Revision Total Hip Arthroplasty for Fractured Ceramic Bearings: A Review of Best Practices for Revision Cases

Bearing-Related Complications of Total Hip Arthroplasty Using Fourth-Generation Ceramic-On-Ceramic Articulations: Does Articular Noise Increase Over Time?

BACKGROUND

We previously reported the mean 6-year outcomes of total hip arthroplasty (THA) using fourth-generation ceramic-on-ceramic (CoC) articulations. With extended observations, this study aimed to report the mean 12-year outcomes focusing on bearing-related complications of CoC THA.

METHODS

We reviewed primary CoC THAs performed between May 2009 and April 2012 at a single institution. Of the 831 hips (739 patients), 716 hips (635 patients) that satisfied a minimum 10-year follow-up were included. The mean age at operation was 54 years (range, 16 to 83). The occurrence of bearing-specific complications, including ceramic fractures and noise generation, was evaluated. The mean follow-up duration was 12 years (range, 10 to 14).

RESULTS

A total of 2 (0.3%) ceramic liner fractures occurred, as previously reported. No additional ceramic fractures were observed during the extended follow-up period. However, the cumulative incidence of audible noise increased from 6.4 (48 of 749) to 8.2% (59 of 716). Of the 59 hips with noise, 26 (44.1%) developed noise within 1 year, whereas 13 (22.0%) presented with noise more than 5 years after THA. The noise was described as clicking in 35 hips (4.9%) and as squeaking in 24 hips (3.4%). No revision surgeries were performed for noise, except in 2 cases of concomitant liner fractures. The implant survivorship free of any revision was 98.1% at 12 years.

CONCLUSIONS

No additional ceramic fractures were identified in this extension study at a minimum follow-up of 10 years. However, the prevalence of articular noise has increased from 6.4 to 8.2% since the previous report. Possible late-onset noise should be considered when performing CoC THA in younger patients.

THA-AID: Deep Learning Tool for Total Hip Arthroplasty Automatic Implant Detection With Uncertainty and Outlier Quantification

BACKGROUND

Revision total hip arthroplasty (THA) requires preoperatively identifying in situ implants, a time-consuming and sometimes unachievable task. Although deep learning (DL) tools have been attempted to automate this process, existing approaches are limited by classifying few femoral and zero acetabular components, only classify on anterior-posterior (AP) radiographs, and do not report prediction uncertainty or flag outlier data.

METHODS

This study introduces Total Hip Arhtroplasty Automated Implant Detector (THA-AID), a DL tool trained on 241,419 radiographs that identifies common designs of 20 femoral and 8 acetabular components from AP, lateral, or oblique views and reports prediction uncertainty using conformal prediction and outlier detection using a custom framework. We evaluated THA-AID using internal, external, and out-of-domain test sets and compared its performance with human experts.

RESULTS

THA-AID achieved internal test set accuracies of 98.9% for both femoral and acetabular components with no significant differences based on radiographic view. The femoral classifier also achieved 97.0% accuracy on the external test set. Adding conformal prediction increased true label prediction by 0.1% for acetabular and 0.7 to 0.9% for femoral components. More than 99% of out-of-domain and >89% of in-domain outlier data were correctly identified by THA-AID.

CONCLUSIONS

The THA-AID is an automated tool for implant identification from radiographs with exceptional performance on internal and external test sets and no decrement in performance based on radiographic view. Importantly, this is the first study in orthopedics to our knowledge including uncertainty quantification and outlier detection of a DL model.

Revision total hip arthroplasty by a ceramic bearing surface after a third- and fourth-generation ceramic head or liner fracture

PURPOSE

Although rare, fractures of ceramic components are difficult to revise, mainly due to the presence of residual ceramic debris that can cause catastrophic wear of the replacement components. Modern ceramic-on-ceramic bearings are suggested to improve outcomes of revision total hip arthroplasty (THA) for ceramic fractures. However, there are few published reports of mid-term outcomes of revision THA using ceramic-on-ceramic bearings. We evaluated clinical and radiographic outcomes of 10 patients who received ceramic-on-ceramic bearings during revision THA for ceramic fractures.

METHODS

All patients but one received fourth-generation Biolox Delta bearings. Clinical evaluation was performed using the Harris hip score at latest follow-up, and all patients received a radiographic evaluation to analyze the fixation of the acetabular cup and of the femoral stem. Osteolytic lesions and the presence of ceramic debris were noted.

RESULTS

After a mean follow-up of 8.0 years, there were no complications or implant failures, and all patients reported satisfaction with their implant. The average Harris hip score was 90.6. There was neither osteolysis nor loosening, but despite our extensive synovial debridement, ceramic debris was noted in the radiographs of five patients (50%).

CONCLUSION

We report excellent mid-term outcomes, with no implant failures after eight years despite ceramic debris being found in a significant proportion of patients. We conclude that modern ceramic-on-ceramic bearings are an advantageous option for the revision of THA due to the fracture of initial ceramic components.

Primary Total Hip Arthroplasty with Ceramic-on-Ceramic Articulations: Analysis of a Single-center Series of 1,083 Hips at a Minimum of 10-Year Follow-Up

BACKGROUND

There are limited long-term results of using ceramic-on-ceramic bearings (COC) in total hip arthroplasty (THA) in a large number of patient cohorts. The purpose of this study was to evaluate the minimum 10-year clinical and radiological outcomes and survivorship in a single surgeon series of CoC-THA.

METHODS

Among the 1,039 patients (1,391 hips) who underwent primary THA at our institution between 2008 and 2011, 49 patients (69 hips) experienced paralysis or death, and 194 patients (239 hips, 19%) were lost to follow-up. The remaining 796 patients (1,083 hips) were assessed at a mean of 11 years (range, 10 to 13 years) using the modified Harris hip score (mHHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a questionnaire on articular noises. Survival analysis was used to estimate the survivorship. Radiological evaluation was performed on 869 hips at the final follow-up.

RESULTS

Survivorship at 11 years was 98.3% for revision or aseptic loosening, and 98.2% for re-operation. At the final follow-up, the mean mHHS and WOMAC scores were 93 (range, 12 to 100) and 14.4 (range, 3 to 66), respectively. There were 131 (12%) hips experienced squeaking, but no patient required revision. No fracture of the ceramic was observed. Radiological evaluation at the final follow-up revealed that three (0.3%) hips exhibited loosening, two (0.2%) had femoral osteolysis, 81(9.3%) acquired radiolucencies, and 35 (4%) showed heterotopic ossification.

CONCLUSION

This ceramic-on-ceramic bearing for THA had a high survivorship and excellent functional outcomes for at least 10 years.

Outcome after Two Sequential Revision Hip Arthroplasties for CoC Bearing Fracture with 10 Years Follow-up: A Case Report

Introduction

Revisions due to the fracture of ceramic-on-ceramic (CoC) bearing are rare, however when they occur, they represent a major challenge to an orthopedic surgeon for ensuring safe and long-term survival of the replaced bearing.

Case Report

We present a case of fractured ceramic liner of total hip prosthesis that underwent revision to a metal-on-polyethylene (MoP) bearing couple, with consequent huge periprosthetic metallosis. Shortly after, the second revision operation followed using the third bearing couple of ceramic-on-polyethylene (CoP). At 10 years follow-up after the operation due to ceramic fracture, the patient is now pain free with full range of motion of the revised hip.

Conclusion

Establishment of diagnostic routes and recommended protocols for CoC bearing fracture would allow easier recognition of potential fracture and diminish its consequences for the patients.

Catastrophic intraoperative failure of a ceramic femoral head

Approximately 17 years after a primary metal-on-metal total hip arthroplasty, a 59-year-old female developed pain, swelling, and weakness in her right hip accompanied by laboratory findings and imaging suggestive of an adverse local tissue reaction. Acetabular revision was performed to upsize the femoral head and improve hip stability. Upon impaction of the new, non-option ceramic femoral head onto the unsleeved retained stem, the head split into two pieces without fragmentation. The surgery was completed using a cobalt-chromium head, which was impacted without issue onto the stem’s taper. Although BIOLOX delta femoral heads do not require titanium sleeves, we believe that careful consideration should be given to their use in revision total hip arthroplasty with ceramic heads, regardless of the extent of trunnion damage noted intraoperatively.

Preventing ceramic liner fracture after Delta ceramic-on-ceramic total hip arthroplasty

BACKGROUND

The results of total hip arthroplasty (THA) with use of Delta ceramic articulation were successful at medium term follow-up. The use of this newest ceramic has markedly reduced the incidence of ceramic head fractures, but not the incidence of ceramic liner fractures. We tested a hypothesis that the ceramic fractures are prevented by use of a metal shell with 18° inner taper angle and a stem design with a reduced neck geometry.

METHODS

We conducted a prospective multicenter study of cementless THA with use of 32/36-mm Delta ceramic bearing, Exceed ABT metal shell and Taperloc stem. We evaluated ceramic fracture, noise, clinical results, radiological changes and survival rate at a minimum of 5-year follow-up.

RESULTS

From April 2010 to February 2012, 246 patients (274 THAs) were enrolled. Among them, 224 patients (130 men and 94 women, 250 hips) were followed-up for 5-8 years (mean 6.0 years). Ceramic malseating or fracture did not occur in any patient. Eight patients (8 hips, 3.2%) reported noise. Mean Harris hip score was 84 points at the latest follow-up. All acetabular and femoral components had bone-ingrown stability. Two hips were revised due to recurrent dislocation and periprosthetic fracture. The survival rate was 99.6% at 8 years postoperatively.

CONCLUSION

Ceramic fractures can be prevented by a use of (1) 32/36-mm Delta ceramic bearing, (2) metal shell with 18° taper angle, and (2) stem with a reduced neck geometry. However, noise remains a concern of the Delta ceramic bearing.

LEVEL OF EVIDENCE

Therapeutic level II.

A case report of cobalt cardiomyopathy leading to electric storm and cardiogenic shock: the importance of the orthopaedic background in patients with heart failure of unknown aetiology

Background 

The first series of cobalt cardiomyopathy was described in the 60s in relation to the abuse of a cobalt containing beer. Since then, millions of metal hip arthroplasties have been performed and a small number of cobalt cardiomyopathies related to metal prosthesis have been reported.

Case summary 

We report a case of a 48-year-old man who developed a severe non-dilated restrictive cardiomyopathy in the setting of a systemic metallosis following several hip arthroplasties. The diagnosis was suspected by exclusion of other more common causes for restrictive cardiomyopathies and confirmed by the levels of cobalt and chromium in the serum and the endomyocardial biopsy performance that showed metal deposits in myocardial tissue. Despite the removal of the metal prosthesis and a significant decrease in serum metal levels, he suffered cardiogenic shock (CS) and electric storm that required emergency mechanical circulatory support as a bridge to heart transplant.

Discussion 

Cobalt cardiomyopathy is a rare condition that has been observed in patients who develop cobalt toxicity after metal hip arthroplasty. The condition may improve after diagnosis and removal of the prosthesis or get worse and progress to end-stage heart failure or CS. The concern about the metal toxicity associated with metal hip prosthesis has increased in the last few years. Orthopaedic surgeons and cardiologists should be aware of this severe complication that is probably under diagnosed.

Cobalt-related cardiomyopathy: A real concern! A review of published evidence

BACKGROUND

Cobalt (Co) toxicity-related cardiomyopathy (CMP) in hip arthroplasty has recently been reported in the literature. The purpose of this review was to identify and assess available published evidence of CMP in hip arthroplasty patients and to derive recommendations for management.

METHODS

We evaluated 23 cases reported till October 2018 and stratified into three categories, based on pre-existing risk factors for CMP, histological confirmation and evidence of systemic signs of Co toxicity.

RESULTS

Co toxicity was considered to be the definite cause of CMP in 8 cases and probably contributory in 13 cases. Two cases were considered to have developed CMP secondary to pre-existing risk factors. Majority of the patients had good recovery of cardiac function after hip revision and cardiac management, but five cases deteriorated and died.

CONCLUSION

Although Co-related CMP has been reported in a small number of cases of hip arthroplasty, a delay or missed diagnosis may lead to significant morbidity and mortality. Timely diagnosis, removal of causative implant and avoidance of metal articulations in revision for fractured ceramic implants may help in effective management.

Local Cellular Responses to Metallic and Ceramic Nanoparticles from Orthopedic Joint Arthroplasty Implants

Over the last decades, joint arthroplasty has become a successful treatment for joint disease. Nowadays, with a growing demand and increasingly younger and active patients accepting these approaches, orthopedic surgeons are seeking implants with improved mechanical behavior and longer life span. However, aseptic loosening as a result of wear debris from implants is considered to be the main cause of long-term implant failure. Previous studies have neatly illustrated the role of micrometric wear particles in the pathological mechanisms underlying aseptic loosening. Recent osteoimmunologic insights into aseptic loosening highlight the important and heretofore underrepresented contribution of nanometric orthopedic wear particles. The present review updates the characteristics of metallic and ceramic nanoparticles generated after prosthesis implantation and summarizes the current understanding of their hazardous effects on peri-prosthetic cells.

What Is the Frequency of Fracture of Ceramic Components in THA? Results from the Norwegian Arthroplasty Register from 1997 to 2017

BACKGROUND

Ceramic bearings in THA have been used to reduce wear and, more recently, to avoid metals in the bearing because of the risk of metal ions adverse effects. Potential disadvantages to ceramic bearings are their brittleness and the ceramic fracture risk, which may lead to revision surgery. The frequency of revision for a fracture ceramic bearing, however, has not been thoroughly studied.

QUESTIONS/PURPOSES

(1) What is the frequency of revision for a fractured ceramic bearing in ceramic-on-polyethylene (CoP) and ceramic-on-ceramic (CoC) THAs, and is there any difference between alumina ceramics and alumina matrix composites (AMC)? (2) What are the factors associated with this complication? (3) To what extent did the patients who underwent revision for a fractured ceramic bearing undergo subsequent revisions, and for what reason?

METHODS

The Norwegian Arthroplasty Register has collected data on hip arthroplasty since 1987 and has a completeness of reporting of 97.3% for primary THAs and 93.3% for revision. From 1997 to 2017, 146,171 primary THAs were registered in the Norwegian Arthroplasty Register. Of these, 31,479 had a CoP articulation and 5790 had a CoC articulation. Two manufacturers produced ceramic heads; one produced 25,678 alumina heads and the other made 2465 alumina heads. All 7901 AMC heads were made by the same manufacturer. Patients who underwent CoP THA were a median (range) of 63 years old (11 to 98) and CoC THA were a median (range) 61 years old (17 to 95); 38% (11,833 of 31,479) of the patients who underwent CoP THA and 41% (2379 of 5790) of the patients who underwent CoC THA were males. Femoral heads made of alumina (n = 28,143), zirconia (n = 1225), and AMC (n = 7901) ceramics were used. To assess revision frequency, we identified patients who underwent revision because of fracture of a ceramic head and/or liner, and calculated the Kaplan-Meier survivorship free of revision for fracture in CoC and CoP articulations. Alumina ceramics and AMC were compared. In terms of factors potentially associated with revision, patient factors (age, sex, and diagnosis), type of articulation (CoP or CoC), femoral head size, and femoral head/neck length were evaluated with Cox regression models to evaluate any association with ceramic fracture and a Poisson regression to compare alumina and AMC head fractures. To evaluate subsequent revisions, hips that were revised for ceramic fracture were evaluated for any further revisions; Kaplan-Meier survivorship free of further revisions was calculated, and revision causes were identified.

RESULTS

Survivorship free from revision for ceramic fracture was 99.9% (95% CI 99.9 to 99.9) for CoP bearings, and 99.8% (95% CI 99.6 to 100) for CoC bearings at 10 years, with 7467 and 1884 hips at risk in the two groups, respectively. The hazard ratio for ceramic head fracture was 3.6 (95% CI 1.7 to 7.6) for CoC compared with CoP. The risk of fracture was greater for alumina ceramics than for AMC heads (adjusted HR 14.1 [95% CI 4.2 to 47.0]; p < 0.001). Factors that were associated with revision for fracture of a ceramic head were male sex (HR 5.2 [95% CI 2.6 to 10.4]; p < 0.001), a CoC articulation compared with CoP (HR 3.6 [95% CI 1.7 to 7.6]; p = 0.001), a 28-mm femoral head compared with a 32-mm head (HR 2.7 [95% CI 1.1 to 6.4]; p = 0.02), and short head/neck length compared with a medium head/neck length (HR 2.5 [95% CI 1.1 to 5.3]; p = 0.03). Five of 50 patients undergoing revision for ceramic fracture underwent further revisions, resulting in a 5-year survivorship free from re-revision of 86% (95% CI 74.4 to 98.0). The reasons for re-revision were infection (n = 2), another ceramic head fracture (n = 2), and cup loosening (n = 1).

CONCLUSIONS

Fracture of a ceramic THA bearing is rare and seems to affect about one in 1000 patients who receive such a bearing. To minimize the risk of this complication, surgeons should avoid small femoral heads (< 32 mm) and the shortest head/neck lengths. Surgeons should also know that the risk is increased in CoC articulations and in males. Bearings made of AMC appear to be at lower risk than those made from alumina ceramics. However, the long-term clinical wear performance of AMC bearings has not been extensively studied and should be studied further.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Fourth generation head fracture in ceramic-on-polyethylene bearing after hip revision surgery: a case report

Fourth generation ceramic bearings (BIOLOX delta, CeramTec AG; Phlochingen, Germany) were developed to reduce wear debris and improve fracture resistance. A case of a fourth generation head fracture in ceramic-on-polyethylene (COP) coupling after hip revision surgery is reported. A 58-year-old man was admitted to our department for increasing hip pain following a direct trauma which occurred during skiing activity 4 months before. Six years earlier, he had undergone a right cementless revision surgery with a 36-mm BIOLOX delta femoral head on polyethylene liner for metallosis and foreign body reaction after primary total hip replacement for hip osteoarthritis. At admission, radiological evaluation revealed a fracture of ceramic femoral head requiring a new revision surgery. Extensive synovectomy, lavage and capsulectomy were performed. Both acetabular cup and femoral stem were well fixed with no damage of trunnion, and therefore they were retained. A 36-mm internal diameter polyethylene acetabular liner was inserted along a 36-mm BIOLOX delta head with a BioBall adapter XL. The postoperative course was uncomplicated. At 1-year follow-up, the patient had a complete functional recovery. To our knowledge, BIOLOX delta ceramic femoral head fracture after COP hip revision surgery has not been previously reported.

A focused update on preventing ceramic fractures in hip arthroplasty

Ceramic bearings have several desirable properties, such as resistance to wear, hardness, and biocompatibility, that favour it as an articulating surface in hip arthroplasty. However, ceramic fracture remains a concern. We have reviewed the contemporary literature, addressing the factors that can influence the incidence of ceramic bearing surface fracture.

Cite this article: Bone Joint J 2019;101-B:897–901.

Severe Wear and multiple Pseudotumor formation due to revision for ceramic head breakage after ceramic-on-ceramic Total hip arthroplasty: a case report

Background

Head breakage is a serious complication following total hip arthroplasty when using Ceramic on Ceramic bearings surfaces. There is still in controversy about the selection of bearing surfaces when conducting revision surgery.

Case presentation

We describe the case of a fifty-year-old man who had undergone right total hip arthroplasty (THA) with ceramic-on-ceramic prostheses in 2011. After a fall 6 years after the primary procedures, radiographs suggested a ceramic head breakage for revision THA with exchange of metal-on-polyethylene bearing. However, 8 months later, severe metallosis and multiple pseudotumor was confirmed in pelvis and surrounding hip after re-revision THA with ceramic-on-polyethylene prostheses. Analysis of the serum metal ion indicated massive wear of the metal head and erosion of the stem neck and taper.

Conclusions

This case vividly demonstrates metal bearings should be avoided and revision with complete synovectomy and thorough debridement should be performed whenever possible for a fractured ceramic bearing.

Cobalt cardiomyopathy in hip arthroplasty

Background

Cobalt toxicity-related cardiomyopathy in hip arthroplasty has recently been reported in the literature. The purpose of this review is to identify and assess available published evidence of cardiomyopathy in hip arthroplasty patients and to derive recommendations for management.

Methods

We evaluated 23 cases reported until October 2018 and stratified them into 3 categories, based upon pre-existing risk factors for cardiomyopathy, histological confirmation, and evidence of systemic signs of cobalt toxicity.

Results

Cobalt toxicity was considered to be the definite cause of cardiomyopathy in 8 cases, and probably contributory in 13 cases. Two cases were considered to have developed cardiomyopathy secondary to pre-existing risk factors. Majority of the patients had a good recovery of cardiac function after hip revision and cardiac management, but 5 cases deteriorated and died.

Conclusions

Although cobalt-related cardiomyopathy has been reported in a small number of cases of hip arthroplasty, a delay or missed diagnosis may lead to significant morbidity and mortality. Timely diagnosis, removal of causative implant, and avoidance of metal articulations in revision for fractured ceramic implants may help in an effective management.

Do rim cracks and backside grinding affect the aging kinetics of alumina-matrix composite acetabular liners?

The acetabular liner malalignment and rim impingement have been problematic issues in ceramic-on-ceramic (CoC) total hip arthroplasty (THA). Commercial ceramic liners made of alumina-matrix composite (AMC) have polished articulation and rim, and roughly ground backside with a button-like apical projection (post) to resist tilting. In this study, we hypothesized that rim cracks and backside grind critically affect the aging kinetics of tetragonal zirconia dispersed in AMC structure. We analyzed phase transformation in the zirconia phase and residual stresses in the alumina matrix during aging by Raman and fluorescence spectroscopy. We demonstrated that the polished surfaces showed environmental stability in vitro, while the roughly-ground backside showed a significant stability loss and tensile stress accumulation as a consequence of enhancing the inter-component fixation between the liner and the metallic shell. Rim cracking locally produced a preferential transformation at the tip and the surrounding of the crack. Note that the tensile stress concentration at the crack tip was counteracted by the phase transformation after a few hours of aging. This suggests the presence of a time lag in vivo before further transformation around the crack could provide a crack shielding effect in the material. © 2018 Wiley Periodicals, Inc. J. Biomed. Mater. Res. Part B, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 791-798, 2019.

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.

Nano-sized Al2O3 particle-induced autophagy reduces osteolysis in aseptic loosening of total hip arthroplasty by negative feedback regulation of RANKL expression in fibroblasts

Aseptic loosening is mainly caused by wear debris generated by friction that can increase the expression of receptor activation of nuclear factor (NF)-κB (RANKL). RANKL has been shown to support the differentiation and maturation of osteoclasts. Although autophagy is a key metabolic pathway for maintaining the metabolic homeostasis of cells, no study has determined whether autophagy induced by Al₂O₃ particles is involved in the pathogenesis of aseptic loosening. The aim of this study was to evaluate RANKL levels in patients experiencing aseptic loosening after total hip arthroplasty (THA) and hip osteoarthritis (hOA) and to consequently clarify the relationship between RANKL and LC3II expression. We determined the levels of RANKL and autophagy in fibroblasts treated with Al₂O₃ particles in vitro while using shBECN-1 interference lentivirus vectors to block the autophagy pathway and BECN-1 overexpression lentivirus vectors to promote autophagy. We established a novel rat model of femoral head replacement and analyzed the effects of Al₂O₃ particles on autophagy levels and RANKL expression in synovial tissues in vivo. The RANKL levels in the revision total hip arthroplasty (rTHA) group were higher than those in the hOA group. In patients with rTHA with a ceramic interface, LC3II expression was high, whereas RANKL expression was low. The in vitro results showed that Al₂O₃ particles promoted fibroblast autophagy in a time- and dose-dependent manner and that RANKL expression was negatively correlated with autophagy. The in vivo results further confirmed these findings. Al₂O₃ particles induced fibroblast autophagy, which reduced RANKL expression. Decreasing the autophagy level promoted osteolysis and aseptic prosthetic loosening, whereas increasing the autophagy level reversed this trend.

Clinical Outcomes and Bearing-Specific Complications Following Fourth-Generation Alumina Ceramic-on-Ceramic Total Hip Arthroplasty: A Single-Surgeon Series of 749 Hips at a Minimum of 5-Year Follow-Up

BACKGROUND

The purpose of this study is to evaluate the minimum 5-year outcomes and bearing-specific complications in a single surgeon series of fourth-generation alumina ceramic-on-ceramic total hip arthroplasties (THAs).

METHODS

We retrospectively analyzed 667 patients (749 hips) who underwent primary THAs by a single surgeon using fourth-generation alumina ceramic bearings. There were 315 men and 352 women with a mean age of 54.2 years. The surgeon used cementless prostheses with an identical design and BIOLOX Delta ceramics in all hips, using a 36-mm head in 472 hips (63%) and a 32-mm head in 227. The mean follow-up duration was 6.5 years (range, 5 to 8 years).

RESULTS

The mean Harris hip score improved from 45.6 points preoperatively to 91.3 points at final follow-up. All but 1 acetabular cup and all femoral stems were well fixed. No radiographic evidence of osteolysis was identified at final follow-up. There were 2 (0.3%) ceramic liner fractures and no ceramic head fractures. A total of 48 hips (6.4%) exhibited audible noise (29 clickings and 19 squeakings), but no patient required revision. Other complications were 1 dislocation, 1 deep infection, 3 iliopsoas tendonitis, and 6 periprosthetic femoral fractures. Kaplan-Meier survivorship for revision for any reason was 98.6% (95% confidence interval, 97.7-99.5) at 6.5 years.

CONCLUSION

Delta ceramic-on-ceramic THAs had a high rate of survivorship without radiographic evidence of osteolysis at 6.5-year follow-up. However, we found 0.3% ceramic liner fractures and 6.4% audible noises associated with the use of Delta ceramics.