Millions of people live with knee osteoarthritis, the slow breakdown of cartilage that leaves bone grinding against bone. This DW documentary follows the medical teams testing whether that damage can actually be reversed. In Freiburg, orthopedic surgeon Kaywan Izadpanah performs knee joint distraction, a Dutch-pioneered technique that pulls the bones of the joint slightly apart to give the body room to regrow its own cartilage. At Basel University Hospital, researchers take a stranger route: a small tissue sample from a patient's nasal septum, grown into new cartilage cells in the lab, then transplanted into the damaged knee. The film also visits the Rostock Seals, a swimming club whose members treat their joint pain with winter dips in the Baltic Sea, and patients who use a cryotherapy chamber chilled to minus 110 degrees for quick relief. Interviews with surgeons, researchers, and patients trace the condition from early symptoms through surgical and non-surgical options, weighing experimental medicine against old-fashioned cold water.