High failure rate of a new pressfit cup in mid-term follow-up

Femoral Head Perforation After Primary Hip Arthroplasty: Unseen Complication of Ceramic-on-Ceramic Interface: A Case Report

CASE

A 33-year-old woman, who underwent bilateral ceramic-on-ceramic total hip arthroplasty 3 years previously, presented with right groin pain and mechanical grinding without a history of trauma. Radiographs revealed luxation of the femoral head, and computerized tomography showed perforation of the ceramic femoral head. The patient underwent revision with a metal-on-polyethylene articulation and retained femoral stem. Two years of follow-up yielded good clinical outcome with no evidence of osteolysis or polyethylene wear.

CONCLUSION

The perforation of a ceramic femoral head should be kept in mind as one of the possible implant failure mechanisms after primary hip arthroplasty.

Ceramic-on-ceramic articulation in press-fit total hip arthroplasty as a potential reason for early failure, what about the survivors: a ten year follow-up

PURPOSE

In press-fit total hip arthroplasty (THA), primary stability is needed to avoid micromotion and hereby aseptic loosening, the main reason for early revision. High aseptic loosening revision rates of the seleXys TH+ cup (Mathys Medical) with Ceramys ceramic-on-ceramic (CoC) bearing are seen in literature. Since CoC is presumed to overcome long-term wear-related revisions, the reason for early failure of this cup is important to clarify. The aim is to investigate its ten year outcomes and differentiate between potential causes and identify risk factors for aseptic loosening.

METHODS

Retrospective screening of a prospectively documented series of 315 THAs was performed. Primary outcome was cumulative incidence of cup revision due to aseptic loosening. Secondary outcomes were component revision and reoperation. Additionally, potential predictive factors for aseptic loosening were evaluated.

RESULTS

At the median follow-up of 9.7 years [IQR 4.4; 10.3], 48 TH+ (15.2%) were revised due to aseptic loosening. Competing risk analysis showed a ten year cumulative incidence of cup revision due to aseptic loosening of 15.6% (95% CI 12.0-20.2). Stabilization of early revision rates was observed, following a high rate of respectively 81.3% (n = 39) and 95.8% (n = 46) within the first two and three years. No significant predictive factors for aseptic loosening were found.

CONCLUSION

The ten year results of seleXys TH+ cup with Ceramys CoC bearing showed an unacceptable high aseptic loosening rate, which stabilized over time after a high early failure incidence. This could be attributed to a problem with osseointegration during the transition of primary to definitive stability.

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.

Midterm analysis of the seleXys cup with ceramic inlay

Background

Ceramic-on-ceramic (CoC) articulations in total hip replacement (THR) has been accepted as giving reliable mid-term results; however recent studies have reported higher revision rates of some implants. This study analyses the nationwide results of the seleXys TPS cup and the Bionit2 liner (Mathys, Bettlach, Switzerland) with respect to implant survival, cause for revision and mortality rates compared to other CoC articulations using the same stem.

Methods

Utilising the New Zealand Joint Registry, we compared the seleXys TPS cup with Bionit2 liner used with an uncemented Twinsys femoral stem to every other uncemented CoC THR using the same stem. Multivariate analysis was used to determine the effects of patient age, gender, ASA score and implant head size on these rates.

Results

Between 2006 and 2013 a total of 1035 seleXys THRs were performed on 862 patients. The comparison group had 375 THRs on 280 patients. There were 77 revisions (1.4/100 component years) in the study group and two in the comparison group (0.12/100 component years). Overall hazards ratio for revision was 12.22 times higher and female gender was associated with an increased risk (hazards ratio 1.77). Causes for revision were disturbing noises (23.4%), acetabular loosening (20.8%), and fracture of the liner (18.2%). Mortality rates were not significantly different (P = .567).

Conclusions

The seleXys TPS cup with the Bionit2 ceramic inlay coupling has an unacceptably high failure rate. We recommend avoiding this implant coupling and would advise that patients treated with this implant need close clinical and radiological follow-up.