Ceramic bearing surfaces

A multi-center retrospective comparative study of third generation Ceramic-on- Ceramic total hip arthroplasty in patients younger than 45 years with or without the sandwich liner: A ten-year minimum

BACKGROUND

Ceramic-on-ceramic couplings are attractive alternative bearing surfaces that have been reported to eliminate or reduce problems related to polyethylene wear debris. However, the material in THA still remains one of the major concerns about the risk of fracture, due to its brittleness.

OBJECTIVE

The present study aims at reporting the fracture rate of a series of ceramic-on-ceramic THAs with use of the sandwich liner combined with a ceramic femoral head, and attempt to detect the relative risk factors, possible cause and assesse the medium-term clinical results.

METHODS

We retrospectively evaluated 282 patients (300 hips) with use of the sandwich liner ceramic-on-ceramic THA between 2001 and 2009 at three-centers. Patient assessment was based on demographic factors, including age, weight, gender and body-mass index. All patients were evaluated clinically and radio-graphically or computed tomography in consideration of dislocation, osteolysis, periprosthetic fracture, infection, loosening and implant fracture.

RESULTS

five ceramic sandwich liners fracture (1.7%) were observed at an average of 7.3 years follow-up. These factors were irrelevant to the ceramic liner fracture, including age (p = 0.205), weight (p = 0.241), gender (p = 0.553), body-mass index (p = 0.736), inclination (p = 0.727), and anteversion (p = 0.606). The overall survival was 91.4% at 12 years with revision as the endpoint. Other complications included dislocation in two, perprosthetic fracture in two and osteolysis in eight hips. No hip had aseptic loosening of the implants was seen.

CONCLUSIONS

We found that the sandwich liner may be lead to a high rate of alumina fracture and osteolysis. We have discontinued the use of sandwich liner with THA since 2009.

Incidence, Risk Factors, and Outcome of Ceramic-On-Ceramic Bearing Breakage in Total Hip Arthroplasty

BACKGROUND

Ceramic-on-ceramic bearing breakage is a rare but significant complication of total hip arthroplasty. This study aimed to identify risk factors for breakage and to determine the outcome of different revision options.

METHODS

All ceramic-on-ceramic primary total hip arthroplasty procedures reported to the Australian Joint Replacement Registry from September 1999 to December 2019 were included. Procedures were subdivided into alumina or mixed ceramic (alumina/zirconia). All breakages were identified. The association between ceramic type and head size was assessed. Subsequent revision rates were compared and cause of revision assessed.

RESULTS

There were 23,534 alumina and 71,144 mixed ceramic procedures. Breakage was the reason for 1^st revision in 84 alumina (5.27% of all revisions and 0.36% of procedures) and 56 mixed ceramic procedures (2.46% of all revisions; 0.08% of procedures). Alumina had a higher breakage rate than mixed ceramic (HR 2.50 (95% CI 1.75, 3.59), P < .001), and breakage was higher for 36-38mm head sizes using alumina (HR 2.84 (1.52, 5.31), P = .001). 17.8% of 2^nd revisions occur by 3 years, due to dislocation, infection, metal-related pathology, and loosening. A neck adapter sleeve did not reduce 2^nd revisions. Numbers were too low to compare revision bearing surface options.

CONCLUSION

Ceramic breakage has reduced with mixed ceramics but has a 0.79/1000 incidence at 15-year follow-up. It is unclear what the risk factors are for modern ceramics with increasing head size a risk for alumina only. Risk of 2^nd revision is high and occurs early. The optimal revision option is unknown.

Custom-Made Zirconium Dioxide Implants for Craniofacial Bone Reconstruction

Reconstruction of the facial skeleton is challenging for surgeons because of difficulties in proper shape restoration and maintenance of the proper long-term effect. ZrO₂ implant application can be a solution with many advantages (e.g., osseointegration, stability, and radio-opaqueness) and lacks the disadvantages of other biomaterials (e.g., metalosis, radiotransparency, and no osseointegration) or autologous bone (e.g., morbidity, resorption, and low accuracy). We aimed to evaluate the possibility of using ZrO₂ implants as a new application of this material for craniofacial bone defect reconstruction. First, osteoblast (skeleton-related cell) cytotoxicity and genotoxicity were determined in vitro by comparing ZrO₂ implants and alumina particle air-abraded ZrO₂ implants to the following: 1. a titanium alloy (standard material); 2. ultrahigh-molecular-weight polyethylene (a modern material used in orbital surgery); 3. a negative control (minimally cytotoxic or genotoxic agent action); 4. a positive control (maximally cytotoxic or genotoxic agent action). Next, 14 custom in vivo clinical ZrO₂ implants were manufactured for post-traumatologic periorbital region reconstruction. The soft tissue position improvement in photogrammetry was recorded, and clinical follow-up was conducted at least 6 years postoperatively. All the investigated materials revealed no cytotoxicity. Alumina particle air-abraded ZrO2 implants showed genotoxicity compared to those without subjection to air abrasion ZrO₂, which were not genotoxic. The 6-month and 6- to 8-year clinical results were aesthetic and stable. Skeleton reconstructions using osseointegrated, radio-opaque, personalized implants comprising ZrO₂ material are the next option for craniofacial surgery.

Early to medium-term outcomes of uncemented ceramic-bearing total hip arthroplasty in teenagers for paediatric hip conditions

AIMS

Despite advances in the treatment of paediatric hip disease, adolescent and young adult patients can develop early onset end-stage osteoarthritis. The aims of this study were to address the indications and medium-term outcomes for total hip arthroplasty (THA) with ceramic bearings for teenage patients.

METHODS

Surgery was performed by a single surgeon working in the paediatric orthopaedic unit of a tertiary referral hospital. Databases were interrogated from 2003 to 2017 for all teenage patients undergoing THA with a minimum 2.3 year follow-up. Data capture included patient demographics, the underlying hip pathology, number of previous surgeries, and THA prostheses used. Institutional ethical approval was granted to contact patients for prospective clinical outcomes and obtain up-to-date radiographs. In total, 60 primary hips were implanted in 51 patients (35 female, 16 male) with nine bilateral cases. The mean age was 16.7 years (12 to 19) and mean follow-up was 9.3 years (2.3 to 16.8).

RESULTS

The most common indication for teenage hip arthroplasty was avascular necrosis secondary to slipped upper femoral epiphysis (31%; n = 16). Overall, 64% of patients (n = 33) had undergone multiple previous operations. The survival at follow-up was 97%; two patients required revision for aseptic loosening (one femoral stem, one acetabular component). Both patients had fused hips noted at the time of arthroplasty. A further two patients had radiolucent lines but were asymptomatic. At latest follow-up the mean Oxford Hip Score was 44 (31 to 48) and a Visual Analogue Scale measurement of 1.5, indicating satisfactory function.

CONCLUSION

Operating on this cohort can be complicated by multiple previous surgeries and distorted anatomy, which in some cases require custom-made prostheses. We have demonstrated a good outcome with low revision rate in this complex group of patients. Cite this article: Bone Joint J 2020;102-B(11):1491-1496.

Adverse Reaction to Zirconia in a Modern Total Hip Arthroplasty with Ceramic Head

Hypersensitivity reactions to zirconia (ZrO2) or similar ceramics is highly unusual. Owing to the stable oxide formed between the base metal and oxygen, ceramics are considered relatively biologically inert. We report the case of an otherwise healthy 50-year-old woman with a 5-year history of progressively worsening right hip pain who underwent a ceramic-on-polyethylene total hip replacement and subsequently developed hypersensitivity reaction. After metal allergy testing showed her to be highly reactive to zirconium, the femoral head was revised to a custom titanium implant and her symptoms resolved.

Early low complication rate of ceramic-on-ceramic total hip arthroplasty by direct anterior approach

Introduction: Ceramic-on-ceramic couplings are an alternative bearing surface to reduce the problems related to polyethylene wear and debris. However, ceramic articulations have their own risk of unique complications: fracture, squeaking, or dislocation. Few studies have assessed the outcomes of ceramic-on-ceramic total hip arthroplasties (THA) by direct anterior approach (DAA). The aim was to evaluate the early complications and revision rate of ceramic-on-ceramic THA by DAA. Material: A retrospective single-center study of 116 consecutive THAs was performed by DAA (106 patients) with ceramic-on-ceramic bearing from January 2015 to February 2018 with a minimum 24 months of follow-up. No patients were lost to follow-up. The mean age was of 55.3 years ± 11.3. The same cementless acetabular shell with a Biolox Delta ceramic insert and head were used. The complication and revision rates were collected at the last follow-up. The positioning of the acetabular implant was assessed on standard radiographs. Postoperative clinical outcomes were assessed by the Harris Hip Score. Results: At a mean follow-up of 31.9 months ± 5.5, no THA was revised. Five patients had late complications: 3 squeaking (2.6%) and 2 psoas impingements (1.7%) and were managed conservatively. All patients had satisfactory bony ingrowth of acetabular component, with no radiolucent lines and no osteolysis. Eight patients (6.9%) had an anterior overhang of the cup. The mean overhang for these patients was 4.1 mm. 111 hips (96%) were perceived as forgotten or having no limitations. Conclusion: This ceramic-on-ceramic coupling and shell by DAA produced excellent clinical outcomes and implant survival rate at a minimum two-year follow-up study. No serious complication was observed during the follow-up.

Ceramic on ceramic total hip arthroplasty and liner fracture. Two case reports and review of literature

BACKGROUND AND AIM OF THE WORK

Ceramic on ceramic bearing surfaces in total hip arthroplasty are rising in number with the purpose of reducing debris osteolysis in young patients. New generation ceramics drastically reduced the well known problem of liner's fracture associated with this material but this still represents a complication.

METHODS

We present the only two cases of acetabular liner fracture we had in our department, on a total of 252 patients, since we use CoC bearing surfaces in THR (2005-2019) analyzing symptoms and causes of this complication. Review of recent literature focused on symptoms and causes of liners fracture, well matched our cases.

RESULTS

In line with the analysis of literature, the major cause of liner fracture is neck-cup impingement resulting in the "edge-loading" effect, followed by other factors like prosthesis design, traumas and patient weight. From data also emerge the role of acoustic phenomena (e.g. squeaking) and CT scan in the diagnostic process.

CONCLUSIONS

Last generation ceramics should be used in CoC THR, implant malposition and prosthesis design have a dominant role in liner fracture, squeaking should always be investigated. CT scan have an important role in diagnosis. Implant revision with substitution of the bearing surfaces is mandatory in case of fracture or impending fracture signs.

Complete wear-through of a metal-backed acetabular cup in an ambulatory patient

We present a rare case of a patient who presented with complete and rapid wear-through of a ceramic femoral head through a polyethylene liner and titanium acetabular cup. In addition, this patient exhibited significantly elevated serum titanium ion levels, which may serve as a marker of severe metallosis in cases where the preoperative plain radiographs underestimate signs of periarticular metal debris. The unique findings of this case include the rapid (less than 1 year time) wear-through of the femoral head in interval radiographs and the dramatic progression of metallosis and pelvic and femoral osteolysis that required both component revision. In addition, the markedly elevated titanium levels secondary to cup wear-through are also of interest and demonstrate a systemic manifestation of abrasive wear of a titanium alloy component.

Revision Total Hip Arthroplasty after Ceramic Bearing Fractures in Patients Under 60-years Old; Mid-term Results

Purpose

Although advances in technology have reduced the risk of ceramic implant fractures in total hip arthroplasty, these injuries do occur and their treatment remains challenging. There is a lack of studies reporting on the effectiveness of ceramic components in revision hip arthroplasty after ceramic bearing fracture. The aim of this study is to evaluate clinical and radiologic outcomes of revision surgery with ceramic-on-ceramic components after ceramic bearing fractures in young (i.e., under 60 years old) and active patients.

Materials and Methods

Eight patients who, from May 2004 to November 2011, underwent ceramic-on-ceramic revision surgery following a ceramic component fracture and had more than 6 years follow up were enrolled in this study. All eight patients were male with mean ages at first and revision surgeries of 39 years (range, 31–50 years) and 43.8 years (range, 33–60 years), respectively. There were 6 and 2 cases of ceramic liner and ceramic head fractures, respectively. The average time from the first operation to revision surgery was 54.3 months (range, 9–120 months), and the average follow up period was 9.7 years (range, 6–13.3 years).

Results

At the last follow up, all patients showed improvement in Harris hip score and pain relief and there were no cases of loosening or osteolysis.

Conclusion

Revision total hip arthroplasty using ceramic-on-ceramic components after ceramic component fracture is a feasible and appropriate surgical option in young and active patients.

Mid-term results of alumina ceramic unlinked total elbow arthroplasty with cement fixation for patients with rheumatoid arthritis

Aims

The aim of this study was to report the mid-term clinical outcome of cemented unlinked J-alumina ceramic elbow (JACE) arthroplasties when used in patients with rheumatoid arthritis (RA).

Patients and Methods

We retrospectively reviewed 87 elbows, in 75 patients with RA, which was replaced using a cemented JACE total elbow arthroplasty (TEA) between August 2003 and December 2012, with a follow-up of 96%. There were 72 women and three men, with a mean age of 62 years (35 to 79). The mean follow-up was nine years (2 to 14). The clinical condition of each elbow before and after surgery was assessed using the Mayo Elbow Performance Index (MEPI, 0 to 100 points). Radiographic loosening was defined as a progressive radiolucent line of >1 mm that was completely circumferential around the prosthesis.

Results

The mean MEPI scores significantly improved from 40 (10 to 75) points preoperatively to 95 (30 to 100) points at final follow-up (p < 0.0001). Complications were noted in ten elbows (ten patients; 11%). Two had an intraoperative humeral fracture which was treated by fixation and united. One had a postoperative fracture of the olecranon which united with conservative treatment and one had a radial neuropathy which resolved. Further surgery was required for one with a dislocation, three with an ulnar neuropathy and one with a postoperative humeral fracture. Revision with removal of the components was performed in one elbow due to deep infection. There was no radiographic evidence of loosening around the components.With any revision surgery or revision with implant removal as the endpoint, the rates of survival up to 14 years were 93% (95% confidence interval (CI), 83.9 to 96.6) and 99% (95% CI 91.9 to 99.8), respectively, as determined by Kaplan-Meier analysis.

Conclusion

With the appropriate indications, the mid-term clinical performance of the cemented JACE TEA is reliable and comparable to other established TEAs in the management of the elbow in patients with RA.

Cite this article: Bone Joint J 2018;100-B:1066–73.

Could larger diameter of 4th generation ceramic bearing decrease the rate of dislocation after THA?

BACKGROUND

Fourth generation (Delta) ceramic bearing was developed to reduce dislocation after total hip arthroplasty (THA) by increasing the head diameter. We tested a hypothesis that 32/36 mm Delta ceramic bearing decreases the dislocation rate. We also evaluated ceramic-related complications and early outcome of this thin liner-on-large head ceramic bearing.

METHODS

We performed a prospective study on patients who underwent THA with use of 32/36 mm Delta ceramic bearing. The dislocation rate was compared with the historical dislocation rate of third generation 28 mm ceramic bearing. We also evaluated ceramic fracture, squeak, short-term results and survival. Follow-up period was minimum 2 years.

RESULTS

Between April 2010 and February 2012, we enrolled 250 consecutive patients (278 hips). All patients received cementless prostheses. Four patients (4 hips) who received metal shells ≤ 46 mm and 28 mm heads were excluded. Three patients died and 2 patients were lost within 2 years. The remaining 241 patients (269 hips) were followed for 24-46 months. There were 142 men (161 hips) and 99 women (108 hips) with a mean age of 53.7 years (range, 17-75 years) at the index operation. Dislocation occurred in three hips (1.1%). An old age was a risk factor for dislocation. Ceramic fracture and squeaking did not occur in any patient. Mean Harris hip score was 90.3 points at the latest follow-up. All acetabular and femoral components had bone-ingrowth stability. No hip had detectable wear or osteolysis. The survival was 99.3% in the best case scenario and 97.8% in the worst at 48 months.

CONCLUSIONS

Total hip arthroplasty with use of 32/36 mm Delta ceramic bearing showed lower incidence of hip dislocation compared with 28 mm third generation ceramic bearing. A caution should be paid to prevent a fall in senile patients even though a large head is used. The short-term results of THA with this type of ceramic articulation are encouraging and we did not find any ceramic-related complications.

Is a ceramic-on-ceramic bearing really superior to ceramic-on-polyethylene for primary total hip arthroplasty? A systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

The outcomes of using a ceramic-on-ceramic (CoC) vs ceramic-on-polyethylene (CoP) bearing surface for primary total hip arthroplasty (THA) are much debated. We performed a systematic review and meta-analysis of randomised controlled trials (RCTs) to compare and evaluate the outcomes of these 2 bearing surfaces.

MATERIALS AND METHODS

Electronic databases (PubMed/Medline, CENTRAL, Embase and Web of Science) were systematically searched for RCTs investigating the association between bearing surfaces and outcomes following primary THA. Two investigators independently reviewed studies for eligibility, assessed the risk of bias, extracted and analysed the data.

RESULTS

In total, 13 RCTs including a total of 2,488 THAs were identified. The Harris Hip Score appeared to be similar between CoC and CoP THAs. The acetabular liner wear rate was lower in CoC than CoP THA, but the meta-analysis showed that the incidence of component-related noise and overall ceramic fracture in CoC group were 14.73 times and 6.02 times higher than CoP THA, respectively. There were no statistically significant differences in rates of radiolucent line formation (&gt;1 mm), osteolysis, loosening, revision with follow-up ≥ 5 years, intraoperative femoral fracture, dislocation, deep infection, deep venous thrombosis and leg length discrepancy between CoC and CoP THAs.

CONCLUSIONS

There appears to be no clear evidence favouring the use of either a CoC or CoP bearing surfaces in primary THA, further studies with high-quality and longer term follow-up to provide more evidence on this topic are still required.

Biological response to prosthetic debris

Joint arthroplasty had revolutionized the outcome of orthopaedic surgery. Extensive and collaborative work of many innovator surgeons had led to the development of durable bearing surfaces, yet no single material is considered absolutely perfect. Generation of wear debris from any part of the prosthesis is unavoidable. Implant loosening secondary to osteolysis is the most common mode of failure of arthroplasty. Osteolysis is the resultant of complex contribution of the generated wear debris and the mechanical instability of the prosthetic components. Roughly speaking, all orthopedic biomaterials may induce a universal biologic host response to generated wear débris with little specific characteristics for each material; but some debris has been shown to be more cytotoxic than others. Prosthetic wear debris induces an extensive biological cascade of adverse cellular responses, where macrophages are the main cellular type involved in this hostile inflammatory process. Macrophages cause osteolysis indirectly by releasing numerous chemotactic inflammatory mediators, and directly by resorbing bone with their membrane microstructures. The bio-reactivity of wear particles depends on two major elements: particle characteristics (size, concentration and composition) and host characteristics. While any particle type may enhance hostile cellular reaction, cytological examination demonstrated that more than 70% of the debris burden is constituted of polyethylene particles. Comprehensive understanding of the intricate process of osteolysis is of utmost importance for future development of therapeutic modalities that may delay or prevent the disease progression.

Third-generation alumina-on-alumina total hip arthroplasty: 14 to 16-year follow-up study

Ceramic-on-ceramic articulation has the lowest wear with little osteolysis. However, the wear and osteolysis in long-term follow-up are not known. Another concern is ceramic fracture, which might occur after repeated stress during a long period. Ninety hips (76 patients with a mean age of 47 years) that underwent cementless total hip arthroplasty using third-generation ceramic-on-ceramic articulation were followed for 14-16 years. At final follow-up, there was no measurable ceramic wear and no periprosthetic osteolysis was identified. No ceramic fracture occurred during the follow-up. One hip was revised because of late infection. All prostheses were bone-ingrown. Two patients experienced a grinding sensation. However, no patient had squeak. The mean Harris hip score at the final evaluation was 89 points and the survival rate was 98.9%.

Comparison between preassembled and modular cups in primary cementless total hip arthroplasty: a two-year minimum follow-up study

We prospectively analyzed 83 patients who underwent ceramic-on-ceramic THA using preassembled (n=22) or modular acetabular components (n=61) between June 2010 and June 2012. There were no significant differences in mean postoperative radiographic outcomes, functional outcomes, or complications between the two groups. Both groups showed satisfactory performance at the 2year follow up. Only the gender of the patients was significantly different between the two groups. Half of the women had smaller acetabular diameters accommodating a cup size of only 48-50-mm. Although a preassembled cup with a 36-mm ceramic liner is proven to be safe in the short term, future research should focus on evaluating the long-term risks.

Effect of neck length on third-generation ceramic head failure; finite element and retrieval analysis

BACKGROUND

Optimized design using finite element analysis (FEA) has considerably increased the longevity of ceramic implants in total hip arthroplasty. Unlike previous FEA studies, a 28-mm head with a short neck was found to be prone to failure, even with third-generation ceramic. We conducted a finite element analysis of the third-generation ceramic head failure according to neck lengths and a retrieval analysis of the four fractured ceramic heads.

METHODS

Models of real specimens were created for short-, medium-, and long-neck heads made of alumina, based on data given by the manufacturer and reverse engineering design. Static loading was simulated in a series of five steps to 46 kN, and fatigue loading consisting of 10(7) cycles was simulated in walking (4.3 kN) and high-impact (10 kN) conditions to determine the safety factor.

RESULTS

Although the maximum principal stress of the long-neck design was the greatest, consistent with a previous FEA study, the safety factor was the lowest at the inner corner between the roof and tapered bore of the ceramic head with the short-neck design in both fatigue-loading conditions. Furthermore, surface analysis of one head revealed that the fracture was propagated from the inner corner between the roof and tapered bore into the base of the ceramic head.

CONCLUSION

Our results suggest that the short-neck design with a 28-mm ceramic head has a greater potential risk of ceramic failure than other designs.

Recurrent catastrophic ceramic femoral head failure in total hip arthroplasty

Fracture of a modern ceramic head component in total hip replacement is an uncommon but catastrophic complication. Hence, the occurrence of a second ceramic head fracture in the same hip replacement of an individual represents a perishingly rare event. We present the case as a means of highlighting potential risk factors for ceramic head fracture and suggest possible management strategies in such cases.

Systematic review of total hip arthroplasty in patients under 30 years old

We performed a systematic review to assess whether joint replacement in this very 
young patient group provides significant functional improvement and whether these procedures are associated with good implant survivorship. The studies included presented the results of 
450 THA procedures. All patients showed an improvement in functional score and symptom relief. Uncemented stems showed good integration with no signs of loosening. Cemented implants showed high rates of loosening. This study shows that THA in the very young patient can provide good functional improvement and relief of symptoms and that the more modern uncemented implant designs used with hard-on-hard bearings can be associated with improved implant survival. Long-term studies are necessary to confirm the superiority and improved survivorship of these newer 
implants.

Failure analysis of alumina on alumina total hip arthroplasty with a layered acetabular component: minimum ten-year follow-up study

This prospective study reports the outcome of total hip arthroplasty (THA) performed in a consecutive series of patients using an alumina ceramic on a ceramic-layered component (Alumina-Bearing-Surface system). The cohort consisted of 270 hips in 229 patients. The study evaluated the clinical and radiological results over a mean follow-up of 11.4 years. Revision THA was performed on 58 hips, including alumina alternative failure in 50 hips, loosening in 4 hips, recurrent dislocation in 2 hips, stem neck fracture in 1 hip and hematoma in 1 hip. The survival rate was 68% with revision for any reason as the end point. The risk factors of implant failure are the preoperative range of motion of the hip joint and postoperative dislocation.

Alternative bearings in total hip arthroplasty in the young patient

Total hip arthroplasty is an effective treatment option for advanced hip arthritis in elderly patients. Studies in young patients have traditionally shown less durable results. With current implants, surgical technique, and cementless fixation methods, the durability of total hip arthroplasty may now be related to the wear performance of the bearing surfaces. To improve implant longevity, there are several bearing surface choices currently available for this demanding group of patients. Alternatives must be evaluated in terms of the risks and benefits associated with each articulation, and all new technologies must be carefully monitored over the long term.

Total hip arthroplasty in teenagers: an alternative to hip arthrodesis

Debilitating arthritis in teenage patients is a complex problem with limited surgical options. Hip arthrodesis is unpopular amongst patients, and contemporary total hip arthroplasty (THA) may be a promising alternative. We report on the outcomes of THA in patients less than 20 years of age. All consecutive teenage patients undergoing THA at a tertiary referral centre were reviewed. Mean follow-up was 3.4 years (range 0.6-6.8) and 9 patients had at least 5 years follow-up. There were 51 THAs in 43 patients with a mean age of 17 years (range 12-19). The commonest indication was osteonecrosis (35 cases), mostly secondary to slipped upper femoral epiphysis (15 cases). Forty-six were uncemented and 5 were reverse hybrid THAs of which 7 were computer assisted design/manufacture (CADCAM) components. The commonest bearing surface used was ceramic on ceramic (40 cases). The survival rate was 96% and there were 2 complications. At latest follow-up, the mean Harris hip score was 90 (range 68-99) and UCLA activity score was 6 (range 4-9). Radiological analysis showed 2 patients with lucent lines around the acetabular component, but no signs of osteolysis or wear. We report good short to intermediate term survivorship and outcomes, and feel THA represents a valid alternative option to hip arthrodesis.

Review: development of clinically relevant scaffolds for vascularised bone tissue engineering

Clinical translation of scaffold-based bone tissue engineering (BTE) therapy still faces many challenges despite intense investigations and advancement over the years. To address these clinical barriers, it is important to analyse the current technical challenges in constructing a clinically relevant scaffold and subsequent clinical issues relating to bone repair. This review highlights the key challenges hampering widespread clinical translation of scaffold-based vascularised BTE, with a focus on the repair of large non-union defects. The main limitations of current scaffolds include the lack of sufficient vascularisation, insufficient mechanical strength as well as issues relating to the osseointegration of the bioresorbable scaffold and bone infection management. Critical insights on the current trends of scaffold technologies and future directions for advancing next-generation BTE scaffolds into the clinical realm are discussed. Considerations concerning regulatory approval and the route towards commercialisation of the scaffolds for widespread clinical utility will also be introduced.

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 total hip arthroplasty in patients younger than 20 years

Total hip arthroplasty (THA) in the adolescent patient has historically shown relatively poor survivorship. This study reports the results of THA in young patients using contemporary ceramic bearings. Twenty-four THAs were performed using ceramic bearing surfaces in patients 20 years old or younger (mean, 16.4; range, 12-20). Average follow-up was 52 months (range, 25-123 months). The survival rate was 96%, with 1 revision for a loose acetabular component. Other complications included a peroneal nerve palsy that resolved and 2 dislocations in 1 patient. Postoperatively, the Modified Harris Hip Score mean was 93.4 (range, 66-100). This study shows promising results at short-term to midterm follow-up in very young patients who undergo THA using ceramic-on-ceramic components.

Fracture of the alumina-bearing couple delta ceramic liner

The fracture rate of third-generation ceramic liners is greatly reduced compared with first- and second-generation liners because of improvements in the design and manufacturing process. Fractures of the alumina-bearing couple are rare for the same reason.This article describes a case of a fracture of an alumina-bearing couple delta ceramic liner without trauma history that was treated with ceramic-on-polyethylene revision total hip arthroplasty. A 57-year-old man was admitted to the hip ward because of an alumina-bearing couple delta ceramic liner fracture. He underwent hip replacement by anterior approach 18 months previously in the same center because of left hip primary osteoarthritis. He received a 54×36-mm modular press-fit cup ceramic alumina-bearing couple delta insert. Probable causes of such fractures are manufacture production failure and edge loading based on cup inclination, but in our patient, inacceptable range of motion, failure of the locking mechanism during implantation insertion, or cracking were possible causes of fracture.Although the fracture rate of third-generation alumina-bearing couples is low, we believe that it may not be possible to eliminate the actual risk of alumina head fracture. Patients should be informed about the potential for this complication before receiving an alumina-bearing couple.

Fractures of a sandwich ceramic liner at ten year follow-up

PURPOSE

The aim of this study was to understand the causes of sandwich liner fractures implanted at our institution by evaluating the long-term results of this device.

METHODS

We retrospectively assessed 143 patients (151 hips) consecutively operated upon in our department by the same senior surgeon between 1999 and 2001 and with a mean follow-up period of 9.9 years (range 8.5-11.5). The components used were Cerasul® sandwich ceramic liners within a cementless cup. Patient assessment was based on demographic factors (age, gender, body mass index), the clinical scores according to Devane (activity), the potential complications and a radiographic analysis from an anteroposterior pelvic radiograph (cup inclination). Revision cases and their cause were classified (implant fracture, loosening, dislocation, periprosthetic fracture).

RESULTS

Five cases of liner fracture (3.7%) were observed at a mean seven year (4.5-8.5) follow-up. The risk factor for implant failure was found to be patient activity: the mean preoperative Devane score was 3.5 in the fracture group vs 2.6 in the control group (p = 0.008). Mean cup inclination was 52°. The survivorship analysis at ten years was 85% with revision as the endpoint. Prosthetic complications accounted for 8.6% of all 151 hips (fractures included): one case of aseptic loosening (0.7%), two cases of sepsis (1.4%), four cases of isolated dislocation (2.8%) and one case of recurrent dislocation (0.7%).

CONCLUSIONS

Alumina sandwich liners remain a subject of concern since the increasing clinical follow-up period may predispose them to fatigue failure. This system has been abandoned in our department since 2005.

Five-year comparison of oxidized zirconium and cobalt-chromium femoral components in total knee arthroplasty: a randomized controlled trial

BACKGROUND

In vitro analysis has shown that oxidized zirconium on ultra-high molecular weight polyethylene has better wear properties than cobalt-chromium on ultra-high molecular weight polyethylene. The purpose of this study was to determine if oxidized zirconium femoral components performed better than cobalt-chromium in vivo and if the use of oxidized zirconium components had clinical adverse effects.

METHODS

Forty consecutive patients (eighty knees) underwent simultaneous bilateral cruciate-retaining total knee arthroplasty for primary osteoarthritis from January 2002 to December 2003. For each patient, the knees were randomized to receive the oxidized zirconium femoral component, with the contralateral knee receiving the cobalt-chromium component. Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index, Knee Injury and Osteoarthritis Outcome Score, Knee Society score, and British Orthopaedic Association patient satisfaction scale. Radiographic outcomes include the Knee Society total knee arthroplasty roentgenographic evaluation and scoring system and measurement of radiographic wear. Patients and assessors were blinded to the treatment groups and results.

RESULTS

There were no significant differences in clinical, subjective, and radiographic outcomes between the two implants at five days, six weeks, and one, two, or five years postoperatively. At five years following surgery, 38% of the patients preferred the cobalt-chromium knee compared with 18% who preferred the oxidized zirconium knee (p = 0.02) and 44% had no preference.

CONCLUSIONS

Five-year outcomes after total knee arthroplasty with oxidized zirconium and cobalt-chromium femoral components showed no significant differences in clinical, subjective, and radiographic outcomes. Patients had no preference or preferred the cobalt-chromium prosthesis to the oxidized zirconium prosthesis at the time of the five-year follow-up. There were no adverse effects associated with the use of oxidized zirconium femoral implants.

Metal neck and liner impingement in ceramic bearing total hip arthroplasty

Although impingement between the neck of the metallic stem and the ceramic liner has been suspected to be the cause of ceramic liner failure in ceramic-on-ceramic total hip arthroplasty (THA), no report has directly demonstrated microscopic damage on ceramic liner. We performed 18 reoperations on 18 patients who had undergone third generation ceramic-on-ceramic THA. Considering impingement, 16 patients, who were reoperated more than 1 year after previous ceramic bearing THA, were evaluated. Retrieved alumina liners, showing evidence of impingement, were examined by means of visual inspection and scanning electron microscopy (SEM). Four of the 16 hips showed neck notching and black stained liners, evidence of metallic neck to ceramic impingement. Impinged alumina bearings had been implanted for an average of 62.5 months (range: 35-99 months) before reoperation. SEM of the black stained area demonstrated disruptive wear and loss of surface integrity. Furthermore, one liner had multiple microcracks, and its cross-sectional SEM analysis revealed one microcrack propagating into the deep portion of the ceramic liner. Our observations suggest that metal neck-to-ceramic impingement in ceramic-on-ceramic THA can cause microcrack formation in ceramic liner.

Minimum five-year follow-up wear measurement of longevity highly cross-linked polyethylene cup against cobalt-chromium or zirconia heads

We investigated the efficacy of combining highly cross-linked polyethylene with ceramic heads on further reduction in polyethylene wear compared with the combination with cobalt-chromium heads via PolyWare computer-assisted method. A prospective cohort study was performed on 102 cementless total hip arthroplasties using Longevity (Zimmer, Warsaw, Ind) highly cross-linked polyethylene liners. Either 26-mm zirconia heads or 26-mm cobalt-chromium heads were randomly used in 51 hips each. At a mean follow-up of 6.7 years, no significant differences were identified between the groups for total penetration rate and steady-state wear rate. Osteolysis was not observed in any hips in either group. In conclusion, no advantage was seen for the 26-mm zirconia head compared with the 26-mm cobalt-chromium head in this period.

Strategies for head and inlay exchange in revision hip arthroplasty

Due to the increasing number of total hip arthroplasties performed during the last three decades and the limited long-term survival, mainly because of wear, the number of revisions has increased during the last two years. If the implant itself is still considered to be stable, only head and inlay exchange is necessary. This requires comprehensive knowledge of the characteristics of the articulating materials by the surgeon as the wrong choice of wear couple can lead to early failure for a second time. The aim of this paper is to present considerations and strategies for head and inlay exchange in case of failure, either due to wear of the articulation material or of other indications for revision hip arthroplasty.

Prospective randomized trial comparing alumina ceramic-on-ceramic with ceramic-on-conventional polyethylene bearings in total hip arthroplasty

This prospective randomized study aims to compare the outcome between an alumina ceramic-on-ceramic (CC) articulation with a ceramic on ultra-high-molecular-weight polyethylene articulation (CP). Fifty-six hips in 55 patients with mean age 42.2 (range, 19-56) each received uncemented components, a 28-mm alumina head with randomization of acetabular liner. Mean St Michael's outcome score for each group with up to 10 years follow-up (median, 8 years; range, 1-10) was 22.8 and 22.9, respectively (P = .819). Wear was identified in all but 1 CP replacement, but only 12 of the 23 CC. Mean wear in the CP group was 0.11 mm/y and 0.02 mm/yr in the CC group (P < .001). Other than significantly greater wear in the polyethylene group, there was no significant difference in midterm outcome between the 2 groups.

Revision total hip arthroplasty for ceramic head fracture: a long-term follow-up

The results of revision total hip arthroplasty (THA) for ceramic head fracture have generally been disappointing, largely due to third body wear after incomplete synovectomy. We have followed 8 patients who sustained ceramic head fractures and were subsequently revised to a metal-on-polyethylene articulation. There were no revisions for osteolysis or aseptic loosening at a mean follow-up of 10.5 years. The yearly wear rates of each of 5 of these THAs after revision were compared with 6 matched metal-on-polyethylene THAs; there were no significant differences in wear rates. Greater than 10-year survivorship with a metal-on-polyethylene bearing couple is possible after revision THA for a ceramic head fracture if a complete and thorough synovectomy can be performed. Our technique of synovectomy will be described.

Incomplete seating of a metal-backed alumina liner in ceramic-on-ceramic total hip arthroplasty

Metal-backed modular ceramic bearing systems using a recessed alumina liner in a titanium sleeve were developed to decrease ceramic chipping or fracture due to femoral neck impingement after total hip arthroplasty (THA). However, malseating of the metal-backed ceramic liner has recently been described. The goal of this study was to assess the prevalence, etiology, and clinical relevance of this event. Between 2005 and 2008, 51 consecutive patients (61 hips) underwent THA with a metal-backed alumina liner housed in a titanium shell. The metal-backed ceramic liner was aligned, seated, and impacted into the shell, and satisfaction in terms of liner stability and seating was confirmed intraoperatively. Postoperative assessment of seating was assessed with standard radiographs. Liner seating was classified as well seated, suspicious, or malseated. Seven liners (11.5%) were found to be malseated and 4 (6.5%) were considered suspicious. Radiographically, there was a gap between the liner and the shell located inferomedially in 4 patients and superolaterally in 3 patients. Two liners subsequently seated at 1 and 3 months postoperatively, respectively. No dislodgement, failures, or adverse events were identified. There were no revision surgeries. The significant percentage of malseated liners were potentially attributed to poor exposure, bony/soft tissue interposition, and surgeon learning curve.

Complete polyethylene wear-through and secondary breakage of the expansion cup in a ceramic-polyethylene total hip

INTRODUCTION

Catastrophic polyethylene failure is an uncommon complication of ceramic-on-polyethylene total hip arthroplasty (THA) because of the favourable tribological characteristics of these implants. We present a case of a 50-year-old woman who formerly underwent bilateral ceramic-on-polyethylene THA with expansion acetabular cups and eleven years later presented with unilateral THA dislocation, secondary to catastrophic polyethylene failure and metal shell fracture.

CASE PRESENTATION

The patient came to our hospital for worsening pain in her left hip and an acute incapacity to bear weight on her left lower limb. Twelve and eleven years earlier she had undergone bilateral ceramic-on-polyethylene THA with acetabular expansion components of identical size on both sides. Radiographically, the left femoral head appeared superiorly dislocated and severe polyethylene wear was detected. The inclination angles of the left and right cups were 60° and 44°, respectively. The patient underwent left acetabular revision, and complete polyethylene wear-through with fracture of a cranial lobe of the expansion metal shell was noted at surgery. One large osteolytic lesion in the roof of the acetabulum and diffuse periarticular metallosis were also present. These findings required the use of a Burch–Schneider reinforcement cage. Two years later the patient is functioning well and has full autonomy in her activities of daily living.

CONCLUSION

The correct inclination of the acetabular component is necessary to prevent accelerated polyethylene wear in THA, even though favourable articular bearing surfaces have been used (e.g., ceramic-on-polyethylene coupling). Should the cup appear well fixed and fairly oriented on follow-up radiographies, the early detection of severe polyethylene wear may permit a revision of only the femoral head and acetabular liner.

Survival of ceramic bearings in total hip replacement after high-energy trauma and periprosthetic acetabular fracture

Surgeons remain concerned that ceramic hip prostheses may fail catastrophically if either the head or the liner is fractured. We report two patients, each with a ceramic-on-ceramic total hip replacement who sustained high-energy trauma sufficient to cause a displaced periprosthetic acetabular fracture in whom the ceramic bearings survived intact. Simultaneous fixation of the acetabular fracture, revision of the cementless acetabular prosthesis and exchange of the ceramic bearings were performed successfully in both patients. Improved methods of manufacture of new types of alumina ceramic with a smaller grain size, and lower porosity, have produced much stronger bearings. Whether patients should be advised to restrict high-impact activities in order to protect these modern ceramic bearings from fracture remains controversial.

Impingement in Total Hip Replacement: Mechanisms and Consequences

The occurrence of total hip impingement, whether or not accompanied by frank dislocation, holds substantial untoward clinical consequences, especially as less-forgiving advanced bearing implant designs come into ever more widespread use. Biomechanical aspects of impingement and dislocation have historically received relatively little scientific attention, although that situation is now rapidly changing. The present article reviews contemporary laboratory and clinical research on the impingement/dislocation phenomena, focusing particularly on how implant design variables, surgical implantation factors and patient activity each act individually and in concert to pose impingement and dislocation challenges. In recent years, several powerful new research methodologies have emerged that have greatly expanded the scope for clinical translation of systematic laboratory study. Transferring the findings from such research into yet better implant designs, and even better surgical procedures, offers encouragement that the clinical impact of this troublesome complication can be further reduced.

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.

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 gamma irradiation in air, and lack of appropriate follow-up. Revision THA was performed without complications.

Alumina inlay failure in cemented polyethylene-backed total hip arthroplasty

Alumina-on-alumina bearings for THA have markedly improved in mechanical properties through advances in technology; however, alumina fracture is still a concern. We retrospectively reviewed 77 patients (82 hips) with cemented alumina-on-alumina THAs to identify factors relating to alumina failure. The mean age of the patients at surgery was 63 years. The prostheses had a cemented polyethylene-backed acetabular component with an alumina inlay and a 28-mm alumina head. Revision surgery was performed because of alumina inlay failure in four hips (three fractures and one dissociation; 5.6%), deep infection in two, and recurrent dislocation in one. The 8-year survival rate was 90.7% with revision for any reason and 94.4% with revision for alumina failure as the end point. There were no differences in age, body mass index, gender, mobility, function, abduction angle, or size of component among the four hips with alumina failure and the remaining 68 hips without it; however, radiolucent lines in the sockets were more apparent in four cases with alumina inlay failure. This alumina-on-alumina THA thus yielded unsatisfactory medium-term results because we observed a high rate of catastrophic alumina inlay failure.

A rare complication of ceramic-on-ceramic bearings in total hip arthroplasty

Each year, approximately 217000 primary total hip arthroplasties (THAs) are performed in the United States (National Center for Health Statistics, 2003). This number is expected to increase as our population ages, and the indication for THA expands to younger and more active patients. Efforts are continually being made to improve implant design and, ultimately, patient outcomes. One area in particular that has undergone tremendous change is bearing surface technology. Ceramic-on-ceramic technology has gained widespread popularity in young patients because of its improved wear characteristics and durability. Bearing surface advancement must be tempered with analysis of implant-specific complications. We report a case of an audible hip complication after the use of ceramic components in THA.