Frequently Asked Questions
What are the components of the knee?
The knee joint is comprised of three bones: the femur (thigh bone), the patella (knee cap), and the tibia (shin bone). It can be divided into the medial compartment, the side of your knee that is closest to the center of your body; the lateral compartment, the side of your knee to the outside of your body; and the patellofemoral compartment, which is the area behind the knee cap.
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What is cartilage?
The end of each of the bones of the knee is covered with a layer of smooth, glossy, elastic tissue known as articular cartilage. Cartilage protects the bones while allowing the joint to glide smoothly. It also acts as a shock absorber. Cartilage has no nerve or blood supply. If damaged or injured, it may be difficult for it to heal or repair itself.
What are ligaments?
Ligaments of the knee link the bones, while muscles and tendons aid in strength, stability, and movement. Ligaments include the anterior cruciate ligment, commonly called the ACL, the posterior cruciate ligament (the PCL), the medial collateral ligament (MCL) and the lateral collateral ligament (LCL). The health and stability of your ligaments can be important determining factors in whether one surgical option is better for you than another.
What are menisci?
On the top of the tibia are two crescent-shaped pieces of cartilage called menisci. These inner and outer pads act as weight distributors when we walk, stand and move about. Their specialized shape also helps to keep the knee stable and conforms to the profile of the femur.
What are condyles?
Condyles are rounded prominences at the end of a bone,most often important for articulation with another bone. Each person’s condyles have unique shapes and sizes.
- What are the components of the knee?
What is osteoarthritis?
In a healthy knee, the ends of the thigh bone, the shin bone, and the knee cap are covered by a layer of articular cartilage. This cartilage acts as a cushion and provides a smooth, gliding surface for the movement of the knee.
Through the years, tremendous demands are placed on our knees. In some, the cartilage can begin to fracture or wear away. If the wear becomes significant, the rubbing of exposed bone can result in debilitating pain. This is called osteoarthritis (OA) and it affects millions worldwide.
What causes osteoarthritis of the knee?
Osteoarthritis (OA) is considered a progressive disease but the exact causes of are not fully understood. OA is very common in adults over the age of 50, but the condition can affect younger adults as well. People who have a history of past knee injuries, or have placed a lot of stress on their knees from heavy physical activity or weight are also at increased risk.
What are the symptoms of osteoarthritis of the knee?
Symptoms of knee osteoarthritis include:
• Pain during movement
• Stiffness, usually after periods of inactivity
• Lack of flexibility and an inability to move through the full range of motion
• Grating sensation
• Bone spurs – small, hard lumps felt around the joint
What are the treatment options for osteoarthritis of the knee?
There is no known cure for knee osteoarthritis, but there are a number of other treatment options available that you should discuss with your doctor, including:
• Lifestyle changes, such as weight loss, exercise or physical therapy
• Over-the-counter anti-inflammatory pain medication (NSAIDs)
• Corticosteroids (anti-inflammatory knee injections)
• Viscosupplementation (hyaluronic acid knee injections, or lubricating fluid for your joint)
• Joint replacement surgery, or arthroplasty
- What is osteoarthritis?
Prior to surgery
Why do I have to get a CT scan?
The CT scan is a diagnostic tool for your surgeon to assess the course of treatment for your knee. It is also an important part of creating a personalized knee implant system. Our design process starts by using CT scan data to create a 3D model of your knee so that your implants and instrumentation can be designed to fit precisely to your anatomy.
How soon do I need to get my CT scan?
It is recommended to book your CT scan appointment as soon as you can. Your personalized knee implant cannot be designed until your CT scan images are received.
Can I go to any Imaging Center?
Your surgeon will recommend an imaging center that has been qualified to perform CT scans that capture the required images to design your individualized implant.
How long will the CT scan take?
The CT scan appointment typically takes 45-60 minutes. It is always a good idea to give yourself more time, and to arrive early to ensure your scan can start on time.
How long does it take to design my implants?
From the time we receive the order and your CT scan it takes 6 weeks to develop your implant. Once the implant is complete, it is sent to the hospital in advance of your surgery date.
How can I prepare for my surgery?
It can be helpful to designate someone as your primary “caregiver.” This person will be there with you on your day of surgery, help carry your belongings and stay in touch with other family or friends during and immediately following your surgery. The primary caregiver may also be helpful following surgery (i.e., driving home, assisting in follow-up doctor visits, physical therapy and completing light chores around the house).
It may also be helpful to complete as many chores and/or errands as possible prior to surgery. Preparing your home by removing tripping hazards such as rugs and moving your living quarters to the ground floor will ensure an easier rehabilitation.
Prior to your day of surgery, be sure to pack a small suitcase with loose fitting comfortable clothing and necessary toiletries. In some cases you may be in the hospital from 1-3 days. Please check with your surgeon on how long you are expected to stay so you can pack accordingly.
- Why do I have to get a CT scan?
Day of surgery
How long is my surgery going to take?
Knee surgery has become a very common procedure. A total knee replacement can take 60–90 minutes to complete. Be sure to consult with your surgeon about his/her expectations for the surgery.
What happens during surgery?
After you have been admitted and prior to the actual surgery you will receive an IV (intravenous) line that is used to administer antibiotics and anesthesia. The actual surgery involves a thin incision on the knee that helps the surgeon gain access to the affected compartment(s). Your surgeon will place your personalized surgical instrumentation on your femur (thigh bone) and tibia (shin bone) in order to make the required bone cuts. Your customized implants are then cemented to your bones and the incision is closed.
- How long is my surgery going to take?
How long will I have knee pain following surgery?
While every case is different, you should expect to feel significant pain relief within weeks. Be sure to follow your surgeon’s recommendations for pain medication and physical therapy.
How soon will I be able to walk?
You should be able to walk, as tolerated, a few hours after surgery. You may be provided with a knee brace and/or aids such as crutches or a walker to assist you.
Will I have to wear a leg brace?
Your surgeon will determine whether or not you will need to wear a brace. If you do, you will likely wear your brace for two weeks or less depending upon your surgeon’s recommended weight-bearing protocol.
Will I be able to drive after surgery?
Following surgery you may not have the full leg control required to work the gas and brake pedals. As a safety precaution, your surgeon may recommend that you not drive for a few days.
When can I go back to work?
Your return to work will be dependent on your job requirements and endurance. Typically, patients return to office work in two to three weeks; jobs that require longer periods of standing may require longer periods of time.
Will I have to take any medication after surgery?
Your surgeon may prescribe medication to control pain after surgery and/or coated aspirin to prevent blood clots. It is important that you consult with your physician before taking any non-prescribed medications.
What care will the incision require?
Following surgery, it is important to keep your incision covered with a clean dressing. Your surgeon will recommend that you use caution while bathing to keep your incision dry. Waterproof bandages are recommended. Be sure to contact your surgeon if you notice any changes in the incision such as swelling or drainage during the recovery period.
Is it normal to have a fever following surgery?
Immediately after your procedure, you may have a low grade fever (up to 101 degrees). It is important to contact your doctor if your temperature elevates above 101 degrees or lasts longer than one week.
Will I have to go to physical therapy?
For some patients, physical therapy is not required. Your surgeon can best determine whether or not this is appropriate for you. In all cases, an immediate postoperative recovery will focus on protecting the knee, minimizing discomfort, and ensuring early return to motion. After that, your surgeon will prescribe a set of simple exercises to aid in recovery and strengthen your knee.
- How long will I have knee pain following surgery?
- Are ConforMIS implants cleared by the FDA?
What material is your implant made out of?
Our implants are made out of cobalt chromium molybdenum, a standard metal used in orthopedic implants. The tibial and patellar inserts are made of ultra high molecular weight polyethylene (UHMWPE) or highly crosslinked vitamin-e infused UHMWPE (iTotal only).
How much does it cost? Are ConforMIS implants more expensive because they are customized?
ConforMIS implants are covered under the same insurance reimbursement codes as “off-the-shelf” knee implants.
Do you have a knee for women?
Since we design each and every implant individually for each person, there is no need to have a “women’s” knee. It is simply your knee.