HEALTH & MEDICINE :: FEBRUARY/MARCH 2007
Minimally Invasive Total Knee Replacement
Osteoarthritis is a degenerative disease of joint cartilage that affects millions of people each year. One of the most commonly affected joints is the knee. Symptoms of knee arthritis can include pain, swelling and stiffness, as well as catching or locking. These symptoms often interfere with daily activities such as walking, running, kneeling and squatting. Nonoperative treatment of knee arthritis usually consists of oral pain medication (acetaminophen, anti-inflammatories, glucosamine), activity modification, bracing, physical therapy and injections with cortisone or viscosupplements. When nonoperative treatment fails, operative treatment can be considered.
The surgical options for advanced knee arthritis include partial or total knee replacement. Partial replacement, or uniarthroplasty, is reserved for those patients with arthritis isolated to one compartment of the knee. This is seen in approximately 15% of patients presenting with knee arthritis. For the remaining patients, in which the arthritis is more diffuse, total joint replacement is more appropriate. This involves removal of the degenerative cartilage surfaces of the knee and replacing them with metal components. This has proven to be an extremely successful procedure for relief of pain.
Traditionally, total knee replacement (TKR) is performed through a long incision (8-9 inches) over the front of the knee that involves cutting into the quadriceps, or thigh muscle and flipping over (everting) the kneecap, or patella. This provides good exposure to the knee joint to allow the replacement components to be inserted. The consequence of cutting into the muscle, however, has been significant postoperative pain, requiring the prolonged use of intravenous narcotic medication. This can result in unwanted complications such as confusion, nausea and constipation, which can slow early recovery. Increased blood loss (often requiring blood transfusion) and a prolonged hospital stay (3 to 5 days) are also typical following the traditional TKR technique. In addition, total recovery after this approach has often taken up to 6 months.
Minimally invasive total knee replacement was developed in an effort to reduce the pain and recovery time associated with traditional TKR. Many older individuals in today’s society continue to lead active lives and undergo joint replacement surgery to maintain that lifestyle. These same individuals desire a quicker return of function and minimal disruption to their lives from the surgery. The minimally invasive technique involves a smaller skin incision (3-4 inches) and does not re-quire cutting of the quadriceps muscle (muscle sparing approach). This results in less postoperative pain and a reduced need for narcotic pain medication. In addition, there is less blood loss (lessening the need for blood transfusion postoperatively) and im-proved early knee range of motion. Patients begin physical therapy on the day of surgery and typically are walking several hours after the procedure. Most patients are discharged home from the hospital 36-48 hours after the surgery, eliminating the need for going to inpatient rehabilitation centers after discharge from the hospital. Most patients are able to ambulate without walking aids (walker or crutches) 1 to 2 weeks after the procedure and are usually fully recovered by 3 months.
Early results with minimally invasive TKR have revealed excellent patient satisfaction including lower pain score levels postoperatively, less knee stiffness and quicker return to functional activities. Patients with prior extensive knee surgery, significant preoperative knee stiffness or pre-existing bone loss are not candidates for this technique. For the majority of patients requiring total knee replacement surgery however, minimally invasive TKR offers excellent pain relief with accelerated recovery time.
Dr Manifold is a board certified Orthopaedic surgeon in Dover, Delaware, specializing in knee and shoulder disorders. He completed his fellowship training in knee replacement and reconstruction at The Insall Scott Kelly Institute/Beth Israel Medical Center, New York, and completed an Orthopaedic residency at New York Orthopaedic Hospital/ Columbia-Presbyterian Medical Center, New York. He graduated medical school from Temple University School of Medicine, Philadelphia. Dr. Manifold’s office practice is at Tooze, Easter & Manifold, MD, PA 720 S. Queen St. Dover, DE. To schedule an appointment, call 302-735-8700.
