Genetic factors contribute more to hip than knee surgery due to osteoarthritis - a population-based twin registry study of joint arthroplasty

Osteoarthritis Cartilage. 2017 Jun;25(6):878-884. doi: 10.1016/j.joca.2016.12.015. Epub 2016 Dec 13.

Abstract

Objective: To explore and quantify the relative strengths of the genetic contribution vs the contribution of modifiable environmental factors to severe osteoarthritis (OA) having progressed to total joint arthroplasty.

Design: Incident data from the Norwegian Arthroplasty Registry were linked with the Norwegian Twin Registry on the National ID-number in 2014 in a population-based prospective cohort study of same-sex twins born 1915-60 (53.4% females). Education level and height/weight were self-reported and Body Mass Index (BMI) calculated. The total follow-up time was 27 years for hip arthroplasty (1987-2014, 424,914 person-years) and 20 years for knee arthroplasty (1994-2014, 306,207 person-years). We estimated concordances and the genetic contribution to arthroplasty due to OA in separate analyses for the hip and knee joint.

Results: The population comprised N = 9058 twin pairs (N = 3803 monozygotic (MZ), N = 5226 dizygotic (DZ)). In total, 73% (95% confidence intervals (CI) = 66-78%) and 45% (95% CI = 30-58%) of the respective variation in hip and knee arthroplasty could be explained by genetic factors. Zygosity (as a proxy for genetic factors) was associated with hip arthroplasty concordance over time when adjusted for sex, age, education and BMI (HR = 2.98, 95% CI = 1.90-4.67 for MZ compared to DZ twins). Knee arthroplasty was to a greater extent dependent on BMI when adjusted for zygosity and the other covariates (HR = 1.15, 95% CI = 1.02-1.29).

Conclusion: Hip arthroplasty was strongly influenced by genetic factors whereas knee arthroplasty to a greater extent depended on a high BMI. The study may imply there is a greater potential for preventing progression of knee OA to arthroplasty in comparison with hip OA.

Keywords: Arthroplasty; Heritability; Osteoarthritis; Twins.

Publication types

  • Twin Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aftercare
  • Aged
  • Aged, 80 and over
  • Arthroplasty, Replacement, Hip / statistics & numerical data
  • Arthroplasty, Replacement, Knee / statistics & numerical data
  • Cohort Studies
  • Diseases in Twins / genetics
  • Diseases in Twins / surgery*
  • Female
  • Humans
  • Information Storage and Retrieval
  • Male
  • Middle Aged
  • Norway
  • Osteoarthritis, Hip / genetics
  • Osteoarthritis, Hip / surgery*
  • Osteoarthritis, Knee / genetics
  • Osteoarthritis, Knee / surgery*
  • Prospective Studies
  • Registries*
  • Twins, Dizygotic
  • Twins, Monozygotic