Introduction. Previous registry studies of ceramic-on-polyethylene (C-PE) and ceramic-on-ceramic (COC) have focused on revision outcomes following primary surgery. Less is known about the effect of ceramic bearings on infection, dislocation, and mortality as outcomes following primary total hip arthroplasty (THA) for the Medicare population. We asked (1) does the use of C-PE bearings influence outcomes following THA as compared with metal-on-polyethylene (M-PE); and (2) does the use of COC bearings influence outcomes following THA as compared with M-PE?. Methods. A total of 315,784 elderly Medicare patients (65+) who underwent primary THA between 2005 and 2014 with known bearing types were identified from the Medicare 100% inpatient sample administrative database. Outcomes of interest included relative risk of 90-day readmission, infection, dislocation, revision, or mortality at any time point after primary surgery. Propensity scores were developed to adjust for selection bias in the choice of bearing type at index primary surgery. Cox regression incorporating propensity score stratification (10 levels) was then used to evaluate the impact of bearing surface selection on outcomes, after adjusting for patient-, hospital-, and surgeon-related factors. Results. For primary THA patients treated with C-PE bearings and COC bearings, there was significantly reduced risk of infection relative to M-PE bearings (C-PE Hazard Ratio, HR: 0.86, p=0.001; COC Hazard Ratio, HR: 0.74, p=0.01). For the C-PE cohort, we also observed reduced risk of 90-day readmission (HR: 0.94, p<0.001); dislocation (HR: 0.81, p<0.001); and mortality (HR: 0.92, p<0.001). There was no significant difference in risk of revision for either the C-PE or COC bearing cohorts when compared with M-PE. For the COC cohort, there was no significant difference in readmission, dislocation, or mortality risk. Conclusions. The results indicate that, after adjusting for selection bias and various confounding patient-, surgeon-, and hospital-related factors, Medicare patients treated with primary THA with ceramic bearings exhibit lower risk of infection than those treated with M-PE bearings. In addition, C-PE bearings were associated with lower risk of dislocation and mortality. As in previous registry studies, we found that ceramic bearings have similar revision risk as M-PE bearings in primary THA at between 8 and 9 years of follow-up. The findings of this study support further research into the long-term association between ceramic bearings in primary THA and clinical outcomes

Introduction. Previous studies of ceramic-on-polyethylene (C-PE) and ceramic-on-ceramic (COC) hip bearings have focused on outcomes following primary surgery. Less is known about the utilization or outcomes of ceramic bearings in revision total hip arthroplasty (R-THA) for the Medicare population in the US. We asked (1) what is the utilization of ceramic bearings for R-THA in the Medicare population and how has it evolved over time; (2) does the use of C-PE bearings influence outcomes following R-THA as compared with metal-on-polyethylene (M-PE); and (3) does the use of COC bearings influence outcomes following R-THA as compared with M-PE?. Methods. A total of 31,809 Medicare patients (aged > 65y) who underwent R-THA between 2005 and 2013 with known bearing types were identified from the Medicare 100% inpatient sample administrative database. Outcomes of interest included relative risk of readmission (90 days) or infection, dislocation, rerevision, or mortality at any time point after revision. Propensity scores were developed to adjust for selection bias in the choice of bearing type at revision surgery. Cox regression incorporating propensity score stratification (10 levels) was then used to evaluate the impact of bearing surface selection on outcomes, after adjusting for patient-, hospital-, and surgeon-related factors. Results. The utilization of C-PE and COC bearings in RHA increased from 5.3% to 26.6% and from 1.8% to 2.5% between 2005 and 2013, respectively. For R-THA patients treated with C-PE bearings, there was reduced risk of 90-day readmission (Hazard Ratio, HR: 0.90, 95% CI: 0.84–0.96, p=0.007). We also observed a trend for reduced risk of infection with C-PE (HR: 0.88, 95% CI: 0.74–1.04) that did not reach statistical significance (p = 0.14). For R-THA patients treated with COC, there was reduced risk of dislocation (Hazard Ratio, HR: 0.76, 95% CI: 0.58–0.99, p=0.04). There was no significant difference in risk of rerevision or mortality for either the C-PE or COC bearing cohorts when compared with M-PE. Discussion. The results indicate that, after adjusting for selection bias and various confounding patient-, surgeon-, and hospital-related factors, Medicare patients treated in a revision scenario with ceramic bearings exhibit similar risk of rerevision, infection, or mortality as those treated with M-PE bearings. Conversely, we found an association between the use of specific ceramic bearings in R-THA and reduced risk of readmission (C-PE) and dislocation (COC). The findings of this study support further research into the association between ceramic bearings in R-THA and lower risk of hospital readmission, dislocation, and, potentially, infection

Aims: Todayñs major challenge for total hip arthroplasty is to minimize wear and osteolysis in our younger and more active patients. Alumina ceramic bearings have known superior wear resistance and lubrication and do not carry a risk of ion release. One objective of this clinical study was to evaluate the use of alumina-on-alumina ceramics with proven implants that have had successful track records with regard to þxation (on a prospective randomized basis)Methods: Utilizing new improved alumina ceramic materials and implant design 514 hips were implanted in a multicenter US IDE prospective and randomized study. The study compared alumina-on-alumina ceramic bearings to a cobalt chrome-on-polyethylene bearing. All patients received the same press-þt hydroxylapatite-coated femoral stem while two-thirds (349 hips) received alumina ceramic bearings and one-third (165 hips) received the cobalt chrome-on-polyethylene bearing. Results: With a mean follow-up of greater than 40 months (36–60 months) there is no signiþcant difference in clinical performance between the two patient cohorts. Radiographically proximal femoral osteolysis has been noted in the control patients but in no patients that received the ceramic bearing. With Continued Access, a total of 947 alumina ceramic bearings have been implanted to date. There have been no ceramic fractures or alumina bearing failures. Conclusions: This new alumina-alumina ceramic bearing provides for a safe option for the younger and more active patient population

Today’s major challenge for total hip arthroplasty is to minimise wear and osteolysis in our younger and more active patients. Alumina ceramic bearings have known superior wear resistance and lubrication and do not carry a risk of ion release. Utilising new improved alumina ceramic materials and implant design 514 hips were implanted in a multicentre US IDE prospective and randomised study. The study compared alumina-on-alumina ceramic bearings to a cobalt chrome-on-polyethylene bearing. All patients received the same press-fit hydroxylapatite coated femoral stem while two-thirds (349 hips) received alumina ceramic bearings and one-third (165 hips) received the cobalt chrome on polyethylene bearing. All patients suffered from non-inflammatory arthritis and were young and active with an average age of 53 years. At a follow-up of 24–60 months (mean 39.8 months) there was no significant difference in clinical performance between the patient cohorts

Aims Osteolysis from polythene debris contributes to loosening of total hip components. Will ceramic/ceramic bearings in conjunction with Hydroxyapatite Ceramic Coated Hips (HAC) survive any better?. Material. Hydroxyapatite Ceramic Coated Hips were first used in Sunderland, U.K. in May 1988. More than 2400 HAC hips have been inserted. There are 521 hips in 441 patients with ceramic/ceramic bearings. I am reporting this consecutive series. These hips are generally inserted into patients with a 20+ year life expectancy. This ranges from 18 to 74. Mean age is 52.4 years. These young patients are mostly active and many are working. Amongst the indications were osteoarthritis 297, hip dysplasia 76, and ankylosing spondylitis 18. Thirty eight had had previous childhood hip disorders, and 19 had rheumatoid arthritis. The series also includes 43 with AVN and 7 revisions from cemented hip replacement. All the patients are assessed using the Harris Hip Score before and after surgery. They are assessed annually. Post operative scores show 22 patients with Harris Hip Scores of less than 80, but only 9 patients have problems attributable to HAC hip surgery. These include 2 patients with infection, 3 fractured ceramic acetabular liners, two broken heads and 2 patients with loose cups, one from aseptic loosening. Apart from this one case, aseptic loosening has not been a problem. Discussion. The results have been rewarding. There are 2400+ HAC hips in the whole series. This sub group of 521 ceramic/ceramic HAC hips is small with a maximum follow up of 14 years. However, there have been few failures which could be attributed to the HA coated device. The broken ceramic components are a concern. It is probable that third body inclusions between the modular components led to stress concentrations. It is also possible that acetabular impingement was a problem and the hips may have been subluxing a few microns with every step and not just gliding with every step. This might overload the alumina implants leading to their failure. All the earlier prostheses are alumina/alumina but 55 hips inserted since august, 2005 have an alumina/zirconia compound head (Biolox Delta®). There have been no cases of periprosthetic osteolysis. Conclusions. Hydroxy Apatite bony bonding secures the implants. No cement or polyethylene is used which can contribute to osteolysis. Wear in ceramic bearings will be negligible. Third body inclusions must be avoided to prevent wear or fracture. The femoral spigot must not impinge on the acetabular margin causing subluxation which may lead to fracture. The ceramic material has to be supported to prevent fracture. The outcome of the patients in this sub-group has been rewarding. Alumina/alumina hip arthroplasty should be considered where life expectancy is substantial

Hydroxyapatite Ceramic Coated Hips (HAC) were first used in Sunderland, U.K. in May 1988. More than 1725 HAC hips have been inserted. There are 264 hips in 237 patients with ceramic/ceramic (alumina) bearings. These hips are inserted into patients with a 20+ year life expectancy. Their mean age is 50.5 years. All patients are assessed using the Harris Hip Score pre. and postoperatively. There are 14 patients with Harris Hip Scores of less than 80, but only 8 patients have problems attributable to HAC hip surgery. These include 1 patient with infection, 3 fractured ceramic acetabular liners, one broken ceramic head, 2 with aseptic loosening and 1 patient who chronically dislocated her hip. Amongst the indications were osteoarthritis 136, hip dysplasia 44, and ankylosing spondylitis 13. Twenty six had had previous childhood hip disorders, and 16 had rheumatoid arthritis. The series also includes 4 revisions from cemented hip replacement. The results have been rewarding. There are 1700+ HAC hips in the whole series. This sub group of 264 ceramic/ceramic HAC hips is small and follow up is relatively short. There have been few failures which could be attributed to the HA coated device. However, there are 4 broken ceramic components. Conclusion: Hydroxy Apatite bony bonding secures the implants. No polyethylene is used which can contribute to debris disease. Wear in ceramic bearings will be negligible. Third body inclusions must be avoided. The femoral spigot must not impinge on the acetabular margin. The ceramic material has to be supported to prevent fracture

Prosthetic joint infections (PJI) are a devastating consequence in total hip arthroplasties (THA) with both significant morbidity and sometimes mortality, posing a significant health economic burden. Studies, both clinical and in-vitro have suggested possible reduction in PJI with the use of ceramic bearings. We have investigated the relationship of ceramic-on-ceramic (CoC), ceramic-on-polyethylene (CoP) or metal-on-polyethylene (MoP) bearing surface in affecting outcome of revision surgery after primary THA using data collected from National Joint Registry for England and Wales, Northern Ireland and the Isle of Man between 2002 and 2016. We used a competing risk regression model to investigate predictors of each revision outcome, such as infection, dislocation, aseptic revision and all cause revisions. The results were adjusted for age, gender, ASA grade, BMI, indication for surgery, intraoperative complications and implant data. We identified 456,457 THA (228,786 MoP, 128,403 CoC and 99,268 CoP). In a multivariable model, the adjusted risk of revision for PJI was lower with CoC (OR-0.748, p<0.001) and CoP (OR-0.775, p<0.001) when compared to MoP bearing. Additionally there was also a significant reduction in the risk of all cause revision for CoC (OR-0.918, p=0.002) and CoP (0.806, p<0.001), bearings as compared with MoP. The protective effect of ceramic bearing was predominantly seen after two years of implantation with a significant (p<0.0001) reduction of revision for PJI in both CoC (by 42.8%) and CoP (by 41.3%) group. Similarly significant effect was seen for aseptic revision beyond two years and overall all cause revision rate beyond two years reduced by 21.6% for CoC and 27.1% for CoP (p<0.001). Within the limits of registry analysis, this study has demonstrated an association between the use of ceramic bearing and lower rates of revision for all cause revisions especially infection and aseptic loosening. This finding supports the use of ceramic bearings in THA

Aims. Will Hydroxyapatite hip (HA) arthroplasty associated with ceramic bearings produce uncomplicated function in younger, active patients’ The incidence of aseptic loosening, dislocation and broken implants has been particularly investigated. Debris disease from plastic debris contributes to aseptic loosening. Hard-Hard bearings should obviate this problem. Metal-metal will release ions which might be deleterious. Experience with metal-metal resurfacing has high lighted problems including pseudo-tumours. Ceramic bearings may fracture but otherwise appear free of complications. Methods. This is a study extending over 19 years of 626 HA hip arthroplasties with ceramic bearings. Annual review using Harris Hip Score to assess pain and function and X-rays to check osseointegration has been performed. Alumina ceramic was inserted in 467 hips. The newer Zirconia Toughened Alumina (ZTA) has been inserted in 169 hips. There are 118 hips still under review at 10 or more years. Results. Aseptic loosening is unusual (one stem, two acetabulae (3 of 1252 components, 0.24%) Failure from mal-orientation with repeated dislocation occurred in six hips (0.96%). Three alumina heads (0.48%) and two alumina liners (0.32%) broke. There has been no failure of ZTA ceramic. No patients have thigh pain. Osteolysis and debris disease have not arisen. Harris Hip Scores show 91.2% scoring over 90 or 100. Lower scores mostly relate to other joint and medical problems. Conclusions. Assessments confirm that patients remain well. Aseptic loosening of HA hips is rare at 0.24%. Failure from broken alumina components is unusual. Alumina has now been superseded by ZTA for implantation. Ceramic on ceramic is a reliable selection for bearing surfaces in patients of any age and either sex

Aim: Alumina ceramic on ceramic bearings have gained popularity in hip arthroplasty due to the properties of low wear, low friction and chemically inert wear debris. In a previous study, we reported the excellent clinical results of a series of cementless ceramic on ceramic primary total hip arthroplasties at a minimum of 5 years. We now present the follow up results at 10 years. Method: Between June 1997 and February 1999, 301 consecutive, primary cementless hip arthroplasties were performed on 283 patients in our unit. The mean age of the patients was 57.8 years, with 145 (51%) being female. All of the hips received the same implant: (Osteonic ABC cup and Secure-Fit or Secure-Fit Plus stem; Stryker Orthopaedics). A third generation alumina ceramic on ceramic bearing (Biolox Forte; CeramTec) was used for articulation in all cases. All the operations were performed through a posterior approach with enhanced posterior repair, and the post-operative protocols were the same for all the patients. The clinical and radiographic outcome at 10 years were analysed. Results: At 10 years, 7.3% had died of unrelated cause and 3% were revised. The average Harris Hip score was 94.3 points at the last follow up. Ninety six percent of patients scored an excellent or good result, with less than 3% have moderate residual pain. Radiographically, all patients assessed had evidence of stable bony ingrowth. There were nine revisions in all, four stem revisions due to periprosthetic fracture, one secondary to aseptic loosening and one to facilitate a femoral shortening osteotomy. There was one cup revision for psoas tendonitis and one for cup repositioning. This same patient subsequently underwent further revision due to acetabular osteolysis with metallosis and some ceramic wear. Overall, the survival rate of the implants was 96% at 10 years. The retrieved femoral heads showed a median wear rate of 0.2 cubic millimeters per year. Conclusions: Alumina ceramic on ceramic bearings in cementless primary total hip arthroplasty had been shown to have good survival rate at 10 years with good function, low wear rate and no adverse radiographic changes. The one case of osteolysis may be due to ceramic wear debris or may be due to metal wear debris from the neck to rim impingement

Aim. Alumina ceramic on ceramic bearings in total hip arthroplasty (THA) may reduce the prevalence of osteolysis due to its properties of low wear and chemical inertness. This is critical in the younger patient population as they place increased demands over a longer period. This study reports on the clinical and radiographic outcomes of a series of modern cementless ceramic on ceramic THA at a minimum of 10 years in this younger group. Method. A series of 120 consecutive third generation ceramic cementless THA were performed at a single centre in 110 patients from 1997 to 1999. The average age of the patients at the time of surgery was 45 years (20 to 55 years). All procedures were carried out via the posterior approach using the same implant by the two senior authors. Results. At 10 years, 4 patients had died and 6 were lost to follow-up (5%). The mean Harris Hip Score was 94.7 points. All surviving implants analysed radiographically had evidence of stable bony ingrowth, with no cases of osteolysis. Wear rates were undetectable. There were 3 revisions (2.5%). One stem was revised following periprosthetic fracture, one stem was revised to facilitate a femoral shortening osteotomy. One cup was revised for anterior impingement causing psoas tendonitis. There was one incident of intraoperative ceramic liner chipping, which was changed without complication. There were no postoperative bearing fractures. Two patients reported intermittent squeaking at extreme hip flexion and internal rotation, the hips otherwise functioned well. The survival for both components with revision for any cause was 97.5%. Conclusion. Alumina ceramic on ceramic bearings in cementless primary THA in this series have resulted in good clinical and radiographic outcomes with low wear rates and excellent function in the demanding younger patient group at 10 years

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

Large bearing surfaces are appealing in total hip arthroplasty (THA) as they may help create a greater range of impingement free motion and reduce the risk of dislocation. However, attempts to achieve this with a metal bearing surface have been blighted by adverse reactions to metal debris. Ceramic bearings have a good long-term track record in more conventional head sizes, and manufacturing techniques now permit the use of larger ceramic bearing surfaces using monoblock uncemented acetabular components. In this study, we are reviewing the early results of the Maxera® acetabular component (Zimmer, Indiana) at our institution. All data was collected prospectively. Maxera® acetabular component is a Titanium (Ti) shell with plasma sprayed Ti for the osteointegrative surface. Delta ceramic liner is inserted & locked into the cup shell by the manufacturer (non-modular). With the Maxera cup system, the bearing diameter is dictated by the acetabular component size. Acetabular components (AC) of 46 and 48 mm have a bearing diameter (BD) of 36 mm, AC of 50 and 52 mm: have a 40 mm BD, AC of 54 and 56 mm: have a BD of 44 mm and AC of 58–64: have a 48mm BD. Delta ceramic femoral head size of 44 and 48 mm have a modular Ti sleeve between the head and femoral stem trunnion. Femoral head sizes of 36 and 40 mm have no Ti sleeve. All THA had an uncemented femoral stem. Implants were inserted with a posterior approach. Patients were reviewed at 6 weeks, 6 months and then annually with radiographs. Clinical function was evaluated using WOMAC and UCLA scores along with joint perception questionnaires. Five hundred components have been implanted in 442 patients (250 women, 192 men) with a mean age of 55, (min 17, max 80) and a mean BMI of 26.9 (min 17.8, max 51). The mean acetabular size was 54 (min 46, max 64), leading to a mean femoral head size of 44. At a minimum of two years follow-up (mean 3.8 years): 5 patients have been revised, 4 secondary to undetected intraoperative fracture of the femur and only one due to early displacement of a Maxera® cup (0.2%). Five patients reported a mild squeaking; two reported clicking and one patient presented with a symptomatic heterotopic ossification. The WOMAC score improved significantly post-operatively, (57.4 compared to 4.4 post-operatively, p<0.001). The mean post-operative UCLA score was 6.9. Sixty percent (60.6%) of patients rated their joint perception as either “natural” or “artificial without limitation”. two patients (0.4%) suffered a dislocation after high velocity trauma without recurrence after closed reduction. No ceramic component fracture was recorded. This prospective study shows that this monoblock acetabular component provides an easy implantation with minimal complications. The ceramic bearing surface provides good clinical function and joint perception. Bearing surfaces of this design may provide an alternative to large head metal on metal (MoM) implants without the side effects of metal debris/ions

Background

The CoCrMo large bearings had shown a high failure rate, because of metal ion and particle release. Alumina matrix composite (AMC) ball heads have shown to mitigate such phenomena. The aim of this study was to investigate the leaching properties of AMC clinically as well as experimentally.

The objective of this study was to determine whether the bearing surface is a risk factor for revision after late dislocation in total hip arthroplasty (THA).

Data from primary THAs were extracted from the New Zealand Joint Registry over a 13-year period. The mean age of patients was 68.9 years; 53.2% were female. The surgical approach used was posterior in 66% of THAs, lateral in 29% and anterior in 5%. There were 53,331 (65.1%) metal-on-polyethylene THAs, 14,093 (17.2%) ceramic-on-polyethylene, 8,177 (10.0%) ceramic-on-ceramic, 461 (0.5%) ceramic-on-metal, 5910, and (7.2%) metal-on-metal.

The primary endpoint was late revision for dislocation, with ‘late’ defined as greater than one year post-operatively. 73,386 hips were available for analysis. The overall revision rate was 4.3% (3,130 THAs), 1.1% (836) were revised for dislocation. Only 0.65% (470) hips were revised for dislocation after the first post-operative year.

The unadjusted hazard ratios (HR) showed significantly higher rates of revision for dislocation in ceramic-on-polyethylene (HR 2.48; p=0.001) and metal-on-polyethylene (HR 2.00; 95% p =0.007) compared to ceramic-on-ceramic. However, when adjusted for head size, age and surgical approach, only ceramic-on-polyethylene (HR 2.10; p=0.021) maintained a significantly higher rate of revision, whereas metal-on-polyethylene approached significance (HR 1.76; 95% p = 0.075).

In New Zealand, dislocation is the most common reason for revision, ahead of aseptic loosening of the acetabular component. The relationships between bearing materials and risk of revision for late dislocation is controversial. However, in this study ceramic-on-ceramic shows lower risk rates for revision than other bearing surface combinations. Low wear and less debris, limited peri-articular inflammatory reaction and an healthy fibrotic pseudo-capsule are potential factors determining long-term stability of the hip joint.

Introduction: There are ongoing concerns regarding metal wear debris following the use of metal-on-metal (MonM) bearings for hip surface and total arthroplasty. A Type IV Hypersensitivity reaction to MonM articulations has previously been identified (aseptic lymphocyte dominated vasculitis associated lesion, ALVAL) but little is known of its incidence, diagnosis or management. Persisting groin pain in MonM patients may be undiagnosed ALVAL. At our single centre we have reviewed and compared three types of MonM articulations to examine the incidence of ALVAL and to identify trends.

Methods: The resurfacing group comprised 250 patients with the ASR prosthesis. In the resurfacing hybrid total hip replacement (THR) group there were 86 patients implanted with an ASR head on a stem. The final group comprised of 625 patients with a MonM THR using a 36mm Pinnacle head. Both the S-ROM and the Corail stems were used in the THR groups. Patients with persisting and activity-restricting groin pain had tests for infection. Patients were counselled and revision was offered if ALVAL was suspected from the clinical picture, blood results and the aspiration result. Specimens for microbiological and histological analysis were taken at the time of revision.

Results: We found 5 cases of histologically proven ALVAL in the absence of infection in 961 patients. The incidence was: 1.2% in the resurfacing group, 2.3% of Resurfacing Hybrid THR group and 0 in the 36 mm THR group. All 5 cases were in female patients. Only 1 case had any radiological abnormality. One patient was initially revised from a resurfacing to a 36mm MonM THR without clinical success. All patients have now been revised to ceramic-on-ceramic bearings with improvements in outcome.

Discussion: ALVAL may be under-diagnosed. The 5 patients we describe showed good clinical recovery following their primary procedure. However, activity levels decreased and pain increased at 6–12 months post-op. All described non-specific systemic symptoms. On examination, a painful straight leg raise was a characteristic finding. This may result from the significant effusion found around the hip at each revision. Fluid aspirated from these hips was of a characteristic colour (green grey) and viscosity. The failure of the revision of a resurfacing to a smaller MonM bearing highlights the problem of sensitisation to the metal debris. Any subsequent revision to a MonM bearing is unlikely to improve clinical outcome. This finding is consistent with previous reports in the literature. Our results suggest the incidence of ALVAL may be higher that previously thought. We suggest all patients with significant groin pain should have inflammatory markers tests and a hip aspiration performed. In the absence of infection, revision to an alternative bearing surface may be indicated.

Ceramic-ceramic articulations have been in used in total hip arthroplasty (THA) since 1970. Although the problems of wear were well recognised in the early days of hip replacement, early ceramic-ceramic implants were plagued by poor design, fixation problems and component fractures. Early designs were often uncemented with no biological coating to augment fixation. Loosening of one side of the joint or the other was common-place.

Improvements in ceramic manufacturing were made and included improved purity, hot isostatic pressing and proof testing. The grain size, an indicator of toughness had dropped from 4.5 um in the 1970’s to 1.8 um in the 1990’s. Ceramic ball heads were approved in both alumina and zirconia in the late 1980’s for use on polyethylene. The hardness and toughness of ceramic pieces had now reached a new level of reliability, worthy of routine use in total hip replacements. Taper technology was also enhanced, resulting in proper load transfer to the ceramic parts. Fracture rates are estimated at 4/100 000. Stem fractures occur at a rate of 35 times higher.

Wear studies label ceramic-ceramic bearings among the lowest in debris generation, up to 200 times less than metal on conventional polyethylene. Modern alumina-alumina ceramic THAs were developed and clinical trials began under the auspices of several FDA Investigational Device Exemptions (IDE). Two have been completed and await full approval from the FDA. With a much better understanding of the aspects of design coupled with successful fixation, both cemented and uncemented, ceramic components can be coupled with these implants with the potential for optimal survivorship. America, brace yourself for the next generation of THA that is truly new and improved.

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.

Introduction: With ceramic on ceramic bearing surfaces in total hip arthroplasty audible noise is a frequently documented problem. With increasing head size, there is less chance of component-on-component impingement and therefore a decreased risk of chipping, breaking and maybe noise occurrence.

Material and Methods: Prospective multicentre follow-up study of n=149 cases (91 males and 58 females). All patients were treated with either 32 or 36mm ceramic on ceramic articulation (Bionit^®) in combination with the non-cemented modular pressfit cup seleXys^® (Mathys Ltd Bettlach, Switzerland). There were n=4 patients with bilateral surgery. 56 patients received a 32mm head whereas 93 patients were treated with a 36mm head. In the group with 32 mm head diameter 79% were women, whereas in the 36 mm group only 16% were women. Patients were operated between December 2005 and January 2007. The mean age at surgery was 67.2 years (range, 46.3 – 86.4 years). Mean body mass index was 28.0 kg/m2 (range, 17.1 – 45.4 kg/m2). Patients were followed clinically and radiographically at three and six months, then after one and two years.

Results: 5 patients died and 2 patients were lost to follow-up. Only one patient reported squeaking noise immediately after the operation. At the one year follow-up the patient reported a feeling of subluxation and the noise turned into a clicking. The patient had to be revised after 14 months with a polyethylene inlay. No other revisions had taken place.

Patients with femoral heads of 32 mm and 36 mm diameter had excellent clinical results after 2 years follow-up for flexion angle, range of motion and Harris Hip Score. The Harris Hip Score increased from a pre-operative mean of 48.7 points to 93.5 points. Hip flex-ion increased from 91° to 113°. The Visual Analogue Scale for pain decreased from 6.7 to 0.9 and VAS for satisfaction increased from 3.2 to 9.3.

Conclusion: Compared to other studies the occurrence of noise and resulting revision procedures is very low. We assume that the insertion of bigger heads may reduce this problem and simultaneously allow the patient a better range of motion. The non-cemented modular cup combined with a ceramic inlay and a ceramic femoral head is a safe implant with excellent clinical results after two years.

The choice to use alumina in the manufacture of a low-wear THR bearing made by Boutin and its co-workers has proven its effectiveness in almost 35 years of clinical use. A continuous development process aimed to improve mechanical properties led to today’s materials that exhibit extreme high reliability.

The recent introduction in clinical use of alumina matrix composites represents the latest evolution of alumina that thanks to high hardness, toughness, and bending strength allow to manufacture new design of ceramic components. Composites obtained introducing zirconia in the alumina matrix, known as Zirconia Toughened Alumina (ZTA) are candidate for use in THA bearings from a long time. A real breakthrough was represented by alumina ceramics toughened both by zirconia both by platelets nucleated in-situ during sintering (Zirconia-Platelet Toughened Alumina - ZPTA).

The chemical composition and the microstructure of ZPTA were optimised to achieve a ceramic material joining strength of more than 1200MPa, Vickers hardness 1975, fracture toughness of 6,5 MPa m-1/2, andextremely low wear also in the most severe simulator tests performed in microseparation mode The paper reviews the improvements introduced in the technology of ceramic for arthoplasty, and their effects on the microstructural properties and on the performances of the past and actual generation of ceramic for THR bearings, and summarise the results obtained in the development of alumina matrix composites.

The choice to use alumina in the manufacture of a low-wear THR bearing made by Boutin and its co-workers has proven its effectiveness in almost 35 years of clinical use. A continuous development process aimed to improve mechanical properties led to today’s materials that exhibit extreme high reliability. The recent introduction in clinical use of an alumina matrix composite developed by CeramTec and available under the trade name Biolox®Delta represents the latest evolution of alumina. This material allow new design in ceramic components thanks to its equilibrium among high hardness, high toughness, and high bending strength.

Composites obtained introducing zirconia in the alumina matrix, known as Zirconia Toughened Alumina (ZTA) are candidate for use in THA bearings from a long time. A real breakthrough was represented by alumina ceramics toughened both by phase transformation both by platelets nucleated in-situ during sintering. Optimised processing and quality control led to optimised material behaviour.

The chemical composition and the microstructure of Biolox®Delta were optimised to achieve a ceramic material joining strength of more than 1200 MPa, Vickers hardness 1975, fracture toughness of 6,5 MPam-1/2, and extremely low wear also in the most severe simulator tests performed in microseparation mode.

The paper reviews the improvements introduced in the technology of ceramic for arthoplasty, and their effects on the microstructural properties and on the performances of the past and actual generation of ceramic for THR bearings, and summarise the results obtained in the development of alumina matrix composite Biolox® Delta.