Nine years follow-up of 100 ceramic-on-ceramic total hip arthroplasty

Third and fourth generation ceramic-on-ceramic total hip arthroplasty at a minimum of ten years

BACKGROUND

Ceramic on Ceramic bearings in Total Hip Arthroplasty (THA) afford a low friction coefficient, low wear rates and extreme hardness. Significant complications include hip squeak, ceramic fracture and poor polyethylene performance in revision procedures due to imbedding of abrasive microscopic ceramic fragments. We report on the results of this bearing at a minimum of 10 years.

METHODS

A single-centre retrospective review of 449 THAs was performed. Primary outcome measures included aseptic revision and all-cause revision rates at a minimum of 10 years post operatively. Evaluation of functionality was performed with WOMAC and SF-36 scores which were performed pre-operatively and at intervals of 6 months, one year, 2 years, 5 years and 10 years post operatively.

RESULTS

There was a 6.2% (n = 28) all-cause and 5.3% (n = 24) aseptic revision rate for ceramic on ceramic total hip arthroplasty at minimum of 10 years with a mean time to revision 4.8 years (range 2 months-11.6 years). Notably, there were 2 revisions for ceramic head fracture, one for ceramic liner fracture, 3 for aseptic loosening and 3 revisions for squeaking. Pain of unknown origin was the most common reason for revision. There was an improvement in postoperative WOMAC scores from a mean of 59.8 (range 15-95) pre-operatively to a mean of 15.6 (range 0-78) at 10 years.

CONCLUSION

This study showed good functional outcomes but high revision rates for CoC THA at a minimum of 10 years. Our rates of ceramic fracture were consistent with other studies.

Ceramic-on-ceramic articulation in press-fit total hip arthroplasty as a potential reason for early failure, what about the survivors: a ten year follow-up

PURPOSE

In press-fit total hip arthroplasty (THA), primary stability is needed to avoid micromotion and hereby aseptic loosening, the main reason for early revision. High aseptic loosening revision rates of the seleXys TH+ cup (Mathys Medical) with Ceramys ceramic-on-ceramic (CoC) bearing are seen in literature. Since CoC is presumed to overcome long-term wear-related revisions, the reason for early failure of this cup is important to clarify. The aim is to investigate its ten year outcomes and differentiate between potential causes and identify risk factors for aseptic loosening.

METHODS

Retrospective screening of a prospectively documented series of 315 THAs was performed. Primary outcome was cumulative incidence of cup revision due to aseptic loosening. Secondary outcomes were component revision and reoperation. Additionally, potential predictive factors for aseptic loosening were evaluated.

RESULTS

At the median follow-up of 9.7 years [IQR 4.4; 10.3], 48 TH+ (15.2%) were revised due to aseptic loosening. Competing risk analysis showed a ten year cumulative incidence of cup revision due to aseptic loosening of 15.6% (95% CI 12.0-20.2). Stabilization of early revision rates was observed, following a high rate of respectively 81.3% (n = 39) and 95.8% (n = 46) within the first two and three years. No significant predictive factors for aseptic loosening were found.

CONCLUSION

The ten year results of seleXys TH+ cup with Ceramys CoC bearing showed an unacceptable high aseptic loosening rate, which stabilized over time after a high early failure incidence. This could be attributed to a problem with osseointegration during the transition of primary to definitive stability.

Wear of composite ceramics in mixed-material combinations in total hip replacement under adverse edge loading conditions

Ceramic composites have performed very well under adverse edge loading conditions when used in like-on-like configurations, where the femoral head and acetabular cup are of the same material. The aim of this study was to determine the wear of pure alumina (Al2 O3 ), alumina toughened zirconia (ATZ) and zirconia toughened alumina (ZTA) when used in mixed bearing combinations, under edge loading conditions due to translational mal-positioning. The head-on-cup configurations of three ceramic materials were ATZ-on-ZTA, ZTA-on-ATZ, Al2 O3 -on-ATZ, ATZ-on-Al2 O3 , Al2 O3 -on-ZTA, and ZTA-on-Al2 O3 . They were tested on the Leeds II hip simulator under microseparation conditions. The bedding in and steady state wear rates of ATZ-on-ZTA were 1.16mm3 /million cycles and 0.18mm3 /million, respectively, and for ATZ-on-Al2 O3 were 0.66 mm3 /million cycles and 0.20 mm3 /million, respectively. The wear rates of the other bearing combinations under these adverse microseparation conditions, Al2 O3 -on-ATZ, Al2 O3 -on-ZTA, ZTA-on-ATZ and ZTA-on-Al2 O3 were very low with no clear bedding in and steady state phases, and with steady state wear rates lower than 0.11 mm3 /million. The mixed material combinations tested in this study have shown slightly higher wear rates when compared to ATZ in like-on-like configuration reported previously, but superior wear resistance when compared to alumina-on-alumina bearings tested previously under the same adverse microseparation conditions. © 2016 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1361-1368, 2017.

A Randomized Trial Comparing Ceramic-on-Ceramic Bearing vs Ceramic-on-Crossfire-Polyethylene Bearing Surfaces in Total Hip Arthroplasty

BACKGROUND

Bearing surfaces in total hip arthroplasty (THA) may affect implant longevity and hence patient outcomes. This randomized clinical trial determined how ceramic-on-ceramic (CERAMIC) bearing THA affected joint-specific pain, function, and stiffness and prosthesis fixation/longevity over 10 postoperative years compared with ceramic-on-highly-crosslinked-polyethylene (POLYETHYLENE) bearing THA. This is a follow-up to previously reported 5-year outcomes.

METHODS

Subjects aged <61 years were randomized to CERAMIC (n = 48) or POLYETHYLENE (n = 44) THA. Subjects were assessed using the Western Ontario McMaster Osteoarthritis Index and the RAND 12-Item Health Survey preoperatively, and at 1, 5, and 10 years postoperatively. Plain radiographs were evaluated at 10 years for fixation, and medical records were reviewed for revisions.

RESULTS

Of 92 subjects, 6 (7%) died within 10 years; 68 (79%) survivors provided radiographic and/or clinical follow-up at 10 years postoperatively. Improvements seen at 5 years in both the Western Ontario McMaster Osteoarthritis Index and RAND 12-Item Health Survey were retained at 10 years with no group differences (P > .48). There were no failures or loss of fixation related to bearing surfaces/wear in either group. Over 10 years, 3 subjects in the POLYETHYLENE group had revisions that were related to recurrent dislocation; 2 revisions were performed within 2 years of surgery, and one further subject underwent revision at 7 years postoperatively.

CONCLUSIONS

This is one of the first randomized clinical trials to examine 10-year outcomes between CERAMIC and POLYETHYLENE bearing THAs. Both bearing surfaces performed well out to 10 years in subjects who were <61 years at time of surgery.

A numerical model to reproduce squeaking of ceramic-on-ceramic total hip arthroplasty. Influence of design and material

BACKGROUND

Modern ceramic (CoC) bearings for hip arthroplasty (THA) have been used in younger patients who expect improved survivorship. However, audible squeaking produced by the implant is an annoying complication. Previous numerical simulations were not able to accurately reproduce in vitro and in vivo observations. Therefore, we developed a finite element model to: (1) reproduce in vitro squeaking and validate the model by comparing it with in vivo recordings, (2) determine why there are differences between in vivo and in vitro squeaking frequencies, (3) identify the stem's role in this squeaking, (4) predict which designs and materials are more likely to produce squeaking.

HYPOTHESIS

A CoC THA numerical model can be developed that reproduces the squeaking frequencies observed in vivo.

MATERIAL AND METHODS

Numerical methods (finite element analysis [ANSYS]) and experimental methods (using a non-lubricated simulated hip with a cementless 32mm CoC THA) were developed to reproduce squeaking. Numerical analysis was performed to identify the frequencies that cause vibrations perceived as an acoustic emission. The finite element analysis (FEA) model was enhanced by adjusting periprosthetic bone and soft tissue elements in order to reproduce the squeaking frequencies recorded in vivo. A numerical method (complex eigenvalue analysis) was used to find the acoustic frequencies of the squeaking noise. The frequencies obtained from the model and the hip simulator were compared to those recorded in vivo.

RESULTS

The numerical results were validated by experiments with the laboratory hip simulator. The frequencies obtained (mean 2790Hz with FEA, 2755Hz with simulator, decreasing to 1759Hz when bone and soft tissue were included in the FEA) were consistent with those of squeaking hips recorded in vivo (1521Hz). The cup and ceramic insert were the source of the vibration, but had little influence on the diffusion of the noise required to make the squeaking audible to the human ear. The FEA showed that diffusion of squeaking was due to an unstable vibration of the stem during frictional contact. The FEA predicted a higher rate of squeaking (at a lower coefficient of friction) when TZMF™ alloy is used instead of Ti6Al4V and when an anatomic press-fit stem is used instead of straight self-locking designs.

DISCUSSION

The current FEA model is reliable; it can be used to assess various stem designs and alloys to predict the different rates of squeaking that certain stems will likely produce.

LEVEL OF EVIDENCE

Level IV in vitro study.

Poor outcome of a spherical pressfit cup with a modern ceramic liner: a prospective cohort study of 181 cups

A spherical pressfit cup with a new ceramic liner was introduced in a clinical trial in order to improve range of motion and reduce wear induced problems. The early clinical and radiological outcome was assessed.In a prospective cohort study 181 hips received a seleXys TH+ cup (Mathys, Bettlach, Switzerland) in combination with a third generation ceramic liner (ceramys, Mathys, Bettlach, Switzerland). The Harris Hip Score (HHS), pain (VAS) and range of motion (ROM) were recorded, cup migration and inclination were measured. Experience of any noise was documented.Fourteen hips were radiologically loose, seven of them were revised. Two-year survival of the cup was 92% with radiological loosening as the endpoint. There was no correlation between head size and ROM, no patient had a dislocation. There were no ceramic fractures. Two patients experienced squeaking and three clicking at final follow-up.Reasons for loosening might have been multifactorial but the rate of failure was unacceptably high. The use of large heads did not improve the ROM and development of noise could not be prevented with the modern ceramic. We abandoned the use of this implant system.

Thirty-day readmission rate and discharge status following total hip arthroplasty using the supercapsular percutaneously-assisted total hip surgical technique

PURPOSE

Recent studies have reported nearly 40% of costs associated with a 30-day episode-of-care for total joint replacements are due to post-discharge activities and 81% of those are specifically due to unplanned readmissions and discharging patients to post-acute care facilities. The purpose of this study was to determine these two key variables for total hip arthroplasty (THA) patients implanted using a tissue-sparing surgical technique and to see how these values compare to those previously reported in the United States.

METHODS

The healthcare databases at three institutions were searched for primary THA patients implanted using the supercapsular percutaneously-assisted total hip (SuperPath) surgical technique between January 2013 and July 2014. Data elements included 30-day all-cause readmission rate, discharge status, transfusion rate, complications, and length of stay (LOS).

RESULTS

Data were available for 479 THAs. The 30-day all-cause readmission rate, transfusion rate, and average LOS was 2.3, 3.3%, and 1.6 days, respectively. Over 91% of patients were discharged routinely home, 4.1% to skilled nursing facilities, 3.8% to home health care, and 0.6% to inpatient rehabilitation facilities. Complications included dislocation (0.8%), periprosthetic fracture (0.8%), and deep vein thrombosis (0.2 %). There were no infections reported.

CONCLUSIONS

Patients implanted using this tissue-sparing technique experienced reduced 30-day all-cause readmission rates (2.3% vs. 4.2%) and more were routinely discharged home (91.5% vs. 27.3%) than have been previously reported for patients in the United States. Use of this tissue-sparing technique has the potential to significantly reduce post-discharge costs.

Future bearing surfaces in total hip arthroplasty

One of the most important issues in the modern total hip arthroplasty (THA) is the bearing surface. Extensive research on bearing surfaces is being conducted to seek an ideal bearing surface for THA. The ideal bearing surface for THA should have superior wear characteristics and should be durable, bio-inert, cost-effective, and easy to implant. However, bearing surfaces that are currently being implemented do not completely fulfill these requirements, especially for young individuals for whom implant longevity is paramount. Even though various new bearing surfaces have been investigated, research is still ongoing, and only short-term results have been reported from clinical trials. Future bearing surfaces can be developed in the following ways: (1) change in design, (2) further improvement of polyethylene, (3) surface modification of the metal, (4) improvement in the ceramic, and (5) use of alternative, new materials. One way to reduce wear and impingement in THA is to make changes in its design by using a large femoral head, a monobloc metal shell with preassembled ceramic liner, dual mobility cups, a combination of different bearing surfaces, etc. Polyethylene has improved over time with the development of highly crosslinked polyethylene. Further improvements can be made by reinforcing it with vitamin E or multiwalled carbon nanotubes and by performing a surface modification with a biomembrane. Surface modifications with titanium nitride or titanium niobium nitride are implemented to try to improve the metal bearings. The advance to the fourth generation ceramics has shown relatively promising results, even in young patients. Nevertheless, further improvement is required to reduce fragility and squeaking. Alternative materials like diamond coatings on surfaces, carbon based composite materials, oxidized zirconium, silicon nitride, and sapphire are being sought. However, long-term studies are necessary to confirm the efficacy of these surfaces after enhancements have been made with regard to fixation technique and implant quality.

Incidental discovery of an undisplaced ceramic liner fracture at total hip arthroplasty revision for squeaking

Squeaking has been reported after ceramic-on-ceramic total hip arthroplasty (THA), but its pathomechanics is not fully understood. Impaired lubrication is suspected to be the main reason. The management of patients impacted by this phenomenon is not well defined and, as it is not considered to be cause for alarm, revision is not strongly recommended. Here, we describe a ceramic insert fracture discovered during revision surgery performed to correct severe squeaking. Preoperative investigation (plain X-rays, ultrasound and computed tomography) did not reveal ceramic fracture or definite component malposition. To date, there are no other published cases of incidental discovery of a bearing component fracture during revision of ceramic-on-ceramic hip replacement due to squeaking. We believe that squeaking is not a trivial phenomenon and recommend careful management of patients suffering with this symptom.

The role of biomechanics and engineering in total hip replacement. Why surgeons need technical help

Implanting the acetabular cup of hard-on-hard bearings, like metal-on-metal or ceramic-on-ceramic, requires considerable surgeon skill to avoid the complications associated with edge loading. Successful cup positioning instruments have been designed in the past by pioneering surgeons, like Peter Ring and Michael Freeman, and these are re-visited in this article. An advantage of these instruments is that they could position the acetabular cup without defining a reference pelvic plane. Computer-assisted cup orientation is able to reduce outliers in cup orientation, but the technology has not been widely adopted. There may be an opportunity to improve the uptake of computer-assisted surgery by incorporating some of the concepts from historically successful manual instruments.

Wear of 36-mm BIOLOX® delta ceramic-on-ceramic bearing in total hip replacements under edge loading conditions

Ceramic-on-ceramic bearings have become of great interest due to the substantial improvements in the manufacturing techniques and material properties and due to polyethylene wear debris–induced osteolysis and the issues with metal wear debris and ion release by metal-on-metal bearings. Edge loading conditions due to translational malpositioning (microseparation conditions) have been shown to replicate clinically relevant wear mechanisms and increase the wear of ceramic-on-ceramic bearings; thus, it was necessary to test new bearing materials and designs under these adverse conditions. The aim of this study was to assess the effect of increasing head size on the wear of BIOLOX® delta ceramic-on-ceramic bearings under edge loading conditions due to rotational (steep cup inclination angle) and translational (microseparation) malpositioning. In this study, six 36-mm ceramic-on-ceramic bearings (BIOLOX delta, CeramTec, Germany) were tested under standard and edge loading conditions using the Leeds II hip simulator and compared to the 28-mm bearings tested and published previously under identical conditions. The mean wear rate under standard gait conditions was below 0.1 mm3/million cycles for both the 28-mm and the 36-mm ceramic-on-ceramic bearings, and increasing the inclination angle did not affect the wear rates. The introduction of microseparation to the gait cycle increased the wear rate of ceramic-on-ceramic bearing and resulted in stripe wear on the femoral heads. Under microseparation conditions, the wear rate of size 36-mm bearings (0.22 mm3/million cycles) was significantly higher ( p = 0.004) than that for size 28-mm bearings (0.13 mm3/million cycles). This was due to the larger contact area for the larger bearings and deprived lubrication under edge loading conditions. The wear rate of BIOLOX delta ceramic-on-ceramic bearings under microseparation conditions was still very low ( <0.25 mm3/million cycles) compared to earlier generation ceramic-on-ceramic bearings (BIOLOX forte, 1.84 mm3/million cycles) and other bearing materials such as metal-on-metal bearings (2–8 mm3/million cycles).

Advantages and disadvantages of ceramic on ceramic total hip arthroplasty: a review

BACKGROUND

Ceramic on ceramic (COC) total hip arthroplasty (THA) was developed to reduce wear debris and accordingly, the occurrence of osteolysis and aseptic loosening especially in younger patients. Based on the excellent tribological behavior of current COC bearings and the relatively low biological activity of ceramic particles, significant improvement in survivorship of these implants is expected.

METHODS

We used manual search to identify all relevant studies reporting clinical data on COC THAs in PubMed. The objective was to determine whether current COC THA offers a better clinical outcome and survivorship than non-COC THA.

RESULTS

Studies with early generation ceramic bearings yielded 68% to 84% mean survivorship at 20 years follow-up which is comparable with the survivorship of non-COC THAs. Studies on current ceramic bearings report a 10-year revision-free interval of 92% to 99%. These outcomes are comparable to the survivorship of the best non-COC THAs. However, there are still concerns regarding fracture of sandwich ceramic liners, squeaking, and impingement of the femoral neck on the rim of the ceramic liner leading to chipping, especially in younger and physically active patients.

CONCLUSION

Current COC THA leads to equivalent but not improved survivorship at 10 years follow-up in comparison to the best non-COC THA. Based on this review, we recommend that surgeons weigh the potential advantages and disadvantages of current COC THA in comparison to other bearing surfaces when considering young very active patients who are candidates for THA.

A mid-term analysis suggests ceramic on ceramic hip arthroplasty is durable with minimal wear and low risk of squeak

BACKGROUND

The incidence of hip replacements in the younger patient is ever increasing. With this in mind, improving the longevity of hip arthroplasties is paramount. Alumina ceramic is a promising bearing surface due to its low wear rate and biological inertness.

PURPOSE

This study aims to review our experience with ceramic-on-ceramic total hip arthroplasty, reporting on the need for revision as well as the cause of failure. Our secondary purpose is to review our experience with the phenomenon of squeaking analysing and its effect on clinical outcome with specific emphasis on component positioning. Also reported are the results of our retrieval analysis of explanted components documenting the wear rate and our analysis of strip wear.

METHODS

A consecutive series of 301 primary cementless alumina-on-alumina total hip arthroplasties at a minimum of 10 years follow-up was reviewed. These arthroplasties all had third-generation ceramic-on-ceramic bearings performed through a posterior approach with repair of capsule and external rotators to bone. We analysed hips both clinically and radiographically. Analysis of wear in 62 ceramic bearings was performed using a Roundtest RA300 machine (Mitutoyo; Andover, UK), which has an accuracy of 0.01 μm.

RESULTS

Overall, the survival rate of the implants was 98% at 10 years. No ceramic fractures were encountered in this study. Seventy-four patients reported squeaking hips, and two cases were revised due to squeaking (0.6%). No failures were related to bearing wear.

CONCLUSIONS

We believe that ceramic-on-ceramic is a safe bearing coupling with excellent survivorship at 10 years.

Large-diameter Delta ceramic-on-ceramic versus common-sized ceramic-on-polyethylene bearings in THA

The higher failure rate of total hip arthroplasty (THA) in young, active patients remains a challenge for surgeons. Recently, larger-diameter femoral heads combined with an alumina matrix composite ceramic (BIOLOX Delta; CeramTec AG, Plochingen, Germany) articulation was developed to improve implant longevity and meet patients' activity demands while reducing the risk of component-related complications. The purpose of this study was to determine whether this new device may provide advantages for young, active patients. A prospective, randomized, controlled trial was conducted on 93 patients (113 THAs) with more than 3 years of follow-up. Patients were randomly divided into a study group (51 THAs) with a 36-mm Delta ceramic-on-ceramic (COC) articulation and a control group (62 THAs) with a common-sized alumina ceramic head on polyethylene liner (COP) articulation. Clinical and radiographic results were collected to compare the outcomes and complications, including implant-related failures, osteolysis, and noises. The large-diameter Delta COC articulation provided greater range of motion improvement (6.1° more), similar Harris Hip Scores, and similar complication rates compared with the alumina COP articulation. This study suggests that in the short term, the large-diameter Delta COC articulation results in better range of motion with no higher complication rates; however, mid-term (8-10 years) or longer follow-up is necessary to determine its superiority in young, active patients.

Ceramic-on-ceramic bearings in hip arthroplasty: state of the art and the future

This systematic review of the literature summarises the clinical experience with ceramic-on-ceramic hip bearings over the past 40 years and discusses the concerns that exist in relation to the bearing combination. Loosening, fracture, liner chipping on insertion, liner canting and dissociation, edge-loading and squeaking have all been reported, and the relationship between these issues and implant design and surgical technique is investigated. New design concepts are introduced and analysed with respect to previous clinical experience.

Ceramic bearings for total hip arthroplasty have high survivorship at 10 years

BACKGROUND

Ceramic bearings were introduced to reduce wear and increase long-term survivorship of total hip arthroplasty. In a previous study comparing ceramic with metal-on-polyethylene at 5 to 8 years, we found higher survivorship and no osteolysis for the ceramic bearings.

QUESTIONS/PURPOSES

We asked whether ceramic bearings have equal or superior survivorship compared with that for metal-on-polyethylene at longer followup; we also determined survivorship of the implant systems, the presence or absence of radiographic osteolysis, and incidence of device squeaking.

METHODS

Five surgeons at five sites have followed 189 patients (216 hips) for a minimum of 10 years and average of 10.3 years (range, 10-12.4 years) comparing alumina ceramic bearings (144 hips) with cobalt chrome-on-polyethylene bearings (72 hips). We determined Kaplan-Meier survivorship of the bearing surface and implant systems and collected radiographic and clinical data.

RESULTS

We observed no difference between the control metal-on-polyethylene and the alumina-bearing couple cohorts with regard to bearing-related failures (98.9% versus 99.1%). Revisions for any reason occurred in 10.5% of the control patients and 3.1% of the patients with alumina bearings. All femoral implants remain well fixed (100%), whereas one acetabular component (1%) is unstable in the control group. Osteolysis occurred in 26% of the control patients and in none of the patients with alumina bearings. Squeaking occurred in two of 144 hips (1.4%) of the patients with ceramic bearings.

CONCLUSIONS

Patients receiving the ceramic-on-ceramic bearings had fewer revisions for any reason and less osteolysis than the control metal-on-polyethylene at 10 years. Our data suggest ceramic bearings continue to provide an option for the young and more active patient and provide for a measure to compare other new alternative bearings that are currently available.

LEVEL OF EVIDENCE

Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.