BROOKLYN HIP AND KNEE
TOTAL KNEE REPLACEMENT
FAQ
WHAT IS THE ANATOMY AND PHYSIOLOGY OF THE KNEE?
The knee is a hinge like joint which is located where the thigh meets the lower leg. The knee joint is formed by the ends of 3 bones: the thigh bone (femur), the shin bone (tibia), and the kneecap (patella).
The thigh bone and shin bone are separated by cartilage, a smooth layer of lining which keeps the bones from rubbing together. This allows for flexible and near frictionless movement.
WHAT IS A TOTAL KNEE REPLACEMENT?
A total knee replacement is a surgical procedure that has been performed in the United States for many decades. In such a procedure a diseased or damaged joint is replaced with an artificial joint. The artificial joint is made up of metal to match the function of bone and high grade plastic to match the function of cartilage. The knee replacement has always been a very successful procedure but now with many improvements in technology and techniques the knee replacement generally results in massive gains in function and reduction of pain.
WHAT ARE THE REASONS FOR A TOTAL KNEE REPLACEMENT?
The main reason to get a knee replacement is when there is a loss of mobility or knee pain. This mostly occurs when the cartilage wears away. The two bones then rub against each other leading to inflammation, swelling and pain. This condition is known as osteoarthritis. Without cartilage there is no shock absorption and friction occurs between the bones. This causes stress to build up around the joint leading to more pain. In addition to normal wear and tear from aging and being active trauma can also cause osteoarthritis leading to the same symptoms.
WHEN SHOULD I GET A TOTAL KNEE REPLACEMENT?
Nonsurgical treatments such as physical therapy and knee injections can always be tried first. However, If the pain you experience is beginning to become unbearable, if your knee is too stiff or feels like it's giving away, or if in general your quality of life is no longer what it used to be, even after exhausting nonsurgical means, a knee replacement should be considered. A knee replacement is an elective surgery. Therefore the main determinant on when you should get surgery should be you.
WHAT ARE THE RISKS ASSOCIATED WITH TOTAL KNEE REPLACEMENTS?
Despite knee replacements being a historically successful surgery, as with any surgery there are some risks. Some of the potential complications from surgery include:
Infection
Blood clots
Nerve/blood vessel damage
Hemorrhage
Anesthetic issues
HOW CAN I REDUCE RISKS ASSOCIATED WITH TOTAL KNEE REPLACEMENTS?
In order to reduce the risk of complications you can take several steps on your part.
Get control of your health. Improvement of modifiable risk factors such as weight, glycemic control, blood pressure control can decrease some of the risk of peri-operative complications
Lose weight: If you are overweight you have the increased risk of complications such as infection. In addition your new knee will be under heavy load post surgery increasing the chance that you will need a second knee replacement in your lifetime which is more complicated and leads to more risks than the initial knee replacement. Every pound you lose will drastically reduce the load you put on your knee, making even a 10 or 20 pound reduction very beneficial for your post surgery outcome.
Control your Diabetes. Keeping a log of your blood glucose levels and monitoring your HbA1c can decrease your risk of peri-operative complications
Quit smoking: When you smoke your risks of blood clots are high and shoot up even higher post surgery. Cessation of smoking prior to surgery drastically decreases post-operative complications and improves functional outcomes after surgery.
HOW LONG WILL A TOTAL KNEE REPLACEMENT LAST?
Similar to our biological knees an artificial knee will eventually wear out if you live long enough. Historically it has been shown that past knee replacements have lasted around 20 years and advancements of technology mean that the current knee replacements can last just as long if not even longer.
HOW DO I GET READY FOR SURGERY?
In order to get ready for surgery you must see your primary care physician for a physical exam. This physical exam will give you a month long window saying you are healthy enough for surgery. Once you have this approval you will be capable of getting surgery.
WHEN WILL I LEAVE THE HOSPITAL?
The length of stay in the hospital is quite short for this type of surgery. Patients typically leave the surgery on the same day or stay one night. Before leaving physical therapy will coach the patient with walking and using assistive devices like a walker or cane in order to ensure a safe discharge.
WHAT MEDICATIONS WILL I NEED AFTER SURGERY?
Two very important medications you will be given to you include pain medicine and medicine to help prevent blood clots in the legs or the lungs. Although the incidence of blood clots are low after surgery, some pre-existing conditions may increase this risk in certain patients. Post-op pain control is also performed in a multi-modal fashion. When possible, a nerve block administered by the anesthesia team will help with the post-op pain for up to 72 hours. You will be discharged home with the same medicine we give in the hospital and pain management will be achieved with the help of NSAIDS and other pain medicine. We often also prescribe medicine to help with some common side effects of pain medicine which may include nausea, upset stomach, constipation etc.
WHAT IS THE LENGTH OF TIME TO RECOVER?
The length of time to recover depends on the person. Most patients will walk on the same day of surgery, usually with a walker for the first few weeks then make the transition to a cane and then without assistance. The majority of your recovery will happen within a few weeks but in order to fully recover it will take several months. Improvement of function can be seen sometimes even up to a year post-operatively
HOW CAN I TAKE CARE OF MY WOUND AND KNEE?
To take care of your wound you will need to wear a bandage over your wound to make sure the risk of infection is minimized. In general, dressings should be kept clean and dry and usually should stay on until your first follow-up visit.
Also, being careful to avoid falls is important as the healing process can take several weeks and months post surgery. You will need to use assistance such as walkers, crutches, canes, handrails, or someone to help you in order to prevent a fall. The physical therapist and surgeon will teach and remind you of these guidelines during your visits and before leaving the hospital.
WHEN AND HOW OFTEN WILL I BE FOLLOWING UP WITH MY SURGEON?
Your first follow up visit will be a week or two after surgery. Then you may have follow-up visits at between 4-6 weeks and at 12 weeks postoperatively. From there based on how you are progressing you may be asked to come back anywhere between 3 to 6 months afterwards.