Knee injury

A knee injury occurs when one or more of the bones, ligaments, tendons, muscles or soft tissues that support the knee become damaged. Knee injuries range from mild sprains to more serious conditions such as ligament tears or fractures, and even minor knee injury symptoms can affect your ability to walk, stand or stay active. With timely care, most people recover well and return to the activities they enjoy.

Find a specialist

Find a location

Side by side comparative medical illustrations of a knee joint with arthritis.

Common causes of knee pain

This video explains common conditions that can lead to knee pain and helps you understand what may be causing your symptoms.

Detailed diagram of the human knee joint with labeled structures including the patella and ligaments.

Anatomy of the knee

The knee is a complex hinge joint formed by the femur, or thighbone, the tibia, or shinbone, and the patella, or kneecap. Cartilage cushions the ends of the bones, allowing smooth movement, while ligaments and tendons provide stability and control motion. Muscles in the thigh and lower leg help power movement and protect the joint.

Because the knee relies on so many structures working together, an injury to any one of them, from a sprained knee ligament to a torn tendon, can lead to knee pain and swelling and instability.

Overview

Symptoms

You may be experiencing a knee injury if you notice:

Pain that gets worse with movement or weight-bearing
Swelling or stiffness in or around the knee
Difficulty bending or straightening the leg
Tenderness or warmth around the joint
A feeling that the knee may buckle or give way

Without proper care, these knee injury symptoms can progress and may lead to joint damage over time.

Causes

Knee injuries can occur suddenly due to trauma or develop over time from stress placed on the joint. Common causes include:

Fractures of the femur, tibia or fibula
Torn ligaments, including the anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL)
Ruptured blood vessels after trauma, leading to fluid or blood buildup in the joint
Dislocation of the kneecap
Tears of the quadriceps or hamstring muscles
Patellar tendon tears

Understanding how your injury occurred helps our specialists determine the most appropriate knee injury treatment approach.

Risk factors

Some knee injuries are mild and improve with rest and conservative treatment. Others, however, can lead to lasting joint damage if not properly evaluated. You may be at higher risk of a more serious knee injury if you notice:

Persistent pain that doesn't improve with rest
Swelling that appears quickly after an injury
Symptoms that occur at night or while resting

Having these signs does not guarantee a serious injury, but early evaluation helps protect the knee and may prevent long-term complications.

Diagnosis

Our orthopedic specialists take a patient-centered approach to diagnosing knee injuries. Your evaluation may include a detailed medical history and physical examination, an assessment of joint stability, strength and range of motion, X-rays to evaluate bone alignment or identify fractures, and additional imaging, such as MRI, if a soft tissue injury involving muscle, tendon or ligament is suspected. We take time to explain your findings clearly, so you understand your diagnosis and next steps.

A medical illustration of a knee anatomy next to an illustration of a knee arthroscopy procedure.

An overview of ACL injuries

Understand knee arthroscopy basics, from knee anatomy and common problems to what the procedure can and cannot treat, plus what to expect before and after.

Videos in our patient education library are available to help you gain a general understanding of the condition or procedure. Read disclaimer.

View treatment options

We offer leading-edge treatments for most sports medicine conditions, treating many with medications, bracing, injections and therapy.

Explore treatments

Is joint pain holding you back?

It only takes a few minutes to help you stay active for years. Our joint health quiz shows you how to stay strong, flexible and moving freely through every stage of life.

Injury prevention for every athlete

An orthopedic surgeon discusses common sports injuries that affect everyone from weekend pickleball players to competitive athletes.

Training matters more as we get older

While going for a brisk walk or jog is great for our health as we age, it’s important to get the benefits of strength and resistance training.

You had questions, our specialists answered

From joint pain to cracking knuckles, one of our orthopedic specialists addresses what you really want to know.