An Analysis of Potential Sex Differences in Knee Osteoarthritis
Condition: Degenerative Joint Disease; Osteoarthritis
MeSH terms: Osteoarthritis; Osteoarthritis, Knee; Joint Diseases
Study type: Observational

Summary: 
      This pilot study will use tissues and fluids that are normally discarded during the course of
      total knee replacement surgery to investigate potential sex differences in knee
      osteoarthritis. Basic clinical demographic information will be obtained as well as
      preoperative functional and pain assessment scores, functional tests, and pressure pain
      threshold measurement. The purpose of the study will be to investigate if any sex differences
      can be identified in these tissues and to investigate if there appears to be any relationship
      between these differences and functional scores and tests.
    

Detailed description: 
      The goal of this study is to determine if sex differences can be identified in the knee joint
      that can contribute to the differences in incidence and severity of knee osteoarthritis
      observed in men and women, particularly over the age of 50. Recent studies assessing the
      responses of articular chondrocytes to systemic factors suggest that there are underlying
      differences in the biochemical and molecular characteristics of male and female cells. It is
      also known that immune responses differ in males and females, suggesting that there may be
      important differences in the levels of immune modulators in the joint tissues, including the
      synovial membrane, the synovial fluid, and the cartilage itself. Responses to the vitamin D
      metabolite 1_,25(OH)2D3 are upregulated in osteoarthritic cartilage, raising the possibility
      that males and females differ in their circulating levels of vitamin D, in the content of
      vitamin D metabolites in the synovial tissues, or in the ability of the cells to respond to
      this steroid. Similarly, in post-menopausal women, circulating estrogen is reduced relative
      to testosterone, but it is not known if this might impact the knee. Most importantly, it is
      not known if potential sex differences can be correlated with severity of disease.

      This study is based on the hypothesis that sex differences exist in different tissues of the
      knee joint, which contribute to the increased incidence and severity of knee osteoarthritis
      in older women as compared to older men.

      To test this hypothesis, the investigators will use tissues and fluids that are normally
      discarded during the course of total knee replacement surgery to investigate potential sex
      differences.
    

Intervention name(s): musculoskeletal
Intervention type(s): Other
Intervention description(s): Many musculoskeletal conditions are impacted by the chromosomal sex of the patient. While osteoarthritis (OA) is predominant in men younger than 50 years of age, after age 50 the condition is more prevalent in women, particularly post-menopause. This has implications for diagnosis and treatment of OA, as well as for joint replacement.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patient enrollment will consist of 10 females and 10 male patients stratified by age.
        Enrollment is anticipated to be completed over a 12 month time period. Only non Hispanic
        White patients will be included in the study. Patients must be between 65 and 75 years of
        age. Patients with a BMI greater than 30 will be excluded
      
Keywords: Sex differences; knee joint; inflammatory mediators; Vitamin D; osteoarthritis