- Medial Collateral Ligament (MCL) sprain
- Lateral Collateral Ligament (LCL) sprain
- ACL sprain
- Patella Femoral pain
- Meniscus injuries
- Knee OA (OsteoArthritis)

MCL sprain/tear
The medial collateral ligament (MCL) is the most commonly damaged ligament in the knee. The MCL can be sprained or torn as a result of a blow to the outer side of the knee, by twisting the knee, or by quickly changing directions while walking or running.
The MCL is a small, thick band of tissue on the inner side of the knee joint. It connects two bones—the thighbone and the shin bone—preventing the knee from bending inward toward the other knee.
Signs and Symptoms: Pain, swelling, stiffness over inside of the knee. Knee may feel like it gives out. Difficulty walking, sitting down, rising up and stair climbing.
LCL sprain/tear
Lateral collateral ligament (LCL) sprain occurs when the ligament on the outer side of the knee is overstretched. Collateral ligament knee injuries make up about 25% of severe knee injuries in the United States.
LCL sprains mainly happen during sporting activities, including contact and noncontact sports, and affect women and men equally.
The lateral collateral ligament is a thick, strong band of tissue that connects the thighbone to the shinbone. It is located on the outer side of the knee. It helps keep the knee joint stable.
Signs and Symptoms: pain, swelling outside of the knee. Difficulty with walking, rising and stair climbing
ACL sprain/tear
Approximately 200,000 ACL injuries are diagnosed in the United States each year. It is estimated that there are 95,000 ruptures of the ACL and 100,000 ACL reconstructions performed per year in the United States. Approximately 70% of ACL tears in sports are the result of non contact injuries, and 30% are the result of direct contact (player-to-player, player-to-object). Women are more likely than men to experience an ACL tear.
The ACL is one of the major bands of tissue (ligaments) connecting the thigh bone (femur) to the shin bone (tibia) at the knee joint. It can tear if you:
- Twist your knee while keeping your foot planted on the ground.
- Stop suddenly while running.
- Suddenly shift your weight from one leg to the other.
- Jump and land on an extended (straightened) knee.
- Stretch the knee farther than its usual range of movement.
- Experience a direct hit to the knee.
When you tear the ACL, you may feel a sharp, intense pain or hear a loud “pop” or snap. You might not be able to walk on the injured leg, because you can’t support your weight through your knee joint.
Usually, the knee will swell immediately (within minutes to a few hours),and you might feel that your knee “gives way” when you walk or put weight on it.
Most people who sustain an ACL tear will undergo surgery to repair the tear; however, some people may avoid surgery by modifying their physical activity to relieve stress on the knee. A select group can actually return to vigorous physical activity following rehabilitation without having surgery. Learn more about ACL grafts
Patella-Femoral pain Syndrome
Patellofemoral pain syndrome (PFPS) refers to pain at the front of the knee, in and around the kneecap. Patellofemoral pain affects more women than men and accounts for 20% to 25% of all reported knee pain.
Pain occurs when friction is created between the undersurface of the kneecap and the thigh bone (femur). The pain also is usually accompanied by tenderness along the edges of the kneecap.
Current research indicates that PFPS is an “overuse syndrome,” which means that it may result from repetitive or excessive use of the knee.
Meniscus Injuries
Meniscal tears are common injuries to the cartilage of the knee. These tears can be either “acute,” meaning they happen as a result of a particular movement, or “degenerative,” meaning they happen over time.
The meniscus is a cartilage disc that absorbs shock and stabilizes the knee joint. Each of your knees has 2 menisci: medial and lateral
Signs and Symptoms: sharp pain, swelling, the knee may be “catching or locking”
Patients with more serious meniscal tears, or those who don’t respond to a course of physical therapy, may need surgery to repair the injured knee: Surgically removing the torn cartilage (a procedure called a meniscectomy) usually is a simple procedure that requires a course of physical therapy treatment following surgery.
Sometimes your surgeon will decide that the torn meniscus can be repaired instead of removed. Research studies show that if a meniscal repair is possible, it can reduce the risk of arthritis developing later in life. Rehabilitation following a meniscal repair is slower and more extensive than with meniscal removal because the repaired tissue must be protected while it is healing.
Many patient with a meniscus tear do not need surgery and studies show same the outcomes for those who undergo surgery and those that opt for conservative care. Learn more
Knee OsteoArthritis (OA)
Osteoarthritis of the knee (knee OA) is the inflammation and wearing away of the cartilage on the bones that form the knee joint
(osteo=bone, arthro=joint, itis=inflammation).
Approximately 14 million people in the United States have symptomatic knee OA. Although more common in older adults, 2 million of the 14 million people with symptomatic knee OA were younger than 45 when diagnosed, and more than half were younger than 65. Knee osteoarthritis (knee OA) is a progressive disease caused by inflammation and degeneration of the knee joint that worsens over time.
It affects the entire joint, including bone, cartilage, ligaments, and muscles. Its progression is influenced by age, body mass index (BMI), bone structure, genetics, muscular strength, and activity level. Knee OA also may develop as a secondary condition following a traumatic knee injury.
Depending on the stage of the disease and whether there are associated injuries or conditions, knee OA can be managed with physical therapy. More severe or advanced cases may require surgery.