Soft tissue sarcoma associated with aluminum oxide ceramic total hip arthroplasty. A case report

Malignant tumors around fracture fixation implants have been reported sporadically for many years. Recently, however, reports of sarcomatous degeneration around a standard cemented hip arthroplasty and around cobalt-chromium-bearing hip arthroplasties raise new questions of the malignant potential of metallic ends prostheses. Sarcomatous changes around aluminum oxide ceramics seem not to have been reported in the literature. The present report may be the first documented case of an aggressive soft tissue sarcoma detected 15 months after the patient had an uncemented ceramic total hip arthroplasty. If a causal relationship exists, the incidence of this phenomenon in the United States is 250 times greater than would be expected from statistics on soft tissue sarcoma at the hip. Because of the similarity on plane roentgenograms of this tumor to lesions known to be caused by wear debris, tumors should be included in the differential diagnosis of cases of total hip loosening.     

Foreign body reaction to polymeric debris following total hip arthroplasty

Two cases of severe foreign body reaction to polymeric debris occurred following cemented total hip arthroplasty. The debris consisted of microfragments of both polyethylene and polymethylmethacrylate. Microfragments are believed to be primarily responsible for the extensive lytic reactions, which represent an extreme degree of the chronic inflammatory response that is commonly associated with loosening of cemented total hip arthroplasties. A schematic representation of the pathogenesis of component loosening, including the foreign body reaction, illustrates the relationship of this phenomenon to the general problem of aseptic loosening. Revision arthroplasty was successful in both cases, followed for a period of nine and 16 months, respectively.     

Titanium wear debris in failed cemented total hip arthroplasty. An analysis of 71 cases.

Seventy-one cemented total hip arthroplasties (THAs) were reviewed following removal of the all-titanium alloy femoral stem. Fifty-one hips were primary arthroplasties that failed due to aseptic loosening, 8 were previous revisions with aseptic loosening, and 12 were removed for infection. The average duration of service for the three groups was 4.5 years, 5.0 years, and 3.7 years, respectively. Femoral bone loss in aseptically loose, primary THA was graded as severe in 51%, moderate in 24%, and mild in 20%. Femoral endosteolysis was present in 94%, while acetabular osteolysis was seen in 6%. Histological evaluation of tissues from failed primary arthroplasties revealed polymethyl methacrylate debris in 75% of cases, polyethylene debris in 80%, metal debris in 75%, and chronic inflammatory cells in all cases. Metallic debris was not seen in the failed revision cases and in only 17% of the infected cases. Examination of retrieved femoral components revealed burnishing of the head in all cases, while 71% of stems with aseptic loosening were abraded from the cement. Metal levels from 12 cases averaged 2,111 mg/g of dry tissue (range, 60-11,823); synovial fluid levels from 8 other cases averaged 106 mg/l (range, 22-340). While it is not certain whether metallic particles are a primary cause of loosening or are generated secondarily, their presence seems to accelerate bone loss and loosening.     

Malignant fibrous histiocytoma arising in the area of total hip replacement

A patient developed a rapidly progressive and extensive periprosthetic osteolysis after a cemented total hip arthroplasty for postradiation necrosis of pelvic bone and femoral head. Malignant tumor is one of the causes of periprosthetic bone loss. The biopsy confirmed the malignant fibrous histiocytoma (MFH). However, majority of periprosthetic bone loss is due to wear debris induced osteolysis. Usually, wear debris induced periprosthetic osteolysis is developed later and the progression is much slower than there of malignant tumor. Also wear debris induced osteolysis is confirmed by chronic inflammation with macrophages containing wear particles. When there is a rapidly progressive and extensive osteolysis a prosthesis following hip replacement arthroplasty, the physician should suspect the possibility of malignant tumor.     

The counterface, surface smoothness, tolerances, and coatings in total joint prostheses

Proper counterface material combinations, surface finish, and tolerances of contact surfaces are important issues in minimizing friction, wear, and corrosion of total joint prostheses. In the current study, the potential of novel amorphous diamond coatings to solve some present problems in total joint prostheses was studied by using tribological tests with a hip joint simulator and pin-on-disk testers. Based on the tests, the wear of amorphous diamond is negligible compared with conventional hip joint materials (10,000 to 1,000,000 times lower). The coefficient of friction of diamond-coated artificial hip joint was 0.03 to 0.06 when tested in saline solution with loads from 200 to 1000 kg for as many as two million cycles. The friction remained stable throughout the tests. Methylmethacrylate (bone cement) is a typical source of third body wear particles in cemented total hip replacements. The wear tests showed that bone cement (containing hard ceramic particles of barium sulfate or zirconia) severely scratched cobalt chromium molybdenum alloy samples. These scratches enhance the wear of softer counterpart materials, such as polyethylene or bone cement, whereas diamond-coated surfaces remained undamaged. High quality amorphous diamond coatings offer superior stability (minimal wear debris release in surrounding tissues) and good biomechanical performance.     

Outcome of total hip arthroplasties with cement: Results after implantation of the Harris Design 2 prosthesis, 1983–1985

Most reports of excellent long-term results of cemented total hip arthroplasty originate from studies of Charnley prostheses. A radiographic and clinical study was performed on 126 patients who underwent a cemented total hip arthroplasty from 1983 to 1985 with the Harris Design 2 prosthesis (Howmedica, Rutherford, NJ). The femoral component was cobalt—chromium and it had a broad, rounded medial border and a collar. The head diameter was 26 mm. A cemented all-polyethylene socket was used in all cases. At the last follow-up examination, 71% of the patients were completely free of pain and no patient had severe pain or pain at rest. Kaplan—Meier survival analysis estimated the revision rate at 10 years after operation to be 5 ± 2% (mean ± SEM) (including planned revisions). The rate of complete acetabular demarcation was 20% at 10 years, and femoral demarcation involving more than 50% of the bone—implant surface or endosteal cavitation was noted in only three cases. These results are as good as the best reported after total hip arthroplasty with the Charnley prosthesis.     

Osteolysis associated with cemented total knee arthroplasty: A case report

Osteolysis induced by particulate debris occurs within 5 years after cementless total knee arthroplasty, but has not been reported to be a problem after cemented total knee arthroplasty. It has been suggested that the bone-cement interface may form a barrier to polyethylene-debris migration, thereby limiting bone loss. The authors have observed osteolysis in a 75-year-old woman 9 years after cemented total knee arthroplasty. An osteolytic area appeared to return to an area of normal bone architecture 3 years after the removal of synovium and particulate debris without implant revision.     

Fatal fat embolism during cemented total knee arthroplasty: a case report

Evidence is accumulating that embolization of bone marrow contents to the lungs can cause the hypotension, hypoxemia, cardiac arrest and death reported after total hip arthroplasty and that the embolism results from high intramedullary pressures exerted during implantation of the prosthesis. The authors describe such an occurrence in an 80-year-old man who had a cemented long-stem total knee prosthesis inserted. Autopsy revealed numerous pulmonary fat emboli that were distributed predominantly in arterioles and capillaries. The possibility of pulmonary fat microembolism occurring during cemented total knee arthroplasty should be recognized, particularly when prostheses with long intramedullary stems are used. Preventive or prophylactic measures that should be considered to avoid fat embolism during implantation include venting the intramedullary canal and meticulous lavage to clear away intramedullary debris. Increasing the inspired oxygen concentration as the prosthesis is inserted and monitoring of cardiopulmonary status to avoid simultaneous hypotension and hypoxemia may help to prevent the cardiopulmonary changes associated with pulmonary fat microembolism.     

The first 32 years of total hip arthroplasty. One surgeon's perspective.

During the first 32 years of total hip arthroplasty, high risk of sepsis, improved prevention of infection, problems of loosening, new disease of bone lysis secondary to particulate debris, and the complexities of cementless fixation have taught orthopedic surgeons many lessons. These lessons include the following: (1) In cemented THA, bone cement can be made five-times stronger just by porosity reduction; the critical interface in a cemented femoral stem is the cement-metal interface, not the cement-bone interface; and no one has solved the long-term fixation problem in cemented sockets. (2) In cementless implants, the disuse osteoporosis that occurs around cementless femoral components can be severe; the use of cementless implants does not eliminate bone lysis; only small amounts of bone ingrowth occur in many cementless implants, particularly in revision cases; and little or no bone ingrowth occurs from grafts. Today, however, some of these lessons are ignored by surgeons. If progress is to be made in arthroplasty, these lessons from the past should be learned and warning signs of the present should be heeded.     

人工全髋关节置换术中髋臼骨缺损的重建

目的 探讨人工全髋关节置换术中各种髋臼骨缺损的特点与重建方法.方法 1998年5月至2008年8月对获得随访的行初次全髋关节置换或翻修的37例(37髋)髋臼缺损患者的临床资料进行回顾性分析,依据AAOS分型采取颗粒性或结构性植骨、生物或骨水泥髋臼假体以及钛网或加强环置入等方法对骨缺损进行重建.术前Harris评分(42±8)分.术后采用Harris评分判断髋关节的功能改善情况,复查X线片了解移植骨愈合及假体在位情况.结果 AAOS Ⅰ型9例,Ⅱ型13例,Ⅲ型15例.颗粒性植骨24例,结构性植骨6例,混合性植骨7例;生物型假体21例,骨水泥型假体16例.平均随访时间53.7个月.术后Harris评分(87±5)分,与术前比较,差异具有统计学意义(P<0.05).移植骨在最后一次复查时均已愈合或基本愈合.结论 对于AAOS Ⅰ型、Ⅱ型等简单的髋臼骨缺损,颗粒性或结构性植骨结合生物型髋臼假体就可以获得很好的初始稳定性,而对于AAOSⅢ型等较严重的缺损,则应行结构性植骨或附加钛网及加强环等重建髋臼.其短、中期疗效是令人满意的.     

Fat embolism associated with cementing of femoral stems designed for press-fit application

The authors report four cases of fat embolism syndrome following total hip arthroplasty using cementless acetabular press-fit components and cemented press-fit femoral components. Factors implicated in the production of this syndrome following "hybrid" total hip arthroplasty include increased canal pressure during femoral reaming and prosthetic insertion, retained marrow elements and reaming debris, and the use of lumbar epidural anesthesia. This potentially fatal syndrome must be a recognized complication following the use of cemented press-fit femoral stems. Specific recommendations for decreasing the incidence of this complication are reviewed.     

In vivo implant fixation of carbon fiber‐reinforced PEEK hip prostheses in an ovine model

Carbon fiber‐reinforced polyetheretherketone (CFR/PEEK) is theoretically suitable as a material for use in hip prostheses, offering excellent biocompatibility, mechanical properties, and the absence of metal ions. To evaluate in vivo fixation methods of CFR/PEEK hip prostheses in bone, we examined radiographic and histological results for cementless or cemented CFR/PEEK hip prostheses in an ovine model with implantation up to 52 weeks. CFR/PEEK cups and stems with rough‐textured surfaces plus hydroxyapatite (HA) coatings for cementless fixation and CFR/PEEK cups and stems without HA coating for cement fixation were manufactured based on ovine computed tomography (CT) data. Unilateral total hip arthroplasty was performed using cementless or cemented CFR/PEEK hip prostheses. Five cementless cups and stems and six cemented cups and stems were evaluated. On the femoral side, all cementless stems demonstrated bony ongrowth fixation and all cemented stems demonstrated stable fixation without any gaps at both the bone‐cement and cement‐stem interfaces. All cementless cases and four of the six cemented cases showed minimal stress shielding. On the acetabular side, two of the five cementless cups demonstrated bony ongrowth fixation. Our results suggest that both cementless and cemented CFR/PEEK stems work well for fixation. Cup fixation may be difficult for both cementless and cemented types in this ovine model, but bone ongrowth fixation on the cup was first seen in two cementless cases. Cementless fixation can be achieved using HA‐coated CFR/PEEK implants, even under load‐bearing conditions. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 485–492, 2013     

Mechanical characteristics of the bone-graft-cement interface after impaction allografting.

Impaction allografting is an attractive procedure for the treatment of failed total hip replacements. The graft-cement-host bone interface after impaction allografting has not been characterized, although it is a potential site of subsidence for this type of revision total hip reconstruction. In six human cadaveric femurs, the cancellous bone was removed proximally and local diaphyseal lytic defects were simulated. After the impaction grafting procedure, the specimens were sectioned in 6 mm transverse sections and push-out tests were performed. From the adjacent sections the percentage cement contact of the PMMA cement with the endosteal bone surface was determined. The host bone interface mechanical properties varied significantly along the femur largely due to different interface morphologies. The apparent host bone interface shear strength was highest around the lesser trochanter and lowest around the tip of the stem. A significant positive correlation was found between the percentage cement contact and the apparent host bone interface shear strength (r2 = 0.52). The sections failed in 69% of the cases through a pure host bone interface failure without cement or allograft failure, 19% failed with local cement failure, and 12% with a local allograft failure. The apparent host bone interface strength was on average 89% lower than values reported for primary total hip replacements and were similar to cemented revisions proximally and lower distally. This study showed that cement penetration to the endosteal surface enhanced the host bone-graft interface.     

Radiographic study of bone resorption at the proximal end of the femur after total hip replacements

Radiography following cemented total hip replacement (THR) often revealed progressive bone resorption at the proximal end of the femur. The purpose of this study is to clarify the relation between this bone resorption and loosening of the acetabular component. The radiographic analysis was done using radiographs of two hundred and ninety-nine Müller type THR for osteoarthritis with minimum five years follow-up at regular intervals. The bone resorption at the proximal end of the femur appeared frequently in cases of loosened acetabular component. As acetabular loosening progressed, the bone resorption increased accordingly. Further study revealed that incidences of loosened acetabular component were statistically higher in cases of progressive bone resorption than in cases of non-progressive, 5.2 years after operation. This study indicates that progressive bone resorption might be a histological reaction caused by debris of pulverized bone cement generated by loosening acetabular component. The degree to which bone resorption progresses, therefore, directly reflects the amount of loosening of the acetabular component and should be a indicator for surgery to reconstruct loosened acetabular component.     

Mid-Term Study of Bone Remodeling After Femoral Cemented Stem Implantation: Comparison Between DXA and Finite Element Simulation

This five-year prospective study was designed to investigate periprosthetic bone remodeling associated with two cemented stem models, ABG-II (Stryker) and VerSys (Zimmer), randomly implanted in patients older than 75 years. The sample consisted of 64 cases (32, ABG-II; 32, VerSys). Inclusion criterion was diagnosis of osteoarthritis recommended for cemented total hip arthroplasty. Besides clinical study, Finite Element (FE) simulation was used to analyze biomechanical changes caused by hip arthroplasty. Bone Mineral Density (BMD) measurements showed a progressive increase in bone mass throughout the entire follow-up period for both stems, well correlated with FE results except in Gruen zones 4, 5, 6 for ABG-II and in zones 4, 5 for VerSys, denoting that remodeling in those zones does not depend on mechanical factors but rather on biological or physiological ones.     

Size of metallic and polyethylene debris particles in failed cemented total hip replacements.

Reports of differing failure rates of total hip prostheses made of various metals prompted us to measure the size of metallic and polyethylene particulate debris around failed cemented arthroplasties. We used an isolation method, in which metallic debris was extracted from the tissues, and a non-isolation method of routine preparation for light and electron microscopy. Specimens were taken from 30 cases in which the femoral component was of titanium alloy (10), cobalt-chrome alloy (10), or stainless steel (10). The mean size of metallic particles with the isolation method was 0.8 to 1.0 microns by 1.5 to 1.8 microns. The non-isolation method gave a significantly smaller mean size of 0.3 to 0.4 microns by 0.6 to 0.7 microns. For each technique the particle sizes of the three metals were similar. The mean size of polyethylene particles was 2 to 4 microns by 8 to 13 microns. They were larger in tissue retrieved from failed titanium-alloy implants than from cobalt-chrome and stainless-steel implants. Our results suggest that factors other than the size of the metal particles, such as the constituents of the alloy, and the amount and speed of generation of debris, may be more important in the failure of hip replacements.     

Analysis of long-term cemented total hip arthroplasty retrievals

A detailed biomechanical, histologic, and histomorphometric analysis of autopsy specimens from patients who previously had cemented total hip arthroplasty has helped to elucidate the skeletal response to cemented components. Bone cement has the capacity to provide long-term implant stability. The biologic response to polyethylene wear debris has a more critical effect on destabilization of cemented sockets compared with the femoral side. In contrast, mechanical events tended to predominate the early mode of destabilization of cemented femoral components with debonding at the metal-cement interface and fracture in the cement. Fractures predominate in cement mantles less than 1 mm thick and are associated with mantle defects, debonded interfaces, and sharp corners of the implants. Correlation of the histologic findings at the cement-bone interface with radiolucencies seen on clinical radiographs show that on the acetabular side radiolucencies represent a soft tissue membrane that is the biologic response to polyethylene debris. In contrast, on the femoral side, most radiolucencies were as a result of skeletal remodeling. Femoral adaptive bone remodeling is a diffuse process that occurs over the entire fixation surface. The most profound disuse osteoporosis occurred proximally in the proximal medial quadrant; however, when one takes into account all four quadrants, anterior, posterior, medial, and lateral, the most severe osteoporosis occurred at the midpoint of the stem.     

THA翻修术中髋臼骨缺损的处理策略

目的探讨全髋关节置换术（THA）翻修术中髋臼骨缺损重建的方法及疗效。方法回顾1999年6月至2007年5月,在THA翻修术中处理的髋臼骨缺损112例（117髋）。根据Saleh KJ的改良分型法,Ⅰ型缺损14髋、Ⅱ型缺损26髋、Ⅲ型缺损47髋、Ⅵ型缺损16髋、Ⅴ型缺损14髋。分别采用大直径非骨水泥假体臼、非骨水泥假体臼＋松质颗粒植骨、骨水泥假体臼＋Cage＋松质颗粒植骨和骨水泥假体臼＋定制型假体＋松质颗粒植骨,对不同类型骨缺损进行修复。术后定期随访,采用Harris方法评估髋关节功能,根据X线片判断假体是否有松动,移植骨是否愈合。结果随访时间平均45（13～118）个月。除4髋因脱位或假体周围骨折进行再翻修外,其余效果良好。术后Harris评分平均86.2分,较术前平均改善40.6分。X线片无假体松动下沉,可见移植骨-宿主骨交界处有连续性小梁骨通过。结论在THA翻修术中,大部分髋臼骨缺损可使用较大型号非骨水泥假体或加松质颗粒植骨进行修复;对于影响假体稳定性的较大缺损,使用骨水泥假体臼＋Cage＋松质颗粒植骨的方法可获得良好效果;定制型假体在处理严重髋臼骨缺损中有具独特优势,有良好的临床应用前景。     

Failure of total hip arthroplasty with Boneloc bone cement

Early failure of Boneloc cemented total hip arthroplasty is well documented. However, information regarding the long term prognosis is scanty. The aim of this study was therefore to assess the long term failure rate of total hip replacement with Boneloc bone cement. Between January 1991 and March 1992, Boneloc bone cement (Polymers Recontructive A/S, Farum, Denmark) was used in 42 consecutive total hip replacements in 42 patients. The average age of the patients was 75 years. There were 25 women and 17 men. The diagnosis at operation was osteoarthritis in all cases. A cemented Muller Taperloc femoral stem was used with a cemented Muller acetabular cup (Biomet, Warsaw, USA). The follow-up time was 9 years. All patients underwent radiographic control the first postoperative year and annually after 1995. To date 21 patients have been revised for aseptic loosening at a mean of 5 years (range: one year to 8 years). Three other patients have definite radiographic evidence of loosening. The overall failure rate is therefore 24/42 = 57%. Our results confirm the previously reported poor results of Boneloc bone cement for hip arthroplasty and support the recommendation of indefinite follow-up for surviving prostheses. New prosthesis designs and new cements should have documentation, including laboratory tests and randomized clinical studies with radiostereometric evaluation. However, the ethical responsibility rests heavily on the shoulders of the clinician to make a correct analysis of the need for a new product before he begins to use it.     

松动人工髋关节周围组织中聚乙烯磨损颗粒观察

为探讨聚乙烯磨损及其与人工髋关节松动的关系,作者对６例因人工髋关节臼侧假体松动而行翻修术病例的假体周围软组织、软组织中聚乙烯碎屑及臼杯内表面进行了肉眼、偏光交易及扫描电镜观察,分析了聚乙烯内杯员颗粒的产生机制及其在假体周围纤维膜形成、假体松动发生过程中的意义。研究结果显示,假体松动时,在聚乙烯内杯磨损式中,夹有第三体粒（如骨块、骨水泥或金属碎屑）的二个负重面磨擦（三体磨损）占有主要地位。表现为表面