The JBJS Quiz of the Month is a collection of 10 relevant questions from each orthopaedic subspecialty. The questions are drawn from JBJS Clinical Classroom, which houses over 4,500 questions and 3,100 learning resources. Take the Quiz to see how you score against your peers!

NOTE: This quiz does not earn users CME credits. The questions must be answered within Clinical Classroom to earn CME credits.

Aggrecan is the major proteoglycan in cartilage and forms stable complexes in the extracellular matrix by interacting with the nonsulfated glycosaminoglycan, hyaluronic acid. Hyaluronic acid can interact with chondrocytes by binding to which of the following chondrocyte membrane receptors?

    • CD44
    • CD44 is a major cell surface receptor for hyaluronic acid and is homologous to cartilage-link proteins.


    • Integrin alpha 5 beta 1
    • Integrin receptor (alpha 5 beta 1) binds to fibronectin.


    • DDR2
    • DDR2 (discoidin domain receptor 2) is a tyrosine kinase receptor that interacts with fibrillar collagens, including type-II collagen.


    • IGF-1 receptor
    • IGF-1 receptor ligands are insulin-like growth factors 1 and 2 (IGF-1, IGF-2).