Dr. Gens Goodman, DO
Hip and Knee Replacement Surgery

KNEE REPLACEMENT SURGERY

 Total knee replacement surgery has become a common orthopedic procedure in the United States. Knee replacements are performed to alleviate conditions caused by osteoarthritis, rheumatoid arthritis, fractures, congenital deformities, and other knee-related problems. The surgery involves replacing the damaged surfaces of the knee. The weight bearing surfaces of the femur and tibia are removed and replaced with metal and polyethylene (plastic). The implants can be made from different materials, but is usually metal, plastic or ceramic.

Lastly, the early benefits of knee replacements are excellent. In most uncomplicated cases, patients can expect to be relatively pain-free, have full knee mobility, and walk with minimal or no limp 2 months after surgery. The operation usually takes about 1-2 hours, much less time than many other surgical procedures. For most patients, the hospital stay is usually 1 day. For many patients, the hospital stay can be shorter and often patients go home the same day.

 PRIMARY TOTAL KNEE REPLACEMENT

Patients frequently ask, “What exactly is a total knee replacement?” The simplest answer is that it is a replacement of the worn and arthritic surfaces of the knee joint. We often tell our patients that a total knee replacement is similar to resurfacing a road full of potholes. In this procedure all parts of the joint that contact each other as the knee bends are covered with an artificial surface.  With arthritis, the cartilage covering the ends of the bone within the knee joint is badly worn. In a knee replacement, the damaged cartilage, along with a very small amount of bone, is removed with precise guides and instruments. The knee replacement implant, which is made of metal and plastic, is then fitted to the bone to provide an artificial surface that eliminates pain. In this operation little bone is actually removed; it is better to think of the procedure as a refinishing of the knee surfaces.

PRIMARY TOTAL HIP REPLACEMENT

Total hip replacement surgery has become a common orthopedic procedure in the United States. Hip replacements are performed to alleviate conditions caused by osteoarthritis, rheumatoid arthritis, fractures, dislocations, congenital deformities, and other hip-related problems. The surgery involves replacing the damaged surfaces of the hip. The head and the neck of the femur (thigh bone) are removed and replaced with a ball and stem, called the femoral component. Then, the damaged hip socket is lined with a metal “cup.” A liner is placed into the cup. The liner can also be made from different materials, but is usually plastic or ceramic. The ball can be made of different material, such as metal or ceramic. The ball of the femoral component fits into this liner, or bearing surface, creating a new, moveable joint.

 Before l983, most hip replacement surgeons in the United States used acrylic cement to attach the prosthetic parts to the femur and pelvis. This method involved filling the area between the metal prosthesis and the surrounding bone with acrylic cement. In 1977 the use of porous-coated implants became more popular in the U.S. The porous-coated method, which involves the use of implants with sintered, metal porous surfaces, requires no cement.

 The major difference between our porous-coated prostheses and the cemented ones is the metal surface of the implants. Cemented implants have a smooth surface, while porous-coated implants have a rough surface that resembles thick metal sandpaper. The surrounding bone grows “into” the porous surface of the prosthesis, essentially making it a part of the body. Close contact to bone helps hold the porous-surfaced implant in place until bone ingrowth has occurred. Most patients are allowed to put full weight on their hip after surgery. Together we will determine how much weight you can put on your hip based on the fit of the stem and the x-rays taken after surgery.

 Although this porous-coated method was initially developed for our young, more active patients, experience has indicated that this method works equally well in patients of all ages and lifestyles. A porous-coated hip replacement is particularly attractive for patients with active lifestyles, regardless of age. It is also the method of choice for revision operations. If either a cemented or porous-coated prosthesis has failed, the we will routinely replace it with a porous-coated one. 

 Lastly, the immediate benefits of total hip replacements are excellent. In most uncomplicated cases, patients can expect to be relatively pain-free, have full hip mobility, and walk with minimal or no limp 2 months after surgery. The operation usually takes about 1-2 hours, much less time than many other surgical procedures. For most patients, the hospital stay is usually 2 to 3 days. For younger, more active patients the hospital stay can be shorter.