Ten-year results of cemented Weller-type total hip arthroplasties

The first 100 consecutive cemented Weller-type total hip arthroplasties carried out between 1976 and 1977 were reexamined. Clinical analysis of 43 implants with more than 10 years follow-up showed that results were excellent in 21 patients (49%), good in 13 (30%), fair in 7 (16%) and poor in 2 (5%). Radiographic analysis revealed 33 (87%) stable femoral and 31 (81%) stable acetabular components. Statistical survivorship analysis of all 100 implants produced a probability of reoperation of 6.2%, a probability of radiographic implant loosening of 28.2% and a probability of radiographic loosening with clinical symptoms of 7.6%. The definition of failure should be radiographic loosening of the prosthesis with clinical symptoms because this evaluation seems to have the best clinical relevance. Concerning the fact that the cement fixation was not performed to today's standard, the results after more than 10 years with this total hip system (Weller long stem) are sufficient.     

The relative cost of cemented and uncemented total hip arthroplasties

The use of uncemented femoral stems in primary total hip arthroplasty (THA) has been slow to develop in the UK because of the lack of encouraging published long-term follow-up data, the continued success of the cemented primary THA, and the perceived excessive relative cost of the uncemented THA. In this article, we argue that the total costs of 3 "proven" uncemented stems are comparable with commonly used cemented femoral components, when all necessary materials are taken into consideration. In addition, we will also discuss other potential benefits and drawbacks for considering the use of uncemented stems.     

Long-term clinical results of cemented revision of primary cemented total hip arthroplasties

Seventy-six patients who had undergone revision of a cemented total hip replacement were reviewed with an average follow-up of almost ten years. The average age at primary total hip replacement (PTHR) was 63.3 years. The average time between primary total hip replacement and revision was 62.5 months. Revision surgery was performed without using special techniques such as acetabulum reconstruction or femoral bone grafting. We evaluated patients pre- and postoperatively using the Merle d'Aubigné-Postel(M d'A) hip score. Clinically we observed an improvement of the hip score after total hip revision, particularly regarding pain. Thirty hips required a second, and six a third revision. If re-revision is used as an end-point, our results are unsatisfactory, as we had a cumulative failure rate of 54% after 12 years. This is mainly due to not using special techniques adapted to revision situations.     

Comparison of cemented and cementless total hip arthroplasty in patients with bilateral hip arthroplasties

A consecutive series of 36 patients underwent primary cemented total hip arthroplasty followed by primary cementless total hip arthroplasty of the contralateral hip. Clinical pain scores between the cementless and cemented hips were not different. Subjectively, patients either had no preference or preferred the cementless side. Comparison of results in the same patient eliminates variability introduced by differences in sex, weight, comorbidities, bone quality, and activity level. Control of these factors permits more meaningful comparison of the type of fixation.     

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     

Metallic debris in femoral endosteolysis in failed cemented total hip arthroplasties.

A prospective study was undertaken to quantitate metallic and cement debris in 12 consecutive patients with femoral endosteolysis (FE) and aseptic loosening of a cemented total hip arthroplasty. The mean interval between primary and revision surgery was 9.6 years. The average time to onset of FE was 8.9 years. There were four stems each of cobalt-chromium (Co-Cr), stainless steel (SS), and titanium alloy. At revision, tissue was retrieved from FE, the femoral bone-cement pseudomembrane, and the joint pseudocapsule. Histology of these tissues was studied using light and polarized microscopy. Metal and barium levels were measured by atomic absorption spectrophotometry. A histiocytic reaction and particulate cement debris were seen in every case. Polyethylene wear debris was noted in 11 of 12 cases (92%), and metallic debris in four cases (33%). Detectable metal levels were found in the FE in all cases. Metal levels were on average 2.5 times higher in FE than in femoral pseudomembrane, and 4.2 times higher than in joint pseudocapsule. This difference was statistically significant for the Co-Cr and SS groups. Barium levels in areas of FE were on average 1.7 times and 42.4 times higher than in femoral pseudomembrane and joint pseudocapsule, respectively. The difference seen between the FE and the joint pseudocapsule tissue was significant for all three alloy groups. The authors' data demonstrated higher metal and barium levels in FE than in the other tissue sites. Polyethylene and cement debris were noted in nearly every case. Cement, polyethylene, and metallic particulate wear debris may contribute to the pathogenesis and progression of FE.     

Autopsy studies of the bone-cement interface in well-fixed cemented total hip arthroplasties

Although knowledge of the clinical status of the implant is important, only instrumented mechanical testing of retrieved specimens provides quantitative assessment of implant fixation. This measurement allows placement of the implant along a continuum of loosening and is the foundation for the interpretation of subsequent findings. Analysis of implants that have been proven to be well fixed by instrumented testing reveals significant differences in the initial events in the loosening of femoral and acetabular components. Although radiolucencies were observed around all of these well-fixed femoral and acetabular components, the histology (and therefore the etiology) of the radiolucency is different and variable on the two sides of the articulation. The majority of femoral radiolucencies appear to be due to age and stress-related remodeling while particulate-induced bone resorption plays an important role in acetabular radiolucencies. A finding common to both sides of the articulation in these stable components, however, was intimate contact of bone with cement without any interposed soft tissue even after 17.5 years of service. Primary incompatibility and/or failure of the cement was not identified as a factor in initiating either femoral or acetabular component loosening. These studies document the long-term compatibility of bone with cement in bulk form. Improvements in cemented femoral component fixation should focus on stem design and cementing technique. Long-term acetabular component fixation can be improved by reduction or elimination of polyethylene wear and optimization of the bone-implant interface.     

Deep infection of cemented total hip arthroplasties caused by coagulase-negative staphylococci

We reviewed a series of 91 patients with deep infection of a cemented total hip arthroplasty caused by coagulase-negative staphylococci (C-NS). Of these, 72 were treated by one-stage exchange arthroplasty with a failure rate of 13% due to recurrence of infection. The other 19 patients have started or completed treatment by a two-stage exchange without failure to date. In 27 of the 91 patients multiple strains of C-NS were discovered, many being resistant to previously used antibiotics. The use of gentamicin-containing cement in the primary arthroplasty was significantly associated with the emergence of gentamicin-resistant C-NS in subsequent deep infection. Bacteriological diagnosis of such infections must take into consideration the possibility that multiple strains of the organism are involved.     

Inter- and intraobserver study of radiographic assessment of cemented total hip arthroplasties

Radiographs are commonly used to identify loosened total hip prostheses. Interobserver and intraobserver variation was studied in an attempt to interpret 60 random pairs of radiographs with a time interval of 6 months to 12 years between the radiographs. Each of the four observers evaluated all pairs of radiographs independently, and the evaluations were repeated after 2 to 4 weeks. Each observer classified the femoral stem and the acetabular cup separately as stable or loose. Radiolucent lines of more than 2 mm were recorded. For the acetabular components, any change in inclination or migration was noted, and for the femoral components, subsidence or any change in varus or valgus of the stem was noted. There was considerable disagreement in observations of the acetabular component; agreement by all four observers was obtained in only 34 of 60 cases (57%). For the femoral component, agreement was obtained in 37 cases (62%). The observers agreed two and two (pairwise) on the acetabular component in 70 to 83% of cases and on the femoral component, in 72 to 82% of cases. Intraobserver variation was great with regard to the acetabular component, with kappa values ranging from 0.489 to 0.633. As to the femoral component, kappa values ranged from 0.737 to 0.800. Interpretation of radiographs of artificial hip arthroplasty is difficult, and comparisons between different series of implants should be made by the same person.     

Radiological factors influencing femoral and acetabular failure in cemented Charnley total hip arthroplasties

We have made a retrospective review of 185 cemented Charnley total hip arthroplasties performed between 1970 and 1974 to determine the relationships between radiological variables and failure of the femoral and acetabular components. We measured the acetabular wear, the orientation of the cup, the thickness and consistency of acetabular and femoral cement mantles, radiolucency and femoral alignment. The mean follow-up was for 11.7 years. Femoral loosening was demonstrable radiologically in 15 hips (8.1%), ten (5.4%) of which were revised during the period of follow-up. Only when the first postoperative radiograph showed a thin cement mantle in Gruen zone 5 was there a significant association with failure of the femoral component. There were 12 loose acetabular components (6.5%), nine (4.8%) of which were revised. When the initial radiograph after operation showed radiolucency in DeLee and Charnley zone 1, the incidence of acetabular loosening was 28.21%. If such radiolucency was not present, the incidence of acetabular loosening was only 0.69%. Our findings emphasise the importance of careful cementing.     

Radiographic analysis of a bone plug in 275 primary cemented total hip arthroplasties

Various designs of cement restrictors for total hip arthroplasty have shown a variability in resistance to intramedullary pressure and migration. The performance of a conical bone plug was studied in 275 cemented total hip arthroplasties with a followup between 5 and 19 years. In a radiographic analysis the relation between the plug position and the cement mantle quality was investigated. The results were compared to the performance of other cement restrictors as reported in the literature. Good to excellent cement mantles were observed in 80% of the femurs. A significant correlation between the stability of the plug and the quality of the cement mantle was found. Forty-nine percent of the plugs were within 1 to 3 centimetres of the Exeter stem hollow centraliser. We also demonstrated that bone plugs performed almost always better than polyethylene or gelatine restrictors reported in other studies.     

Cementless revisions of failed aseptic cemented and cementless total hip arthroplasties. 284 cases

Over the past 13 years, 284 revisions of aseptic total hip arthroplasty failures have been performed with cementless implants. There were 213 cases involving cemented implant failures and 71 involving cementless ones. Considered as salvage procedures, these revisions provided a satisfactory result in about 70% of the reviewed patients after five years. A biologic fixation by bony ingrowth can be expected under certain conditions from decorticated living bone, a tight mechanical fitting, and a retentive corrugated surface of the implant. A prosthetic reimplantation, safely done without cement, appears more economical for the bone stock and prevents the long-term complications related with cement. Bone grafts are often required but cannot ensure the incoming osteogenic fixation of the implant. Long-term results and complications mandate harmless extractability of the revisional implant, a forged stem, an easy exchange of the plastic liner (in a two-part acetabular component), and an updated low-friction system (high-density polyethylene wear being a potential long-term problem).     

Radiographic performance of two different total hip cemented arthroplasties. A survivorship analysis

Detailed serial radiographic analysis of the femoral and acetabular components of 367 Charnley (cobalt-chrome alloy) and 383 STH (titanium alloy) primary cemented total hip prostheses was conducted. The follow-up of the Charnley prosthesis ranged from 1 to 16 years (mean follow-up, 9 years), and for the STH from 1 to 11 years (mean follow-up, 80 months). Both single period and survivorship analyses were done to evaluate the radiographic performance. The analysis revealed that the curved STH prostheses' overall radiographic performance was less satisfactory than the Charnley prostheses. However, the STH with a straight stem had significantly better radiographic performance compared with the Charnley prostheses in all parameters except in the incidence of bone-cement radiolucent lines.     

Histologic analysis of the periprosthetic tissues of long-term surviving cemented total hip arthroplasties

Qualitative and semiquantitative features of the interfacial membranes of five long-term (> 16 years) surviving cemented total hip arthroplasties (four revision cases and one autopsy case) were compared with those of thirty short-term surviving (< 15 years) cemented hip prostheses. Cement granulomas, micron-sized polyethylene particles-induced giant-celled granulomas, sheets of submicron-sized polyethylene particles-laden macrophages, and aggregated, metallic particles-laden macrophages were scattered in the fibrous tissue of all interfacial membranes. Quantitatively, characteristics of the interfacial membranes of the two groups differed from one another. The dominant species of prosthetic debris in the interfacial membranes of the short-term surviving joint replacements was derived from the polyethylene acetabular socket, and, correspondingly, giant-celled granulomas and macrophagic sheets predominated. Metallic particles and the macrophagic reaction thereto dominated in the interfacial membranes of the long-term surviving arthroplasties, and large cement and polyethylene chunks typically were incorporated in the fibrous tissue of the membranes without an accompanying macrophagic response. In long-term surviving hip arthroplasties, metallic particles may be at least as important as polymeric detritus in stimulating the formation of the bone-resorbing, granulomatous interfacial membrane, which is the hallmark of aseptically loosened arthroplasties. Differences in mechanical settings may account for unlike modes and rates of generation of prosthetic breakdown products, explaining the disparate survivorship of different patients' artificial joints.     

Short to long term outcomes of 154 cemented total hip arthroplasties in ankylosing spondylitis

BackgroundLong-term outcome of Total Hip arthroplasty (THA) in Ankylosing Spondylitis (AS) remains unreported. Literature suggests a higher overall failure rate in ankylosing spondylitis as compared to osteoarthritis. Concern has been expressed regarding joint survival, given that recipients are generally young. The results of cemented THA in patients with ankylosing spondylitis were studied to determine the utility of THA for these patients.MethodsConsecutive series of 96 patients (77 males (80%) and 19 females (20%)) with ankylosing spondylitis who underwent 154 cemented THAs at a tertiary referral orthopaedic centre between January 1990–September 2015 were retrospectively analyzed for clinical and radiological outcomes; 58 patients (60.4%) underwent bilateral surgery.ResultsMean age at surgery was 48 years. Average follow up was 12.8 (2.1–24.8) years. 95% of the patients had a good or excellent post-operative outcome.Out of the total 154 hips operated on, 11% (17 hips) developed post-operative complications. Overall, 15 hips (9.7%) required a revision of the procedure, with the most common indication being aseptic loosening of the acetabulum. Average time to revision was 8.5 years (2–15). Survivorship analysis revealed probability of survival of both components at the end of 10 years, with revision due to any reason as the end point to be 92% (with 95% confidence intervals).21 hips (14%) developed heterotopic ossification post-operatively, of which 4 patients (2%) had clinically significant ossification (Brooker III or IV).ConclusionThis is one of the largest series of patients with ankylosing spondylitis with long term follow up available. Cemented THA in patients with ankylosing spondylitis provided consistently good and predictable long term results, with low rate of complications and revisions.     

Long-term survival of the T-28 versus the TR-28 cemented total hip arthroplasties

Between 1974 and 1980, 550 total hip arthroplasties (THAs) (479 patients) were performed using T-28 and TR-28 cemented prostheses (TR-28 is shot-blast chrome and T-28 is polished stainless steel). There were 379 cemented THAs in 321 patients in the T-28 group and 171 cemented THAs in 158 patients in the TR-28 group. Average follow-up of the patients still alive at the end of the study was 20.96 years in the T-28 group and 17.54 years in the TR-28 group. When considering failure as revision of the hip for aseptic acetabular loosening, there were 36 (9.5%) failures in the T-28 group and 12 (7%) failures in the TR-28 group. This difference was statistically significant (P = .0132). When considering failure as radiographic acetabular loosening with or without radiographic femoral loosening, there were 52 failed acetabula (13.7%) in the T-28 group and 18 failed acetabula (10.5%) in the TR-28 group. These differences were not statistically significant. When considering failure as revision for aseptic femoral loosening with or without acetabular component loosening, there were 42 failures (11.1%) in the T-28 group and 22 failures (12.8%) in the TR-28 group. This difference was not statistically significant. When considering failure as radiographic femoral loosening with or without acetabular component loosening, there were 42 failures (11.1%) in the T-28 group and 27 failures (15.8%) in the TR-28 group. This difference was statistically significant for log-rank test (P = .0318) and Wilcoxon's test (P = .0083). Surface finish may be an important contributor to the survival of cemented femoral stems.     

Localised endosteal bone lysis in relation to the femoral components of cemented total hip arthroplasties

Four cases are described of localised endosteal bone lysis in the femur occurring in association with cemented femoral components that were not obviously 'loose' radiologically. In each, the area of lysis was shown at operation to be related directly to a region in which there was a local defect in the cement mantle surrounding the stem. Via the space between the stem and cement, such defects provide a route through which the contents of the joint cavity may reach the endosteal surface of the femur, subsequently leading to localised bone lysis, and later to frank loosening.