Surgery
Why is the operation called a "total" hip or "total" knee arthroplasty?
The word "total" means that all the moving surfaces in the hip or knee joint are resurfaced.
Knee: There are three places where cartilage rubs against cartilage. These are the medial (inside of the knee), lateral (outside of the knee) and patello-femoral (the part underneath the kneecap) compartments. A "total knee" consists of resurfacing all three of these compartments.
Total knee replacements are far more common than any type of partial knee replacement. Typically, by the time patients seek attention for their arthritic knee, more than one compartment is affected. Many people have an inflammatory type of arthritis that affects the entire knee. Total knee replacement have superb long-term results, and with the new quadriceps-sparing procedures promising earlier and faster recoveries, it is hard to argue in favor of partial replacements unless many criteria are met. In most practices, including ours, partial knee replacements are done less frequently than total knee replacements.
The inside of the knee is commonly diseased, leading to bone-on-bone disease in the medial compartment, and a bow-legged deformity. When this happens, assuming that the arthritis has not affected the other two compartments of the knee and that that patient meets other criteria for the procedure, it is possible to perform a partial knee replacement (unicompartmental knee replacement). This type of surgery typically has a smaller incision, very little blood loss and a rapid recovery compared to a total knee replacement.
If only the outside of the knee is arthritic and the patient has a knock-knee deformity with no disease of the other two compartments, it is possible to replace the lateral compartment of the knee. Recovery is faster compared to a total knee replacement.
If only the kneecap is worn down to bone, and the other two compartments of the knee are spared, the kneecap and the part of the knee that the kneecap glides in can be replaced. This procedure is called a patellofemoral arthroplasty, and it is performed rarely.
Hip: In the hip, the joint consists of a simple ball-in-socket. Both the socket and the ball are replaced in a "total" hip replacement.
There are procedures that consist of replacing only the ball part of the hip joint. Surgeons refer to these as a hemiarthroplasty of the hip joint. We do these very rarely. The typical case is an elderly person with no arthritis falls and breaks away the ball from the femur bone. Only the ball needs to be replaced, sized to match the inner diameter of the bony socket in the pelvis. The operation is less invasive than a complete hip replacement and it is not suitable for anyone with arthritis of the joint.
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Do you use computer-assisted surgery? What are the advantages?
Computer-assisted surgery is another evolutionary step in performing hip and knee replacement surgery. At the present time, its application in knee surgery offers the benefit of very precise alignment of the artificial parts. Errors in alignment and rotation of the artificial knee components can compromise the performance of the implants and shorten their life.
Currently, all knee systems use rods that are placed inside the hollow femur and tibia bones. Using these rods, special jigs are assembled to tell the surgeon where to make the cuts during surgery. The rods serve as guides for the surgeon, allowing alignment of the parts relative the long axis of the femur and tibia bones.
True alignment of the knee is anatomically based on the position of the hip and ankle joints. Computer navigation systems allow the imaging software to "read" the position of the individual's knee and hip joints during surgery, without exposing the patient to X-ray radiation. Using these mapped images, the software can precisely align the knee joint in a position that is customized and optimized for each individual patient. The trauma of inserting long rods into the bone marrow of the tibia and the femur is entirely avoided. This is certainly the approach of the future, particularly as the knee replacements are done through ever smaller incisions.
Ultimately, in the hip and in the knee joints, computer-assisted navigation technology, combined with small-incision, minimally-invasive exposures, will make the operations safer and more predictable and the results longer-lasting. We use and continue to develop both these technologies in our surgical procedures. Our software and equipment is made by Stryker Corporation.
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Who will be doing my surgery?
An experienced attending surgeon will perform the procedure, because it is complicated and requires judgment gained from experience. Each case is unique, requiring active thinking on the part of the surgeon. The surgeon is conscious of his results and has much invested in the services he performs. Some of the brightest resident physicians in the country assist him during the surgery. They may perform certain parts of the operation under his direction, and these portions of the procedure are best done by the assistant, while the attending physician carefully observes and directs. Rest assured that nothing is turned over to the assistant entirely. The attending surgeon remains responsible and actively involved in the entire operation and is physically present during the entire procedure, right up until you leave the operating room.
Where is the surgery done?
Usually at Columbia Regional Hospital, but we can accommodate any special needs or desires of individual patients. Complex hip and knee procedures typically require instruments and equipment localized to certain hospitals.
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What type of anesthetic will I have?
Usually, our anesthesia doctors use a spinal anesthetic combined with a sedative, so that you will not remember any details of the operation. Some people prefer a general anesthetic, with a tube helping them breathe. The recovery from a spinal anesthetic is excellent and superior to that of a general anesthetic.
The anesthesia doctors will also do a femoral nerve block for almost all the knee operations that we do. At the time of surgery, the tissues in the knee joint are injected with a local pain killer. This way, pain is decreased dramatically during the first day after surgery.
Most of the time, patients with a knee replacement will have pain on the second or third day after surgery, when these anesthetics have worn off. By that time, the overall intensity of pain is lower, and we have other pain medications to treat you.
For outpatient knee arthroscopic procedures, we use a short-acting general anesthetic. You should have someone drive you home. In some cases, we are able to do the knee arthroscopic procedure using a local anesthetic injected in the knee, some sedative and not much more.
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