Patient Education


Why do my knees hurt?

Mid Florida Ortho

Why do my knees hurt?

The knee is the largest joint in the body. A healthy knee moves easily, allowing you to walk, turn, and do many other activities without pain.

Every day, your knees must support your full body weight. Cartilage is the “shock absorber” of your knee joints, but over a lifetime it can start to wear away. This "wear and tear" arthritis (osteoarthritis) is the most common cause of knee pain.

Without your cartilage protecting your knees, your bones grind against each other, which causes you pain: pain that you can feel climbing stairs, working in the garden, or just trying to sit down. It may even keep you up at night.

Symptoms of Osteoarthritis

Your first sign might be a bit of discomfort and stiffness in one or both of your knees. The aching pain can flare up when you are active, and gets better when you rest. Your knees may become stiff and swollen, making it difficult to bend or straighten them. You could feel weakness in your knee, like it’s locking or buckling. People also commonly report that cold weather or rainstorms can make their joint pain worse.

Ready for the Next Step?

If you or a loved one suffers from knee pain, you know firsthand how it can sideline you from your daily life, and keep you from the activities you enjoy. Surgery can be intimidating, but those who are living with arthritis experience continually worsening discomfort as the joint deteriorates and the cartilage is worn away.

When knee pain becomes so bad that it actually interferes with the things you need or want to do, talk to your doctor about knee replacement surgery.

Understanding Unicompartmental Knee Replacement

The goal of knee replacement surgery is to decrease pain and restore function. Although total knee replacement (also called "arthroplasty") is an excellent option for patients with osteoarthritis of the knee, other surgical options exist.

Patients living with osteoarthritis that is just limited to one part of the knee may be candidates for unicompartmental knee replacement (also called a "partial" knee replacement).

What is Unicompartmental Knee Replacement?

Unicompartmental knee replacement is an option for some patients with osteoarthritis of the knee. Your doctor may recommend partial knee replacement if your arthritis is confined to a single part (compartment) of your knee.

Your knee is divided into three major compartments: The medial compartment (the inside part of the knee), the lateral compartment (the outside part), and the patellofemoral compartment (the front of the knee between the kneecap and thighbone).

In a unicompartmental knee replacement, only the damaged compartment is replaced.

Advantages of Unicompartmental Knee Replacement

Research has shown that unicompartmental knee replacement surgeries are successful. In fact, over 50,000 partial knee replacements are performed each year in the United States.

The advantages of partial knee replacement over total knee replacement may include:

Quicker recovery
Reduced pain after surgery
Smaller incisions

Also, because the bone, cartilage, and ligaments in the healthy parts of the knee are kept, most patients report that a unicompartmental knee replacement feels more "natural" than a total knee replacement as up to 75% of your natural knee may remain.

Zimmer® Unicompartmental Knee Replacement

The Unicompartmental Knee from Zimmer is designed for patients with isolated damage in medial or lateral portions (compartments) of the knee. This knee may help maintain natural ligaments, reduce bone resection (removal) and incision size as compared to total knee replacement in addition to the potential for quicker recovery and less pain.

The Zimmer Unicompartmental Knee is also designed to be anatomically-friendly by accommodating 155 degrees of flexion (joint movement). In addition, the knee has 42 possible size combinations to accommodate varying anatomies as well as a variety of fixation features to assist with strong fixation between the implant and natural bone.

* Information provided by Zimmer Biomet Creative Lab