Mortality and implant revision rates of hip arthroplasty in patients with osteoarthritis: registry based cohort study - PubMed (original) (raw)

Mortality and implant revision rates of hip arthroplasty in patients with osteoarthritis: registry based cohort study

D J W McMinn et al. BMJ. 2012.

Abstract

Objectives: To examine mortality and revision rates among patients with osteoarthritis undergoing hip arthroplasty and to compare these rates between patients undergoing cemented or uncemented procedures and to compare outcomes between men undergoing stemmed total hip replacements and Birmingham hip resurfacing.

Design: Cohort study.

Setting: National Joint Registry.

Population: About 275,000 patient records.

Main outcome measures: Hip arthroplasty procedures were linked to the time to any subsequent mortality or revision (implant failure). Flexible parametric survival analysis methods were used to analyse time to mortality and also time to revision. Comparisons between procedure groups were adjusted for age, sex, American Society of Anesthesiologists (ASA) grade, and complexity.

Results: As there were large baseline differences in the characteristics of patients receiving cemented, uncemented, or resurfacing procedures, unadjusted comparisons are inappropriate. Multivariable survival analyses identified a higher mortality rate for patients undergoing cemented compared with uncemented total hip replacement (adjusted hazard ratio 1.11, 95% confidence interval 1.07 to 1.16); conversely, there was a lower revision rate with cemented procedures (0.53, 0.50 to 0.57). These translate to small predicted differences in population averaged absolute survival probability at all time points. For example, compared with the uncemented group, at eight years after surgery the predicted probability of death in the cemented group was 0.013 higher (0.007 to 0.019) and the predicted probability of revision was 0.015 lower (0.012 to 0.017). In multivariable analyses restricted to men, there was a higher mortality rate in the cemented group and the uncemented group compared with the Birmingham hip resurfacing group. In terms of revision, the Birmingham hip resurfacings had a similar revision rate to uncemented total hip replacements. Both uncemented total hip replacements and Birmingham hip resurfacings had a higher revision rate than cemented total hip replacements.

Conclusions: There is a small but significant increased risk of revision with uncemented rather than cemented total hip replacement, and a small but significant increased risk of death with cemented procedures. It is not known whether these are causal relations or caused by residual confounding. Compared with uncemented and cemented total hip replacements, Birmingham hip resurfacing has a significantly lower risk of death in men of all ages. Previously, only adjusted analyses of hip implant revision rates have been used to recommend and justify use of cheaper cemented total hip implants. Our investigations additionally consider mortality rates and suggest a potentially higher mortality rate with cemented total hip replacements, which merits further investigation.

PubMed Disclaimer

Conflict of interest statement

Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi\_disclosure.pdf (available on request from the corresponding author) and declare: DJWMcM and RBCT were designers of Birmingham hip resurfacing and were shareholders in Midland Medical Technologies before the company was sold to Smith and Nephew in 2004. DJWMcM is an unpaid consultant to Smith and Nephew Orthopaedics UK. The McMinn Centre receives institutional research funding for specific research projects but no funding has been received for the research or preparation of this manuscript.

Figures

None

Fig 1 Population averaged (adjusted) survival curves (with 95% confidence intervals shown by dashed lines) for cemented versus uncemented with mortality or revision as endpoint

None

Fig 2 Population averaged (adjusted) survival curves (with 95% confidence intervals shown by dashed lines) for men comparing cemented, uncemented, and Birmingham hip resurfacing patients, with mortality or revision as endpoint

None

Fig 3 Population averaged (adjusted) survival curves for men aged under 55 comparing cemented, uncemented, and Birmingham hip resurfacing patients, with mortality or revision as endpoint

None

Fig 4 Transoesophageal echocardiogram in patient after cemented total hip replacement, showing fat and marrow echogenic material in right atrium and right ventricle. No echogenic material in left atrium or left ventricle, indicating that debris has been filtered in pulmonary vasculature

Comment in

Similar articles

Cited by

References

    1. Charnley J. Surgery of the hip joint. Present and future developments. BMJ 1960:i;821-6. - PMC - PubMed
    1. Charnley J. Low friction arthroplasty of the hip Berlin. Springer-Verlag, 1979.
    1. Wroblewski BM, Siney PD, Fleming PA. Charnley low-friction arthroplasty. Survival patterns to 38 years. J Bone Joint Surg Br 2007;89:1015-8. - PubMed
    1. McMinn DJ, Daniel J, Ziaee H, Pradhan C. Indications and results of hip resurfacing. Int Orthop 2011;35:231-7. - PMC - PubMed
    1. Treacy RB, McBryde CW, Shears E, Pynsent PB. Birmingham hip resurfacing: a minimum follow-up of ten years. J Bone Joint Surg Br 2011;93:27-33. - PubMed

Publication types

MeSH terms

LinkOut - more resources