The patella is your kneecap. Even though it protects your joint, it’s not just a cover for your knee. It also helps muscles, tendons and ligaments work correctly, as well as helps you move your knee. If your bones are weakened by osteoporosis, you have an increased risk for fractures.
The patella is your kneecap. It’s the bone at the front of your knee joint. It’s the biggest bone in your body embedded in a tendon (a sesamoid bone). Your patella helps your quadriceps muscle move your leg, protects your knee joint, and supports lots of important muscles, tendons and ligaments.
Traumas that hurt your knee are the most common patella injuries, including dislocations and bone fractures. If you do experience an injury, you might need surgery to repair your bone and physical therapy to help you regain your strength and ability to move.
Your patella — like all bones — can be affected by osteoporosis.
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Your patella has two main jobs:
The patella is at the front of your knee and covers the knee joint itself. It’s a bridge between your quad muscle and your lower leg.
The patella is shaped like an oval with a slight point at the bottom. The top (base) is connected to your quad muscle by the quadriceps tendon. The patellar ligament connects the bottom (apex) of your patella to your tibia (shin bone).
The patella’s medial facet (the side closer to the inside of your body) articulates (moves) with your femur’s medial condyle. The lateral facet (the side closer to the outside of your body) moves with your femur’s lateral condyle.
These parts and labels are usually more for your healthcare provider to use, as they describe where you’re having pain or issues. If you ever break your patella — a patellar fracture — your provider might use some of these terms to describe where your bone was damaged.
Most adults’ patellae (the plural for patella) are around 1.75 inches long and 1.5 inches wide.
Lots of conditions cause knee pain (anterior knee pain or chondromalacia patella). Many of the most common causes of knee pain damage the patella or the area around it, including:
Some people might think they have a patellar dislocation when they actually have a patellar subluxation.
A subluxation is a partial dislocation. It means that your bone is unstable in the joint and may have strayed a little out of place, but it hasn’t popped all the way out. When you have a patella subluxation, your kneecap still fits in its groove and you can still walk. You may feel uncomfortable or unsteady, and you may hear a popping noise as your patella moves. Injuries or your joint being too loose can cause patellar subluxation.
Visit a healthcare provider if you’re experiencing new symptoms in your knees or have trouble walking or moving.
Osteoporosis can affect any bone in your body, including your patella. Osteoporosis weakens bones, making them more susceptible to sudden and unexpected fractures. Many people don’t know they have osteoporosis until after it causes them to break a bone. There usually aren’t obvious symptoms.
Women and people assigned female at birth and adults older than 50 have an increased risk for developing osteoporosis. Talk to your provider about a bone density test that can catch osteoporosis before it causes a fracture.
The most common test providers do on the patella is the patella reflex test.
Your provider will tap your knee just below your patella with a special hammer. The sudden stimulation on your tendons triggers an involuntary reflex — a reaction you can’t control — which should make your leg extend. This is the patellar reflex.
Your provider might perform this test as part of your routine examination or if they suspect something is affecting your body’s nervous system.
If you’ve experienced a patellar injury or fracture, your provider or surgeon might need imaging tests, including:
Usually, your patella won’t need treatment unless you’ve experienced an injury or fracture or have knee pain.
Many issues that affect your patella can be treated with similar treatments, including:
Talk to your provider about which treatments you’ll need and how long you should expect them to take.
How your fracture is treated depends on which type it is and what caused it. You’ll need some form of immobilization — like a splint or cast — and might need surgery to realign (set) your bone to its correct position and secure it in place so it can heal. Ask your provider or surgeon how long it will take your specific fracture to recover.
Treatments for osteoporosis can include:
Exercise and taking supplements are usually all you’ll need to prevent osteoporosis. A healthcare provider can help develop a treatment plan that’s customized for you and your bone health.
Following a diet and exercise plan that’s healthy for your and seeing a healthcare provider for regular checkups will help you maintain your bone (and overall) health. Talk to a provider about a bone density test if you’re older than 50 or have a family history of osteoporosis.
Follow these general safety tips to reduce your risk of an injury:
A note from Cleveland Clinic
Your patella, or kneecap, does a lot of work for a relatively small bone. It’s an important bridge between your upper and lower leg. It protects the rest of your knee joint and helps it function as it should. Anything you do to improve your overall health will also help keep your bones strong. Talk to your provider about your osteoporosis risk, and ask them about ways you can support your bones as you age.
Last reviewed by a Cleveland Clinic medical professional on 06/01/2023.
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