A case-driven hypothesis for multi-stage crack growth mechanism in fourth-generation ceramic head fracture

Incidence of Ceramic Component Fractures in Total Hip Arthroplasty Using Contemporary Ceramic-On-Ceramic Bearings: A Retrospective Study Spanning Two Decades From Two Tertiary Referral Hospitals

INTRODUCTION

Ceramic-on-ceramic (CoC) bearings have been widely used in total hip arthroplasty (THA) due to their excellent wear properties. However, ceramic component fractures remain a concern. This study aimed to report the incidence of third- and fourth-generation ceramic component fracture and identify factors that might influence this complication.

METHODS

A total of 9,280 hips that underwent THA with third- and fourth-generation CoC bearings at two tertiary institutions between 1997 and 2023 were retrospectively reviewed, and the incidence and associated factors of CoC bearing fracture were determined. We performed a Kaplan-Meier survival analysis to assess implant survivorship. Logistic regression was applied to evaluate the influence of implant size and patient-specific factors on the risk of revision.

RESULTS

Out of the 9,280 THA procedures, there were 33 (0.36%) revisions for CoC bearing fracture. Specifically, revisions for fracture were performed for zero out of 6,654 fourth-generation CoC heads, 26 (0.990%) of 2,626 third-generation CoC heads, two (0.030%) of 6,654 fourth-generation CoC liners, and five (0.190%) of 2,626 third-generation CoC liners. All ceramic head fractures occurred in a 28 mm head. Younger age was related to both ceramic head and liner fracture.

CONCLUSIONS

To our knowledge, this is the largest two-center retrospective study on CoC bearing fractures to date. The risk of revision for fracture of CoC bearings is low, as previously reported. Our data were comparable to recent evidence suggesting that the latest generation of ceramic components can significantly decrease the incidence of head fracture but not liner fracture. Factors such as younger age and men may be associated with an increased risk of ceramic component fractures.

LEVEL OF EVIDENCE

III, therapeutic.

Ceramic fragmentation after total hip arthroplasty: two case reports and literature review

Background

Ceramic fragmentation is a rare but serious complication after total hip arthroplasty (THA). We reviewed the PubMed literature from 1990 to 2023 and found only 31 case reports of ceramic fragmentation after THA. Our case reports help to expand understanding of this rare complication. We shared our surgical experience and identified an ideal material for revision surgery, which can serve as a useful reference for other orthopedic surgeons to perform ceramic fragmentation revision surgery in the future. We also analyzed the possible causes, diagnosis, and treatment opinions of ceramic fragmentation.

Case presentation

This study presents two cases of ceramic fragmentation after THA. One patient had ceramic head fragmentation 10 years after the primary THA, and one patient had ceramic liner fragmentation 5 years after the primary THA. Both patients presented with pain, and one patient also reported a clicking sound in the hip. The two patients described here had BMIs of 23.7 and 23.1, respectively. Both patients' ceramic fragmentation were due to aseptic loosening, not periprosthetic joint infections, as confirmed by negative microbiological cultures. Radiographic examinations of both patients revealed radio-opaque wear debris around the hip joint prostheses and we describe the surgical protocols and intraoperative findings in both cases in detail.

Conclusion

Our cases and the literature suggest that ceramic fragmentation can occur at any time after THA. The most immediate symptoms are pain and noise, but some patients may be asymptomatic. Ceramic on polyethylene bearings is recommended for revision surgery whenever possible; metal bearings should be avoided.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

FEM wear prediction of ceramic hip replacement bearings under dynamic edge loading conditions

Hard-on-Hard hip implants, specifically ceramic tribo-pair, have produced the highest in-vivo wear resistance, biocompatibility, superior corrosion resistance, and high fracture toughness. However, this ceramic tribo-pair suffers from edge loading, sharply increasing wear and accelerating early implant failures due to micro-separation. Even though in-vitro studies have tested the occurrence of wear due to dynamic edge loading, the Finite Element Method (FEM) gives the advantage of accurately estimating the wear, minimizing the experimental time and cost. A new fundamental FEM model is developed to predict wear for ceramic hip replacement bearings under dynamic edge loading conditions for a fixed separation and fixed inclination angle. The model is directly validated with the existing hip simulator data up to 3 million cycles in terms of wear depth, wear scar and volumetric wear rate. The results from the model show that the accuracy in wear prediction was more than 98% for the wear depth and volumetric wear rate for the dynamic edge loading condition. A stripe wear scar is captured, depicting the edge loading conditions. The developed model from this study can predict wear under pure standard and dynamic edge loading conditions.