Successful Performance of the Bi-Metric Uncemented Femoral Stem at a Minimum Follow-Up of 13 Years in Young Patients

Davies, H. T. O.; Ollivere, B.; Motha, Joseph; Porteous, Matthew; August, Adrian

doi:10.1016/j.arth.2008.11.105

Cited by 13 publications

(8 citation statements)

References 30 publications

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“…This tapered titanium stem was associated with an excellent crude and adjusted 10-year survival, both considering stem revisions for any reason and those that were due to aseptic loosening. This finding is in line with previous reports ( Davies et al 2010 ), and revisions of THAs using the Bimetric stem are frequently associated with failure of the cup but not the stem component ( Isaac et al 2007 ). Low revision rates of the Bimetric stem have also been described in a Finnish registry study ( Eskelinen et al 2006 ).…”

Section: Discussionsupporting

confidence: 93%

Hydroxyapatite coating does not improve uncemented stem survival after total hip arthroplasty!

Hailer¹,

Lazarinis²,

Mäkelä³

et al. 2014

Acta Orthopaedica

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Background and purposeIt is still being debated whether HA coating of uncemented stems used in total hip arthroplasty (THA) improves implant survival. We therefore investigated different uncemented stem brands, with and without HA coating, regarding early and long-term survival.Patients and methodsWe identified 152,410 THA procedures using uncemented stems that were performed between 1995 and 2011 and registered in the Nordic Arthroplasty Register Association (NARA) database. We excluded 19,446 procedures that used stem brands less than 500 times in each country, procedures performed due to diagnoses other than osteoarthritis or pediatric hip disease, and procedures with missing information on the type of coating. 22 stem brands remained (which were used in 116,069 procedures) for analysis of revision of any component. 79,192 procedures from Denmark, Norway, and Sweden were analyzed for the endpoint stem revision. Unadjusted survival rates were calculated according to Kaplan-Meier, and Cox proportional hazards models were fitted in order to calculate hazard ratios (HRs) for the risk of revision with 95% confidence intervals (CIs).ResultsUnadjusted 10-year survival with the endpoint revision of any component for any reason was 92.1% (CI: 91.8–92.4). Unadjusted 10-year survival with the endpoint stem revision due to aseptic loosening varied between the stem brands investigated and ranged from 96.7% (CI: 94.4–99.0) to 99.9% (CI: 99.6–100). Of the stem brands with the best survival, stems with and without HA coating were found. The presence of HA coating was not associated with statistically significant effects on the adjusted risk of stem revision due to aseptic loosening, with an HR of 0.8 (CI: 0.5–1.3; p = 0.4). The adjusted risk of revision due to infection was similar in the groups of THAs using HA-coated and non-HA-coated stems, with an HR of 0.9 (CI: 0.8–1.1; p = 0.6) for the presence of HA coating. The commonly used Bimetric stem (n = 25,329) was available both with and without HA coating, and the adjusted risk of stem revision due to aseptic loosening was similar for the 2 variants, with an HR of 0.9 (CI: 0.5–1.4; p = 0.5) for the HA-coated Bimetric stem.InterpretationUncemented HA-coated stems had similar results to those of uncemented stems with porous coating or rough sand-blasted stems. The use of HA coating on stems available both with and without this surface treatment had no clinically relevant effect on their outcome, and we thus question whether HA coating adds any value to well-functioning stem designs.

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Section: Discussionsupporting

confidence: 93%

Hydroxyapatite coating does not improve uncemented stem survival after total hip arthroplasty!

Hailer¹,

Lazarinis²,

Mäkelä³

et al. 2014

Acta Orthopaedica

View full text Add to dashboard Cite

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“…Other studies on smaller numbers of patients who had received this stem have shown survival rates of between 95% and 100% at 10 years (Isaac et al 2007, Davies et al 2010). A low revision rate of the Bi-Metric stem was also found in a large Finnish registry analysis with 10-year survival of 96% based on aseptic loosening as the endpoint (Eskelinen et al 2006).…”

Section: Discussionmentioning

confidence: 97%

Effects of hydroxyapatite coating on survival of an uncemented femoral stem

2011

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Background and purposeHydroxyapatite (HA) is widely used as a coating for uncemented total hip arthroplasty components. This has been suggested to improve implant ingrowth and long-term stability. However, the evidence behind the use of HA coating on femoral stems is ambiguous. We investigated survival of an uncemented, tapered titanium femoral stem that was available either with or without HA coating (Bi-Metric).Patients and methodsThe stem had been used in 4,772 total hip arthroplasties (THAs) in 4,169 patients registered in the Swedish Hip Arthroplasty Register between 1992 and 2009. 59% of the stems investigated were coated with HA and 41% were uncoated. Kaplan-Meier survival analysis and a Cox regression model with adjustment for age, sex, primary diagnosis, and the type of cup fixation were used to calculate survival rates and adjusted risk ratios (RRs) of the risk of revision for various reasons.ResultsThe 10-year survival rates of the HA-coated version and the uncoated version were about equal when we used revision for any reason as the endpoint: 98% (95% CI: 98–99) and 98% (CI: 97–99), respectively. A Cox regression model adjusting for the covariates mentioned above showed that the presence of HA coating did not have any influence on the risk of stem revision for any reason (RR = 1.0, 95% CI: 0.6–1.6) or due to aseptic loosening (RR = 0.5, CI: 0.2–1.5). There was no effect of HA coating on the risk of stem revision due to infection, dislocation, or fracture.InterpretationThe uncemented Bi-Metric stem showed excellent 10-year survival. Our findings do not support the use of HA coating on this stem to enhance implant survival.

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“…Thus, according to the criteria of Engh et al [5], fixation of the stem by bone ingrowth occurred in all hips. Davies et al [4] reported on 64 uncemented stems of the same design implanted in 54 patients with a minimum followup of 13 years (mean, 15.2 years) and noted no stem failures or stem revisions. A previous study from out institution reviewed 2321 uncemented THAs using this same stem for the purpose of comparing results in Dorr A, B, and C bone [20].…”

Section: Discussionmentioning

confidence: 99%