results but with a 15 percent rate of loosening. Revision of a cemented acetabular component solely on the basis of the duration that it was in vivo or whether a previous revision had been done does not appear to be warranted. Our findings suggest that acetabular components with a grade of A, B, C, or D at the time of a femoral revision may be retained, as these components continued to function at the time of the five to thirteen-year follow-up in the current study.     

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.     

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.     

Failures after revision hip arthroplasties with threaded cups and structural bone allografts: Loosening of 13/18 cases after 1-4 years

Uncemented threaded, smooth cup acetabular components and structural deep-frozen bone allografts harvested from femoral heads during arthroplasties were used for reconstruction of the acetabulum in 18 revision hip arthroplasties. Autogenous bone grafts were also used in every case. The mean follow-up time was 2.5 (1-4) years. Loosening of the prosthetic component occurred in 13 cases. In 8 cases revision of the acetabular component has already been performed, and 5 cases remain to be reoperated. The use of uncemented, threaded cups in combination with reconstruction of bone defects with structural allografts cannot be recommended in acetabular revisions.     

Simultaneous primary total hip arthroplasty and contralateral revision hip arthroplasty: role for use of femoral head autograft

We report the outcome of revision hip arthroplasty for patients with acetabular bone loss in whom the femoral head retrieved from arthritic contralateral hip during the same anesthesia was used as autograft for acetabular reconstruction. Thirty-two hips in 16 patients with a mean age of 63.8 years (range, 43-79 years) were followed for an average of 3.5 years. All primary arthroplasties were successful. Evidence of autograft incorporation was found in all except 2 patients. The acetabular component failed and required revision in the latter 2 patients. The use of femoral head autograft in a select group of patients with symptomatic arthritis of hip and a failed prosthetic hip with severe bone loss in the contralateral side is a viable option. However, this technique should not be applied to acetabular reconstructions in which protected weight-bearing in the postoperative period may be necessary.     

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.