How Do ACL and Meniscus Injuries Differ?

An ACL tear involves the anterior cruciate ligament, which provides forward and rotational knee stability. In contrast, a meniscus tear damages the shock-absorbing cartilage inside the knee joint. ACL injuries usually cause sudden instability and a feeling of ‘giving way’. Meanwhile, meniscus injuries usually lead to localized joint line pain and knee locking.

At Total Orthopedics and Sports Medicine, our surgeon, Dr. Charles Ruotolo, an AAOS member, analyzes your symptom pattern in detail to determine if an ACL injury or meniscus tear is causing your knee pain. To confirm your diagnosis, he also reviews MRI scans and conducts physical examinations to assess the exact location and type of tear. Contact us to book your appointment at our Syosset clinic.

What Is the Difference Between ACL vs Meniscus Injuries?

An ACL injury is a tear in the stabilizing ligament at the center of the knee, while a meniscus injury affects the C-shaped shock-absorbing cartilage between the thigh bone and shin bone. If you have an ACL tear, you may hear a loud popping sound and experience sudden knee instability. In contrast, meniscus tear symptoms usually include catching, clicking, or locking in the knee.

In addition, meniscus injuries often cause pain along the inner or outer joint line, especially during twisting motions. On the other hand, ACL pain often feels deeper in the knee and usually worsens during weight-bearing, pivoting, or sudden movements. Similarly, swelling patterns also differ in both conditions. After an ACL injury, you may experience immediate swelling within 1 to 2 hours. However, swelling from a meniscus tear often develops gradually over 1 to 2 days.

Here are some other differences between ACL and meniscus injuries:

ACL injury	Meniscus injury
Affects the ligament control	Affects cartilage cushioning
Require ACL reconstruction	Can be re-attached with sutures
Occurs at the exact moment of landing without contact	Occurs suddenly or develops from repeated stress
Develops with meniscus or cartilage damage	Causes minor ligament strain

What Are the Common Causes of ACL and Meniscus Tears?

ACL and meniscus tears are primarily caused by sudden twisting, quick stops, direct blows, pivoting, and awkward landings. Similarly, sports that involve jumping, cutting, or sudden direction changes can increase the risk of ACL tears. On the other hand, meniscus injuries are more common during deep squatting, heavy lifting, or repeated knee-bending movements. While ACL tears are often caused by a single acute trauma, meniscus damage may develop gradually because of repetitive stress or age-related cartilage degeneration.

Can ACL and Meniscus Tears Happen at the Same Time?

Yes, ACL and meniscus tears can happen at the same time. The same forceful twist, pivot, or impact that ruptures the ACL can also trap the meniscus and cause tissue damage. In fact, a study published in the Journal of Orthopaedic Research found that almost 55.8% of patients had both ACL and meniscus injuries together. The study was conducted on 43 patients with ACL tears. After analysis, researchers found the following meniscus tear patterns with ACL injuries: 

• 17 patients experienced a lateral meniscus injury with an ACL tear
• 4 patients had a medial meniscus injury with an ACL tear
• 3 patients reported both medial and lateral meniscus injuries with an ACL tear

How Do Doctors Diagnose ACL vs Meniscus Injuries?

To diagnose ACL injuries, our knee specialist, Dr. Charles Ruotolo, conducts physical exams, including the Lachman test and anterior drawer test. On the other hand, he uses the McMurray and Thessaly tests for meniscus injuries. Here’s how these physical tests help confirm anterior cruciate ligament (ACL) and meniscus injuries:

• Lachman test: The surgeon bends your knee and checks how far the shin bone slides forward under the thigh bone. Excessive movement with reduced ligament resistance suggests an ACL tear.
• Anterior drawer test: During this test, surgeons bend your knee to 90° and pull the shin bone forward. If the shin bone slides excessively compared to the other knee, it indicates ACL damage.
• McMurray test: The orthopedist bends, rotates, and straightens your knee while checking for pain, clicking, or catching. These signs indicate a torn meniscus if they occur along the joint line.
• Thessaly test: This test requires controlled standing and knee rotation while the foot stays planted. Pain, locking, or catching during the movement may suggest meniscus damage.

In both cases, Dr. Charles Ruotolo also analyzes your injury history and symptom pattern for an accurate diagnosis. For example, if you report hearing an audible “pop” or experience rapid swelling after sudden pivoting, he may assess your ligament for a possible ACL tear. In contrast, symptoms like knee locking or catching, especially after twisting movements, often suggest a meniscus tear.

Besides meniscus tear and ACL symptoms, our orthopedic surgeon also analyzes your imaging test results. He may review X-rays to rule out fractures or bone injuries. Similarly, he assesses MRI scans to confirm which knee structure is damaged. MRI also helps confirm the location and severity of both ACL and meniscus tears. Call 855-321-6784 to schedule a visit and get an accurate diagnosis for your knee injury.

Do ACL and Meniscus Tears Heal on Their Own?

Yes, some ACL and meniscus tears can heal on their own, depending on the severity and location of the injury. For example, meniscus tears in the outer “red zone” may heal within 6 to 8 weeks with rest and targeted exercises, as this area has a good blood supply. Similarly, small tears in the ACL may stabilize with conservative treatment options if the ligament fibers are only partially damaged.

In contrast, meniscus tears in the inner “white zone” have a very limited blood supply. Therefore, they cannot heal independently and often require arthroscopic surgery or partial removal. Likewise, complete ACL tears cannot heal naturally as the torn ligament loses its ability to reattach and regain functional tension.

When Is Surgery Required for Knee Injuries?

Our board-certified orthopedic surgeon, Dr. Charles Ruotolo, may recommend surgery for severe structural damage, including complete ligament ruptures or large meniscus tears. He may also advise surgical intervention if conservative treatment fails to reduce pain and restore knee stability. In addition, you may require surgical treatment in the following conditions:

• Persistent knee instability: Your knee continues to shift, buckle, or give way during walking, stairs, or sports activities.
• Combined ACL and meniscus injuries: Damage to both structures can significantly affect knee stability and joint function, which makes surgical reconstruction necessary for long-term recovery.

• Locked knee movement: A displaced meniscus fragment blocks normal bending or straightening.
• Repeated sports injuries: The knee experiences recurrent instability during pivoting, jumping, or direction-changing activities.
• Associated cartilage damage: ACL or meniscus injuries accompanied by cartilage damage can increase the risk of joint deterioration, requiring surgery to protect long-term joint health.
• Loss of knee function: Difficulty walking, climbing stairs, squatting, or bearing weight comfortably may indicate severe structural damage to the knee.

How Do Surgeons Repair a Torn ACL or Meniscus?

To repair a torn ACL or meniscus, surgeons usually perform arthroscopic knee surgery. During this procedure, they make small incisions around the knee joint to insert a tiny camera and specialized surgical instruments. This approach allows surgeons to clearly visualize damaged knee structures and minimize tissue trauma during surgery.

Then, depending on the injury type, they may perform the following procedures:

ACL Reconstruction

If you have a complete rupture in the ACL ligaments, surgeons may recommend ACL reconstruction. In this procedure, they first remove the damaged ACL and replace it with a tendon graft. This graft can be taken from your patellar tendon, hamstring tendon, or quadriceps tendon. In some cases, surgeons may also use an allograft, depending on your age, activity level, injury severity, and overall knee health. Then, they secure the graft using screws or fixation devices to support long-term knee function.

Ligament Augmentation

Surgeons may perform ligament augmentation during ACL reconstruction to strengthen the surgical repair. During this procedure, they use internal bracing materials or supportive graft tissue to reduce excessive strain on the healing ACL graft. Here are the two main types of ligament augmentation used during ACL reconstruction:

• Biological augmentation: Surgeons preserve the remaining ACL tissue and use it with a biological graft. This approach supports natural healing and strengthens the reconstructed ligament.
• Internal brace augmentation: Orthopedic surgeons place strong synthetic tape alongside the reconstructed ACL. The tape protects the healing ligament, limits excessive strain, and supports a safe recovery.

Meniscus Repair

Meniscus repair preserves the damaged cartilage instead of removing it. Surgeons usually choose this procedure when the tear is located in an area with enough blood supply. During surgery, they align the torn meniscus edges and secure them with sutures, anchors, or small fixation devices. This helps the cartilage heal while maintaining its shock-absorbing role in the knee. In fact, a study published in Current Reviews in Musculoskeletal Medicine reported an 89% survival rate for repaired meniscus tissue after 10 years.

Partial Meniscectomy

If the torn meniscus cannot heal properly because of severe damage or poor blood supply, surgeons may recommend meniscectomy. In such cases, they usually perform one of the following procedures to restore knee function:

• Partial meniscectomy removes only the damaged portion of the meniscus while preserving as much healthy cartilage as possible.
• Total meniscectomy involves the complete removal of the meniscus when the cartilage is extensively damaged.

Meniscus Transplantation

If meniscectomy fails to reduce knee pain, you may need meniscus transplantation. In this surgery, surgeons replace the missing meniscus with donor cartilage. This procedure restores shock absorption and improves load distribution inside the knee joint. In addition, a study published in PubMed reported a 95% survival rate for meniscus transplants five years after surgery.

What Is the Success Rate of ACL Reconstruction?

ACL reconstruction has a success rate of approximately 75% to 90%, according to a study published by the National Center for Biotechnology Information. The researchers also reported Cincinnati scores of 86-94 after primary ACL reconstruction. These scores indicate strong knee function, better stability, reduced pain, and improved ability to resume sports and daily activities. Similarly, patients showed an average IKDC score of around 84 after surgery. This score reflects successful recovery with strong knee movement and functional improvement.

Here are some common factors that may affect the success rate of ACL reconstruction:

• Type of ACL graft used
• Severity of the ACL tear
• Presence of meniscus injuries or damaged cartilage
• Age and activity level of the patient
• Consistency with postoperative exercise programs
• Muscle strength before and after surgery
• Surgical technique and graft placement

How Long Does Recovery Take for ACL and Meniscus Tears?

An ACL tear usually requires 6 to 12 months for complete recovery, especially after ACL reconstruction. In contrast, meniscus tears may heal within 6 to 12 weeks after partial meniscectomy, while meniscus repair recovery often requires 4 to 6 months. In both cases, you must follow a structured recovery plan that includes the following steps:

Swelling and Pain Control

During the initial recovery stage, you may experience significant swelling, pain, and stiffness for several weeks. To manage these symptoms, our surgeon, Dr. Charles Ruotolo, often recommends ice therapy, elevation, compression, and anti-inflammatory medications.

Range of Motion Exercises

As your swelling improves, we introduce range-of-motion exercises to prevent stiffness and slowly restore normal knee movement. Here are some common exercises that may help improve knee mobility:

• Heel slides
• Assisted knee bends
• Seated knee extensions
• Straight leg raises
• Passive knee stretching
• Quadriceps sets

Strength Building

Once you regain knee mobility, your post-recovery program progresses to strength building. During this phase, we advise you to perform exercises that strengthen the quadriceps, hamstrings, hips, and calf muscles to support the knee joint. Some common strengthening exercises that help regain strength in the knee include:

• Leg presses
• Step ups
• Mini squats
• Hamstring curls
• Glute bridges
• Calf raises
• Wall sits

Balance and Control Training

After strength building, you must focus on improving knee coordination and movement control during walking, turning, jumping, and direction changes. In this phase, exercises such as single-leg balance, lateral stepping, and step-down control can help restore knee stability and reduce the risk of reinjury.

Gradual Return to Activity

Once your knee strength, motion, and stability improve, you can return to everyday activities like walking, driving, and light household tasks. However, before resuming sports, our doctor will perform the following physical tests to ensure a safe return to high-impact activity:

• Single-leg hop test
• Triple hop distance test
• Crossover hop test
• Quadriceps strength testing
• Hamstring strength testing
• Balance and stability testing
• Agility and cutting movement drills
• Landing mechanics assessment

What Braces or Supports Help After a Knee Injury?

For ACL and meniscus injuries, our knee specialist, Dr. Charles Ruotolo, often recommends hinged braces, compression sleeves, or post-operative range-of-motion (ROM) braces. Depending on your injury severity and recovery stage, he may also advise functional knee braces, unloader braces, or assistive devices such as crutches to support a full recovery.

Here’s how these braces and supports can help after an ACL or meniscus injury:

• Hinged braces limit side-to-side knee movement after a knee injury. They also reduce excessive stress on healing ligaments during walking and weight-bearing activities.
• Compression sleeves apply gentle pressure around the knee to reduce swelling and improve comfort during early movement.
• Postoperative ROM braces are adjustable devices that restrict excessive knee bending after surgery. As healing improves, surgeons adjust the brace to increase the permitted range of motion.
• Unloader braces shift pressure away from the injured meniscus, especially during walking, climbing stairs, or other weight-bearing activities.
• Functional knee braces support knee stability during recovery, especially when you resume sports drills or higher-demand activities.
• Crutches transfer body weight to the ground, allowing you to walk without placing excessive pressure on the injured knee.

Which Has a Higher Re-Tear Risk: ACL or Meniscus?

Meniscus repair generally has a slightly higher re-tear rate than ACL reconstruction. According to the Journal of Clinical Medicine, patients who underwent meniscus surgery had a re-tear rate of 38.2%. In contrast, a study published in The Archives of Bone and Joint Surgery found that overall reinjury rates after ACL reconstruction ranged from 1.5% to 37.5%.

However, according to these studies, the re-tear rates for both injuries can vary depending on the following factors:

• Age: Patients under 18 had a 49% re-tear rate after meniscus repair. Similarly, patients under 20 faced a 35% risk of a second ACL injury after initial reconstruction.
• Athletic activity: Reinjury rates after ACL reconstruction also varied by sport. Soccer players had a 28.7% reinjury rate, while football players faced a 30% risk of secondary ACL injuries.
• Type of meniscus tear: Patients with medial tears have a re-injury risk of 46%. In contrast, lateral meniscus repair cases involve a reoperation rate of only 17%.
• Type of ACL reconstruction graft: The study reported a 54% re-operation rate in allograft ACL reconstruction. Meanwhile, autograft cases showed lower failure rates of 30-32%.
• Mental confidence: Lower scores on the ACL RSI scale (which measures psychological confidence and fear before returning to sports) increased the risk of a repeat ACL injury.
• Poor functional recovery: Weak quadriceps and poor hop-test performance increased the risk of reinjury. However, patients who passed these return-to-sport tests had lower re-tear rates.

Unsure If You Have an ACL or Meniscus Injury? Book an Appointment with Dr. Charles Ruotolo in Syosset!

It is difficult to differentiate between meniscus and ACL injuries. Both conditions cause knee pain, swelling, and limited mobility. Without an accurate diagnosis, an ACL or meniscus tear can progress into chronic instability or severe joint deterioration. Therefore, you must consult an orthopedist who conducts a proper clinical assessment.

At Total Orthopedics and Sports Medicine, our surgeon, Dr. Charles Ruotolo, provides detailed diagnosis, advanced imaging, and conservative or surgical treatment for knee injuries. He also schedules structured follow-up visits to track your knee strength, stability, pain level, and return to activity. Then, he adjusts your treatment based on recovery progress to support targeted care. Contact us or visit 115 Eileen Way, Syosset, to consult Dr. Charles Ruotolo.

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