The knee is composed of three parts: the femur or “thigh bone”; the tibia or “shin bone”; and the patella or “knee cap”. The ends of these three bones are coated with a 3 – 5 millimeter layer of cartilage which serves as a shock absorber. (Cartilage functions similar to the padding on an upholstered chair.)
The knee is anatomically divided into three sections: the medial compartment, which is the side closest to the other knee; the lateral compartment, which is the outer side of the knee; and the patellofemoral joint, which is where your kneecap tracks on the front of your knee.
Many knee injuries are overuse conditions or sprains and strains. When treated properly, these conditions usually resolve with conservative treatment such as medications, injections, bracing, activity modification and therapy.
At times, more traumatic injuries of the knee can result in dislocations, meniscus tears, ligament tears or cartilage lesions.
These severe injuries often require surgical repair and reconstruction.
Over time and with aging, the cartilage in the knee can degenerate and thin out. Like the tread on your tires wears off, the cartilage in your knee can wear off. In the early phases, this is called Chondromalacia. In the later phases, this is Arthritis. Initial treatment includes anti-inflammatory medications, bracing, activity modification and joint injections. When conservative care no longer relieves the symptoms, surgery is an option which can include both partial or total knee replacement.
The term “total joint replacement” is an unfortunate misnomer because it implies that the entire joint is being replaced. It’s not. The end of the femur, tibia and patella are merely resurfaced, similar to having a tooth capped. A total knee replacement is a highly successful procedure for treating a knee with severe arthritis and degeneration.
Computers have become more involved in joint replacement surgery. CAT scan or MRI images can be used to create custom knee replacement components for each patient. Because the component is custom fit to the patient, it requires less bone resection during implantation and it fits the normal anatomy of the knee.
Many implant companies offer computer matched components for their total joint replacements. The computer matched components allow for a more accurate fit and alignment which can improve the function and longevity of the knee after surgery.