A knee replacement is really a bone and cartilage replacement with an artificial surface. The knee itself is not replaced, but rather an implant is inserted on the bone ends. This is done using a metal alloy on the femur and a plastic spacer on the tibia and patella (kneecap). This creates a new, smooth cushion and a functioning joint that can reduce or eliminate pain.
A hip replacement is an operation that removes the arthritic ball of the upper femur (thighbone) and damaged bone and cartilage from the hip socket. The ball is replaced with a metal ball that is fixed solidly inside the femur. The socket is replaced with a plastic or metal liner that is usually fixed inside a metal shell to create a smoothly functioning joint.
Your orthopaedic surgeon can determine if you are a candidate for the surgery based on your history, exam, X-rays and response to conservative treatment.
Results will vary depending on the quality of the surrounding tissues, the severity of the arthritis at the time of surgery, your activity level and your adherence to your health care team's orders.
While uncommon, complications can occur during and after surgery. Some complications include infection, blood clots, implant breakage, malalignment, dislocation and premature wear, any of which may necessitate implant removal/replacement surgery. While these devices are generally successful in attaining reduced pain and restored function, they cannot be expected to withstand the activity levels and loads of normal healthy bone and joint tissue. In most cases, implant surgery is extremely successful. Some patients will still experience pain and stiffness. No implant will last forever, and factors such as a patient's post-surgical activities and weight can affect longevity. Your surgeon will discuss all of the risks with you.
In many cases, patients with joint replacement think the new joint feels completely natural. However, it is a good idea to avoid extreme position or high-impact physical activity.
You are encouraged to participate in low-impact activities such as walking, dancing, golf, hiking, swimming, bowling and gardening. High-impact activities like running and basketball or activities that increase your likelihood of injury, such as downhill skiing are not recommended. You should discuss any specific restrictions with your physician.