left shadow
1313 HERMANN DR
HOUSTON, TX 77004
gutter shadow
Sports Medicine & Orthopedics 
Stephen Brown, M.D., Park Plaza Orthopedic Surgeon 
Tuesday, 20 May 2008 
 
 
When a patient presents with persistent knee pain, mechanical symptoms, decreased motion, instability, deformity, or swelling, a visit to an orthopedic surgeon is recommended. The surgeon’s first priority is to establish a diagnosis. Knee problems can be caused by a variety of problems, including degenerative disease, inflammatory conditions, traumatic events, ligamentous instability, loose bodies, meniscal tears or systemic diseases.

For those with chronic pain secondary to an arthritic condition, (degenerative, inflammatory, or traumatic in nature) initial treatment options may include weight loss, activity modification, physical therapy, anti-inflammatory medications, bracing, and injections. If these approaches fail, it is time to explore the possibility of a total knee replacement (TKR).

It is no surprise then that a TKR also known as a total knee arthroplasty, is one of the most common medical procedures performed in the United States on an annual basis. According to the American Academy of Orthopedic Surgeons (AAOS), 300,000 TKRs are performed each year in this country. As the Baby Boomer generation continues to age, the number of TKRs performed annually will no doubt increase.

Before recommending a TKR, a physician needs to consider the patient’s pain and level of disability – as well as his or her age. Careful consideration needs to be given if the candidate is under 60 years of age. For younger patients, the likelihood that the knee replacement will wear out during the patient’s lifetime is considerable, and a more complex revision replacement would be necessary.

A total knee replacement is generally performed under spinal or general anesthesia. The operation generally takes between 45 and 90 minutes. Blood loss is typically minimal. The procedure involves removing the bone and cartilage at the distal femur and proximal tibia. This is replaced with a metal and plastic mechanism that acts like a joint and is shaped to allow continued motion at the knee. This apparatus consists of three or four main parts: the metallic femoral component; the metallic tibial component, and the polyethylene insert between the two. If the patella proves to have extensive damage, it will be resurfaced with a polyethylene component as well. The implants are generally cemented to the bone using methyl methacrylate bone cement, which acts as a grout.

Recovery:

Within a day, the patient usually notices an immediate difference in the type of pain experienced. The deep, arthritic ache is gone, and is replaced by a different temporary surgical pain. Physical therapy is begun immediately at the hospital. A patient can expect to be on crutches or use a walker until the quadriceps muscle has healed and regained its strength. The patient can expect to be in the hospital anywhere between one and seven days depending on his or her health and the support system available at home. Physical therapy (both supervised and home exercise program) is paramount in the success of this procedure. The primary goal is to restore motion to the knee. Full range of motion usually is restored within the first few weeks. Complete recovery time may take up to three months.

Complications following TKRs are low, according to the AAOS. Risks include deep vein thrombosis (DVT), infection, numbness on the lateral aspect of the knee, decreased motion and continued pain. Younger patients should be aware of the need for future revision. Because of the high risk of DVT with this type of procedure, patients are placed on blood thinners, such as Coumadin or Lovenox, in the postoperative period. Swelling and warmth of the joint is common for the first several months. Continued, mild tenderness is not uncommon in the first several months as well.

With time, the components may eventually loosen in some patients, requiring revision. Most TKRs can be expected to last at least 10-15 years. Patients my need to give up high-impact activities following such a procedure to prevent early loosening of the components.

Recent Advances:

Recent advances have shown renewed interest in unicompartmental (partial) knew replacements. A unicompartmental, or partial, knee replacement is a suitable alternative in a limited number of patients. This procedure is indicated when a patient has degenerative changes limited to only one region of the knee, usually the medial compartment. According to the AAOS, only 6 to 8 percent of arthritic knees are candidates for such a procedure. Because of the smaller incisions and limited tendon disruption, patients are usually able to be discharged after just one day. Overall recovery time is also faster with this procedure.

Additionally, new techniques and instruction have given rise to minimally invasive TKR, utilizing smaller incisions and less tissue disruption. These techniques, while not always indicated, allow for less tissue disruption and thus faster recovery.

As in my medical procedure, the degree of pain, mobility of lack thereof and lifestyle need to be considered when recommending any type of knee replacement surgery.
 
 
 
 
 
right shadow
right shadow right shadow right shadow right shadow right shadow