Arthritis is a general term covering numerous conditions where the joint surface or cartilage wears out. The joint surface is covered by a smooth articular surface that allows pain free movement in the joint. This surface can wear out for a number of reasons; often the definite cause is not known.
When the articular cartilage wears out the bone ends rub on one another and cause pain. This condition is referred to as Osteoarthritis or “wear and tear” arthritis as it occurs with aging and use. It is the most common type of arthritis.
When arthritis affects the knee joint, it commonly occurs in two compartments, usually the medial and patellofemoral compartment. It is not common for a patient to have arthritis isolated to the patellofemoral compartment, but it does occur and is more commonly seen in women. Patellofemoral arthritis is diagnosed when the arthritic damage is only located in the patellofemoral compartment, affecting the back of the knee cap.
Patellofemoral Arthritis or knee cap arthritis causes pain and decreased mobility that is usually localized to the front of the knee joint. The patellofemoral compartment is involved in activities such as walking up and down hills or stairs, kneeling or squatting and standing back up. These activities can be become almost impossible to do when the pain from the arthritic damage is severe enough. Patients with this type of arthritis usually have no pain when walking on flat surfaces even when walking long distances.
Patellofemoral Knee Replacement surgery may be recommended by your surgeon if you have osteoarthritis contained to the patellofemoral compartment and you have not obtained adequate relief with conservative treatment options.
Traditionally, a patient with only one compartment of knee arthritis would undergo a Total Knee Replacement surgery. Patellofemoral Knee Replacement is a minimally invasive surgical option that preserves the knee parts not damaged by arthritis as well as the stabilizing anterior and posterior cruciate ligaments, ACL and PCL. This less invasive bone and ligament preserving surgery is especially useful for younger, more active patients as the implant placed more closely mimics actual knee mechanics than does a total knee surgery. Importantly, Patellofemoral Knee Arthroplasty surgery will not alter the ability of the patient to eventually move to a Total Knee Replacement in the future should that become necessary.
Partial Knee Replacement surgery is performed in an operating room under sterile conditions with the patient under general anesthesia or spinal anesthesia with sedation. It is usually performed on an outpatient basis as day surgery but the patient can stay one night in the hospital if preferred.
As with any major surgery there are potential risks involved. Specific complications related to Patellofemoral Knee Replacement surgery include:
The normal knee joint consists of the femur, the patella, and the tibia bones, all of which are all held together securely with soft tissue structures including ligaments and tendons. The bones are separated by shock-absorbing cartilage and lubricating synovial fluid. All of these structures move naturally through an arcing, hinge-like range-of-motion during daily activity. The knee can be divided into three main compartments or areas: the medial or inner compartment, the lateral or outer compartment, and the patellofemoral compartment under the kneecap.