Problems with the immune system, body chemistry or blood flow can result in:

• Non-wear-and-tear arthritis (inflammation of the joint) and damaged joint surfaces (cartilage surface)
      • Gout, rheumatoid, lupus, psoriatic, pseudo-gout
• Weakened and painful bone (avascular necrosis, osteochondritis)
      • Patella, tibia and femur bones
• These can all cause pain, swelling, stiffness, locking, catching, grinding, popping, fatigue, weakness, instability, deformity and disordered gait