An ACL injury is a tear or sprain of the anterior cruciate (KROO-she-ate) ligament (ACL) — one of the major ligaments in your knee. ACL injuries most commonly occur during sports that involve sudden stops or changes in direction, jumping and landing — such as soccer, basketball, football and downhill skiing.

Many people hear or feel a "pop" in the knee when an ACL injury occurs. Your knee may swell, feel unstable and become too painful to bear weight.

Depending on the severity of your ACL injury, treatment may include rest and rehabilitation exercises to help you regain strength and stability or surgery to replace the torn ligament followed by rehabilitation. A proper training program may help reduce the risk of an ACL injury.

Symptoms

Signs and symptoms of an ACL injury usually include:

• A loud "pop" or a "popping" sensation in the knee
• Severe pain and inability to continue activity
• Rapid swelling
• Loss of range of motion
• A feeling of instability or "giving way" with weight bearing

When to see a doctor

Seek immediate care if any injury to your knee causes signs or symptoms of an ACL injury. The knee joint is a complex structure of bones, ligaments, tendons and other tissues that work together. It's important to get a prompt and accurate diagnosis to determine the severity of the injury and get proper treatment.

A concussion is a traumatic brain injury that is caused by a blow to the head or when the head and upper body are violently shaken. Concussions are common in contact sports, such as football, hockey and soccer. If you've had a concussion, your brain needs time to rest in order to recover and heal properly.

Signs and symptoms of a concussion may include:

• Headache or a feeling of pressure in the head 
• Temporary loss of consciousness
• Confusion or feeling as if in a fog
• Amnesia surrounding the traumatic event
• Dizziness or "seeing stars"
• Ringing in the ears
• Nausea
• Vomiting 
• Slurred speech  
• Delayed response to questions
• Appearing dazed
• Fatigue

A dislocation is an injury to your joint in which the ends of your bones are forced from their normal positions. Your shoulder and fingers are common locations for a dislocation to occur. Other common places for a dislocation include your elbows, knees and hips.

You may experience tingling or numbness near or below the injury, such as in your foot for a dislocated knee or in your hand for a dislocated elbow. If you have a dislocation, your joint may be:

• Immovable
• Intensely painful
• Swollen or discolored
• Visibly deformed or out of place

If you have a history of dislocations, we can provide you with options to help prevent this from recurring. 

One common site for a dislocation is your shoulder, which is a ball-and-socket joint. The ball is your upper arm bone (humerus), and the socket is part of your shoulder blade (scapula). In a shoulder dislocation, these two bones are forced from their normal positions.  

See Fractures & Trauma under Conditions & Treatments.

A torn meniscus is one of the most common knee injuries. Any activity that causes you to forcefully twist or rotate your knee, especially when putting your full weight on it, can lead to a torn meniscus.

Each of your knees has two menisci — C-shaped pieces of cartilage that act like a cushion between your shinbone and your thighbone. A torn meniscus causes pain, swelling and stiffness. You also might feel a block to knee motion and have trouble extending your knee fully.

Conservative treatment — such as rest, ice and medication — is sometimes enough to relieve the pain of a torn meniscus and give the injury time to heal on its own. In other cases, however, a torn meniscus requires surgical repair.

Symptoms

If you've torn your meniscus, you might have the following signs and symptoms in your knee:

• A popping sensation
• Swelling or stiffness
• Pain, especially when twisting or rotating your knee
• Difficulty straightening your knee fully
• Feeling as though your knee is locked in place when you try to move it

When to see a doctor

Contact your doctor if your knee is painful or swollen, or if you can't move your knee in the usual ways.

The rotator cuff is a group of muscles and tendons that surround your shoulder joint, keeping the head of your upper arm bone firmly within the shallow socket of the shoulder. If you're an athlete or individual who repeatedly performs overhead motions with your job or sport, you're most at risk for a rotator cuff injury.

When is rotator cuff surgery right for you? Watch the video below to find out.

A sprain occurs when you overstretch or tear your ligaments — the tough bands of fibrous tissue that connects two bones together in your joints. The most common location for a sprain is in your ankle.

A strain occurs when you overstretch or tear your muscle or tendon. A tendon is a fibrous cord of tissue that connects muscles to bones. Strains most likely occur in the lower back and in the hamstring muscle in the back of your thigh.

To treat a sprain or a strain, use rest, ice, compression and elevation. If the injury is severe, you may need surgery to repair torn ligaments, muscles or tendons.

The pain of lateral epicondylitis (tennis elbow) occurs primarily where the tendons of your forearm muscles attach to the bony prominence on the outside of your elbow. The pain may result from tiny tears in the tendon.

The pain associated with tennis elbow may radiate from the outside of your elbow into your forearm and wrist. Pain and weakness may make it difficult to:

• Shake hands 
• Turn a doorknob 
• Hold a coffee cup 

Make an appointment with our orthopedic team if rest, ice and use of over-the-counter pain relievers don’t ease your elbow pain and tenderness.