Institute of Human Anatomy on Instagram: "What Do a Knee Joint and a Kidney Have in Common? GOUT. Looking at a real knee with arthritis - you can see gouges in the cartilage and areas that are bone-on-bone. But when we posted about this knee, people started asking about another joint condition: gout. WHAT IS GOUT? A buildup of urate crystals within joints that causes intense pain during flare-ups. While the knee can be affected, the most common site is the big toe - specifically the metatarsopha