There’s no precise formula for determining when you should have a knee replacement. But if you’re having trouble getting up to answer the phone or walk to your car, you may be a candidate. A thorough examination by an orthopedic surgeon should yield a recommendation. It might also be beneficial to receive a second opinion.

For some, lifestyle modifications, physical therapy, medication, or alternative treatment methods such as acupuncture and prolotherapy (which involves injecting fluid to strengthen connective tissue) can help manage knee problems. Also, you may want to speak to your surgeon about other procedures that are commonly recommended before resorting to knee replacement surgery, including steroid or hyaluronic acid injections and arthroscopic surgery that addresses the damaged cartilage.However, delaying or declining a necessary knee replacement could result in a less favorable outcome. Ask yourself: Have I tried everything? Is my knee holding me back from doing the things I enjoy?

The surgeon will make an incision on the top of your knee in order to expose the damaged area of your joint. The standard incision size can be as long as 10 inches, but a minimally invasive procedure can result in incisions as short as 4 inches. During the operation, the surgeon moves your kneecap aside and cuts away damaged bone and cartilage, which are then replaced with new metal and plastic components. The components combine to form a synthetic (but biologically compatible) joint that mimics the movement of your natural knee. Most knee replacement procedures take 1.5 to two hours to complete.

Implants are comprised of metal and medical-grade plastic. To seal these components to your bone, two methods are used: bone cement, which typically takes about 15 minutes to set; and a cement-less approach that uses components with a porous coating that grows into tissue or attaches to bone. In some cases, a surgeon may use both techniques in the same surgery.

Any surgery with anesthesia has risks. However, complication rates and mortality for general anesthesia are extremely low. An anesthesia team will determine whether general anesthesia or spinal, epidural, or regional nerve block anesthesia is best.

Although you will experience some pain after surgery, it should diminish quickly—within four or five days max. Your doctor will most likely prescribe medication to help you manage the pain, which will be administered through intravenously (IV) immediately after surgery. After you are released from the hospital, you will switch to painkillers taken in a pill or tablet form. After you have recovered from surgery, you should experience significantly less pain in your knee but there’s no way to predict exact results—some patients have knee pain for a full year after the surgery. Your willingness to engage in physical therapy and make lifestyle modifications can have a significant impact on your post-surgery level of pain and adjustment to the implant.

You will wake up with a bandage over your knee and, in most cases, a drain to remove fluid from the joint. It is likely that you will wake up with your knee elevated and cradled in a continuous passive motion (CPM) machine that gently extends and flexes your leg while you are lying down. A doctor might also insert a catheter so you don’t have to get out of bed to get to a toilet. In addition, you may wear a compression bandage or sock around your leg to improve blood circulation and reduce the odds of a clot. Your doctor will administer antibiotics intravenously and you may receive anticoagulants (blood thinners) to reduce the odds of a clot. Many patients experience an upset stomach during the immediate post-surgery period—this is normal, and your doctor or nurse can help provid medication to ease stomach pain.

Most patients are up and walking within a day or two—with the aid of a walker or crutches. A physical therapist will help you bend and straighten your knee a few hours after your surgery. After you return home, therapy will continue regularly for weeks and you will be asked to engage in specific exercises designed to improve the functionality of the knee. If your condition is more severe, or if you don’t have the needed support at home, the doctor may recommend you first stay at rehabilitation or nursing facility, though this is rare. During the weeks after surgery, your doctor will wean you from pain medication.

If you live in a multiple story house, prepare a bed and space on the ground floor so that you can avoid the stairs when you first return. Make sure the house is free of obstructions and hazards including power cords, area rugs, clutter, and furniture. Focus specially on pathways, hallways, and other places where you are likely to have to walk through. It’s wise to make sure that handrails are secure and a grab bar is available in the tub or shower you plan to use. You may want to add a bath/shower seat.

Your doctor will likely recommend that you use a CPM machine at home, while lying on a flat surface or bed. You may be sent home from the hospital with this device, but if you aren’t, your doctor or therapist will arrange that one be delivered to you. A CPM machine helps to increase your knee motion during the first few weeks after surgery, and is usually prescribed to slow the development of scar tissue and to help you achieve the maximum range of motion from your implanted knee. It is crucial to use the device as prescribed by your doctor or PT. Additionally, your doctor will prescribe mobility equipment that you need, like a walker, crutch, etc.

You should be able to resume normal daily activities—such as walking and bathing—within several days. Low impact exercise should also be doable after your rehabilitation period, typically six to 12 weeks. Consult with your physical therapist about introducing new activities during this rehabilitation period. You should avoid running, jumping, bicycling up and down hills and other high impact activities.

Studies show that upwards of 85 percent of patients still have a functioning artificial joint 20 years after receiving it. However, wear and tear on the joint can adversely affect its performance and lifespan. Younger patients are more likely to have the joint wear out and require a revision during their lifetime. Consult with a doctor about what’s right for you.

In the hip joint there is a layer of smooth cartilage on the ball of the upper end of the thigh bone (femur) and another layer within the hip socket. This cartilage serves as a cushion and allows for smooth motion of the hip. Arthritis is a wearing away of this cartilage. Eventually it wears down to bone. Rubbing of bone against bone causes discomfort, swelling and stiffness.

A total hip replacement is an operation that removes the arthritic ball of the upper thigh bone (femur) as well as damaged 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 liner that is usually fixed inside a metal shell. This creates a smoothly functioning joint that does not hurt.

Your orthopaedic surgeon will decide if you are a candidate for the surgery. This will be based on your history, an examination and X-rays. Your orthopaedic surgeon will ask you to decide if your discomfort, stiffness and disability justify undergoing surgery. There is no harm in waiting if conservative, non-operative methods are controlling your discomfort.

Age is not a problem if you are in reasonable health and have the desire to continue living a productive, active life. You may be asked to see your personal physician for an opinion about your general health and readiness for surgery.

We expect most hips to last more than 10–15 years. However, there is no guarantee, and 5–10 percent may not last that long. A second replacement may be necessary.

Yes. You should discuss preoperative physical therapy and exercise with your surgeon. Exercises should begin as soon as possible.

We reserve approximately two to two-and-a-half hours for surgery. Some of this time is taken by the operating-room staff to prepare for the surgery.

Yes, but we will keep you comfortable with appropriate medication. Generally most patients are able to stop very strong medication within one day. The day of surgery, most patients control their own medicine with a special pump that delivers the drug directly into their IV. Your surgeon will discuss with you what pain control option is best for you.

The scar will be approximately 6–8 inches long. It will be along the side of your hip.

Yes. Until your muscle strength returns after surgery, you will need a walker, a cane or crutches. Your equipment needs will be determined by the physical therapist and ordered for you by the Center for Advanced Joint Replacement case manager and delivered to you before you leave the hospital.

After hip-replacement surgery, you will need a high toilet seat for about three months. If needed, you will also be taught by the occupational therapist to use adaptive equipment to help you with lower body dressing and bathing. You might also benefit from a bath seat or grab bars in the bathroom. Your home equipment needs will be arranged while you are in the hospital.

High-impact activities such as contact sports, running, singles tennis and basketball are not recommended. Injury-prone sports such as downhill skiing are also dangerous for your new joint. You will be restricted from crossing your legs. Your surgeon and therapist will discuss further limitations with you following surgery. You are encouraged to participate in low-impact activities such as walking, dancing, golfing, hiking, swimming, bowling and gardening.