Knee osteoarthritis is the gradual wearing away of the cartilage that cushions the knee joint. It causes pain on climbing stairs, stiffness after sitting, swelling and a grinding sensation, and it becomes more common with age, previous injury and excess weight. The good news is that a diagnosis of knee arthritis does not automatically mean you need a knee replacement. There is a wide middle ground of effective treatments. The foundation of care is weight management and muscle strengthening. Every kilogram of weight lost removes roughly four kilograms of load across the knee, and strong thigh (quadriceps) muscles are the single most evidence-backed way to reduce pain and improve function without any drug. When simple measures are not enough, injections can help. Hyaluronic acid injections lubricate the joint and give temporary relief for mild to moderate arthritis. Platelet-rich plasma (PRP), which uses a concentrate of your own blood, shows growing evidence of improving pain and function in earlier-stage osteoarthritis, and often outperforms hyaluronic acid, though results vary and it is not a cure. For advanced arthritis in patients who cannot or do not want surgery, radiofrequency ablation of the knee's sensory (genicular) nerves can provide months of relief. Knee replacement is excellent surgery, but timing matters and it is not automatically better to do it sooner. It becomes the sensible choice when the arthritis is advanced, pain is constant and daily life is severely limited despite a fair trial of the measures above. Be cautious of anyone promising that a single injection will cure arthritis. The right plan depends on your arthritis grade, age, activity goals and how you respond to a structured trial, so it is worth getting an individual assessment from a pain or joint specialist before making a decision.