Long-term results of 32-mm alumina-on-alumina THA for avascular necrosis of the femoral head

Outcomes of Ceramic Composite in Total Hip Replacement Bearings: A Single-Center Series

Despite the fact that total hip replacement is one of the most successful surgical procedures for treatment of a variety of end-stage hip diseases, the process of osteolysis and implant loosening remains a significant problem, especially in young and high-demand patients. More than 40 years ago, ceramic bearings were introduced due to their mechanical advantage in order to obtain a reduction in wear debris, and due to the conviction that it was possible to minimize friction and wear owing to their mechanical hardness, high chemical stability, surface lubrication by fluids and low friction coefficient. Together with excellent mechanical properties, ceramics have a biological inertness: eventual ceramic debris will lead to a reactive response with a high predominance of fibrocystic cells, rather than macrophagic cells, and absence of giant cells, which is ideal from a biological perspective. As a consequence, they will not trigger the granulomatous reaction necessary to induce periprosthetic osteolysis, and this clearly appears to be of great clinical relevance. In recent years, tribology in manufacturing ceramic components has progressed with significant improvements, owing to the development of the latest generation of ceramic composites that allow for an increased material density and reduced grain size. Currently, ceramic-on-ceramic bearings are considered the attractive counterparts of ceramic- or metal-on-polyethylene ones for patients with a long life expectancy. The aim of this paper is to report the results of total hip replacements performed with a ceramic-on-ceramic articulation made from a ceramic composite in a single center, focusing on its usefulness in specific preoperative diagnosis.

Long-Term Survivorship of Total Hip Arthroplasty with Highly Cross-Linked Polyethylene for Osteonecrosis

BACKGROUND

Osteonecrosis of the hip is the underlying etiology for 3% to 12% of total hip arthroplasties (THAs). Compared with patients who undergo THA because of osteoarthritis, those who do so because of osteonecrosis typically are younger, have a greater number of underlying diagnoses, and have inferior clinical outcomes and implant survivorship. The purpose of this study was to compare the long-term implant survivorship (median follow-up, 10 years), functional outcomes, and radiographic results of contemporary THAs with a highly cross-linked polyethylene (HXLPE) liner between patients with osteonecrosis and those with osteoarthritis.

METHODS

All patients who underwent primary THA with an HXLPE liner from 1999 to 2007 were identified from our institutional total joint registry. Patients with a primary diagnosis of osteonecrosis were matched 1:1, on the basis of age, sex, and body mass index (BMI), to patients with a diagnosis of osteoarthritis. This resulted in 461 hips in 413 patients with osteonecrosis matched to 461 hips in 427 patients with osteoarthritis (mean age, 59 years; 47% female; and mean BMI, 29 kg/m). Long-term implant survivorship, patient-reported outcomes, and radiographic findings were compared. In addition, a subgroup analysis of the osteonecrosis group was performed to see whether certain underlying etiologies portended poor outcomes. The median follow-up was 10 years.

RESULTS

The 15-year cumulative rates of revision were 6.6% and 4.5% in the osteonecrosis and osteoarthritis groups, respectively (hazard ratio [HR] = 1.8, p = 0.09). The 15-year cumulative rates of any reoperation were 10.5% and 6.4% in the osteonecrosis and osteoarthritis groups, respectively (HR = 2.2, p = 0.008). There were no radiographic signs of component loosening or osteolysis in the entire cohort. Despite a lower median preoperative Harris hip score (HHS) for patients with osteonecrosis, both groups had marked improvements in their scores, which were similar at all time points after surgery. The cumulative rate of reoperations at 15 years was 0% for hips with radiation-induced osteonecrosis, 6.3% for those with alcohol-induced osteonecrosis, 9.0% for those with posttraumatic osteonecrosis, 12.1% for those with steroid-induced osteonecrosis, and 25% for those with idiopathic osteonecrosis.

CONCLUSIONS

Contemporary THA with an HXLPE liner offers excellent long-term implant survivorship and functional outcomes for patients with osteonecrosis; however, the risk of a reoperation is higher when compared with patients with osteoarthritis.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

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.

A minimum 20-year outcome of 100 consecutive alumina-on-alumina arthroplasties performed by a single surgeon

BACKGROUND:

Ceramic-on-ceramic (CoC) is currently a viable bearing combination in primary total hip arthroplasty (THA) and, due to its mechanical properties, it can be used in young patients requiring a long-lasting implant. The aim of this study is to report the results of a series of CoC THAs at a minimum 20 years follow-up.

METHODS:

A retrospective study was conducted on the 1st 100 consecutive alumina-on-alumina arthroplasties performed by a single surgeon on 51 females and 40 males with an average age of 60.7 years. The mean preoperative Harris Hip Score was 35. The press-fit cup consisted of a pure titanium core with a titanium alloy mesh. Both the inlay and the head were made of dense polycrystalline surgical-grade alumina. The 32-mm femoral head was anchored on 3 different femoral components.

RESULTS:

19 patients with 22 THAs were died or lost, 2 anatomic cementless stems were revised due to sinking, 1 THA was revised for periprosthetic infection. 2 patients sustained a Vancouver B1 periprosthetic femoral fracture. None of the 78 THAs eligible for this study were revised for wear, breakage, noise of the ceramic components. None of the cups, none of the cemented stems, none of the cementless straight stems failed. HHS raised up to a mean value of 95.

CONCLUSIONS:

The present report demonstrates that CoC coupling offers minimal wear at a long-term follow-up. Further studies are needed to evaluate whether the modern ceramic composites will confirm such excellent results in total hip replacement.

Bearing Surfaces for Total Hip Arthroplasty

Metal-on-highly cross-linked polyethylene is considered the preferred bearing surface for conventional total hip arthroplasty because of its safety profile and excellent results in the first 10 to 15 years of use. However, with younger patient age, activity expectations increase, and the life expectancy of patients with total hip arthroplasty also has increased, so interest remains in other bearing couples. These other options include the use of various ceramic composites for the femoral head on highly cross-linked polyethylene, the so-called second-generation antioxidant polyethylenes, and ceramic acetabular liners. Several of these bearing couples have shown excellent wear rates in vitro, and short-term clinical studies have demonstrated favorable wear and safety results. It is uncertain whether any of these bearing couples should be adopted at present. Understanding the unique properties and possible complications of these bearing couples is critical for appropriate implant selection.

Third-generation pure alumina and alumina matrix composites in total hip arthroplasty: What is the evidence?

Wear, corrosion and periprosthetic osteolysis are important causes of failure in joint arthroplasty, especially in young patients.

Ceramic bearings, developed 40 years ago, are an increasingly popular choice in hip arthroplasty. New manufacturing procedures have increased the strength and reliability of ceramic materials and reduced the risk of complications.

In recent decades, ceramics made of pure alumina have continuously improved, resulting in a surgical-grade material that fulfills clinical requirements.

Despite the track record of safety and long-term results, third-generation pure alumina ceramics are being replaced in clinical practice by alumina matrix composites, which are composed of alumina and zirconium.

In this review, the characteristics of both materials are discussed, and the long-term results with third-generation alumina-on-alumina bearings and the associated complications are compared with those of other available ceramics.

Cite this article: EFORT Open Rev 2018;3:7-14. DOI: 10.1302/2058-5241.3.170034

An evidence-based guide to the treatment of osteonecrosis of the femoral head

Non-traumatic osteonecrosis of the femoral head is a potentially devastating condition, the prevalence of which is increasing. Many joint-preserving forms of treatment, both medical and surgical, have been developed in an attempt to slow or reverse its progression, as it usually affects young patients. However, it is important to evaluate the best evidence that is available for the many forms of treatment considering the variation in the demographics of the patients, the methodology and the outcomes in the studies that have been published, so that it can be used effectively. The purpose of this review, therefore, was to provide an up-to-date, evidence-based guide to the management, both non-operative and operative, of non-traumatic osteonecrosis of the femoral head. Cite this article: Bone Joint J 2017;99-B:1267-79.

Short stem total hip arthroplasty for osteonecrosis of the femoral head in patients 60 years or younger: a 3- to 10-year follow-up study

Background

In young patients with osteonecrosis of the femoral head (ONFH), short-stem total hip arthroplasty (THA) could allow a potential advantage in preserving metaphyseal bone-stock, when revision surgery might become necessary. However, only a few studies have evaluated the outcome of short-stem THAs in ONFH. We reviewed the prospectively collected data of a cementless partial neck-retaining short-stem with ceramic-on-ceramic bearings in ONFH patients.

Methods

Thirty patients (37 hips) younger than 60 years (mean age at surgery, 51.5 years) underwent THA with the NANOS® stem (Smith and Nephew, Marl, Germany) from January 2006 to December 2012. All patients received a 32-mm or 36 mm ceramic femoral head. Harris hip score, WOMAC and UCLA activity score were recorded. Postoperative radiographs were evaluated for bone-implant fixation and osteolysis. Further analysis correlated clinical findings with implants characteristics and patient demographics at mean 5.6 years’ follow-up (range, 3–10 years).

Results

The clinical and functional results improved significantly (p < 0.001). At latest follow-up, mean HHS, WOMAC, and UCLA activity scores were 90 (range, 71–100), 94 (range, 76–100), and 6.3 (range, 4–10) points, respectively. The diameter of the femoral head did not influence the clinical outcome (p = 0.661). All hips showed bone ingrowth fixation of the acetabular and femoral components. No patients showed osteolysis. No revision for any reason was performed during the study period.

Conclusions

The excellent clinical results and fixation pattern at mean 5.6 years’ follow-up reveal this implant as a reliable option in advanced stage of ONFH either. Further investigations are crucial to determine the long-term durability and to assess whether the association of ceramic-on-ceramic bearings, can be useful to achieve longer survivorship and lower complications rates.

Trial registration

Registry number: ISRCTN 91336248; date of registration: 04/07/2017.

The evolution of an uncemented acetabular component in alumina-on-alumina total hip arthroplasty has improved clinical outcome

Aims

To determine the effect of a change in design of a cementless ceramic acetabular component in fixation and clinical outcome after total hip arthroplasty

Patients and Methods

We compared 342 hips (302 patients) operated between 1999 and 2005 with a relatively smooth hydroxyapatite coated acetabular component (group 1), and 337 hips (310 patients) operated between 2006 and 2011 using a similar acetabular component with a macrotexture on the entire outer surface of the component (group 2). The mean age of the patients was 53.5 (14 to 70) in group 1 and 53.0 (15 to 70) in group 2. The mean follow-up was 12.7 years (10 to 17) for group 1 and 7.2 years (4 to 10) for group 2.

Results

No hips were revised due to complications related to bearing fracture or to stem loosening. A total of 15 acetabular components were revised for aseptic loosening in group 1 and two in group 2. The survival rate for acetabular component aseptic loosening at eight years was 96.8% (95% confidence interval (CI) 94.8 to 98.7) for group 1 and 99.2% (95% CI 98.0 to 100) for group 2. The risk for aseptic loosening of the acetabular component was higher in group 1 (p = 0.04, Hazard Ratio (HR) 4.99), dysplastic acetabula (p = 0.01, HR 4.12), components outside Lewinnek´s zone (p < 0.001, HR 6.13) and in those with a hip rotation centre distance greater than 5 mm (p = 0.005, HR 4.09).

Conclusion

Alumina ceramic-on-ceramic THA is an excellent option for young patients. Although newer components appeared to improve fixation, acetabular reconstruction is essential to obtain a satisfactory outcome. Cite this article: Bone Joint J 2017;99-B:749–58.

Cementless total hip arthroplasty using Biolox®delta ceramic-on-ceramic bearing in patients with osteonecrosis of the femoral head

PURPOSE

The purpose of this study was to evaluate the results of cementless total hip arthroplasty (THA) using a 32 mm or larger Biolox®delta ceramic-on-ceramic (CoC) bearing in patients with osteonecrosis of the femoral head after a minimum of 5 years of follow-up.

MATERIALS AND METHODS

We retrospectively analysed 44 patients (53 hips) who underwent cementless THA using Biolox®delta CoC bearing. There were 33 men (40 hips) and 11 women (13 hips) with the mean age of 49 years. A 36 mm head was used in 42 (79%) of 53 hips and a 32 mm head was used in 11 hips with smaller acetabular shells. The mean duration of follow-up was 5.3 years (range 5-6 years).

RESULTS

The mean Harris Hip Score improved from 50 points preoperatively to 97 points at final follow-up (p&lt;0.001). All acetabular and femoral components showed radiographic evidence of osseointegration. No osteolysis was observed. No patients sustained ceramic fracture. An audible hip noise was identified in 2 (4%) of the 53 hips (1 squeaking and 1 clicking). Survivorship with revision for any reason at a minimum of 5 years was 100% in the best-case scenario and 95 % in the worst-case scenario.

CONCLUSIONS

The minimum 5-year results of cementless THA using a 32 mm or larger Biolox®delta CoC bearing in patients with osteonecrosis of the femoral head were encouraging with excellent survivorship. However, it was also found that the risk of noise development remains even for the new alumina matrix composite ceramic.

Densitometric evaluation of bone-prosthetic counterface in hip and knee arthroplasty with modern implants

INTRODUCTION

Recent acquisitions of the complex mechanisms of osseointegration between implants and host bone have gained attention, accordingly to the methods of evaluation of these interactions. DEXA analysis is considered an useful tool to assess such phenomena, in order to analyse in a quantitative manner the local metabolic activity of the bone, and to evaluate over the time the integration between host bone and prosthetic components. The purpose of the present study is to report about a preliminary experience in the analysis of osseointegration processes of patients undergoing a primary Total Hip Arthroplasty (THA) or a revision Total Knee Arthroplasty (rTKA).

MATERIALS AND METHODS

Thirty patients undergoing THA and nineteen undergoing rTKA were included in this study. In fifteen cases of THA a standard cementless stem was used; in the other fifteen a short cementless stem was chosen. In all cases a cementless cup was implanted. In all patients undergoing rTKA, all implants had pressfit femoral and tibial diaphyseal stems; only the femoral component and the tibial plateau were cemented. DEXA evaluation was performed preoperatively, and at 3, 6, 12, and 24 months postoperatively for rTKA, and at 6 and 12 months for THA.

RESULTS

DEXA in THA showed a significant decrease at the femoral ROIs 1 and 7, and an increase in ROI 4. In rTKA a reduction of femoral BMD in R1, R7, and R4 was found, with maximum values of -13.6% in R1 and -11.89% in R7 at 24 months and a value of -2.55% in R4 at 12 months. On the tibial side, an increase in BMD R4 (with values of 2.18% still at 24 months), and a reduction in R7 (progressively lesser over the time) and in R1 (progressively higher) were found.

CONCLUSIONS

After a joint replacement a full adhesion of the prosthetic surface to the host bone should be achieved through a local biological process named osseointegration. In some cases this process may not fully realize, so the secondary stability of the implant may fail. DXA is a valuable tool to follow over time the bone remodelling at the bone-prosthesis counterface in THA and in rTKA, in order to early detect any alterations of such phenomenon.

Hip resurfacing for osteonecrosis

Aims

Hip resurfacing arthroplasty (HRA) is an alternative to conventional total hip arthroplasty for patients with osteonecrosis (ON) of the femoral head. Our aim was to report the long-term outcome of HRA, which is not currently known.

Patients and Methods

Long-term survivorship, clinical scores and radiographic results for 82 patients (99 hips) treated with HRA for ON over a period of 18 years were reviewed retrospectively. The mean age of the 67 men and 15 women at the time of surgery was 40.8 years (14 to 64). Patients were resurfaced regardless of the size of the osteonecrotic lesion.

Results

The mean clinical follow-up was 10.8 years (2 to 18). The mean University of California, Los Angeles hip scores at the last follow-up were 9.3, 9.4, 9.2 and 6.8 for pain, walking, function and activity, respectively. A total of six hips underwent revision surgery, four for loosening of the femoral component and two for loosening of the acetabular component. Using any revision as an end point, the 15-year Kaplan-Meier survivorship was 90.3%. There were no wear-related failures. There were no femoral failures among the hips reconstructed with a cemented metaphyseal stem. A total of five hips showed narrowing of the femoral neck; all stabilised and remain asymptomatic, 21 showed signs of femoral neck impingement.

Conclusion

To our knowledge, this is the first report of a series of HRA performed for ON with 15-year survivorship. Our data confirm that patients with advanced stages of ON of the femoral head are excellent candidates for HRA. Cite this article: Bone Joint J 2016;98-B:901–9.

Primary ceramic-on-ceramic total hip arthroplasty using a 32-mm ceramic head with a titanium-alloy sleeve

BACKGROUND

Modern ceramic-on-ceramic bearings have become attractive alternatives to conventional polyethylene in total hip arthroplasty (THA) as a result of their low wear and minimal particle production. However, 28-mm heads in ceramic-on-ceramic bearing couples have been associated with ceramic fracture. To address these issues, 32-mm and larger ceramic heads with a titanium-alloy sleeve have been introduced, although limited data are available on their durability and clinical outcomes.

QUESTIONS/PURPOSES

We determined (1) the survivorship of the primary ceramic-on-ceramic THA using a 32-mm ceramic head with a titanium-alloy sleeve at a minimum followup of 5 years; (2) Harris hip scores; (3) the incidence of ceramic fracture and noisy hip; and (4) the proportion of hips showing radiographic evidence of osteolysis.

METHODS

From November 2005 to August 2009, we performed 301 ceramic-on-ceramic THAs using a 32-mm ceramic head with a titanium-alloy sleeve in 270 patients. Of these, 12 patients (12 hips [4%]) died from problems unrelated to surgery and 13 patients (15 hips [5%]) were lost during followup before a minimum of 5 years had been reached, leaving 245 patients who had 274 THAs with a minimum followup of 5 years (mean, 6.5 years; range, 5-9 years) in this retrospective analysis. During the study period, 30% (301 of 997 hips) were performed with this articulation based on the operating surgeon's discretion. The mean patient age at the time of surgery was 55 years (range, 16-82 years). All operations were performed at a single center. All of the ceramic implants were hot isostatic-pressed, laser-marked, proof-tested third-generation alumina. We determined the implant survival, Harris hip scores, incidence of ceramic fracture or noisy hips (based on a questionnaire), and presence of osteolysis.

RESULTS

The survival rate of ceramic-on-ceramic bearings in primary THA using a 32-mm ceramic head with a titanium-alloy sleeve was 98% (95% confidence interval, 96%-100%) at 9 years. The Harris hip score improved from a mean of 47 points preoperatively to 93 points at last followup. One ceramic head fractured at 6 years postoperatively. No ceramic liners fractured. Audible hip clicking and squeaking were identified in four hips and one hip, respectively. Osteolysis was detected in three hips, but none had symptoms.

CONCLUSIONS

Primary ceramic-on-ceramic THA using a 32-mm ceramic head with a titanium-alloy sleeve has a survivorship of 98% at 9-year followup. Nevertheless, surgeons should be aware of the potential risks of ceramic fracture, noise, and osteolysis associated with the use of a ceramic head with a titanium-alloy sleeve.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Long-term result of cementless femoral stem in avascular necrosis of the hip

Avascular necrosis (AVN) of the hip may have extensive involvement of the proximal femur which may affect boney ingrowth into cementless femoral stems. From 1994 to 2004, 182 total hip arthroplasties (in 144 patients, 117 AVN hips and 65 non-AVN hips) were performed using hydroxyapatite coated femoral stems. All patients were followed up prospectively. Mean age was 51 years and mean follow-up 14.7 years (range 9.7-19.1 years). Four stems were revised because of aseptic loosening, 3 in AVN group and 1 in non-AVN group. The overall mechanical failure rate was 2.2%, the mechanical failure rate in AVN and non-AVN group was 2.6% and 1.5% respectively (p = 1). The 19.1 year survival using revision for aseptic loosening as an endpoint for AVN and non-AVN patients were 97.1% and 96.2% respectively (p = 0.654). Stable boney ingrowth was present in 99.5% hips. This study represents 1 of the largest series reporting the long-term follow-up of the use of cementless femoral stems in treating AVN of the hip. We report excellent long-term survival of cementless total hip arthroplasty used in managing AVN of the hip and is comparable to that seen in non-AVN total hip arthroplasty.

Short-term outcome of ceramic-on-ceramic total hip replacement in young adult patients

Background: Ceramic-on-ceramic (CoC) total hip replacement (THR) was developed to minimize debris and osteolytic reaction. The major concern is its brittleness. The aim of this study was to evaluate the short-term outcome of CoC THR in young adult patients. Methods: 11 patients, 13 THR procedures, were followed up until six months after surgery in Cipto Mangunkusumo Hospital. Evaluation included Harris hip score (HHS), visual analog scale (VAS), patients’ complaint, short form-36 (SF-36), and acetabular and femoral component angles. Data were analyzed using Wilcoxon signed rank test, paired t-test, and Spearman test. Results: The average age of the patients was 33.6 years old and 55% of them were female. Systemic lupus erythematosus was the main causative disease for THR. The VAS average decreased before surgery and after six months of surgery (5 to 1). Pre- and post-operative HHS and SF-36 increased significantly by (25 to 92) and (21 to 54) respectively. Squeaking sound was reported by two patients. No correlation was found between acetabular and femoral component and squeaking incidence.Conclusion: CoC THR showed excellent short term outcome for young adult patients. With proper indications, CoC THR ensures excellent clinical outcomes and promising survivorship.

Nontraumatic Osteonecrosis of the Femoral Head: Where Do We Stand Today? A Ten-Year Update

➤ Although multiple theories have been proposed, no one pathophysiologic mechanism has been identified as the etiology for the development of osteonecrosis of the femoral head. However, the basic mechanism involves impaired circulation to a specific area that ultimately becomes necrotic.➤ A variety of nonoperative treatment regimens have been evaluated for the treatment of precollapse disease, with varying success. Prospective, multicenter, randomized trials are needed to evaluate the efficacy of these regimens in altering the natural history of the disease.➤ Joint-preserving procedures are indicated in the treatment of precollapse disease, with several studies showing successful outcomes at mid-term and long-term follow-up.➤ Studies of total joint arthroplasty, once femoral head collapse is present, have described excellent outcomes at greater than ten years of follow-up, which is a major advance and has led to a paradigm shift in treating these patients.➤ The results of hemiresurfacing and total resurfacing arthroplasty have been suboptimal, and these procedures have restricted indications in patients with osteonecrosis of the femoral head.

Outcomes of total hip arthroplasty in patients with osteonecrosis of the femoral head-a current review

The purpose of this review was to analyze (1) patient-reported outcomes and implant survivorship of osteonecrosis (ON) patients following total hip arthroplasty (THA), (2) if prior hip-preserving procedures influence these outcomes, (3) if resurfacing procedures alter outcomes; and (4) how these outcomes may have been impacted by the choice of different bearing surfaces. Today, with implant innovations such as cementless constructs, ceramic bearing surfaces, and highly cross-linked polyethylene, ON patients derive great benefit and have high survivorship following THA. Most studies have shown that previous hip-preserving procedures do not have a deleterious effect on outcomes. Literature on the use of ceramic and highly cross-linked polyethylene bearing surfaces have shown that these implant designs are useful in younger and more active patients. Future research should evaluate the long-term outcomes and survivorship of these new THA constructs.

Epidemiology of nontraumatic osteonecrosis of the femoral head in Japan

OBJECTIVES

To elucidate the epidemiology of nontraumatic osteonecrosis of the femoral head (ONFH), and to estimate the annual incidence rate in Japan.

METHODS

We examined, over the course of 3 years, personal records and radiographic images from the national registry of documents used for the study of nontraumatic ONFH in patients in Aichi Prefecture, Japan (population: 7.4 million). Those patients not meeting the diagnostic criteria according to the Japanese Investigation Committee for nontraumatic ONFH were excluded from this study.

RESULTS

A total of 285 out of the 327 patients who applied for the national registration of nontraumatic ONFH during the 3-year study met the diagnostic criteria for personal records, radiographic images, and magnetic resonance images. Forty-two patients (12.8%) were not considered to have nontraumatic ONFH. The mean age of patients was 50.4 years, and the male-female ratio was 2.1:1. Nontraumatic ONFH was steroid-induced in 135 cases (47.4%), alcohol-associated in 87 cases (30.5%), steroid-induced and alcohol- associated in 14 cases (4.9%), and idiopathic in 49 cases (17.2%).

CONCLUSIONS

The age-adjusted annual incidence of nontraumatic ONFH in Aichi Prefecture was estimated at 138.5 patients.Thus the annual incidence rate in Japan (population 128 million) was 1.91/100,000.

Orthopaedic implant failure: aseptic implant loosening–the contribution and future challenges of mouse models in translational research

Aseptic loosening as a result of wear debris is considered to be the main cause of long-term implant failure in orthopaedic surgery and improved biomaterials for bearing surfaces decreases significantly the release of micrometric wear particles. Increasingly, in-depth knowledge of osteoimmunology highlights the role of nanoparticles and ions released from some of these new bearing couples, opening up a new era in the comprehension of aseptic loosening. Mouse models have been essential in the progress made in the early comprehension of pathophysiology and in testing new therapeutic agents for particle-induced osteolysis. However, despite this encouraging progress, there is still no valid clinical alternative to revision surgery. The present review provides an update of the most commonly used bearing couples, the current concepts regarding particle–cell interactions and the approaches used to study the biology of periprosthetic osteolysis. It also discusses the contribution and future challenges of mouse models for successful translation of the preclinical progress into clinical applications.

High survivorship with a titanium-encased alumina ceramic bearing for total hip arthroplasty

BACKGROUND

Although ceramic-on-ceramic bearings for total hip arthroplasty (THA) show promising results in terms of bearing-surface wear, fracture of the bearing, insertional chips, and squeaking remain a concern.

QUESTIONS/PURPOSES

Our primary objective of this report was to determine overall survivorship of a titanium-encased ceramic-on-ceramic bearing couple. Our secondary objectives were to evaluate for ceramic fracture, insertional chips, osteolysis, and device squeaking.

METHODS

Six surgeons at six institutions implanted 194 patients (209 hips) with an average age of 52 years with cementless hips and alumina ceramic bearings. One hundred thirty-seven patients (146 hips) have 10-year followup (70%). We determined Kaplan-Meier survivorship of the bearing surface and implant system and collected radiographic and clinical data to evaluate for osteolysis and squeaking.

RESULTS

Survivorship using revision for any reason as the end point was 97% at 10 years and survivorship end point bearing surface failure or aseptic loosening of 99%. There was one ceramic insert fracture (0.5%), there were no insertional chips, there was no visible osteolysis on AP and lateral radiographs, and there was a 1% patient-self-reported incidence of squeaking at the last clinical followup. Six hips underwent revision (3.7%).

CONCLUSIONS

Ceramic bearings for THA with a titanium-encased insert have high survivorship at 10 years followup and a fracture risk of 0.5%. We found at last followup on routine radiographs no evidence of osteolysis, and no patient has been revised for squeaking or has reported dissatisfaction with the clinical result because of noise. IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Is bipolar hemiarthroplasty a reliable option for Ficat stage III osteonecrosis of the femoral head? 15- to 24-year follow-up study

PURPOSE

The long-term results of a bipolar hemiarthroplasty (BHA) for osteonecrosis (ON) of the femoral head have not been favorable. The causes have been attributed to cup migration and osteolysis or groin pain. The purpose of this study was to analyze the long-term outcomes and the survivorships of bipolar hemiarthroplasty applied to Ficat stage III ON.

MATERIALS AND METHODS

Between 1985 and 1993, 49 patients (63 hips) underwent cementless BHA for Ficat stage III ON. Of these 49 patients, 43 patients (55 hips) of mean age 42.2 years were available for follow-up review at a mean duration of 20.3 years post operation. Anteroposterior hip serial (including extreme abduction/adduction) radiographs were used to evaluate osteolysis, migration, cartilage wear rate, and the ratio of outer/inner bearing motion (O/I ratio) at the latest follow-up.

RESULTS

The mean Harris hip score improved to 80.8 points at the latest follow-up. Survivorship at 24 years was 79 and 69 % with revision for any reason and development of acetabular osteolysis as the end point. Groin pain was present in 20 (36.4 %) of the 55 hips, and isolated groin pain was not a reason for revision. The patients had revision surgery performed, which showed that the cartilage wear rate was significantly high, and that the O/I ratio was significantly low (p < 0.05).

CONCLUSION

Survivorship determined in this study was more favorable than that of previous studies, and exceeded expectation. The BHA for Ficat stage III ON is not reliable option anymore, considering low survival rate and high osteolysis developmental rate.