What factors predict ceramic liner malseating after ceramic-on-ceramic total hip arthroplasty?

Evaluating the Feasibility and Reproducibility of a Novel Insertion Method for Modular Acetabular Ceramic Liners

Modern hip implants have a modular design. In case of wear or other damage it allows surgeons to change the tribological partners, i.e., the acetabular liner and femoral ball. In both revision and primary surgery, the secure joining of the implant components is important for the success of the operation. The two components, namely the ceramic liner and hip cup, are connected via a conical press connection and should be concentrically aligned to avoid chipping. Malseated liners can reduce the life span in situ. The amount of the joining force, which is usually applied via a hammer, depends on the surgeon. In this study, an alternative joining method for acetabular ceramic liners in hip cups was investigated, which intends to make the process more reproducible and thus safer. For this purpose, a handpiece was used to apply a defined force impulse of 4 kN. For the concentric alignment of a ceramic liner in the hip cup, an adapter was developed based on findings via a qualitative finite element (FE) analysis. Insertion and pushout tests of the acetabular cup-liner connection were performed in the laboratory with the new instrument (handpiece with the connected adapter) to evaluate the functionality of the instrument and the reproducibility of the new insertion method. For comparison, liners and acetabular cups were joined using a testing machine according to the standard. The presented results demonstrate the technical proof-of-concept of the new joining method under laboratory conditions. They meet the acceptance criteria of established manufacturers, which proves the equivalency to proven methods for joining modular implant components. To verify the improvement of the new joining method compared to the conventionally used joining method, an application-oriented study with different surgeons and the new joining instrument under clinical conditions is necessary.

No clinical consequence of liner malseating in dual-mobility THAs at short term: a systematic review

BACKGROUND

Liner malseating is well described in ceramic-on-ceramic total hip arthroplasties (THAs). However, limited information is known on this complication among dual-mobility articulations. As such, this systematic review analyzed liner malseating in dual-mobility THAs concerning prevalence, clinical implications, and associated risk factors.

METHODS

A PRISMA criteria-based systematic review was performed, and PubMed, Web of Science, MEDLINE, and Cochrane used as data bases. All original studies from 1980 to 2022 were considered eligible for inclusion, and Methodological Index for Nonrandomized Studies (MINORS) used for quality assessment.

RESULTS

In total, five retrospective cohort studies with 2330 patients (2673 dual-mobility THAs) were included. Mean age was 66.9 years, mean BMI was 29.8 kg/m2, and 35% of patients were female. Rates of malseating ranged from 0.15% to 5.8%, with a total of 53 malseated liners identified throughout all studies (1.98%). Based on THA manufacturer, malseating occurred in 48 Stryker (1.96%) and 5 Biomet Zimmer (2.14%) THAs. Mean clinical follow-up was 2.2 years (mean range, 1.3 to 6.4 years). Except one patient reporting of pain at 2 years, no revision or negative clinical implication was noted in any of the malseated liners, including normal ranged metal ions measured in four cases. A smaller acetabular component size was identified as a statistically significant risk factor for malseating in one study. Mean MINORS score was 9.8.

CONCLUSIONS

Liner malseating is a rare finding in patients undergoing THAs with dual-mobility articulations. While prelim results demonstrate no negative clinical consequences to date, existing studies are limited, refer to short-term outcomes only, and do not prospectively follow-up affected patients.

LEVEL OF EVIDENCE

IV.

Spontaneous resolution of asymptomatic alumina matrix composite ceramic liner dissociation: a case report

Background

Total hip arthroplasty(THA)is widely used to treat end-stage hip disorders. Ceramic-on-ceramic total hip prostheses are widely used because of their durability. Alumina matrix composite (AMC), known as the fourth-generation ceramics, reduces implant fracture and wear rate compared to their predecessors. However, ceramic acetabular liner dissociation is a complication that necessitates revision of the AMC prostheses. To date, only few cases of AMC liner dissociation have been reported and all of which have been treated with revision surgery. Therefore, the prognosis of non-operated AMC liner dissociation remains unknown so far.

Case presentation

A 57-year-old man with avascular necrosis of the femoral head was treated with THA, wherein a Pinnacle® (DePuy, J&J, Warsaw, IN) acetabular cup and AMC liner were implanted. Intraoperative examination confirmed proper seating of the liner, whereas the initial postoperative radiograph revealed liner dissociation. The patient refused surgical revision due to the absence of symptoms and was discharged and followed-up. The patient made an uneventful recovery, and radiographic follow-up at 6-month post-operation showed that the liner was re-seated to its right position. No clinical or radiographic anomaly was found at the 15-month of postoperative follow-up.

Conclusions

Here, we report an unprecedented case of AMC ceramic liner dissociation with spontaneous resolution. This case shows that ceramic liner dissociation could be asymptomatic, and careful postoperative examination of the patient is important. Spontaneous resolution is possible, but the underlying mechanism and the eligible patient to benefit from it must be investigated. Before clarifying these questions, revision surgery should be the first-line treatment.

Alumina ceramic-on-ceramic hybrid total hip arthroplasty. A median of 15 years follow-up

INTRODUCTION

The optimum choice of bearing surfaces in total hip replacement (THR) in the younger and active patient remains controversial. The aim of this study was to report the 10 year clinical outcomes, and a median of 15 year implant survival and incidence of complications in a series of Alumina ceramic-on-ceramic THRs utilising an uncemented shell and cemented stem.

METHODS

From January 2004 to December 2007, 175 consecutive patients (195 hips) underwent primary THR. The acetabular components was Trident Peripheral Self Locking (Stryker Orthopaedics) with a third-generation ceramic head and liner (Alumina ceramic, Stryker Orthopaedics). The stem utilised was an Exeter V-40 (Stryker Orthopaedics). Data were collated on demographics, surgical factors, clinical outcomes, radiographic outcomes and revision.

RESULTS

23 patients (27 THRs) died during the follow-up period at a median of 7.8 (3.8 to 9.0) years post-operatively due to causes unrelated to the THR. Median age at time of surgery was 55 (interquartile range 48-60) years. Median follow-up for surviving patients was 15.2 years. Survivorship for all-cause revision was 97.2%. Increasing patient age at time of surgery was associated with a higher OHS at 10 years (p = 0.022). 32 mm head diameter had an improved OHS at 3 months (p = 0.014) and 10 years (p = 0.030). Posterior surgical approach had a statistically significant better OHS at 3 months (p = 0.015) and 1 year (p < 0.001), but the effect was not significant at 10 years (p = 0.440).

CONCLUSION

The findings of this study support excellent long-term outcomes and survivorship of Alumina ceramic-on-ceramic bearing in a hybrid THR in a younger population. Surgical factors leading to a more favourable outcome were the use of a 32 mm femoral head and a posterior approach. Increasing age at surgery demonstrated the most sustained improvement in 10 year clinical outcomes.

Long-Term Outcome on the Mal-Seating of Ceramic-on-Ceramic Articulation in Total Hip Arthroplasty

BACKGROUND

Total hip arthroplasty with ceramic-on-ceramic articulation aims to decrease wear, osteolysis, and aseptic loosening. A metal-backed ceramic liner was developed to reduce the risk of liner fracture. However, a significant number of cases of mal-seating of the metal-backed ceramic liner were observed in the 2000s, and there were concerns about their outcome. This review aims to investigate the long-term performance of the mal-seated ceramic liner.

METHODS

From July 2003 to March 2007, 35 ceramic-on-ceramic total hip arthroplasties were performed with the Trident acetabular system. Clinical assessment, radiological analysis, and outcome assessment were performed. The prevalence of liner mal-seating and its long-term outcomes were investigated.

RESULTS

There was liner mal-seating in 8 hips (22.9%). One liner was exchanged in the early postoperative period. No revision surgery was required for the remaining 7 hips at a mean follow-up of 14 years. All patients were free of hip pain with a mean Harris Hip Score of 94.7 at the most recent follow-up. No adverse event was observed.

CONCLUSION

The long-term outcomes of the mal-seated liner were favorable. However, surgeons should exercise meticulous surgical technique to achieve a properly aligned liner within the acetabular shell to minimize this potentially correctable error.