1. When is the right time to undergo a knee replacement?
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.
2. Is there a way to avoid surgery?
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?
3. What will occur during surgery and how long will the knee replacement operation take?
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.
4. What pieces are used in a knee replacement and how are they kept in place?
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.
5. Should I be concerned about anesthesia during 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.
6. How much pain will I experience after surgery?
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.
7. What should I expect immediately following surgery?
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.
8. What can I expect during recovery and rehabilitation from knee replacement?
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.
9. What do I need to do to prepare my home for recovery?
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.
10. Will I require any special equipment?
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.
11. What activities will I be able to engage in?
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.
12. How long will the artificial knee joint last and will I ever require a revision (a second knee replacement)?
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.
The Shoulder Arthroplasty
Total Shoulder Arthroplasty involves replacement of the worn out ball with a smooth metal ball. This ball is connected to a metal stem that is placed on the inside of your arm bone (humerus) [FIGURE 1]. The stem is held in place with some of your own bone that is taken from the ball (humeral head). The socket (glenoid) component is made out of plastic and is held in place with a small amount of bone cement [FIGURE 2]. The final replacement consists of a smooth metal ball moving on a smooth plastic socket. [FIGURES 3 4 5 & 6]
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FIGURES 5: X-rays of the same woman in Figures 3 & 4 after Total Shoulder Arthroplasty. Note that the bone spurs have been removed and that the humeral component has been placed inside of the arm bone. The plastic glenoid component is not visible on x-ray.
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FIGURES 6: X-rays of the same woman in Figures 3 & 4 after Total Shoulder Arthroplasty. Note that the bone spurs have been removed and that the humeral component has been placed inside of the arm bone. The plastic glenoid component is not visible on x-ray.
Not all surgical cases are the same, this is only an example to be used for patient education.
Who should consider Total Shoulder Arthroplasty?
Individuals who want the quickest and most reliable path to a comfortable shoulder should strongly consider Total Shoulder Arthroplasty. Resurfacing the ball with metal and the socket with plastic provides an immediate smooth surface for your shoulder. This means that your shoulder should be quite comfortable within weeks following the surgery. Although daily exercises are still encouraged they do not have to be quite as rigorous as in individuals who opt for the Ream and Run surgery. If you anticipate having difficulty doing exercises multiple times per day for several months total shoulder arthroplasty may be a better option for you. Additionally individuals who live sedentary lifestyles smokers diabetics and those who require heavy narcotics for shoulder or other pain are generally better off with a total shoulder arthroplasty than a Ream and Run procedure.
What is the 'Ream and Run' procedure?
The Ream and Run procedure involves replacement of the worn out ball with a smooth metal ball that is connected to a metal stem just like in the total shoulder (below). The stem is placed inside of the arm bone (humerus) and held in place with some of your own bone that is taken from the ball (humeral head). The main difference between a ‘Ream and Run’ and a Total Shoulder Arthroplasty is that with the ‘Ream and Run’ a plastic glenoid component and bone cement are not needed. Instead the socket (glenoid) is ground down so that it is a smooth shallow cup – a shape that resembles that of the normal socket [FIGURES 7 & 8]. The final replacement consists of a smooth metal ball moving on smooth socket bone. [FIGURES 9 10 11 & 12] The grinding process allows bone cells to come to the surface of the socket. These cells can form a new surface that is very similar to the cartilage that normally covers the socket however this process can take 3 to 12 months to occur.
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FIGURES 11: X-rays of the same woman in Figures 9 & 10 after the Ream and Run procedure. Note that the bone spurs have been removed and that the humeral component has been placed inside of the arm bone. Figure 12 shows space between the metal ball and socket that implies that a new cartilage-like surface has formed.
FIGURES 12: X-rays of the same woman in Figures 9 & 10 after the Ream and Run procedure. Note that the bone spurs have been removed and that the humeral component has been placed inside of the arm bone. Figure 12 shows space between the metal ball and socket that implies that a new cartilage-like surface has formed.
Who should consider Ream and Run?
Individuals who enjoy strenuous activities such as weightlifting, waterskiing, contact sports, landscaping and chopping wood should strongly consider having a Ream and Run procedure. These activities put a lot of stress on the shoulder joint. Over time these stresses can wear out or loosen the plastic socket of a Total Shoulder Arthroplasty. If this occurs it may be necessary to have another surgery to remove the plastic component. Individuals less than 50 years old may wear out or loosen the plastic glenoid component even with less strenuous activities so they too should consider having a Ream and Run instead of Total Shoulder Arthroplasty.
What aspects of shoulder replacement surgery are the same for Total Shoulder Arthroplasty and Ream and Run?
Regardless of which of the two procedures you choose to have certain aspects of the surgery will be the same. An incision is made across the front of the shoulder from the collarbone to the middle of the arm bone so that the surgeon can gain access to the shoulder without having to cut either the deltoid or the pectoralis major muscles. One of the four rotator cuff tendons needs to be released to access the shoulder joint. This tendon (the subscapularis) is repaired at the end of the surgery and takes 3 months to completely heal back to the bone. The tight soft tissues and bone spurs that have formed as a result of the arthritis need to be released and removed for both procedures.
The metal ball and the stem that is attached to it are the same for both procedures. In both cases the stem is held in place inside your arm bone by bone that has been removed from the arthritic portion of the ball. This bone supports the metal ball and stem in the proper position.
For either procedure you usually have a choice of a general anesthetic or a brachial plexus block for your surgery. The block completely numbs your arm for approximately 12 hours and thus helps keep you comfortable immediately following surgery. When the block wears off the pain comes back and needs to be managed with medication given by mouth or in the IV.
Both procedures take approximately 2 hours to complete. Typically you will stay in the hospital for 2 nights regardless of which procedure you have done. Your rehabilitation exercises will start the evening of surgery or the very next morning. The exercises that you do are the same regardless of which procedure you have done. However the Ream and Run procedure requires a very strong dedication to the exercises as your shoulder is more likely to get stiff following this procedure than Total Shoulder Arthroplasty.
After either procedure there may be bleeding into the shoulder from cutting the bone. Bone is not in fact ‘dry as a bone’ but has many small blood vessels in it that may leak a bit after surgery. Often a drain is used for a day after surgery to remove this blood.
A study performed here at University of Washington showed Total Shoulder Arthroplasty and Ream and Run are equally likely to provide patients with a comfortable and functional shoulder. Article on Nonprosthetic Glenoid Arthroplasty (PDF) (0.09 MB).
What aspects of shoulder replacement surgery are different for Total Shoulder Arthroplasty and Ream and Run?
The main difference between the two procedures is in the work that is done on the socket. In Total Shoulder Arthroplasty the socket is resurfaced with a plastic component that is cemented into your bone. In the Ream and Run no plastic or cement used. Instead the socket is ground down so that it is smooth and will mate with the smooth metal ball. The ground down bone bleeds and this bleeding allows bone cells to cover the surface of the socket. Over time these cells form what is known as fibrocartilage which is similar but not the same as the cartilage that covers the socket in normal shoulders.
While patients who undergo Ream and Run may ultimately achieve the same level of comfort and function as those who undergo Total Shoulder Arthoplasty it may take some patients longer to reach this level. Some patients achieve it just as quickly as those who undergo Total Shoulder Arthroplasty some take up to 12 months to achieve this level and a few never achieve the same level of comfort that they would with Total Shoulder Arthroplasty. Article on Nonprosthetic Glenoid Arthroplasty (PDF) (0.09 MB).
Because the Ream and Run relies on the bone cells to form fibrocartilage certain individuals are not good candidates for the procedure. Smokers and patients with diabetes do not have the robust bone cells that are necessary for this healing to take place and are thus better off with a Total Shoulder Arthroplasty
What happens if my Total Shoulder Arthroplasty fails?
The most likely way that Total Shoulder Arthroplasty fails is by loosening or wear of the plastic glenoid component. If this occurs a second surgery is necessary to remove the loose component. It is usually not possible to place a new plastic component because there is typically not enough bone remaining to support it. If that is the case we usually try to smooth the remaining bone so that it can accommodate the metal ball. Surprisingly many patients have very good comfort and function following such an operation.
What happens if my Ream and Run fails?
Although most patients have very good return of comfort and function to their shoulder following the Ream and Run a few never get the type of pain relief that they had hoped for. It is difficult to predict who will fall into this category but in our experience it is fewer than 1 in 20 patients. These patients are often those who found it difficult to maintain their range of motion after surgery. It is possible to go in via a second surgery either to release the soft tissues to restore the range of motion or to place a plastic glenoid component in essence converting the Ream and Run to a Total Shoulder Arthroplasty. Most of the work has already been done with the first operation so the recovery is not quite as long as with the first surgery.