Fracture of the alumina-bearing couple delta ceramic liner

Long-Term Results of Delta Ceramic-on-Ceramic Total Hip Arthroplasty

Background

Ceramic-on-ceramic (COC) bearings in total hip arthroplasty (THA) have long been considered the coupling with the lowest overall wear. However, concerns about complications such as ceramic breakage and noise, combined with the improved performance of polyethylene, have limited its use in the United States. This postapproval follow-up reports long-term (10 years) results of Delta COC in THA patients primarily enrolled in an Investigational Device Exemption study.

Methods

Patients received Delta COC THA in a prospective multicenter study with either 28-mm (N = 105 hips in 104 patients) or 36-mm (N = 81) articulations. Annual clinical and radiographic evaluations were performed for years 5 to 10, and study patients were asked about hip noises and reproducibility.

Results

There have been 4 additional reports of noise in 4 patients (COC 28, n = 3; COC 36, n = 1). The cumulative incidence rate for squeaking or noise at 10 years is 5.9% for COC 28 and 13.5% for COC 36. There have been 2 additional reports of dislocation in 2 patients (COC 28, n = 1; COC 36, n = 1). The cumulative incidence rate for dislocation at 10 years is 3.7% for COC 28 and 3.5% for COC 36. At 10 years, there were greater than 40 hips available for follow-up. At mean 10-year follow-up, there were a total of 3 ceramic liner fractures, but none since the previous report. There were no revisions in the 28-mm cohort, and 2 revisions in the 36-mm cohort (1 for recurrent dislocation and 1 for pain and noise). Overall Kaplan-Meier survivorship was 95.96% at 10.5 years (28 mm: 97.68% at 10.2 years; 36 mm: 94.11% at 10.4 years.)

Conclusions

At 10-year follow-up, we report excellent results in regard to survivorship, with one patient revised for pain with associated squeaking.

Early Short-Term Postoperative Mechanical Failures of Current Ceramic-on-Ceramic Bearing Total Hip Arthroplasties

Although ceramic-on-ceramic (CoC) bearings have been shown to produce the smallest amount of wear volume in vitro as well as in vivo studies when used for total hip arthroplasties (THA), concerns about the failure of these bearing surfaces persist due to early failures observed after short postoperative time. In this study, an exhaustive analysis of the early failure occurred on the new generation of ceramic bearings, consisting of a composite alumina matrix-based material reinforced with yttria-stabilized tetragonal zirconia (Y-TZP) particles, chromium dioxide, and strontium crystals, was performed. For this study, 118 CoC bearings from 117 patients were revised. This article describes a group of mechanical failure CoC-bearing BIOLOX THA hip prosthesis patients without trauma history. The retrieved samples were observed under scanning electron microscopy (SEM), composition was analyzed with energy dispersive X-ray spectroscopy (EDX), and damaged surfaces were analyzed by grazing-incidence X-ray diffraction (GI-XRD) and white light interferometry. In the short term, CoC articulations provided similar mechanical behavior and functional outcome to those in XLPE cases. However, 5% more early mechanical failures cases were observed for the ceramic components. Although the fracture rate of third generation CoC couples is low, the present study shows the need to further improve the third generation of CoC-bearing couples for THA. Despite the improved wear compared to other materials, stress concentrators are sources of initial crack propagation, such as those found in the bore-trunnion areas. Moreover, in view of the evidence observed in this study, the chipping observed was due to the presence of monoclinic phase of the Y-TZP instead of tetragonal, which presents better mechanical properties. The results showed that total safety after receiving a THA is still a goal to be pursued.

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.

Atraumatic Fracture of the BIOLOX delta Ceramic Liner in Well-Fixed Total Hip Implants

A newer alumina matrix composite ceramic (BIOLOX delta; CeramTec, Plochingen, Germany) was developed to improve resistance to wear while reducing the risk for fractures with alumina-on-alumina design. This article describes a case of fracture of the BIOLOX delta ceramic liner without history of trauma in well-fixed total hip implants. A 61-year-old woman underwent total hip replacement via the posterior approach 20 months earlier because of osteonecrosis of the femoral head. A cementless cup and a stem with a 52/36-mm BIOLOX delta couple bearing were used. The authors found signs of stripe wear on the inner surface of the ceramic liner, leading them to believe the possible cause of fracture in this patient was edge loading due to joint laxity. The authors performed revision surgery with the use of another ceramic couple-bearing implant and converted the head component from short to long (+4 mm). More cases should be collected to verify the mechanism of the fracture of the BIOLOX delta ceramic liner with a well-fixed cup. [Orthopedics. 2018; 41(6):e880-e883.].

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

Midterm Results of Delta Ceramic-on-Ceramic Total Hip Arthroplasty

This study reports mid-term results of Delta ceramic on ceramic (COC) in total hip arthroplasty (THA). Subjects received Delta COC THA in a prospective multi-center study with either 28 mm (n=177) or 36 mm (n=168) articulations. Annual clinical and radiographic evaluations were performed, and patients were asked about hip noises. At mean 5.3-year follow-up there were 3 (0.9%) post-operative liner fractures. Nine revisions were performed (2 liner fracture, 4 stem loosening, 3 deep infection). Kaplan-Meier survivorship at 6 years was 96.9% (94.0-98.4). Twenty-six (7.5%) subjects reported squeaking, of whom none were revised. One (0.3%) subject could reproduce a sound in clinic. More patients reported squeaking with a 36 mm bearing (28 mm: 7/177, 36 mm: 19/168, P=0.013).

Does Biolox Delta ceramic reduce the rate of component fractures in total hip replacement?

Biolox Delta ceramic has been optimized with nano-sized, yttria-stabilized tetragonal zirconium and strontium oxide to help limit cracking propagation. Although its mechanical properties are better than those of earlier generation ceramics, existing data on this material are limited, thus the goals of this study were to determine: 1) the remaining rate of implant fracture; 2) the ideal combination of head diameter and component position. Hypothesis. We hypothesized that the use of the ceramic composite Biolox Delta had reduced the risk of implant fracture. Materials and methods. The bibliographic search (in Pubmed database with the key words «ceramic fracture» and «total hip prosthesis ») identified 46 articles on fractures in third or fourth generation ceramic components, including 5 involving Biolox Delta. Manufacturer's data and ANSM (Agence nationale de sécurité du médicament et des produits de santé) (National Agency for Safety of Drugs and Medical Products) reports were compared with the few clinical cases published in the literature. Results. According to the manufacturer (CeramTec GmbH, Plochingen, Germany), the use of Biolox Delta ceramic has reduced the rate of femoral head fractures to 0.003% compared to 0.021% with alumina ceramic. The fracture rate of liners has remained stable, at approximately 0.03%. The number of ANSM reports confirmed these tendencies. The rate of head component fractures decreases as the head diameter increases. The quality of impaction on the morse taper (cleanliness of the taper, insertion along the axis) plays an important role. Although it is generally only available for cup sizes above 50mm, a 36-mm head diameter seems to be optimal because it prevents impingement between the cup rim and the neck of the stem, without increasing micro-separation with larger diameters. Conclusion. Although Biolox Delta ceramic is more resistant to fractures than alumina ceramic, it can be fractured under suboptimal implantation conditions including edge loading. Its use requires the same precautions as other hard-on-hard bearings and requires special attention to cup position, insertion on or in morse tapers and adjustment of leg length.

LEVEL OF EVIDENCE

V expert's opinion.

Wear of a composite ceramic head caused by liner fracture

Third-generation composite ceramics (eg, Delta; DePuy Orthopaedics, Warsaw, Indiana; Ceramtec, Plochingen, Germany) have greatly improved material characteristics compared with second-generation products. This case report presents a patient after total hip arthroplasty with a fractured ceramic liner and a heavily worn ceramic head (both third-generation ceramics) retrieved 9 months after surgery. The patient showed no symptoms in the involved hip but presented to the hospital because of other symptoms. The failure was caused by a tilted liner that was overlooked after surgery and fractured consecutively. Rim chipping and splitting were the 2 fracture modes observed for the liner. The head did not fracture completely because of its high strength but became roughened by the ceramic fragments, causing major wear of the metal back of the cup. The phase transformation of the zirconium grains from tetragonal to monoclinic in the aluminum oxide matrix was shown by radiographic diffraction analysis in the heavily worn areas of the head. This transformation increases the fracture strength of the head. Metal debris caused by a roughened ceramic head without fracture is an unreported phenomenon for third-generation ceramic bearings in hip arthroplasty. This case shows that proper impaction of the ceramic liner into the metal shell to prevent later tiling during reduction is as important as correct component positioning. If a tilted ceramic liner is observed postoperatively, the position must be corrected immediately to prevent the major consequences observed in this patient.

Advances in zirconia toughened alumina biomaterials for total joint replacement

The objective of this article is to provide an up-to-date overview of zirconia-toughened alumina (ZTA) components used in total hip arthroplasties. The structure, mechanical properties, and available data regarding the clinical performance of ZTA are summarized. The advancements that have been made in understanding the in vivo performance of ZTA are investigated. This article concludes with a discussion of gaps in the literature related to ceramic biomaterials and avenues for future research.

Fracture of ceramic bearing surfaces following total hip replacement: a systematic review

Ceramic bearing surfaces are increasingly used for total hip replacement, notwithstanding that concern is still related to ceramic brittleness and its possible mechanical failure. The aim of this systematic review is to answer three questions: (1) Are there risk factors for ceramic component fracture following total hip replacement? (2) Is it possible to perform an early diagnosis of ceramic component failure before catastrophic fracture occurs? (3) Is it possible to draw guidelines for revision surgery after ceramic components failure? A PubMed and Google Scholar search was performed and reference citations from publications identified in the literature search were reviewed. The use of 28 mm short-neck femoral head carries an increased risk of fracture. Acetabular component malposition might increase the risk of ceramic liner fractures. Synovial fluid microanalysis and CT scan are promising in early diagnosis of ceramic head and liner failure. Early revision is suggested in case of component failure; no consensus exists about the better coupling for revision surgery. Ceramic brittleness remains a major concern. Due to the increased number of ceramic on ceramic implants, more revision surgeries and reports on ceramic components failure are expected in the future. An algorithm of diagnosis and treatment for ceramic hip failure is proposed.