Highly crosslinked polyethylene (XLPE) was introduced to decrease
Aims: Given that all previous reports on the increased-crystalinity, increased modulus of elasticity, yield strength and density Hylamer polyethylene have been based on observations on uncemented metal-backed acetabular cups, the aim of the present study is to investigate the rate of wear of a cemented Hylamer UHMWPE acetabular cup. Methods: 36 consecutive cases of THA (mean age: 54.7 years) using a cemented Hylamer UHMWPE acetabular cup and a cemented femoral stem were prospectively followed-up with yearly radiographs for an average period of 54.4 months. Two-dimensional femoral head penetration was determined from AP pelvic radiographs, using computeraided uniradiographic methodology. Multiple regression analysis was used to identify all predictor variables that may account for increased average linear and calculated volumetric wear (Kabo’s formula), as well as for increased total area of
Introduction: Electron beam irradiated highly cros-slinked polyethylene has been used in total hip arthroplasty for over 8 years. Due to its low wear characteristics, the use of femoral heads that are greater than 32mm in diameter is now available, allowing for an increase in range of motion and increased stability against dislocation when necessary. The purpose of this study is to provide a summary report on the radiographic analysis of the longest term data available on primary THR patients receiving highly cross-linked polyethylene and to compare the results of two methods of measuring femoral head penetration. Methods: Three prospective clinical studies involving electron beam irradiated highly cross-linked polyethylene have been initiated at our center. To date, the results of: 200 hips with a minimum of 6 year follow-up with conventional sized femoral heads (primarily 28 and 32mm); 45 hips with minimum 5 year follow-up with larger sized femoral heads (primarily 36 and 38mm); and 30 hips with 5 year follow-up enrolled in a Radiostereometric analysis (RSA) study (15 patients with 28mm and 15 patients with 36mm diameter femoral heads); were available for this summary report. Data from patient administered questionnaires (Harris Hip score, UCLA activity score, and WOMAC), radiographic review, and wear analysis using RSA or the Martell Hip Analysis Suite™. In addition, for comparative purposes, wear was measured in a subset of patients using the Devane Polyware™ program. Results: All hips had good clinical outcome at longest follow-up regardless of which femoral head size was used. There were no revisions due to polyethylene wear and no evidence of
Introduction. The first highly crosslinked and melted polyethylene acetabular component for use in total hip arthroplasty was implanted in 1998. Numerous publications have reported reduced wear rates and a reduction in particle induced
The most frequent cause of failure after total
hip replacement in all reported arthroplasty registries is peri-prosthetic
osteolysis. Osteolysis is an active biological process initiated
in response to wear debris. The eventual response to this process
is the activation of macrophages and loss of bone. Activation of macrophages initiates a complex biological cascade
resulting in the final common pathway of an increase in osteolytic
activity. The biological initiators, mechanisms for and regulation
of this process are beginning to be understood. This article explores current
concepts in the causes of, and underlying biological mechanism resulting
in
INTRODUCTION. The hip arthroplasty implant is currently growing up both in orthopedic and trauma practice. This increases the frequency of prosthesis revision due to implant loosening often associated with periprosthetic osteolysis that determine the failure and lead to a loss of bone substance. Nowadays there are numerous biotechnologies seeking to join or substitute the autologous or omologous bone use. These biotechnologies (mesenchymal stromal cells, growth factors and bone substitutes) may be used in such situations, however, the literature doesn't offer class 1 clinical evidences in this field of application. MATERIALS AND METHODS. We performed a literature review using the universally validated search engines in the biomedical field: PubMed / Medline, Google Scholar, Scopus, EMBASE. The keywords used were: “Growth Factors”, “Platelet Rich Plasma”, “OP-1”, “BMP”, “BMP-2”, “BMP-7”, “Demineralized Bone Matrix”, “Stem Cell”, “Bone Marrow”, “Scaffold”, “Bone Substitutes” were crossed with “hip”, “revision”, “replacement” / “arthroplasty”, “bone loss” / “osteolysis.”. RESULTS. The search led to 321 items, of these were considered relevant: as regards the growth factors 21 articles related to in vivo animal studies and 2 articles of human clinical use of BMPs and 1 single article on the use of PRP; as regards the mesenchymal stromal cells 2 items of application in animals; as regards the use of bone substitutes we have analyzed a review of this application. DISCUSSION. The use of biotechnologies in hip prosthetic revisions has produced conflicting results: autologous growth factors (PRP) have definitely been proven effective in maxillofacial surgery, in animal studies the results of BMPs are inconsistent with articles that validate their use and others that don't recommend it. Clinical application has demonstrated, today, the limited use of BMP-7 in revisions with even an increased risk of early re-mobilization, PRP appears to be rather effective only in the early stages of
INTRODUCTION. The hip arthroplasty implant is currently growing up both in orthopedic and trauma practice. This increases the frequency of prosthesis revision due to implant loosening often associated with periprosthetic osteolysis that determine the failure and lead to a loss of bone substance. Nowadays there are numerous biotechnologies seeking to join or substitute the autologous or omologous bone use. These biotechnologies (mesenchymal stromal cells, growth factors and bone substitutes) may be used in such situations, however, the literature doesn't offer class 1 clinical evidences in this field of application. MATERIALS AND METHODS. We performed a literature review using the universally validated search engines in the biomedical field: PubMed / Medline, Google Scholar, Scopus, EMBASE. The keywords used were: “Growth Factors”, “Platelet Rich Plasma”, “OP-1”, “BMP”, “BMP-2”, “BMP-7”, “Demineralized Bone Matrix”, “Stem Cell”, “Bone Marrow”, “Scaffold”, “Bone Substitutes” were crossed with “hip”, “revision”, “replacement” / “arthroplasty”, “bone loss” / “osteolysis.”. RESULTS. The search led to 321 items, of these were considered relevant: as regards the growth factors 21 articles related to in vivo animal studies and 2 articles of human clinical use of BMPs and 1 single article on the use of PRP; as regards the mesenchymal stromal cells 2 items of application in animals; as regards the use of bone substitutes we have analyzed a review of this application. DISCUSSION. The use of biotechnologies in hip prosthetic revisions has produced conflicting results: autologous growth factors (PRP) have definitely been proven effective in maxillofacial surgery, in animal studies the results of BMPs are inconsistent with articles that validate their use and others that don't recommend it. Clinical application has demonstrated, today, the limited use of BMP-7 in revisions with even an increased risk of early re-mobilization, PRP appears to be rather effective only in the early stages of
Osteoclasts are cells that resorb bone. They derive from haemopoietic precursors in the presence of Macrophage-Colony Stimulating Factor (M-CSF) and the osteoclast growth factor, Receptor Activator of Nuclear Factor–kB Ligand (RANKL). Tumour Necrosis Factor-a (TNF-a) and M-CSF has been shown to form mature osteoclastic bone resorption in vitro murine cultures in the absence of RANKL. The aim of this study was to investigate the mechanism of action of the pro-inflammatory cytokine Tumour Necrosis Factor-a (TNF-a) with respect to osteoclastic bone resorption. Development of osteoclasts was performed using an in vitro assay of healthy human peripheral blood mononuclear culture (PBMNC) in the presence of M-CSF and RANKL. In the same cultures RANKL was replaced by TNF-a over a wide range of concentrations. Osteoclasts were generated in the presence of M-CSF, TNF-a and RANKL from human PBMNC. However, in the same experiments M-CSF and TNF-a in the absence of RANKL failed to support human osteoclast formation. Aseptic loosening and osteolysis are considered the main long-term complications of hip arthroplasty. Pathogenesis of
Background: This report presents the long term (over 20 years) experience with the use of a grit-blasted, press-fit femoral prosthesis. Methods: The first 300 consecutive primary THA procedures using a collarless, three-dimensional tapered, straight, titanium alloy stem with a grit-blasted surface (performed in 299 patients) were evaluated up to twentytwo years. A cementless all-polyethylene socket in 80 percent of the cases, were used. Radiographic evaluation, performed by an independent observer using a zonal analysis method, included assessment of component migration, Engh’s implant-bone femoral fixation score, implant-bone demarcations, and periprosthetic osteolysis. The average duration of long-term radiographic follow-up was 12.6 years (range; 10 to 16 years). Results: At last examination only five hips were lost to follow-up and 84 patients were deceased. The femoral revision rate was 7 percent (two hips for aseptic loosening, five hips for septic loosening, and twelve hips with osseointegrated stems for severe progressive femoral osteolysis) and the acetabular revision rate was 28% (revised for either socket migration or progressive peri-acetabular osteolysis or both). Survivorship, based on any revision (femoral or acetabular) was 89% at ten years and 65% at twenty years; survivorship of the femoral component was 95% at ten years and 89% at twenty years. The incidence of femoral periprosthetic osteolysis, was 47%, with 5% of distal endosteal osteolysis. Radiographic femoral implant-bone fixation was stable, bone-ongrowth in 97%; stable, fibrous-fixation in 1%. Conclusions: The grit-blasted, press-fit, collarless, tapered femoral component continued to perform well clinically and radiographically up to twenty years of follow-up despite the challenging environment of
INTRODUCTION. The advantages of large diameter metal on metal total hip arthroplasty (MoM THA) and hip resurfacing arthroplasty are decreased wear rate, preservation of bone stock, anatomical restoration and enhanced stability. Large amounts of metal wear particles and metal ions are released which may induce adverse reactions including local soft tissue toxicity, hypersensitivity reactions, bone loss and risk of carcinogenesis. Aseptic loosening can be the result of a
There is a renewed interest in unicompartmental knee arthroplasty. The present report describes the minimum ten-year results associated with a – unicompartmental knee arthroplasty design that is in current use. Sixty-two consecutive unicompartmental knee arthroplasties that were performed with cemented modular Miller-Galante implants in 51 patients were studied prospectively both clinically and radiographically. All patients had isolated unicompartmental disease without patellofemoral symptoms. No patient was lost to follow-up. Thirteen patients (13 knees) died after less than 10 years of follow-up, leaving 38 patients (49 knees) with a minimum of 10 years of follow-up. The average duration of follow-up was 12 years. The mean Hospital for Special Surgery knee score improved from 55 points preoperatively to 92 points at the time of the final follow-up. Thirty-nine knees (80%) had an excellent result, six (12%) had a good result, and four (8%) had a fair result. At the time of final follow-up, 39 knees (80%) had flexion to at least 120 degrees. Two patients (two knees) with well-fixed components underwent revision to total knee arthroplasty, at seven and 11 years, because of progression of patello-femoral arthritis. At the time of the final follow-up, no component was loose radiographically and there was no evidence of
Introduction:
Peri-prosthetic bone loss may contribute to aseptic loosening after THA. The aims of this randomised controlled trial extension study were to study the effect of pamidronate therapy on Peri-prosthetic bone mineral density (BMD) and
Introduction: By compromising bone structure,
Improved cement technique by interposing less than two layers of hydroxyapatite (HA) granules between bone and bone cement at the cementing (Interface Bio-active Bone Cement : IBBC) have been performed in total knee arthroplasty (TKA) since 1987. We performed IBBC technique in 153 knees (130 patients) in TKA from 1987 to 1993. One hundred and forty knees (120 patients) could be followed up clinically and radiologically. Follow up rate was 91.5%. A mean follow-up period was 9.5 years (6 to 13 years) after surgery. As a control, clinical results of TKA with conventional cementing (Non-IBBC) which were operated in 44 knees (44 patients) in 1986 were used. In IBBC cases, radiolucent lines on the tibial components were seen 7.1%, 2.9%, 1.4%, 3.6%, 0%, 0% and 0% at Zone ‡T to ‡Z of the anteroposterior view, while in Non-IBBC cases, 40.9%, 13.6%, 9.1%, 27.3%, 11.4%, 4.5% and 13.6% at Zone ‡T to ‡Z, respectively. In IBBC cases
Highly cross-linked polyethylene (HXLPE) is one of the most widely utilized bearing surfaces for total hip arthroplasty (THA). The first patients to receive XLPE will be 10 years post-op as of December 31, 2008. The purpose of this study is to report the long-term clinical and radiographic outcomes of patients implanted with HXLPE. A group of 247 primary total hip replacements (224 patients) using HXLPE liners (Longevity or Durasul, Zimmer Inc.) with 22, 26, 28, or 32mm femoral heads were implanted between 1999 and 2001. Clinical evaluation measures included the Harris hip, EQ-5D, SF-36 functional scores, and UCLA activity scores. In addition to plain radiograph assessment, the computerized Martell method was used to measure head penetration over time. A matched group of 241 primary total hip replacements (201 patients) with the same head sizes using conventional polyethylene (PE) with a minimum of 7 years follow-up was used as a Martell method control group. The steady state penetration rate was defined as the slope of the linear regression line of the plot of head penetration from the 1 year film to each subsequent film to discount the early bedding-in process. A student’s t-test was used to compare wear rates between head sizes in each group, and a repeated-measures mixed model ANOVA was used to compare the groups for the 28mm head size. There were no osteolytic lesions around the cup or stem, and no revisions were performed for polyethylene wear or liner fracture. Clinical outcome scores were averaged: Harris Hip 88.1±11.97, EQ-5D 74.0±27.0, SF-36 physical activity scores 53.3±8.4, SF-36 mental score 46.9±11.1, and UCLA activity 6.4±2.1. The steady state wear of the conventional polyethylene patients increased with time for both 26 and 28mm head sizes (0.144 and 0.127mm/year, respectively). No significant difference was found between the head sizes coupled with conventional polyethylene (p=0.14). Femoral head penetration in the highly cross-linked polyethylene did not increase over time after the first year. The steady state wear rates of HXLPE liners with 28mm or 32mm femoral heads were not significantly different than a slope of zero (p=0.54 for both head sizes). Clinical follow-up results are typical of a primary THR patient population, and the radiographic results are excellent with no signs of
Total knee arthroplasty (TKA) is a common and safe orthopaedic procedure. Zimmer Biomet's NexGen is the second most popular brand of implant used in the UK. The primary cause of revision after the first year is aseptic loosening. We present our experience of using this implant, with significant concerns around its performance with regards early aseptic loosening of the tibial component. A retrospective, single-surgeon review was carried out of all of the NexGen Legacy Posterior Stabilized (LPS) TKAs performed in this institute. The specific model used for the index procedures was the NexGen Complete Knee System (Legacy Knee-Posterior Stabilized LPS-Flex Articular Surface, LPS-Flex Femoral Component Option, and Stemmed Nonaugmentable Tibial Component Option).Aims
Methods
Introduction: Our group has previously reported on microarray gene expression profiling of failed aseptic and septic THRs. The data obtained from the Affymetrix DNA chips suggested a range of 21 differentially expressed genes between the tissue samples obtained from the control and study patients with failed aseptic THRs. The variation in expression that was demonstrated did not suggest that the basis of the local tissue reaction that occurs in aseptic loosening of THR is primarily inflammatory in nature. In order to validate these results we have performed quantitative real-time polymerase chain reaction (RT-PCR) to analyse the transcriptional levels of genes expression in the samples used in our original study and to formulate a hypothesis of how these candidate genes can be related to aseptic join loosening. Methods: 3 control and 6 aseptic samples of peri-prosthetic membrane were subjected to RNA extraction. RNA quality analysis and quantification were performed. SYBRâ Green I real time quantitative PCR (RT qPCR) assays were designed using Primer Express [Applied Biosystems] and BLAST searching the resulting sequences. The comparative method for quantitation of gene expression levels, which utilizes arithmetic formulas to give the similar results to those achieved with standard curves, was utilised to validate the cDNA microarray data. Results: We were able to devise successful quantitative real-time PCR for 15 of the 21 candidate genes plus the reference gene GAPDH. The genes coding for complement component C4B, Osteonectin , ATP2A2 (an ATPase linked to the regulation of adhesion, differentiation and proliferation in tissue that expresses this gene such as bone) and Phospholipase2A, were all found to be under-expressed whereas SLC2A5 (a solute carrier that can facilitate glucose/fructose transport)and NPC1 (intimately involved in cholesterol and glycolipid trafficking and inversely related to PLA2-mediated release of eicosanoids such as PGE2) were found to be over-expressed. Conclusions: The data from our gene expression and RT-PCR studies have suggested novel pathways that may be intimately involved in the development of
Aseptic loosening is generally associated with the presence of wear particle-associated macrophages in the pseudomembrane commonly formed around failed prosthetic implants. The extent of the macrophage response evoked by the wear particles has been shown to correlate with the amount of periprosthetic osteolysis. Numerous studies have shown that wear particle-associated macrophages contribute to osteolysis by (i) releasing inflammatory cytokines and/or (ii) differentiating into bone resorbing osteoclasts. Although macrophages and macrophage polykaryons are the main inflammatory cells found in periprosthetic tissues, numerous fibroblasts are also present in the connective tissue pseudomembrane. The recently identified molecule, RANKL has been shown to play a central role in the osteoclast formation and bone resorption observed in aseptic loosening. We have shown that arthroplasty macrophages, which express RANK, the receptor for RANKL, are capable of osteoclast differentiation; this process is inhibited by osteoprotegerin (OPG), the soluble decoy receptor for RANKL. As fibroblasts are known to express RANKL, the aim of the present study was to determine whether fibroblasts isolated from periprosthetic tissues could induce the generation of bone resorbing osteoclasts that would contribute to the osteolysis commonly seen in the periprosthetic loosening. Fibroblast-like cells were isolated from pseudomembrane from patients (n=5) undergoing hip revision due to aseptic loosening, by routine collagenase enzyme digestion. The isolated cells were seeded in flasks for 2–4 weeks before being passaged for a further 3–4 times. Generated fibroblast-like cells (10. 4. ) were then co-cultured with 5x10. 5. normal human peripheral blood monocytes (n=5) on glass coverslips and dentine slices in the presence of (i) no added factors, (ii) macrophage colony stimulating factor (M-CSF) and (iii) M-CSF plus OPG. All cultures were maintained for 1,17 and 21 days. The extent of osteoclast differentiation was then determined by the expression of specific osteoclast markers including tartrate-resistant acid phosphatase (TRAP) and vitronectin receptor (VNR) and evidence of lacunar resorption. In the absence M-CSF, no osteoclast formation was noted in 24 hours, 17 or 21 days in fibroblast/monocyte cultures. However, in the presence of M-CSF alone, large numbers of TRAP. +. and VNR. +. multinucleated cells capable of lacunar resorption were noted in these co-cultures. The addition of OPG, which is known to inhibit RANKL-mediated osteoclast formation, significantly reduced the extent of osteoclast formation and lacunar resorption in these co-cultures. These results indicate that one means whereby
The world-wide experience with metallic implants provides the evidence for biocompatibility of modern cobalt- and titanium-based alloys. However, a corrosion process leading to release of ions has to be taken into account, and controversial data are available about the ‘endogenous’ metal exposure resulting from implants. Adverse tissue reactions, cytotoxicity and toxic/ sensitizing effects of corrosion products on the immune system, as well as an involvement of metal ions in the pathogenesis of prosthesis loosening, are the main undesired effects. Moreover, metal ions could be responsible of long-term toxic effects, such as genotoxicity and carcinogenicity. The aim of our study was to analyze the levels of serum metal ions in a large series of patients who underwent total hip and knee replacement (THR and TKR, respectively); both stable and loosened implants were considered. Furthermore, a group of subjects with fracture fixation devices was evaluated. A consecutive series of 471 individuals (193 M; 278 F) was enrolled in the study, including 151 with hip prosthesis loosening (Group A: 52 M; 99 F; median age 67; median follow up 90 months) and 100 patients with stable hip prosthesis (Group B: 44 M; 56 F; median age 59; median follow up 34 months). Group A and B comprised implants with different coupling, i.e. ceramic-on-ceramic (alumina), metal-on-metal and metal-on-polyethylene, and different stem alloy (TiAlV-THR and CoCrMo-THR). 20 patients with knee prosthesis loosening (Group C: 3 M; 17 F; median age 67; median follow up 25 months), and 12 subjects with failed fracture fixation devices (Group D: 6 M; 6 F; median age 35; median follow up 12 months) were enrolled, too. Osteoarthritis was the most frequent disease that led to joint replacement (59%), followed by hip dysplasia (19%), and trauma (13%). Ion reference ranges were obtained from 188 subjects (88 M; 100 F; median age 52), including 56 healthy subjects and 132 candidates to primary THR or TKR. Serum samples were analyzed for chromium (Cr), cobalt (Co), molybdenum (Mo), nickel (Ni), aluminum (Al), titanium (Ti) and vanadium (V) content, in relation with the presence in the implant alloy, using a graphite furnace atomic absorption spectrometer (GFAAS), equipped with double background correction Deuterium/ Zeeman, autosampler and pyrolytic carbon-coated graphite tubes (Unica Solaar 939 QZ, Cambridge, UK). The highest value found for subjects with no implant was considered the upper reference limit for each element. Group A (loosened THR) and B (well-fixed THR) patients, compared with controls, showed different behaviour depending on the prosthesis coupling and stem composition. Metal-on-PE coupling and CoCrMo/Ni stem: a significant increase of Cr and Co serum values was observed, in both groups, even if the increase in loosened implants was higher than in the stable ones. Mo and Ni concentration did not show a significant variation. Ceramic-on-ceramic coupling: a high Cr release, and a high Al, Ti release was shown in loosened implants with CoCrMo stem, and TiAlV stem, respectively, whereas normal values were measured in patients with stable prostheses. Metal-on-metal coupling and CoCrMo stem: a significantly higher Co and Cr release, both in group A and B patients. The conspicuous corrosion rate in metal-on-metal implants, even if stable, was confirmed in the same population in the short- and medium-term. A serum Co, Cr increase was demonstrated in Group C patients, too, who had a failed knee prosthesis, and a Cr, Ni increase was observed in Group D patients with stainless steel fracture fixation devices. Metal corrosion leading to ion release needs further consideration, because it may enhance the inflammatory reaction, depress the immune system, and facilitate peri-prosthetic bacterial growth. Especially metal-on-metal coupling introduces additional biologic risks associated with increased degradation products of prosthetic materials. Otherwise, histiocytic/giant-cell reaction and
Purpose of the study: The ceramic-on-ceramic bearing for total hip arthroplasty (THA) has been widely used in Europe for many years. There have however been few publications on its long-term outcome. The purpose of this study was to examine the outcome at nine years follow-up of 100 THA implanted without cement using a ceramic-on-ceramic bearing. Material and methods: The first 100 ceramic-on-ceramic THA implanted from November 1999 in our unit in patients aged less than 65 years were studied. The clinical assessment included the physical examination with search for complications and the Harris and Postel-Merle-d’Aubigné scores noted preoperatively and at last follow-up. The radiographic assessment was performed by two surgeons (double reading) to search for
Periprosthetic osteolysis following total knee replacement is a well recognized intermediate to long term complication. Over the last four decades, the prevalence of osteolysis following total knee replacement has increased. Development of periprosthetic osteolysis after knee replacment surgery is related to three factors, generation of wear debris, access of that debris to bone, and the biologic reaction to the wear debris. Although more common in association with loose components, osteolysis can occur with stable cementless implants and less commonly stable cemented implants. Polyethylene particles have been isolated from tissue around failed total knee replacements. When compared to total hip replacements, polyethylene wear particles from knee replacesments are larger. However, the majority of particles are still less than one micron in size and are biologically active. Several important factors impact polyethylene wear. The polyethylene itself is one of the most important variables. Research over the past decade has demonstrated the importance of manufacturing technique, sterilization methods, packaging and shelf life on wear performance. It is now known that polyethylene sterilized with gamma radiation and stored in oxygen with a long shelf life is associated with higher prevalence of osteolysis. Oxidized polyethylene has a lower resistance to wear thus increasing the particle load. Modularity has been associated with a higher prevalence of osteolysis most likely because it can result in a higher particle load from backside wear. One study compared the prevalence of osteolysis with all polyethylene tibial components and modular tibial components. At comparable follow-up, none of the patients with all polyethylene tibial components developed osteolysis. In contrast, 18% of the patients with modular tibial base-plates developed
Total hip replacement (THR) still is a rare intervention
in many African countries. In Burkina Faso it is not performed on
a regular basis. A visiting programme for THR was started in a district
hospital with no previous relevant experience. In this paper we
present an analysis of the surgical technical problems and peri-operative
complications of 152 THRs in 136 patients and three bipolar hemiarthroplasties
in three patients undertaken in this new programme with limited
orthopaedic equipment. There were 86 male and 53 female patients
with a mean age of 49 years (21 to 78). We identified 77 intra-operative
technical problems in 51 operations. There were 24 peri-operative complications
in 21 patients, 17 of which were bony in nature. So far, ten revision
THRs have been performed in nine patients. Regular analysis of the technical problems and complications
was used to improve quality, and we identified patient selection
adapted to the local circumstances as important to avoid complications.
Our reflections on the problems encountered in initiating such a
programme may be of help to other teams planning similar projects. Cite this article:
Little is known about the long-term outcome of
mobile-bearing total ankle replacement (TAR) in the treatment of end-stage
arthritis of the ankle, and in particular for patients with inflammatory
joint disease. The aim of this study was to assess the minimum ten-year
outcome of TAR in this group of patients. We prospectively followed 76 patients (93 TARs) who underwent
surgery between 1988 and 1999. No patients were lost to follow-up.
At latest follow-up at a mean of 14.8 years (10.7 to 22.8), 30 patients
(39 TARs) had died and the original TAR remained Cite this article:
We compared the results of 146 patients who received an anatomic modular knee fixed-bearing total knee replacement (TKR) in one knee and a low contact stress rotating platform mobile-bearing TKR in the other. There were 138 women and eight men with a mean age of 69.8 years (42 to 80). The mean follow-up was 13.2 years (11.0 to 14.5). The patients were assessed clinically and radiologically using the rating systems of the Hospital for Special Surgery and the Knee Society at three months, six months, one year, and annually thereafter. The assessment scores of both rating systems pre-operatively and at the final review did not show any statistically significant differences between the two designs of implant. In the anatomic modular knee group, one knee was revised because of aseptic loosening of the tibial component and one because of infection. In addition, three knees were revised because of wear of the polyethylene tibial bearing. In the low contact stress group, two knees were revised because of instability requiring exchange of the polyethylene insert and one because of infection. The radiological analysis found no statistical difference in the incidence of radiolucent lines at the final review (Student’s We found no evidence of the superiority of one design over the other at long-term follow-up.
Peri-prosthetic bone loss caused by stress shielding may be associated with aseptic loosening of femoral components. In order to increase primary stability and to reduce stress shielding, a three-dimensional, cementless individual femoral (Evolution K) component was manufactured using pre-operative CT scans. Using dual energy x-ray absorptiometry, peri-prosthetic bone density was measured in 43 patients, three months, six months, 3.6 and 4.6 years after surgery. At final follow-up there was a significant reduction in mean bone density in the proximal Gruen zones of −30.3% (zone 7) and −22.8% (zone 1). The density in the other zones declined by a mean of between −4% and −16%. We conclude that the manufacture of a three-dimensional, custom-made femoral component could not prevent a reduction in peri-prosthetic bone density.
We investigated the incidence of soft-tissue
lesions after small head metal-on-metal total hip replacement (MoM THR).
Between December 1993 and May 1999, 149 patients (195 hips) underwent
primary cementless MoM THR. During the follow-up period, three patients (five THRs) died
and eight patients (14 THRs) were lost to follow-up. We requested
that all patients undergo CT evaluation. After exclusion of five
patients (six THRs) who had undergone a revision procedure, and
22 (28 THRs) who were unwilling to take part in this study, 111
patients (142 THRs) were evaluated. There were 63 men (88 THRs)
and 48 women (54 THRs) with a mean age of 45.7 years (37 to 56)
at the time of surgery. The mean follow-up was 15.4 years (13 to
19). A soft-tissue lesion was defined as an abnormal peri-prosthetic
collection of fluid, solid lesion or asymmetrical soft-tissue mass. At final follow-up, soft-tissue lesions were found in relation
to 28 THRs (19.7%), including 25 solid and three cystic lesions.
They were found in 20 men and eight women; 26 lesions were asymptomatic
and two were symptomatic. The mean maximal diameter of the soft-tissue
lesion was 42.3 mm (17 to 135). The relatively high rate of soft-tissue lesions
observed with small head MoM THR remains a concern. Cite this article:
We reviewed the long-term results at ten to 12 years of 118 total hip replacements in 109 patients using a second-generation hemispherical cementless acetabular component (Reflection) designed to address the problem of backside wear. Five patients (five hips) died and six patients (seven hips) were lost to follow-up. The remaining 98 patients (106 hips) had a mean age of 62.9 years (34.0 to 86.2) A rate of revision for aseptic loosening of 0.9%, and predictable results were found with respect to radiological evidence of fixation, lack of pain, walking ability, range of movement and function. One component was revised for aseptic loosening, and of the 101 hips (95.2%) that did not have a revision, minor osteolytic lesions of the pelvis were seen in six (5.9%). Kaplan-Meier survival analysis for the total cohort of 118 hips revealed a 96.4% survival at both ten (95% confidence interval 90 to 98) and 12 years (95% confidence interval 86 to 98).
We compared the clinical and radiographic results
of total ankle replacement (TAR) performed in non-diabetic and diabetic
patients. We identified 173 patients who underwent unilateral TAR
between 2004 and 2011 with a minimum of two years’ follow-up. There
were 88 male (50.9%) and 85 female (49.1%) patients with a mean
age of 66 years ( The mean AOS and AOFAS scores were significantly better in the
non-diabetic group (p = 0.018 and p = 0.038, respectively). In all,
nine TARs (21%) in the diabetic group had clinical failure at a
mean follow-up of five years (24 to 109), which was significantly
higher than the rate of failure of 15 (11.6%) in the non-diabetic
group (p = 0.004). The uncontrolled diabetic subgroup had a significantly
poorer outcome than the non-diabetic group (p = 0.02), and a higher
rate of delayed wound healing. The incidence of early-onset osteolysis was higher in the diabetic
group than in the non-diabetic group (p = 0.02). These results suggest
that diabetes mellitus, especially with poor glycaemic control,
negatively affects the short- to mid-term outcome after TAR. Cite this article:
Pre-operative planning for total hip replacement
(THR) is challenging in hips with severe acetabular deformities, including
those with a hypoplastic acetabulum or severe defects and in the
presence of arthrodesis or ankylosis. We evaluated whether a Rapid
Prototype (RP) model, which is a life-sized reproduction based on
three-dimensional CT scans, can determine the feasibility of THR
and provide information about the size and position of the acetabular component
in severe acetabular deformities. THR was planned using an RP model
in 21 complex hips in five men (five hips) and 16 women (16 hips)
with a mean age of 47.7 years (24 to 70) at operation. An acetabular
component was implanted successfully and THR completed in all hips.
The acetabular component used was within 2 mm of the predicted size
in 17 hips (80.9%). All of the acetabular components and femoral
stems had radiological evidence of bone ingrowth and stability at
the final follow-up, without any detectable wear or peri-prosthetic
osteolysis. The RP model allowed a simulated procedure pre-operatively
and was helpful in determining the feasibility of THR pre-operatively,
and to decide on implant type, size and position in complex THRs. Cite this article:
Bisphosphonates reduce peri-prosthetic bone loss in the short term after total hip replacement but the mid- and longer term effects are not known. The aims of this randomised trial were to examine the effect of a single dose of 90 mg of pamidronate on the clinical and radiological outcome and peri-prosthetic bone mineral density in 50 patients (56 hips) over a five-year period, following total hip replacement. At five years, 37 patients (42 hips) returned for assessment. The Harris hip scores were similar in the pamidronate and placebo groups throughout the study. Also at five years, four patients, two from each group had osteolytic lesions on plain radiography. These were located around the acetabular component in three patients and in the femoral calcar in one. The femoral and acetabular peri-prosthetic bone mineral density in the pamidronate group and the control group was similar at five years. Pamidronate given as a single post-operative dose does not appear to influence the clinical outcome or prevent the development of osteolytic lesions at five years after total hip replacement.
We retrospectively reviewed 30 two-stage revision
procedures in 28 patients performed for fungal peri-prosthetic joint
infection (PJI) after a primary total knee replacement. Patients were
followed for at least two years or until the infection recurred.
The mean follow-up for patients who remained free of infection was
4.3 years (2.3 to 6.1). Overall, 17 patients were assessed as American
Society of Anesthesiologists grade 3 or 4. The surgical protocol included
removal of the infected implant, vigorous debridement and insertion
of an articulating cement spacer. This was followed by at least
six weeks of antimicrobial treatment and delayed reimplantation
in all patients. The mean interval between removal of the prosthesis
and reimplantation was 9.5 weeks (6 to 24). After reimplantation,
patients took antifungal agents orally for a maximum of six months. Fungal PJIs can be treated successfully by removal of all infected
material, appropriate antimicrobial treatment and delayed reimplantation.
Following the recall of modular neck hip stems
in July 2012, research into femoral modularity will intensify over
the next few years. This review aims to provide surgeons with an
up-to-date summary of the clinically relevant evidence. The development
of femoral modularity, and a classification system, is described.
The theoretical rationale for modularity is summarised and the clinical
outcomes are explored. The review also examines the clinically relevant problems
reported following the use of femoral stems with a modular neck. Joint replacement registries in the United Kingdom and Australia
have provided data on the failure rates of modular devices but cannot
identify the mechanism of failure. This information is needed to
determine whether modular neck femoral stems will be used in the
future, and how we should monitor patients who already have them implanted. Cite this article:
We determined the midterm survival, incidence
of peri-prosthetic fracture and the enhancement of the width of
the femur when combining struts and impacted bone allografts in
24 patients (25 hips) with severe femoral bone loss who underwent
revision hip surgery. The pre-operative diagnosis was aseptic loosening
in 16 hips, second-stage reconstruction in seven, peri-prosthetic
fracture in one and stem fracture in one hip. A total of 14 hips
presented with an Endoklinik grade 4 defect and 11 hips a grade
3 defect. The mean pre-operative Merle D’Aubigné and Postel score
was 5.5 points (1 to 8). The survivorship was 96% (95% confidence interval 72 to 98) at
a mean of 54.5 months (36 to 109). The mean functional score was
17.3 points (16 to 18). One patient in which the strut did not completely
bypass the femoral defect was further revised using a long cemented
stem due to peri-prosthetic fracture at six months post-operatively.
The mean subsidence of the stem was 1.6 mm (1 to 3). There was no
evidence of osteolysis, resorption or radiolucencies during follow-up
in any hip. Femoral width was enhanced by a mean of 41% (19% to
82%). A total of 24 hips had partial or complete bridging of the
strut allografts. This combined biological method was associated with a favourable
survivorship, a low incidence of peri-prosthetic fracture and enhancement
of the width of the femur in revision total hip replacement in patients
with severe proximal femoral bone loss.
We report the effectiveness of revision of total
elbow replacement by re-cementing. Between 1982 and 2004, 53 elbows
in 52 patients were treated with re-cementing of a total elbow replacement
into part or all of the existing cement mantle or into the debrided
host-bone interface, without the use of structural bone augmentation
or a custom prosthesis. The original implant revision was still
We reviewed 123 second-generation uncemented total hip replacements performed on 115 patients by a single surgeon between 1993 and 1994. The acetabular component used in all cases was a fully porous-coated threaded hemispheric titanium shell (T-Tap ST) with a calcium ion stearate-free, isostatically compression-moulded polyethylene liner. The titanium femoral component used was a Taperloc with a reduced distal stem. No patient was lost to follow-up. Complete clinical and radiological follow-up was obtained for all 123 hips at a mean of 14 years (12 to 16). One femoral component was revised after a fracture, and three acetabular components for aseptic loosening. No additional femoral or acetabular components were judged loose by radiological criteria. Mild proximal femoral osteolysis was identified in two hips and minor acetabular osteolysis was present in four. The mean rate of penetration of the femoral head was 0.036 mm/year (0.000 to 0.227). These findings suggest that refinements in component design may be associated with excellent long-term fixation in cementless primary total hip replacement.
There have been comparatively few studies of the incidence of osteolysis and the survival of hybrid and cementless total hip replacements (THRs) in patients younger than 50 years of age. We prospectively reviewed 78 patients (109 hips) with a hybrid THR having a mean age of 43.4 years (21 to 50) and 79 patients (110 hips) with a cementless THR with a mean age of 46.8 years (21 to 49). The patients were evaluated clinically using the Harris hip score, the Western Ontario and McMaster Universities (WOMAC) osteoarthritis score and the University of California, Los Angeles (UCLA) activity score. Radiographs and CT scans were assessed for loosening and osteolysis. The mean follow-up was for 18.4 years (16 to 19) in both groups. The mean post-operative Harris hip scores (91 points Although the long-term fixation of the acetabular metallic shell and the cemented and cementless femoral components was outstanding, wear and peri-acetabular osteolysis constitute the major challenges of THR in young patients.
Four uncemented Symax hip stems were extracted at three weeks and nine, 13 and 32 months, respectively, for reasons other than loosening. The reasons for implant removal were infection in two cases, recurrent dislocation in one and acetabular fracture in one. They were analysed to assess the effect and behaviour of an electrochemically deposited, completely resorbable biomimetic BONIT-hydroxyapatite (HA) coating (proximal part) and a DOTIZE surface treatment (distal part) using qualitative histology, quantitative histomorphometry and scanning electron microscopy (SEM). Early and direct bone-implant bonding with signs of active remodelling of bone and the HA coating were demonstrated by histology and SEM. No loose BONIT-HA particles or delamination of the coating were observed, and there was no inflammation or fibrous interposition at the interface. Histomorphometry showed bone-implant contact varying between 26.5% at three weeks and 83.5% at 13 months at the HA-coated implant surface. The bone density in the area of investigation was between 24.6% at three weeks and 41.1% at 32 months. The DOTIZE surface treatment of the distal part of the stem completely prevented tissue and bone apposition in all cases, thereby optimising proximal stress transfer. The overall features of this implant, in terms of geometry and surface texture, suggest a mechanically stable design with a highly active biomimetic coating, resulting in rapid and extensive osseo-integration, exclusively in the metaphyseal part of the stem. Early remodelling of the HA coating does not seem to have a detrimental effect on short-term bone-implant coupling. There were no adverse effects identified from either the BONIT-HA coating or the DOTIZE surface treatment.
Between 2002 and 2008, 130 consecutive ankles were replaced with an hydroxyapatite (HA) and titanium-HA-coated Ankle Evolutive System total ankle prosthesis. Plain radiographs were analysed by two independent observers. Osteolytic lesions were classified by their size and location, with cavities >
10 mm in diameter considered to be ‘marked’. CT scanning was undertaken in all patients with marked osteolysis seen on the plain radiographs. Osteolytic lesions were seen on the plain films in 48 (37%) and marked lesions in 27 (21%) ankles. The risk for osteolysis was found to be 3.1 (95% confidence interval 1.6 to 5.9) times higher with implants with Ti-HA porous coating. Care should be taken with ankle arthroplasty until more is known about the reasons for these severe osteolyses.
We evaluated triple-phase bone scintigraphy in the differential diagnosis of peri-prosthetic infection in 46 patients with a total hip replacement or bipolar hemiarthroplasty who were due for revision surgery. There were 18 men and 28 women, with a mean age at operation of 64.6 years (28 to 81). We defined peri-prosthetic infection as an increased uptake of radioisotope in all the phases of triple-phase bone scintigraphy and validated these results against the histological and/or microbiology results in every case. The positive and negative predictive values for the presence of infection were 83% and 93%, respectively. The diagnostic sensitivity was 88% and the specificity was 90%. This study indicates that triple-phase bone scintigraphy is a useful tool in the detection of peri-prosthetic infection and offers a cost-effective method of screening.
We determined the ten-year life expectancy of 5831 patients who had undergone 6653 elective primary total hip replacements at a regional orthopaedic centre between April 1993 and October 2004. Using hospital, general practitioner and the local health authority records, we recorded the dates of death for those who died following surgery. The mean age at operation was 67 years (13 to 96) with a male:female ratio of 2:3. Of 1154 patients with a ten-year follow-up 340 (29.5%) had died a mean of 5.6 years (0 to 10) after surgery. Using Kaplan-Meier curves, the ten-year survival was 89% in patients under 65 years at surgery, 75% in patients aged between 65 and 74 years, and 51% in patients over 75. The standardised mortality rates were considerably higher for patients under 45 years, 20% higher for those between 45 and 64 years, and steadily reduced in patients aged 65 and over. The survival of cemented hip replacement derived from the Swedish Hip Arthroplasty Register Annual Report 2004 exceeds the life expectancy of patients over the age of 60 in our area, suggesting that cemented hip replacement is the procedure of choice in this population.
In a randomised study, 28 patients with a mean age of 62.2 years (32 to 81) with osteoarthritis or avascular necrosis of the hip received either a ceramic-on-ceramic or a metal-on-metal total hip replacement. Apart from the liners the acetabular and femoral components were made of Ti-Al-Nb alloy. The serum aluminium and cobalt levels were measured before, and at one year after surgery. The 15 patients in the ceramic-on-ceramic group had a median pre-operative aluminium level of 1.3 μg/l (0.25 to 8.4) and a cobalt level below the detection limit. At one year the aluminium level was 1.1 μg/l (0.25 to 2.3) and the cobalt level was 0.4 μg/l (0.15 to 0.7). The 13 patients in the metal-on-metal group had a median pre-operative aluminium level of 1.9 μg/l (0.25 to 4.4) and a cobalt level below the detection limit. At one year the median aluminium level was 0.9 μg/l (0.25 to 3.9) whereas the cobalt level was 1.4 μg/l (0.5 to 10.5). This increase in the cobalt level at one year was significant (p <
0.001). Our findings indicate that ceramic-on-ceramic bearings do not cause elevated levels of serum aluminium in the first post-operative year.
We have compared four computer-assisted methods to measure penetration of the femoral head into the acetabular component in total hip replacement. These were the Martell Hip Analysis suite 7.14, Rogan HyperOrtho, Rogan View Pro-X and Roman v1.70. The images used for the investigation comprised 24 anteroposterior digital radiographs and 24 conventional acetate radiographs which were scanned to provide digital images. These radiographs were acquired from 24 patients with an uncemented total hip replacement with a follow-up of approximately eight years (mean 8.1; 6.3 to 9.1). Each image was measured twice by two blinded observers. The mean annual rates of penetration of the femoral head measured in the eight-year single image analysis were: Martell, 0.24 (SD 0.19); HyperOrtho, 0.12 (SD 0.08); View Pro-X, 0.12 (SD 0.06); Roman, 0.12 (SD 0.07). In paired analysis of the six-month and eight-year radiographs: Martell, 0.35 (SD 0.22); HyperOrtho, 0.15 (SD 0.13); View Pro-X, 0.11 (SD 0.06); Roman, 0.11 (SD 0.07). The intra- and inter-observer variability for the paired analysis was best for View Pro-X and Roman software, with intraclass correlations of 0.97, 0.87 and 0.96, 0.87, respectively, and worst for HyperOrtho and Martell, with intraclass correlations of 0.46, 0.13 and 0.33, 0.39, respectively. The Roman method proved the most precise and the most easy to use in clinical practice and the software is available free of charge. The Martell method showed the lowest precision, indicating a problem with its edge detection algorithm on digital images.
Modern metal-on-metal bearings produce less wear debris and osteolysis, but have the potential adverse effect of release of ions. Improved ceramic-on-ceramic bearings have the lowest wear of all, but the corrosion process has not been analysed. Our aim was to measure the serum ion release (ng/ml) in 23 patients having stable hip prostheses with a ceramic-on-ceramic coupling (group A) and to compare it with the release in 42 patients with a metal-on-metal bearing (group B) in the medium term. Reference values were obtained from a population of 47 healthy subjects (group C). The concentrations of chromium, cobalt, aluminium and titanium were measured. There was a significant increase of cobalt, chromium and aluminium levels (p <
0.05) in group B compared with groups A and C. Group A did not differ significantly from the control group. Despite the apparent advantage of a metal-on-metal coupling, especially in younger patients with a long life expectancy, a major concern arises regarding the extent and duration of ion exposure. For this reason, the low corrosion level in a ceramic-on-ceramic coupling could be advantageous.
We conducted a randomised prospective study to evaluate the clinical and radiological results of a mobile- and fixed-bearing total knee replacement of similar design in 174 patients who had bilateral simultaneous knee replacement. The mean follow-up was for 5.6 years (5.2 to 6.1). The total knee score, pain score, functional score and range of movement were not statistically different (p >
0.05) between the two groups. Osteolysis was not seen in any knee in either group. Two knees (1%) in the mobile-bearing group required revision because of infection; none in the fixed-bearing group needed revision. Excellent results can be achieved with both mobile- and fixed-bearing prostheses of similar design at mid-term follow-up. We could demonstrate no significant clinical advantage for a mobile bearing.
We studied a consecutive series of 285 uncemented total hip replacements in 260 patients using the Taperloc femoral component and the T-Tap acetabular component. The outcome of every hip was determined in both living and deceased patients. A complete clinical and radiological follow-up was obtained for 209 hips in 188 living patients, followed for a mean of 14.5 years (10 to 18.9). They were divided into two groups, obese and non-obese, as determined by their body mass index. There were 100 total hip replacements in 89 patients in the obese cohort (body mass index ≥ 30 kg/m2), and 109 in 99 non-obese (body mass index <
30 kg/m2) patients. A subgroup analysis of 31 patients of normal weight (body mass index 20 kg/m2 to 25 kg/m2) (33 hips) and 26 morbidly obese patients (body mass index ≥ 35 kg/m2) (30 hips) was also carried out. In the obese group five femoral components (5%) were revised and one (1%) was loose by radiological criteria. Femoral cortical osteolysis was seen in eight hips (8%). The acetabular component was revised in 57 hips (57%) and a further 17 (17%) were loose. The mean Harris hip score improved from 52 (30 to 66) pre-operatively to 89 (49 to 100) at final follow-up. Peri-operative complications occurred in seven patients (7%). In the non-obese group six (6%) femoral components were revised and one (1%) was loose. Femoral cortical osteolysis occurred in six hips (6%). The acetabular component was revised in 72 hips (66%) and a further 18 (17%) were loose. The mean Harris hip score increased from 53 (25 to 73) prior to surgery to 89 (53 to 100) at the time of each patient’s final follow-up radiograph. No statistically significant difference was identified between the obese and non-obese patients with regards to clinical and radiological outcome or complications. The subgroup analysis of patients of normal weight and those who were morbidly obese showed no statistically significant difference in the rate of revision of either component. Our findings suggest there is no evidence to support withholding total hip replacement from obese patients with arthritic hips on the grounds that their outcome will be less satisfactory than those who are not obese.
We carried out a prospective randomised study designed to compare the penetration rate of acetabular polyethylene inserts of identical design but different levels of cross-linking at a minimum of four years follow-up. A total of 102 patients (102 hips) were randomised to receive either highly cross-linked Durasul, or contemporary Sulene polyethylene inserts at total hip replacement. A single blinded observer used the Martell system to assess penetration of the femoral head. At a mean follow-up of 4.9 years (4.2 to 6.1) the mean femoral head penetration rate was 0.025 mm/year (
Between January 1998 and December 1998, 82 consecutive patients (86 hips) underwent total hip arthroplasty using a trabecular metal monoblock acetabular component. All patients had a clinical and radiological follow-up evaluation at six, 12 and 24 weeks, 12 months, and then annually thereafter. On the initial post-operative radiograph 25 hips had a gap between the outer surface of the component and the acetabular host bed which ranged from 1 to 5 mm. All patients were followed up clinically and radiologically for a mean of 7.3 years (7 to 7.5). The 25 hips with the 1 to 5 mm gaps were studied for component migration at two years using the Einzel-Bild-Roentgen-Analyse (EBRA) digital measurement method. At 24 weeks all the post-operative gaps were filled with bone and no acetabular component had migrated. The radiographic outcome of all 86 components showed no radiolucent lines and no evidence of lysis. No acetabular implant was revised. There were no dislocations or other complications. The bridging of the interface gaps (up to 5 mm) by the trabecular metal monoblock acetabular component indicates the strong osteoconductive, and possibly osteoinductive, properties of trabecular metal.
Primary uncemented femoral stems reported to the Norwegian arthroplasty register between 1987 and 2005 were included in this prospective observational study. There were 11 516 hips (9679 patients) and 14 different designs of stem. Kaplan-Meier survival probabilities and Cox regression were used to analyse the data. With aseptic loosening as the end-point, all currently used designs performed excellently with survival of 96% to 100% at ten years. With the end-point as stem revision for any cause, the long-term results of the different designs varied from poor to excellent, with survival at 15 years ranging between 29% and 97%. Follow-up for longer than seven years was needed to identify some of the poorly-performing designs. There were differences between the stems; the Corail, used in 5456 hips, was the most frequently used stem with a survival of 97% at 15 years. Male gender was associated with an increased risk of revision of × 1.3 (95% confidence interval 1.05 to 1.52), but age and diagnosis had no influence on the results. Overall, modern uncemented femoral stems performed well. Moderate differences in survival between well-performing stems should be interpreted with caution since the differences may be caused by factors other than the stem itself.