Degenerative joint disorder.
This is when wear and tear in joints just starts to erode the cartilage and eventually the bone itself.
Presentation
Chronic pain or stiffness of a larger weight bearing joint. Pain on movement and weight bearing. Often presents with early morning stiffness lasting fewer than 30 mins. It can advance leading to less function and more pain.
Pathology
Subchondral cysts may be seen on cross section
burnishing and ivorisation of bone may be seen, as well as streaked stress lines emanating from bone on bone contact