Purpose. Primary total hip arthroplasty (THA) has been a very successful surgical intervention for the management of end-stage arthritis in geriatric patients (> age 65). The mid- to long-term results have been less satisfactory however, in younger patients primarily due to the wear of the acetabular liner and loosening of the femoral component. The primary study purpose was to compare pain, function and stiffness over the first five years in a population less than 60 years of age who received either an alumina liner/alumina femoral head (alumina group) or a crossfire UHMWPE liner/alumina head (Poly group) following primary THA. Secondarily, we compared re-operation rates over five years between these two groups. Method. This was a randomized, controlled clinical trial of subjects with non-inflammatory OA who were booked for primary THA and consented to participate in the study. Subjects were evaluated pre-operatively and again at one and five years post-operatively by an evaluator who was blinded to group allocation. At each assessment, subjects completed the WOMAC Osteoarthritis Index (WOMAC); complications and re-operations were also recorded. All analyses were performed on an intention to treat basis. Results. 92 subjects were enrolled in the study. The mean age of subjects was 52.4 (SD 6.8) and 50 (54%) were male and was similar between groups (p>0.10). Baseline pain, function and stiffness as measured by the WOMAC were also similar between groups (p>0.48). Five-year follow-up data was available for 78 (85%) patients. Both groups showed substantial improvement in pain, function and stiffness within one year that was maintained out to five years post-operatively; there were no statistically significant differences between groups (p>0.50). Four subjects required re-operation within five years; no re-operation was related to liner type two cases were dislocation due to the malposition of the cup while the remaining two re-operations occurred in the immediate post-operative period for removal of hematoma. Conclusion. Our prospective randomized controlled trial showed substantial post-operative improvements in pain, stiffness, and function that were maintained out to five years, with no statistically significant differences seen between the two groups. No re-operations that were related to the liner type occurred in the first five post-operative years

Introduction. Third body wear caused by contaminated bearing environment with debris that may have been generated by a worn or fractured revised bearing coupling, but also originated by generation of metal/cement particles during the primary or revision surgery, may be a relevant issue for the implant life. Objectives. To evaluate the wear behavior of a last generation alumina matrix ceramic composite (AMC) bearing in a worst case scenario consisting of highly contaminated test lubricant with alumina particles in a hip joint simulator study. Methods. AMC (BIOLOX®delta - Group 1) and alumina (BIOLOX®forte - Group 2) liners with an internal diameter of 32mm were articulated against AMC BIOLOX®OPTION heads (all CeramTec GmbH, Plochingen). Coarse alumina particles (D(50):60µm) and fine alumina particles (D(50):0.30µm) with a concentration of 48mg/ml were used as environmental contamination of the first 2mlc and the second 2mlc, respectively. All components were tested according to ISO14242-1(2012) using the EndoLab®hip joint simulator. Each group consisted of 3 couples plus one axially loaded control consisting of a 32mm AMC head on an alumina liner. The test fluid was exchanged every 500'000 cycles. Two different test regimes describing level walking and subluxation of the insert from the femoral head were used as test input. The first regime included 500 standard walking cycles followed by a second block of 5 subluxation cycles. Head subluxation is assumed to increase the number of third-body particles that enter the otherwise closely conforming articular bearing space, when compared to level-walking cycles alone. To maintain the particle suspension in the test fluid, the test fluid of each test chamber was circulated by peristaltic pumps. The wear rate was determined by gravimetric method. The surface of ball heads was subjected to visual inspection every 500'000 cycles by optical and laser microscope. The depth of scratches was measured by the laser microscope. Results. After 2 million load cycles with the test fluid contaminated with coarse alumina particles, no significant wear was detected by the gravimetric method. The qualitative surface inspection by laser microscope individuated an increasing, but low concentration of sparse tiny scratches about 40nm deep on ball head surface at every simulator stop. Nevertheless, after loading the chambers with fine alumina particles, bearing surface wear seemed to increase consistently, since opaque areas appeared after 3 million load cycles, but the wear-rate remained close to the gravimetric measurement detection limit (about 0.1–0.2mg) indicating the still extremely low wear-rate of the tested ceramic couplings. Conclusions. This study confirms the high wear and scratch resistance of AMC used in THA. Even in heavily contaminated environment with hard alumina particles, which may occur after fracture of a ceramic component, gravimetry wasn't able to detect significant wear. The visual inspection by laser microscope exhibited only slight damaged surface characterized by tiny scratches and more opaque areas in the main wear zone as result of using fine alumina particles. Ceramic-on-ceramic is a safe bearing even in the case of revision for ceramic fracture, maintaining the excellent wear resistance of this bearing

In total hip arthroplasty (THA), aseptic loosening induced by polyethylene (PE) wear debris is the most important cause that limits the longevity of implants. Abrasive wear generated through the mechanism such that micrometer-roughened regions and small asperities on the metallic femoral heads surface locally plow through the PE cup surface. Abrasive wear results in the PE material being removed from the track traced by the asperity during the motion of the metallic femoral heads surface. For the purpose of reducing wear, alumina ceramics was introduced in Europe and Japan in 1970s. The clinical results of ceramic-on-PE bearings regarding the wear resistance have been superior to that of the metal-on-PE bearings. Compared with Co–Cr–Mo alloys, alumina ceramics is advantageous for precision machining because of its higher hardness, enable to form spherical and smooth surface. The fracture resistance of the alumina ceramics itself is related to grain size; the grain size reduction leads to the improvement of its resistance. In this study, we evaluated the roundness and the roughness of retrieved two distinct alumina ceramics having different grain size, and Co–Cr–Mo alloy heads. Fourteen retrieved alumina ceramic femoral heads; ten heads with a diameter of 28 mm made of small grain size alumina (SG-alumina; mean grain size is 3.4 μm) with clinical use for 16–28 years and four heads with a diameter of 26 mm made of extra-small grain size alumina (XSG-alumina; mean grain size is 1.3 μm) with clinical use for 14–19 years, were examined. Six retrieved Co–Cr–Mo alloy femoral heads with a diameter of from 22 to 32 mm with average clinical use for 12–28 years were examined. SG-alumina and XSG-alumina heads showed significantly lower roundness compared with Co–Cr–Mo alloy heads, due to higher precision machining [Fig. 1]. The surface roughness for the contact area of the heads increased in order of XSG-alumina, SG-alumina and Co–Cr–Mo alloy. The surface roughness of the non-contact area for all kinds of heads was lower than that for the contact area [Fig. 2]. Surface profiles of the SG-alumina and XSG-alumina showed the reentrant surface while Co–Cr–Mo alloy heads showed the protrusion surface. The roundness and roughness of the Co–Cr–Mo alloy or ceramic surface and the presence or absence of hard third-body particles correlate to the amount of abrasive PE wear. When the third-body was entrapped during the clinical use, a reentrant surface might be formed on the ceramic while protrusion surface formed on the Co–Cr–Mo alloy. The differences in clinical results may be due in part to the influence of third-body particles. The ceramic becomes more resistant than Co–Cr–Mo alloy against the scratching by the entrapped abrasive contaminants because of its harder surface. From the good clinical results of more than 20 years using SG-alumina, the greater long term clinical results using XSG-alumina will be expected

Purpose. The fourth generation ceramic, in which zirconia is incorporated into the alumina matrix, was developed to reduce the risk of ceramic fractures. The purpose of this study was to evaluate the survivorship, clinical and radiographic results, and bearing-related failures associated with total hip arthroplasty using zirconia-toughened alumina ceramic-on-ceramic bearings over a minimum follow-up of 5 years. Materials and methods. We retrospectively analysed 135 patients (151 hips) who underwent cementless total hip arthroplasty using zirconia-toughened alumina ceramic-on-ceramic bearings. There were 58 men and 77 women with mean age of 55.9 years (range, 20 to 82 years) at index surgery. Acetabular and femoral components were cementless in all hips. A 36 mm head was used in 81 of 151 hips and a 32 mm head was used in 70 hips with smaller acetabular shells. The mean duration of follow-up was 6.1 years (range, 5 to 6.8 years). Results. Kaplan-Meier survival analysis with an end point of revision for any reason was 100% at 6.8 years. All acetabular and femoral components showed bony ingrowth. No radiographic evidence of osteolysis was identified. No ceramic fracture occurred. There were 4 (2.6%) noisy hips (1 squeaking and 3 clickings), but no patient could reproduce the noise and required revision. Other complications included one iliopsoas tendonitis and one dislocation. Conclusions. The minimum 5-year results of total hip arthroplasties performed using 32 mm or 36 mm zirconia-toughened alumina ceramic-on-ceramic bearings were encouraging with excellent survivorship. However, it was also found that the risk of noise development remains even for the newest generation of ceramics

Different types of highly cross-linked polyethylene (HXLPE) have been introduced widely in acetabular cups in hip prostheses to reduce the incidence of wear debris-induced osteolysis. Also, we reported that HXLPE cups with 28-mm alumina ceramic femoral head exhibited lower wear than conventional PE cups. Recently, the combination of HXLPE cup and larger diameter femoral head is used widely to prevent dislocation. In this study, we examined the wear of HXLPE with 32-mm alumina ceramic femoral head and compared it with the wear of HXLPE with 28-mm alumina ceramic femoral head. The in vivo wear of 60 HXLPE cups (Aeonian; Kyocera Corp., Kyoto, Japan, currently Japan Medical Materials Corp., Osaka, Japan) with 28-mm alumina ceramic femoral head with clinical use for 3.1–9.1 years (mean 7.4 years) and eight HXLPE cups with 32-mm alumina ceramic femoral head used for 2.3–3.2 years (mean 2.8 years) were examined by radiographic analysis. The early wear rate for the first year of HXLPE cups with 28-mm and 32-mm alumina ceramic femoral head were 0.24±0.10 mm/year and 0.29±0.12 mm/year respectively. There was no significant difference in both femoral head groups (p>0.05). The steady wear rate after 1 year were 0.001±0.03 mm/year and −0.03±0.10 mm/year respectively. There was no significant difference either in both femoral head groups (p>0.05). These findings from this radiographic analysis suggest that the early wear rate in the first 1 year probably represents the creep deformation in bedding-in stage; and the steady wear rate after 1 year probably represents mainly the wear than of the creep deformation. By the radiographic analysis, HXLPE cups in both femoral head groups exhibited low steady wear rate. In conclusion, we expect that the combination of HXLPE cup and 32-mm diameter alumina ceramic femoral head has favorable wear properties with possibility of prevention of dislocation in long-term clinical use

Edge loading commonly occurs in all bearings in hip arthroplasty. The aim of this study compares metal bearings with edge loading to alumina bearings with edge loading and to metal bearings without edge loading. Seventeen failed large diameter metal-on-metal hip bearings (8 total hips, 9 resurfacings) were compared to 55 failed alumina-on-alumina bearings collected from 1998 to 2010. The surface topography of the femoral heads was measured using a chromatically encoded confocal measurement machine (Artificial Hip Profiler, RedLux Ltd.). The median time to revision for the metal hip bearings and the alumina hip bearings was 2.7 years. Forty-six out of 55 (84%) alumina bearings and 9 out 17 (53%) metal bearings had edge loading wear (p<0.01). The average volumetric wear rate for metal femoral heads was 7.87 mm3/yr (median 0.25 mm3/yr) and for alumina heads was 0.78 mm3/yr (median 0.18 mm3/yr) (p=0.02). The average volumetric wear rate for metal heads with edge loading was 16.51 mm3/yr (median 1.77 mm3/yr) and for metal heads without edge loading was 0.19 mm3/yr (median 0 mm3/yr) (p=0.1). There was a significant difference in gender, with a higher ratio of females in the alumina group than the metal group (p=0.02). Large diameter metal femoral heads with edge loading have a higher wear rate than smaller alumina heads with edge loading. Metal-on-metal bearings have low wear when edge loading does not occur

Introduction. Alumina Ceramic liners are increasingly used in patients undergoing Total Hip Replacement (THR). The rate of fracture of ceramic liner is decreasing with improved manufacturing techniques from 1. st. to 3. rd. generation alumina-ceramic liners. We report the first case of a fracture of a modern, 4. th. generation alumina bearing ceramic liner, which incorporates a metal sheath to help avoid fracture. Our case is a 60 years old female presenting two years and three months after a bilateral total hip replacement using Stryker Trident cup, securfit stem and alumina on alumina bearing ceramic liner. Ceramic liners are commonly used, especially in young patients because of their excellent biocompatibility, low wear rate and superior tribology. Although fracture of ceramic liner is a less common complication of modern total hip arthroplasty, it is a major concern with the use of ceramic on ceramic THR, the reason being brittleness of ceramic. Cases of 3. rd. generation ceramic liner fracture have been reported which might be associated with impingement due to excessive anteversion of the socket in Asian patients who habitually squat. Habitual squatting, sitting cross legged and kneeling were not characteristic of this case. Methods. The patient presented with complains of mechanical grinding in left hip. She also reported a past history of clicking sound from left hip on extension of left hip and long stride gait. There was no history of trauma or fall. On examination she had a nonantalgic gait and left hip had audible and palpable crepitations. The range of motion on left hip was intact with no subluxation. Right hip was symptom free and examination did not detect any abnormalities. Evaluation & Results. Radiographs of left hip revealed eccentric positioning of the head [Fig. 1] within the socket and excessive anteversion of the socket, which likely caused edge-loading in extension, leading to catastrophic failure in form of fracture of ceramic liner on left hip. She was treated with revision surgery using polyethylene liner with metal head. Intra-operative findings confirmed the ceramic liner fracture [Fig. 2] and revealed impingement of the metal neck against the metal rim of the liner. Discussion & Conclusion. Although ceramic on ceramic hips have excellent wear properties, it is subject to fracture due to its brittle nature. This can lead to catastrophic failure with edge loading. In this case, the alumina-ceramic liner fractured; despite of being surrounded by a metal rim to prevent fracture. It fractured at the anterior edge, which is where it was loaded in extension. We believe that careful attention must be paid not only to inclination, but version of the socket, so as to avoid this complication. Other factors which might lead to such complication are obesity, high activity level, improper manufacturing teachniques for ceramic liners and entrapment and impingement of a micromm sized foreign body between ceramic liner and prosthetic head which initiates wear

Introduction and Aims. The 21. st. Century has seen ceramic bearings become an increasingly popular choice in total hip arthroplasty due to their high wear resistance and inert wear debris without osteolysis promising a long term bearing solution. Early ceramic bearings were hindered by fracture but improved manufacturing processes and materials subsequently produced stronger ceramics. These third generation ceramics showed greatly reduced fracture rates but there is limited evidence in the literature reporting their long term survival and wear characteristics. The purpose of this study was to determine osteolysis and survival rates of Alumina ceramic bearings in cementless total hip arthroplasties with a minimum follow-up of 15 years. Methods. We analyzed a series of 301 third-generation alumina-on-alumina cementless primary total hip replacements in 283 patients. The average age of the patients at the time of the arthroplasty was fifty-eight years, 51% were in women and 54% were right sided. All procedures were performed using the same surgical technique and the same implant at a single centre. Patients were followed up at six weeks, one, two, five, ten and 15 years. At 15 years postoperatively 46 patients (17%) had died of unrelated causes and 31 (10.2%) were lost to follow-up. Patients were assessed clinically and radiographically. Retrieved bearings were analyzed for wear. Results. At the time of the latest follow-up the mean Harris Hip Score was 94 points and 97% of the patients scored an excellent or good result with less than 4% having moderate residual pain. Radiographically, all patients assessed had evidence of stable bony ingrowth. Minor osteolysis was seen adjacent to 4% of cups and in none of the stems. There were eleven revisions in all, four stem revisions due to periprosthetic fracture, one secondary to aseptic loosening and one to facilitate a femoral shortening osteotomy. One cup was revised for aseptic loosening and one cup was revised for soft tissue impingement. One cup underwent revision due to acetabular osteolysis due to metallosis with some ceramic wear caused by neck impingement. There were two revisions for ceramic fracture, one liner and one femoral head. Overall, the survival rate of the implants for any cause revision was 96% at 15 years, with. The rate of survival of both components, with revision because of aseptic loosening or osteolysis as the end point, was 99% at 15 years. Analysis of retrieved femoral heads identified a median wear rate of 0.2mm3/year. Conclusion. Ceramic bearings were designed to overcome the problem of osteolysis due to wear from polyethylene bearings. This study has shown that Alumina bearings in cementless primary total hip arthroplasty have an excellent survival rate at 15 years with good function, low wear rate and no adverse radiographic changes typical of osteolysis. The fracture rate was low in our study. These findings strongly supporting the use of Ceramic as a bearing choice for the 21. st. Century

Aim. Local concentration of antibiotic at the site of infection is a major parameter for its efficiency. However, bone diffusion is poor leading either to their non-use (ex: gentamicin) or the use of high concentration (ex: vancomycin). Local administration could optimize their local concentration combined with lower side effects. We report the clinical experience and pharmacological results of an antibiotic loaded porous alumina used to replace infected bone in 4 patients. Method. Two patients had a destroyed sternum following mediastinitis; one presented a femoral chronic osteomyelitis due to MRSA and one had an infected ankle arthroplasty. The ceramic was loaded with gentamicin in three cases and vancomycin for the ankle infection. Local dosages thanks to Redon's drain and blood samples were performed. Loading was done to protect the device while implanted in an infected area and was combined with conventional antibiotic therapy. Results. In comparison to pharmacological parameters: C. max. /MIC>8 for gentamicin or AUC/MIC>400 for vancomycin, local concentrations were dramatically higher than the one needed (table). Vancomycin concentration was still high after H48. Meanwhile, blood samples didn't find the presence of gentamicin during the 48 hours following implantation. After more than one year of follow-up for all the patients, there is no relapse of infection or signs of device infection, whereas all samples perform during implantations grew with bacteria, meaning that loaded antibiotic played a major role avoiding device colonization in combination with surgical debridement and cleaning. Conclusions. This mode of administration allows an optimization of the antibiotic delivery, maximizing local concentrations while reducing systemic toxicity. In addition, ceramic mechanical characteristics allow bone replacement (strength >3 times the one of the cancellous bone and osseointegration) and thus enables one-stage surgery instead of two-stage like for the patient with chronic osteomyelitis thanks to a good primary stability. For any figures or tables, please contact the authors directly

The RIPO register collects data of all primary and revision hip replacement surgeries performed in Region Emilia-Romagna, Italy since 1stJanuary 2000.

The present study is aimed to analyze the survival rate of patients with Biolox®delta and Biolox®forte components, (CeramTec, Plochingen Germany) considering possible confounding factors. Only patients living in the region are considered in analysis, to avoid the bias resulting from the ‘loss’ of non-resident patients. The analysis has been conducted only on uncemented THA and monoblock, double mobility cups as well as such with pre-assembled inserts were excluded. Therefore, the finally analyzed database consists of 30’617 cases; 13’323 Biolox®forte and 17’294 Biolox®delta heads, articulating against ceramic or PE.

Unadjusted survival analysis was calculated according to Kaplan Meier method; with prosthesis failure as end point, defined as the revision of any prosthetic component for any cause.

To avoid a possible bias, revision of the prosthesis due to breakage of modular necks of the stem have not been considered. The results are summarized in Table 1.

*survival at 6 yrs follow-up

After adjusting for age and gender it resulted that Biolox®delta - XLpoly and Biolox®forte – poly increase the risk of revision (HR 1.4 and 1.2) compared to Biolox®delta - Biolox®delta;

When only ceramic fractures are considered, we observed 1 fracture of a 36 mm Delta head (1/8’917 = 0.01%) and 38 fractures of 28 mm Forte heads. The 38 fractures occurred mainly in cer-cer coupling (35/3’537 implants= 1%) and occasionally in cer-poly couplings (3/4’246 implants = 0.07%).

Fracture or damage of the Biolox®delta insert occurred in 10 implants out of 14’260(0.07%), while it had a higher incidence in Forte inserts (36 casesout of 6’932 implants = 0.52%).

It can be concluded that the presence of a poly liner decrease the survival of the implant. Beside this Biolox®delta significantly improved the resistance to fracture of both head and insert.

Introduction. Ceramic ball heads are well known in hip arthroplasty for their superior tribology performance and high burst strength. To assess the ball head performance and the in-vivo fracture risk Pandorf et al 2008 examined the burst strength of BIOLOX®forte (pure aluminium oxide ceramic, CeramTec GmbH, Plochingen, Germany) ball heads on clean standard test tapers and contaminated test tapers. They found that fat tissue and scratches are reducing the burst strength to 40% and to 20% of the reference burst strength, respectively. The aim of this work is to investigate if BIOLOX®delta (alumina matrix ceramic, CeramTec GmbH, Plochingen, Germany) ball heads show a similar behaviour as BIOLOX®forte ball heads with respect to taper contamination. Materials and Methods. Each test series consisted of n=5 BIOLOX®delta 28–12/14 L ball heads and n=5 metal test tapers (Ti-6Al-4V, ISO 5832-3). For the reference series the metal tapers remained untouched representing the CeramTec standard test procedure. For the fluid series the ball heads were filled up with tap water or calf blood serum. For the solid series the metal test tapers were contaminated with small particles of bovine bone, commercially available bone cement and porcine fat tissue in the engagement zone. A chisel and a slight hammer tap were used to scratch the proximal region of the metal test taper. The ball heads were then manually attached to the contaminated metal test tapers without further force appliances. An apparatus according to ISO 7206-10 was used for burst testing. The tests were performed at CeramTec in-house test laboratory. Results. The contamination of the taper region showed an influence on the resulting burst strength which was qualitatively similar to the previously performed investigations with pure alumina ball heads. Discussion. Sterilized water is used for cleaning the surgical wound before attaching the ball head on the metal taper. A contamination of the metal taper with water is reducing the burst strength of BIOLOX®delta ball heads to 80% reference burst strength. Remains of blood and bone particles on the metal taper can lead to 63% of the reference burst strength. Remains of fat tissue on the metal taper can lead to 38% of the reference burst strength. The fat tissue is reducing the coefficient of friction, which leads in further consequence to a change of the stress distribution and a raise of the stress magnitude in the ceramic ball head. Scratches and grooves have the ability to reduce the burst strength to only 29% reference burst strength. The results confirm that the taper connection of the components have to be clean and dry in order to provide a sufficient and strong connection

Introduction. Oxide-based alumina (Al2O3) is used to manufacture femoral heads for total hip arthroplasty (THA). Silicon nitride (Si3N4) is a non-oxide ceramic used to make spinal implants. Ceramic materials are believed to be bioinert, (i.e., stable under hydrothermal conditions). Indeed, clinical data have shown 15–20 year longevity of Al2O3 bearings in THA. In this work, we examined the surfaces of Al2O3 and Si3N4 after exposure to physiologic conditions to see if these ceramics are truly inert. Materials and Methods. Four self-mated Ø28 mm diameter Al2O3 femoral heads (n=2 each of BIOLOX®forte, CeramTec, Plochingen, Germany; and BIOCERAM®, Kyocera Co., Kyoto, Japan), were retrieved during revision THA, between 7.7–10.7 years post-implantation. To simulate in vivo material aging, comparable, new Al2O3 and Si3N4 femoral heads (AMEDICA Corporation, Salt Lake City, UT, USA) were exposed to autoclave conditions (100°C-121°C; 300 hrs; n=3 heads, per material). Advanced Raman and cathodoluminescence spectroscopy, and electron microscopy were used to examine surface characteristics of each specimen, and quantify oxygen ion vacancy formation and composition. Results. The naturally hydroxylated free surfaces of retrieved Al2O3 demonstrated lattice dissociation. Dehydroxylation of Al2O3 produced hydroxyls and proton radicals, which in turn promoted the formation of surface vacancies for preserving electrical charge neutrality. During frictional sliding of Al2O3, the continuous formation, subsequent adsorption, and frictional removal of hydroxylated sites repeatedly created and annihilated a population of different oxygen-vacancy sites. Moreover, protein by-products and in vivo released ions sub-valent with respect to Al3+ (e.g., Ca2+, Mg2+, and Na+) were found to preferentially link to oxygen-vacancy sites, inducing irreversible stoichiometric alterations of the Al2O3 surface. Oxygen vacancy formation was seen in all samples, (i.e., all retrievals and all in vitro hydrothermally exposed samples). Cation substitution and spinel formation were only observed in retrievals because these cations are not available during in vitro testing, (i.e., Ca2+, Mg2+ and Na+ come from the synovial fluid). In contrast, Si3N4 surfaces showed no evidence of direct hydrogen bond formation, and therefore no dissociative interaction with water molecules, when subjected to accelerated aging conditions (Fig. 1). Discussion. Because of its molecular polarity, water can dissolve ionic substances, since the ionic compound interacts with either side of the water dipole. This phenomenon leads to dissociation of the ionic molecule by dehydroxylation. Our results show that Si3N4 surfaces are stable in hydrothermal environments. In contrast, Al2O3 surfaces demonstrate surface changes under in vivo and in vitro conditions because of modifications of the lattice structure (e.g., vacancy generation and formation of a soft MgAl2O4 spinel phase), which alters local mechanical properties and tribological wear resistance. Cations, such as Na+ are released from dilution of sodium hyaluronate; a phenomenon that occurs in patients with rheumatoid arthritis. Conclusion. These data suggest that surface dehydroxylation may lead to the long-term in vivo degradation of Al2O3 bearings in THA. Covalently-bonded bioceramics, such as Si3N4 are impervious to such degradation. Si3N4 may be truly bioinert in vivo, ensuring multi-decade durability and superior performance of orthopaedic bearings

Introduction. The success of total hip arthroplasty has meant its indications have been extended to the younger more active patient. Due to the higher activity levels and increased demands of these patients, revision rates have been traditionally higher than when compared to older patients [1]. Ceramic on ceramic bearings may offer a viable long term solution as manufacturing methods have evolved resulting in improved mechanical properties, particularly of third and fourth generation ceramics. We report the outcome of primary cementless, alumina-on-alumina hip arthroplasty with a minimum 10 year follow up in 110 patients under the age of 55 years of age at time of surgery. Methods. A series of 120 consecutive total hip arthroplasties in 110 patients were performed between June 1997 and February 1999 by the two senior authors. All patients had an Osteonics ABC acetabular component and SecurFit or SecurFit Plus femoral component (Stryker Orthopaedics, Mahwah, NJ) with an alumina C-taper ceramic head (Biolox Forte, Ceramtec, Plochingen, Germany). Results. Of the 110 patients originally in the study, 4 (3.6%) patients died, 6 (5%) were lost to follow up and 4 hips (3.6%) were revised by the time of the latest follow up. Clinical information was available for 106 hips in 96 surviving patients at a minimum of ten years of follow-up, and radiographic information was available for 90 hips from the same 96 patients. The mean follow up was 11.5 years (range 10 to 13.5 years). Survivorship analysis with revision for any reason as an endpoint was 96.5% at 10 years (CI 94.5% −98.7%) using the Kaplan-Meier method. Modified mean UCLA scores improved from 6.4 (range 4 to 10) pre operatively to 9 (range 4 to 10) at latest follow up. The mean Harris Hip Score improved from 53.4 points (range 15 to 86) preoperatively, to 94.7 points (range 63 to 100) at latest follow up. All femoral stems had stable bone ingrowth, with no migration. Osteolysis was not observed around the femoral or acetabular components and there were no signs of radiological wear. 98 patients (92.4%) managed to continue with their current occupations during the follow up period whilst 5 patients (4.7%) changed occupation to work that required increased activity. Complications included 3 cases of iliopsoas tendonitis, 2 cases of squeaking, a ceramic liner chipping during insertion and sciatic nerve palsy. There were no cases of ceramic fracture in this younger, active cohort of patients. No evidence of bearing failure was demonstrated nor any signs of adverse reaction to wear debris. Conclusions. Alumina ceramic on ceramic bearings in cementless primary total hip arthroplasty show good clinical and radiological outcomes in the higher demand younger age patient. Based on these results we now support heavy occupational work and regular impact sports in these patients once they have recovered from surgery

Introduction. Total knee arthroplasty (hereinafter TKA), it is thought that the setting position of each component and the angle have a big influence on surgical results. Preoperative planning with accurate and detailed 3D templates are has been done in many facilities in TKA. However, in the setting position, the 2D evaluation with X-rays is still common after operation, and there are few facilities going in 3D image. A three-dimensional evaluation method of the TKA includes a rating system using CT and the MRI, but influence (artifactual) with the metal occurs, and a detailed evaluation becomes difficult. In this study, we evaluated it after the matching method with the 3D plan using “Physio-Knee” where the materials of the femoral component were alumina ceramics in the preoperation of each component setting position by the CT before and after operation. Patients and methods. We intended for 12 knees which we performed TKA used the Physio-Knee by December, 2011 from October, 2010. The all cases woman, the operation average age were 68.9 years old (62 to 79 years). For these, we performed CT photography of the whole lower limbs after operation like preoperation and each component setting was located after operation using evaluation software made in LEXI company and evaluated it. Results and Discussion. Like 2D evaluation result, as for one, the error with the plan did not recognize errors more than 3 degrees at the setting angle of the each component in the coronal and sagittal plane in preoperation either. A detailed evaluation was possible about the slightly difficult rotation by the 2D evaluation. As for the 3D image matching method that we performed this time, a visual instant evaluation was possible and, in addition, the evaluation of the rotation position was possible and was able to evaluate it in detail and precisely more in comparison with conventional 2D evaluation. A conclusion. In TKA, we think to evaluate correct implant setting, acquisition to alignment that the 3D image matching method that we performed this time is a useful tool

Introduction. Protective hard coatings are appealing for several technological applications like solar cells, organic electronics, fuel cells, cutting tools and even for orthopaedic implants and prosthetic devices. At present for what concerns the application to prosthetic components, the coating of the surface of the metallic part with low-friction and low-wear materials has been proposed [1]. Concerning the use of ceramic materials in joint arthroplasty, zirconia-toughned-alumina (ZTA) reported high strength, fracture toughness, elasticity, hardness, and wear resistance [2]. The main goal of this study was to directly deposit ZTA coating by using a novel sputter-based electron deposition technique, namely Pulsed Plasma Deposition (PPD) [3]. The realized coatings have been preliminary characterized from the point of view of morphology, wettability, adhesion and friction coefficients. Materials and methods. ZTA coatings were deposited by PPD technique, which is able to maintain the stoichiometry of the starting target. In this case we started from a cylindrical ZTA target (30 mm diameter × 5 mm thickness, 75% alumina / 25% zirconia). The morphology, micro-structure and chemistry of deposited coatings were characterized by Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray Spectrosopy (EDS) and Atomic Force Microcscope (AFM). Coating-substrate interface quality were investigated by microscratch tests. The degree of wetting was estimated by measuring the contact angle between a drop of 1 ml of ultrapure water and the surface of the sample. Preliminary ball-on-disk tribological tests were carried out in air and deionized water coupling ZTA-coated stainless steel ball (AISI 420, 3 mm radius, grade 200) against medical grade UHMWPE to evaluate the friction of the proposed coupling. Results. Deposited ZTA films exhibited a smooth nanostructured surface. Coatings up to several microns thick have been deposited by PPD [Fig. 1 – SEM image (left) and cross section (right)]. Mechanical tests showed a well-adherent films were deposited. In particular, the good interface adhesion was assessed by scratch tests, reporting at about 0.8 N the first formation of cracking in the coating during testing. The contact angles revealed an hydrophobic behavior of the coating (average contact angle 116° ± 2°), probably due to the nano-roughness of the coating itself [Fig. 2 – Contact angle]. Preliminary tribological tests carried out in deionized water after up to 10000 m tracks showed good average friction coefficient ranging from 0.12 to 0.15 [Fig. 3 – Friction coefficient]. Conclusions. We have presented the preliminary results of a novel approach aiming to the drastically improve the performance of prosthetic couplings by introducing hard ceramic coating. The results showed suggested the feasibility of pursuing this approach of realizing ZTA coatings by means of PPD technique. Further analyese on mechanical properties, nano-roughness and tribology should be performed. Well-adherent ZTA films deposited directly on the surface of prosthetic components of a joint implant would then allow a drastic improvement of the actual prosthetic behaviour

Introduction. Wear of the ultra high molecular weight polyethylene (UHMWPE) cup and the resulting loosening has been shown to limit the long-term results of the Charnley low-frictional torque arthroplasty (LFA). Factors affecting wear rates have been studied: level of patient activity, effective roughness of the stainless steel head, impingement and the possible variations in wear characteristics of UHMWPE. Since patients' activity level cannot be predicted or modified, alternative materials were examined. Methods and Results. The Charnley 22.225 mm diameter head of alumina ceramic in combination with chemically cross-linked polyethylene cup has now reached over 23 years of clinical and radiographic follow-up. Of the initial 17 patients (19 hips) in the study, 4 patients (4 hips) have died, 1 hip has been revised for deep infection and 3 patients (3 hips) are unable to attend follow-up due to medical problems unrelated to the hip. Nine patients (11 hips) are still attending follow-up at a mean of 22 years 5 months (21 year 3 months-23 years 6 months). The mean age at surgery in this group was 47 years (26-58) and the mean weight 81kgs (54-102). The mean penetration rate was 0.02mm/year and none have exceeded 0.41mm total penetration. Conclusion. Since the problem of cup wear and loosening is mechanical rather than biological the long-term solutions are more likely to come from materials rather than radical changes of design of methods of component fixation

INTRODUCTION. Young patients (< 50 years old) have been reported to have a higher risk of revision following total hip arthroplasty (THA) than older patient cohorts, possibly to due higher activity, a higher incidence of deformity and greater probability of prior surgery. Ceramic-on-ceramic bearing surfaces have been proposed for use in young and active individuals due to their low wear, low risk of adverse biologic reaction, and long-term survivorship. We assessed the clinical results and long-term survivorship of uncemented ceramic-on-ceramic THA in a young patient population. METHODS. Between August 1999 and December 2007, 220 total hip arthroplasties in 191 patients under 50 years of age at the time of surgery were performed using alumina ceramic-ceramic bearings as part of a prospective, non-randomized study. All patients received uncemented acetabular components with flush-mounted acetabular liners using an 18 degree taper, and uncemented femoral components. The average patient age at the time of surgery was 42.1 ±7.2 years (range: 17.4 years to 49.9 years), and the average time to follow-up was 10.1 ±2.4 years (range: 4.2 years to 15.2 years). We evaluated implant-related complications and performed Kaplan-Meier analyses to determine survivorship of the THA components with revision for any reason as the endpoint. RESULTS. There were no dislocations or failures due to osteolysis or aseptic loosening. There was one patient death not related to the THA procedure. Through 15-years, the Kaplan-Meier survivorship of all components was 94.9% (CI: ±8.0) with 8 revisions (3.6%) of either the cup, the stem, or both. For the acetabular component, the 15-year survivorship was 97.0% (CI: ±6.1) and included 4 revisions (1.8%), and 98.1% (CI: ±1.9) for the femoral component including 4 revisions (1.8%). One patient had both the femoral and acetabular components revised. There were two liner fractures (0.59%) and one head fracture (0.3%), two of which were sustained as a result of a fall from significant height. There were three failures of osseointegration (1.3%), and one acetabular component dislodged (0.4%) immediately following surgery. Two patients reported non-reproducible squeaking. One hip was revised at an outside institution for unknown reasons. Using the National Institutes for Health and Clinical Excellence (NICE) guidelines, our results are well within the 1% per year acceptable failure rate for this young patient population (acetabular components: 0.1% per year, femoral components: 0.1% per year, all revisions: 0.2% per year). From our experience, ceramic-on-ceramic THA in patients less than 50 years of age is very reliable with a low revision rate and absence of wear-related osteolysis. Component fracture typically occurs with high-energy trauma, and squeaking occurrence is rare in the flush-mounted ceramic liners used in our study. CONCLUSION. Total hip arthroplasty in young patients demonstrates excellent survivorship when uncemented titanium implants are coupled with ceramic-ceramic bearings

Introduction. Femoral heads made from zirconia-toughened alumina (ZTA) are the most advanced bioceramic available for total hip arthroplasty. ZTA's superior mechanical properties result from the polymorphic transformation of its zirconia (ZrO. 2. ) phase in the presence of a propagating crack. In vitro derived activation energies predict that several human lifetimes are needed to reach a state of significant transformation;. 1. but in vivo confirmation of material stability is still lacking. This investigation determined if transition metal ions might be responsible for triggering the tetragonal to monoclinic (t®m-ZrO. 2. ) phase transformation in this bioceramic. Materials and Methods. BIOLOX. ®. delta femoral heads (CeramTec GmbH, Plochingen, Germany) were acquired and characterized for their surface monoclinic content, Vm, using Raman spectroscopy. Then they were physiologically scratched with different metals (i.e., Ti, CoCr, and Fe, n=3 each) to simulate in vivo staining as a result of acetabular shell impingement due to subluxation or dislocation. They were subsequently hydrothermally aged for up to 100 h in an autoclave at 98∼132. °. C and 1 bar pressure. Raman maps, each consisting of 120 spectra, were compiled and monoclinic contents, Vm, calculated for zones adjacent to and away from the metal stains. 2. Activation energies for the t®m transformation in stained and non-stained zones were derived and compared to retrieved heads having service lives of between ∼45 days and ∼8 years. Results. The fractions of m-ZrO2 in the as-received and treated heads are presented in Table 1. In all cases, significantly greater amounts of m-ZrO. 2. were found on the metal stained areas, with the transformation amounts similar to retrieved heads. Activation energies for the t®m transformation in non-stained, CoCr-, Fe-, and Ti-stained zones were found to be 79, 60, 62, and 67 kJ/mol, respectively. Extrapolated t®m time-transformation curves at 37. °. C are shown in Figure 1 along with average m-ZrO. 2. fractions from 15 short- and medium-term retrievals. Data are compiled for values obtained on the main-wear-zones (MWZ) and non-wear-zones (NWZ) versus their elapsed time in vivo. Discussion. This experiment suggests a discrepancy in predicted (in vitro) versus observed (in vivo) phase transformation rates for metal stained ZTA femoral heads. 1. This phenomenon should be carefully considered because of its potential effect after reductions of dislocations and in the taper of these heads. While explaining the gap between in vitro predictions and in-vivo observations for phase transformation rates in ZTA components, an intrinsic incompatibility between ZTA and metal ions was also demonstrated. This phenomenon arises from a catalytic reaction at the ceramic surface by enhanced hydroxyl concentrations near the metal stains. Conclusion. Metal ions have an apparent detrimental role in destabilizing the zirconia phase at the surface of ZTA femoral heads which may impact mechanical or wear performance. Metal ions naturally present in the prosthetic joint space, metal staining of the head from hip instability, or metal ions released from modular taper corrosion may contribute to ZTA instability, even in well-functioning THA prostheses

Introduction

The optimal bearing for hip arthroplasty is still a matter of debate. in younger and more active patients ceramic-on-polyethylene (CoP) bearings are frequently chosen over metal-on-polyethylene (MoP) bearings to reduce wear and increase biocompatibility. However, the fracture risk of ceramic heads is higher than that of metal heads. This can cause serious issue, as ceramic fractures pose a serious complication often necessitating major revision surgery – a complication more frequently seen in ceramic-on-ceramic bearings. To date, there are no long-term data (> 20 years of follow-up) reporting fracture rates of the ceramic femoral heads in CoP bearings.

Introduction

The ceramic-on-ceramic strategy in acetabular revision faces potential limitations due to the femoral stem, as the implantation of ceramic ball head on a previously used taper is not recommended. Delta (r) ball heads with titanium sleeves have been proposed to avoid femoral revision. The study reports a minimum 3 years follow-up experience using this strategy.