Knee injuries can be a real pain – literally. Imagine you’re playing your favorite sport or just jogging and you feel that sudden, alarming twist or pop in your knee.
The knee is a large joint that is susceptible to injury. It is subject to high weight bearing and twisting forces. If you’re a sports fan, you’ve likely seen athletes suffer from a knee strain, sprain or tear.
Two of the most common sports-related knee injuries are tears to the meniscus or the anterior cruciate ligament (ACL).
Knowing the basics of each can help you better understand knee injuries, take proper steps to heal and get back to what you love sooner. With the help of two orthopedic surgeons and sports medicine specialists, we break down what makes ACL and meniscus tears unique, how to recognize each and what treatments can help.
The basics: ACL vs. meniscus – what are they?
Your knee is a complicated joint with many moving parts, making it strong but vulnerable to injury. The ACL and meniscus play important roles in how your knee works:
- ACL: This ligament (or band of tissue) connects your thigh bone (femur) to the shin bone (tibia).
“The role of your ACL is to stabilize your knee during quick directional changes and keep it from moving too far forward,” said Anup Shah, MD, an orthopedic surgeon and sports medicine specialist with Banner – University Health.
- Meniscus: The meniscus is a C-shaped cartilage piece that cushions between the femur and tibia.
“There are two menisci in each knee – one on the inside (medial) and one on the outside (lateral),” said Rafael Buerba Siller, MD, an orthopedic surgeon and sports medicine specialist with Banner – University Medicine. “The meniscus absorbs shock and stabilizes the knee, which helps prevent wear and tear over time.”
How ACL and meniscus tears happen
ACL and meniscus tears can happen suddenly, often during sports or high-impact activities. However, they can happen in slightly different ways.
- ACL tears: Imagine an intense game of basketball or soccer. You’re dribbling or running full speed, you make a sharp pivot to dodge an opponent and suddenly you feel a painful pop in your knee.
This kind of quick, twisting motion can strain or tear the ACL. ACL injuries are more common in sports that require fast changes in direction, like soccer, basketball and skiing.
- Meniscus tears: Meniscus tears usually occur when a person twists their upper leg while the foot is planted and the knee is bent. These are called traumatic tears and they often happen during sudden movements, moments of high impact or awkward, off-balance motion. Sometimes, even simple movements like standing up quickly from a squat can cause a tear.
While ACL and meniscus tears often occur individually, they can happen together. “About 40% of people with ACL tears also sustain a meniscus tear,” Dr. Shah said. “This is because the meniscus can act as a secondary stabilizer for the knee when the ACL is injured.”
Specifically, lateral meniscus often occurs with acute ACL injuries. This makes the injury more serious and can mean a longer recovery time.
Symptoms of ACL vs. meniscus tears: How to tell them apart
Some signs and symptoms of ACL and meniscus tears can overlap but there are some subtle differences. Here’s how to distinguish between them:
- ACL tear symptoms: If you tear your ACL, you may immediately feel a popping sensation and your knee may give out. Pain and swelling usually set in quickly, often within a few hours. You may also feel unstable when you try to stand or walk, making it hard to move around normally. But Dr. Shah points out, “The instability sensation with pivoting and twisting is different from meniscus injuries.”
- Meniscus injury symptoms: Meniscus tears may or may not cause immediate pain. Sometimes, you can continue the activity before the pain sets in. Swelling usually develops gradually over the next day or two.
“Classic symptoms of meniscus tears are pain with twisting and squatting and possibly a locking sensation, where the knee feels stuck and won’t fully straighten or bend,” Dr. Buerba said.
Treatment of ACL and meniscus tears
The treatment plan depends on the tear's severity, activity level and age. Both injuries can range from mild to severe, with different options for recovery.
- ACL tear treatments: Minor ACL tears might heal with rest, physical therapy and a knee brace, but complete tears often require surgery to reconstruct the ligament.
Recovery from ACL surgery can take six to nine months and physical therapy is important for regaining strength and mobility. After passing a return-to-sports test, most athletes can return to sports around the nine-month mark.
“Surgical recovery can vary based on whether an autograft (the patient's own tissue) or allograft (donor tissue) is used,” Dr. Buerba said. “Allografts tend to feel better earlier. However, it takes longer for the allograft to integrate into the knee than autografts.”
- Meniscus tear treatments: Many meniscus tears can heal with rest, physical therapy and time. However, severe or persistent tears may need surgery. Unlike ACL surgery, which often involves reconstructing the ligament, meniscus surgery may include trimming the torn part or stitching it back together.
“Recovery after surgery depends on what procedure was performed. Recovery after a meniscectomy (removal of torn tissue) can take up to six weeks, while meniscus repair may take up to four to six months,” Dr. Shah said.
“The main goal after ACL surgery and meniscus surgery is to restore stability to the knee and to have pain-free range of motion so you can return to activities of daily living and sporting activities,” Dr. Buerba said.
Prevention: Exercises and techniques to strengthen your knee
While not all knee injuries can be prevented, you can take steps to lower your risk.
- Strengthen the muscles around your knee: Building strong muscles in your thighs, hips and core can give your knees better support and stability. Exercises like squats, lunges and leg presses can help.
- Practice balance and flexibility: Exercises like yoga, Pilates and balance drills improve coordination and control, possibly reducing injury risks.
- Use proper technique: Whether running, lifting weights or playing sports, use proper form. When jumping, focus on landing softly with your knees bent to reduce impact. Avoid twisting with your feet planted when pivoting, as this can strain the meniscus. If you’re unsure about technique, consider working with an athletic coach or physical therapist.
- Try an ACL injury prevention program. These programs are designed to train muscles and joints to respond safely during intense activity. They can greatly reduce ACL injuries, especially when they include neuromuscular training, plyometrics, strengthening, agility and jumping/landing techniques.
“ACL-specific programs like the FIFA 11+ warm-up have proven highly effective, especially with young female athletes, reducing ACL injuries up to 50%,” Dr. Buerba said. “These programs are endorsed by professional societies, like the Academy of Orthopaedic Physical Therapy and the American Academy of Sports Physical Therapy and are supported by several comprehensive studies.”
Bottom line
ACL and meniscus injuries are treatable, but recovery takes time. Early treatment, physical therapy and regular knee exercises can help you get back to what you love.
If you have knee pain, don’t delay treatment. “Delaying treatments for injuries like ACL tears can lead to more meniscus injuries and knee arthritis,” Dr. Shah said. “Similarly, meniscus tears are more likely to heal and be repaired if seen right after the injury rather than waiting several months. If you wait too long, a meniscus tear may not be able to be repaired and a trim may be required instead.”
See an orthopedic surgeon or sports medicine specialist to understand your options and avoid complications. You can also find a Banner Health specialist near you.
