Alumina Ceramic Femoral Heads Research Articles

Mean 16-Year Results of Total Hip Arthroplasty With Alumina Ceramic Femoral Heads on Highly Cross-Linked Polyethylene in Patients 50 Years or Less

BackgroundHighly cross-linked polyethylene (HXLPE) is a widely used bearing surface in total hip arthroplasty (THA); long-term results in young patients are limited. We previously demonstrated excellent results in HXPLE on cobalt-chrome femoral heads at 15-year mean follow-up. The purpose of the present study was to investigate polyethylene wear rates, implant survivorships, wear-related revisions, and patient-reported outcomes (PROs) in a young patient cohort who had alumina ceramic on HXPLE coupling at an average 16-year follow-up. MethodsThis was a retrospective study of 128 hips that underwent THA with HXLPE on alumina ceramic bearings between March 1, 2004, and April 15, 2007. The patient’s mean age was 38 years (range, 13 to 50). All THAs utilized HXPLE liners with alumina ceramic heads. The University of California, Los Angeles activity score and modified Harris hip scores were collected preoperatively and at each follow-up. Martell hip analysis suite was used for wear calculations. ResultsAt average 16 years (range, 13 to 18), aseptic revision survivorship was 93.3% and osteolysis/wear survivorship was 99.2%. The mean linear wear rate was 0.0191 mm/year and mean volumetric wear rate was 19.43 mm3/y, both of which were clinically undetectable. We observed excellent PROs with a significant increase in mean modified Harris hip scores (43.6 to 87.4, P < .0001) and the University of California, Los Angeles activity scores (4.0 to 6.0, P < .0001). There were no statistically significant differences in PROs or wear rates between ceramic and cobalt-chrome groups. ConclusionAt a mean 16-year follow-up, young patients who had HXLPE on ceramic coupling had excellent wear properties, PROs, and acceptable survivorships.

Mechanical behaviour investigation of PEEK coated titanium alloys for hip arthroplasty using finite element analysis

The poor mechanical strength of CP-Ti and the toxic properties of Ti6Al4V due to aluminum and vanadium contents stand out as essential issues to consider while using for total hip arthroplasty (THA). In this concern, the current study focused on investigating the stress-deformation and fatigue behaviour of three different titanium alloy stems (Ti6Al4V, Ti6Al7Nb, and Ti6Al4V ELI) with alumina ceramic femoral head and PEEK coatings using finite element analysis. The stress-deformation and fatigue behaviours were examined with and without PEEK coatings for estimating their feasibility in reducing stress-shielding effects considering knee bend gait activity for average 75 wt standard loading conditions. The fatigue behaviours were investigated using Goodman's mean stress fatigue theory by numerically analyzing employed materials' S-N (alternating stress-life cycles) curves. It was observed from the investigation that the Ti6Al7Nb stem with alumina ceramic femoral head employing PEEK coatings performed superior to other studied material combinations as it showed the lowest equivalent von-mises stresses (265.12 MPa) and the highest factor of safety (2.2895). The investigation showed that all the studied material combinations could survive for at least 10 million cycles according to their S-N curves data and respective yield strengths. Further, the employment of PEEK coatings showed their feasibility in reducing stress-shielding effects compared to bare hip implant models with a considerable increase in factor of safety.

A 28-year clinical and radiological follow-up of alumina ceramic-on-crosslinked polyethylene total hip arthroplasty: a follow-up report and analysis of the oxidation of a shelf-aged acetabular component.

Our aim in this study was to describe a continuing review of 11 total hip arthroplasties using 22.225 mm Alumina ceramic femoral heads on a Charnley flanged femoral component, articulating against a silane crosslinked polyethylene. Nine patients (11 THAs) were reviewed at a mean of 27.5 years (26 to 28) post-operatively. Outcome was assessed using the d'Aubigne and Postel, and Charnley scores and penetration was recorded on radiographs. In addition, the oxidation of a 29-year-old shelf-aged acetabular component was analysed. The mean clinical outcome scores remained excellent at final follow-up. The mean total penetration remained 0.41 mm (0.40 to 0.41). There was no radiographic evidence of acetabular or femoral loosening or osteolysis. There was negligible oxidation in the shelf-aged sample despite gamma irradiation and storage in air. These results highlight the long-term stability and durability of this type of crosslinked, antioxidant containing polyethylene when used in combination with a small diameter alumina ceramic femoral head. Cite this article: Bone Joint J 2017;99-B:1286-9.

Incidence of Modern Alumina Ceramic and Alumina Matrix Composite Femoral Head Failures in Nearly 6 Million Hip Implants

BackgroundBecause of improvements in ceramic materials and manufacturing, the incidence of ceramic failures has decreased over time. Recent concerns with corrosion have contributed to an increase in ceramic ball head utilization. The purpose of this study is to report the incidence of modern alumina bearing failures from a single major ceramic manufacturer in nearly 6 million hip implants and to identify trends in the modes of failure of these implants. MethodsBeginning in the year 2000, CeramTec AG (Plochingen, Germany) began a comprehensive program for reporting and gathering failure data on its products. From January 1, 2000, to December 31, 2013, over 3.2 million pure alumina (PA) and 2.78 million alumina matrix composite (AMC) ceramic ball heads were implanted worldwide. During this period, there were 672 PA and 28 AMC femoral head fractures. The fractures were analyzed with respect to time to failure, head size, and implant factors. ResultsThe incidence of clinical fractures of modern PA femoral heads and AMC femoral heads was 1 in 5000 (0.0201%) and 1 in 100,000 (0.0010%), respectively (P < .0001). The majority of implant failures (80%) occurred within 48 months following surgery (P < .01). Fractures were usually associated with specific events such as trauma, mismatched components, and dislocations. Large-diameter PA heads were associated with a lower rate of fracture compared to smaller-diameter femoral heads (0.0316% for 28-mm heads vs 0.0080% for heads 32 mm or greater [P < .01]). Similar trends were observed with AMC heads. The neck lengths of the femoral ball heads were also a factor: a short-taper 28-mm ball head was more likely to fracture compared to other neck lengths (P < .01). ConclusionModern PA ceramic heads are reliable with extremely low risk of fracture. The reliability is even better with AMC heads.

Wear Performance of Sequentially Cross-Linked Polyethylene Inserts against Ion-Treated CoCr, TiNbN-Coated CoCr and Al2O3 Ceramic Femoral Heads for Total Hip Replacement

The aim of the present study was to evaluate the biotribology of current surface modifications on femoral heads in terms of wettability, polyethylene wear and ion-release behavior. Three 36 mm diameter ion-treated CoCr heads and three 36 mm diameter TiNbN-coated CoCr heads were articulated against sequentially cross-linked polyethylene inserts (X3) in a hip joint simulator, according to ISO 14242. Within the scope of the study, the cobalt ion release in the lubricant, as well as contact angles at the bearing surfaces, were investigated and compared to 36 mm alumina ceramic femoral heads over a period of 5 million cycles. The mean volumetric wear rates were 2.15 ± 0.18 mm3·million cycles−1 in articulation against the ion-treated CoCr head, 2.66 ± 0.40 mm3·million cycles−1 for the coupling with the TiNbN-coated heads and 2.17 ± 0.40 mm3·million cycles−1 for the ceramic heads. The TiNbN-coated femoral heads showed a better wettability and a lower ion level in comparison to the ion-treated CoCr heads. Consequently, the low volumes of wear debris, which is comparable to ceramics, and the low concentration of metal ions in the lubrication justifies the use of coated femoral heads.

Long-Term Performance of Ceramic and Metal Femoral Heads on Conventional Polyethylene in Young and Active Patients

Ceramic femoral heads produce less wear of the opposing polyethylene than do metal femoral heads in wear simulation studies. This is a matched-pair analysis of the wear of ceramic and metal femoral heads on conventional polyethylene in uncemented total hip replacements in young, active patients at a minimum of fifteen years of follow-up. From June 1989 to May 1992, thirty-one matched pairs of alumina ceramic or cobalt-chromium metal femoral heads were identified. Patients were matched on the basis of age, sex, body weight, diagnosis, and activity level. The mean age was 55 ± 9 years (range, twenty-three to sixty-five years) at the time of surgery. All procedures were performed with a posterolateral surgical approach by a single surgeon using press-fit Ranawat-Bernstein femoral stems, Harris-Galante-II acetabular cups, GUR 4150 conventional polyethylene (sterilized in argon), and 28-mm-diameter femoral heads. Wear measurements were performed by two independent observers using the computer-assisted Roman software. The average duration of follow-up was 17 ± 1.7 years (range, fifteen to twenty years). The mean Hospital for Special Surgery hip scores (and standard deviation) in the ceramic and metal groups were 39 ± 4 and 40 ± 3 at the time of final follow-up. The University of California Los Angeles activity score at the time of the final follow-up was 6 ± 2 for both groups. The mean wear rates for the ceramic group and the metal group were 0.086 ± 0.05 mm/yr and 0.137 ± 0.05 mm/yr, respectively (p = 0.0015). There was one reoperation in the ceramic group because of distal femoral osteolysis. There were three failures in the metal group, requiring isolated liner exchange in two hips and revision of the acetabular component in one hip because of wear-induced osteolysis and/or loosening that caused symptoms. Five hips in the ceramic group and six hips in the metal group had radiographic evidence of acetabular or femoral osteolysis, but none were symptomatic. Ceramic femoral heads produced significantly less wear on conventional polyethylene liners at the time of long-term follow-up than did metal heads in this matched-pair analysis of young and active patients with uncemented fixation.

Radiographic and retrieval wear analyses of the first generation highly cross‐linked polyethylene cup against a ceramic femoral head

In this study, the in vivo wear of highly cross-linked polyethylene (CLPE) cups against alumina ceramic femoral heads was evaluated by radiographic and retrieval analysis. The radiographic wear of six ethylene oxide gas-sterilized (i.e., non-cross-linked) conventional polyethylene (PE) cups with the mean follow-up of 20.9 years and 60 CLPE cups with the mean follow-up of 7.4 years was measured. The retrieved 16 PE cups with clinical use for mean 21.5 years and 10 CLPE cups with clinical use for mean 2.9 years was evaluated as a retrieval analysis. In the radiographic analysis, the linear wear of CLPE cups was significantly lower (99% reduction) compared to conventional polyethylene cups. The results of retrieval analyses for both cups were similar to those of radiographic analyses. Even when third-body wear occurred during clinical use, no surface damage was observed on the surface of ceramic femoral heads. The surface is not sensitive to third-body wear, and hence, the ceramic femoral head has a great advantage in terms of the wear of CLPE under third-body wear conditions. In conclusion, CLPE cups used with alumina ceramic femoral heads in total hip arthroplasty should have favorable wear resistance in several in vivo situations.

A Polyethylene Liner Scratch After Revision Hip Arthroplasty Performed to Repair Ceramic Fracture

A 61-year-old man who had undergone revision total hip arthroplasty in 2000 was evaluated at our clinic in 2008, 1 day after feeling an abnormal clicking sensation in his left hip. Radiographs showed a fracture of the alumina ceramic liner of his acetabular component. A second revision total hip arthroplasty was performed with a 28-mm highly crosslinked polyethylene acetabular liner and an alumina femoral head. Sixteen months after the second revision, the patient experience sudden-onset hip pain. Radiographs revealed a fatigue fracture of the neck of a displaced stem. Analysis by scanning electron microscopy of the surface of the retrieved alumina ceramic femoral head revealed no scratches or wear, but analysis of the highly crosslinked polyethylene socket revealed third-body wear, scratches, irregularly shaped dips, and white ceramic particles. Elemental analysis of the white particles by an x-ray microanalyzer revealed the presence of aluminum and oxygen.

Wear and Creep of Highly Crosslinked Polyethylene against Cobalt Chrome and Ceramic Femoral Heads

The wear and creep characteristics of highly crosslinked ultrahigh-molecular-weight polyethylene (UHMWPE) articulating against large-diameter (36mm) ceramic and cobalt chrome femoral heads have been investigated in a physiological anatomical hip joint simulator for 10 million cycles. The crosslinked UHMWPE/ceramic combination showed higher volume deformation due to creep plus wear during the first 2 million cycles, and a steady-state wear rate 40 per cent lower than that of the crosslinked UHMWPE/cobalt chrome combination. Wear particles were isolated and characterized from the hip simulator lubricants. The wear particles were similar in size and morphology for both head materials. The particle isolation methodology used could not detect a statistically significant difference between the particles produced by the cobalt chrome and alumina ceramic femoral heads.

Tribological and material analyses of retrieved alumina and zirconia ceramic heads correlated with polyethylene wear after total hip replacement

It has been suggested that the wear of ultra-high molecular weight polyethylene (UHMWPE) in total hip replacement is substantially reduced when the femoral head is ceramic rather than metal. However, studies of alumina and zirconia ceramic femoral heads on the penetration of an UHMWPE liner in vivo have given conflicting results. The purpose of this study was to examine the surface characteristics of 30 alumina and 24 zirconia ceramic femoral heads and to identify any phase transformation in the zirconia heads. We also studied the penetration rate of alumina and zirconia heads into contemporary UHMWPE liners. The alumina heads had been implanted for a mean of 11.3 years (8.1 to 16.2) and zirconia heads for a mean of 9.8 years (7.5 to 15). The mean surface roughness values of the explanted alumina heads (Ra 40.12 nm and Rpm 578.34 nm) were similar to those for the explanted zirconia heads (Ra 36.21 nm and Rpm 607.34 nm). The mean value of the monoclinic phase of two control zirconia heads was 1% (0.8% to 1.5%) and 1.2% (0.9% to 1.3%), respectively. The mean value of the monoclinic phase of 24 explanted zirconia heads was 7.3% (1% to 26%). In the alumina group, the mean linear penetration rate of the UMWPE liner was 0.10 mm/yr (0.09 to 0.12) in hips with low Ra and Rpm values (13.22 nm and 85.91 nm, respectively). The mean linear penetration rate of the UHMWPE liner was 0.13 mm/yr (0.07 to 0.23) in hips with high Ra and Rpm values (198.72 nm and 1329 nm, respectively). This difference was significant (p = 0.041). In the zirconia head group, the mean linear penetration rate of the UHMWPE liner was 0.09 mm/yr (0.07 to 0.14) in hips with low Ra and Rpm values (12.78 nm and 92.99 nm, respectively). The mean linear penetration rate of the UHMWPE liner was 0.12 mm/yr (0.08 to 0.22) in hips with high Ra and Rpm values (199.21 nm and 1381 nm, respectively). This difference was significant (p = 0.039). The explanted zirconia heads which had a minimal phase transformation had similar surface roughness and a similar penetration rate of UHMWPE liner as the explanted alumina head.

Catastrophic Failure of Ceramic-Polyethylene Bearing Total Hip Arthroplasty

Complications of ceramic-polyethylene bearing total hip arthroplasty (THA) include osteolysis, loosening, dislocation, and component failure. Catastrophic acetabular component failure involves severe damage to both the polyethylene liner and metal shell. This case study presents the first reported complete wear-through of the acetabular portion of a ceramic-polyethylene arthroplasty presenting as a dislocation and a review of the literature. In this study, a patient's alumina ceramic femoral head penetrated the polyethylene liner and titanium shell and presented as a dislocated THA. The contributing factors for this catastrophic failure include young patient age, high activity level, thin polyethylene liner, backside wear, component positioning, polyethylene sterilization with γ irradiation in air, and lack of appropriate follow-up. Revision THA was performed without complications.

Fracture of an Alumina Femoral Head Used in Ceramic-on-Ceramic Total Hip Arthroplasty

A case report regarding the fracture of an alumina ceramic femoral head used in ceramic-on-ceramic total hip arthroplasty is presented. The patient, who was seen in the emergency room with pain, grinding, and instability in the hip immediately after a slip-without-fall event, also reported having fallen from a height of 8 ft 6 months earlier. Characterization of the alumina fracture surfaces by light and scanning electron microscopy suggests that the previous fall may have favored the nucleation and growth of subcritical cracks in the ceramic, which lead to fracture during the slip-without-fall event. The case report addresses the significance of impact trauma on the structural integrity of ceramic materials, which should not be ignored by patient or physician regardless of perceived severity.

Clinical Results for 19 to 21 Years on Total Hip Prosthesis with Ceramic Head Combined with UHMWPE Socket

In total hip prosthesis (THP), we have been using alumina ceramic femoral heads to reduce polyethylene debris and the modified cementing technique, which was named “interface bioactive bone cement (IBBC)” method to improve implant fixation. In this study, we investigated the long-term clinical performance of THPs with an alumina ceramic head and IBBC method. From 1986 to 1988, 285 joints (215 patients) were operated on by a senior surgeon, and 265 joints (192 patients) could be followed up. The presence of radiolucent lines, loosening, osteolysis and ultrahigh-molecular-weight polyethylene (UHMWPE) socket wear were observed. In IBBC, a radiolucent line appeared as a ’space’, and loosening appeared as a ’separation’ between the HA layer and the cement. A ‘space’ appeared in 3 joints (1.4%) on the acetabulum and in 4 joints (1.8%) on the femur, while a ‘separation’ appeared in 3 joints (1.4%) on the acetabulum. Osteolysis was noted in 1 joint (0.5%) on the acetabulum and in 2 joints (0.9%) on the femur. No revision surgery was required. In our previous study, we reported that the thickness of the socket affected its clinical wear rate and that the wear rate of sockets with an alumina ceramic head was 20% lower than that of sockets with a metal head. By reducing wear debris through the use of ceramic heads, osteolysis could be reduced. Long-term fixation of THPs to the bone has been achieved by using IBBC. Thus, the long-term clinical results of THPs with an alumina head that were fixed using IBBC were excellent.

Low-friction arthroplasty of the hip using alumina ceramic and cross-linked polyethylene

We report the results of our continued review of 11 total hip arthroplasties using 22.225 mm alumina ceramic femoral heads on a Charnley flanged stem, articulating with chemically cross-linked polyethylene. There was an initial bedding-in of up to 0.41 mm at the articular surface in the first two years. This had not progressed further, at a minimum follow-up of 15 years. Radiographically no femoral or acetabular component showed loosening or osteolysis.

Temperature prediction in a finite element model for sliding contact analysis of total hip prosthesis

A finite-element model for sliding contact in total hip joint prosthesis is presented in this paper. The hip prosthesis studied consists of an ultra-high molecular weight polyethylene (UHMWPE) acetabular cup articulating against cobalt-chrome and alumina-ceramic femoral heads. Various aspects of prosthesis operation were analysed using the finite-element model. For example, bulk material and surface stresses were analysed under varying conditions of elastic modulus, friction coefficient, sliding speed, and radial clearance. The resulting variations of temperature were also recorded. The results obtained from the model are useful in understanding the operating conditions and the causes of wear in the hip prosthesis.

Effect of alumina femoral heads on polyethylene wear in cemented total hip arthroplasty

We examined the behaviour of alumina ceramic heads in 156 cemented total hip arthroplasties, at a minimum follow-up of eight years. They were divided into three groups according to the size of the femoral head; 22, 26, and 28 mm. We measured polyethylene wear radiologically using a computer-aided technique. The linear wear rate of polyethylene sockets for the 28 mm heads was high (0.156 mm/year), whereas those for the 22 and 26 mm heads were relatively low (0.090 and 0.098 mm/year, respectively). Moreover, the surface roughness data of retrieved femoral heads clearly showed maintenance of an excellent surface finish of the current alumina. We conclude that the alumina ceramic femoral heads currently used are associated with a reduced rate of polyethylene wear.

Revision total hip arthroplasty performed after fracture of a ceramic femoral head. A multicenter survivorship study.

The alumina ceramic femoral head was introduced for total hip arthroplasty approximately thirty years ago. One of its main drawbacks was the risk of implant fracture. The aim of this study was to examine the results of revision total hip replacement performed specifically to treat a fracture of a ceramic femoral head and to identify technical factors that affected the outcomes. One hundred and five surgical revisions to treat a fracture of a ceramic femoral head, performed at thirty-five institutions, were studied. The patients were examined clinically by the operating surgeon at the time of the last follow-up. The surgeon provided the latest follow-up radiographs, which were compared with the immediate postoperative radiographs. The success of the revisions was assessed with Kaplan-Meier survivorship analysis, with the need for repeat revision as the end point. We evaluated the complication rate and radiographic changes indicative of implant loosening. The average duration of follow-up between the index revision and the last clinical and radiographic review was 3.5 years (range, six months to twenty years). Following the revisions, radiographic evidence of cup loosening was seen in twenty-two hips (21%) and radiographic evidence of femoral loosening was seen in twenty-two (21%). One or several repeat revisions were necessary in thirty-three patients (31%) because of infection (four patients), implant loosening (twenty), osteolysis (eight), or fracture of the revision femoral head component (one). The survival rate at five years was 63% (95% confidence interval, 51% to 75%). The survival rate was significantly worse when the cup had not been changed, when the new femoral head was made of stainless steel, when a total synovectomy had not been done, and when the patient was less than fifty years old. Fracture of a ceramic femoral head component is a rare but potentially serious event. A suitable surgical approach, including total synovectomy, cup exchange, and insertion of a cobalt-chromium or new ceramic femoral ball minimizes the chance of early loosening of the implants and the need for one or more repeat revisions. Therapeutic study, Level IV (case series [no, or historical, control group]).

Mechanical Strength of Used Ceramic Femoral Heads

Twenty retrieved 32mm alumina ceramic femoral heads were investigated for surface structure or mechanical strength. All heads were retrieved at revision hip surgery after (on average) eight and a half years in vivo. In all cases cementless stems (titanium-alloy) and spherical acetabular components with a polyethylene inlay had been used. For surface analysis EDX analysis and scanning electron microscopy were used. Fracture strength of the heads according to ISO 7206–5 was measured and a fracture analysis was performed. Frequently appositional metal marks on the ceramic surface were found. These were allocated to three zones. Depending on surface zone different metal composites were detected. Their possible origin and relevance are discussed. The fracture strength ranged from 46 kN to 104 kN. Ceramic femoral heads of high quality seem to maintain a high degree of fracture strength for a considerable period after implantation.

The performance of two hydroxyapatite-coated acetabular cups compared with Charnley cups

We have compared the survival of two hydroxyapatite (HA)-coated cups, 1208 Atoll hemispheric and 2641 Tropic threaded, with cemented Charnley all-polyethylene cups (16 021) using the Cox regression model. The Tropic cup used in combination with an alumina ceramic femoral head, had good results, similar to those of the Charnley cup. When used in combination with a stainless-steel head, however, the risk of revision beyond four years was increased 3.4 times for the Tropic cup compared with the Charnley cup (p &lt; 0.001). Over the same period, the Atoll cup had an increased risk of revision of 3.8 times when used with the alumina heads (p &lt; 0.001) and an increased risk of 6.1 times when used with stainless-steel heads (p &lt; 0.001). Revision because of wear and osteolysis was more common with both types of HA-coated cup than with the Charnley cup. The rate of revision of the Atoll cup because of aseptic loosening was also increased. We found that HA-coated cups did not perform better than the Charnley cup.

A comparison of the wear and physical properties of silane cross-linked polyethylene and ultra-high molecular weight polyethylene

Cross-linked polyethylenes are being introduced widely in acetabular cups in hip prostheses as a strategy to reduce the incidence of wear debris–induced osteolysis. It will be many years before substantial clinical data can be collected on the wear of these new materials. Silane cross-linked polyethylene (XLPE) was introduced into clinical practice in a limited series of acetabular cups in 1986 articulating against 22.225-mm alumina ceramic femoral heads and showed reduced wear rates compared with conventionally sterilized (gamma irradiation in air) ultra-high molecular weight polyethylene (UHMWPE). We compared the wear of XLPE manufactured in 1986 with the wear of UHMWPE manufactured in 1986 in nonirradiated and irradiated forms. In the nonirradiated forms, the wear of XLPE was 3 times less than UHWMPE when articulating against smooth counterfaces. The nonirradiated materials did not show signs of oxidation. In the irradiated forms, only UHMWPE showed high levels of oxidation, and this caused a substantial increase in wear. Antioxidants added to XLPE during processing gave resistance to oxidative degradation. When sliding against scratched counterfaces, the wear of UHMWPE increased by a factor of 2 to 3 times. Against the same scratched counterfaces, the wear of XLPE increased dramatically by 30 to 200 times. This difference may be attributed to the reduction in toughness of XLPE. Clinically, XLPE has been articulated against damage-resistant ceramic heads, and this probably has been an important factor in contributing to reduced wear. New cross-linked polyethylenes differ considerably from XLPE. This study indicates that it is prudent to examine the wear of new polyethylenes under a range of conditions that may occur in vivo.