Mini-Knee Replacement: Procedure Description

Total knee replacement (also known as total knee arthroplasty--TKA) is an operation that relieves chronic knee pain resulting from arthritis. It can also improve the range of motion in knees that have become stiff from arthritis.  TKA basically involves shaving off the worn out joint surfaces and ?“capping” them with metal or ceramic components separated by a shim of plastic which takes the place of the patient’s cartilage.

TKA was typically done through a 6-10 inch incision down the front of the knee. However, with the advent of minimally invasive surgical techniques (MIS), total knee replacements can now be done through 4 – 4 ½ inch incisions, and partial (unicompartmental) knee replacements through 2-3 inch incisions. Minimizing the deep soft tissue dissection (more than minimizing the length of the incision) reduces pain, shortens hospital stays, reduces blood loss, and hastens recovery. Additionally, Dr. Swanson often utilizes computer assisted surgical navigation (CAS), utilizing a computer to accurately align the new components so that the knee is perfectly straight when replaced. This technology uses sensors placed on the patient’s leg to ensure absolute accuracy in aligning the artificial knee components in the patient’s knee joint. Accurate alignment increases the chance of low wear and a longer-lasting total knee replacement.

Knee replacement surgery removes the diseased joint surfaces, restores the leg to a straight position, and permits the knee to move smoothly again. Most patients require several weeks of physical therapy after their surgery in order to gain the best function and from their knee.  However, recovery is much quicker that it was using older techniques.  Often, patients are 75-80% recovered within 4-6 weeks, what used to take 3-4 months.

Total knee replacement does not require removing and replacing the entire knee joint. Instead, the diseased surfaces of the joint are planed down by about ¼”, and each is carefully fitted with a polished metal or ceramic cap, something like capping a tooth. A plastic “shim” slides between the 2 metal surfaces, restoring smooth, pain-free motion of the knee. The backside of the kneecap (patella) may also be shaved down and fitted with a smooth plastic cap if it is arthritic.

Patients check into the hospital on the day of surgery and usually stay for about two to three days. The surgery, itself, normally takes about one hour. Most patients are able to stand and take a few steps with a walker on the day of surgery with help of a physical therapist (PT). The PT will teach proper use of a walker or crutches, common activities such as using the toilet or entering and exiting a car, and basic exercises to improve motion and strength of the knee.

An occupational therapist (OT) may also see the patient before hospital discharge in order to teach basic skills of washing, toileting, and dressing that accommodate the newly operated knee. Assistive devices may also be provided to the patient. The OT can also help plan for any challenges of daily living that the patient will face at home, such as feeding pets or doing occasional light laundry.

Today, almost all patients are able to return directly home after surgery, rather than going to a rehabilitation hospital. Patients who adhere to their daily exercise regimen can often return to most normal daily activities by 4-6 weeks.

Photo Comparison: Mini Knee Replacement Incision Photo vs. Traditional Knee Replacement Incision Photo