Knee replacement is a permanent solution to debilitating knee pain that is often the result of severe arthritis. It involves resurfacing the affected, arthritic joint, with metal components.
introduction
One of the most common knee injuries is an anterior cruciate ligament sprain or tear. Meniscus tears are another common injury-see below.
Athletes who participate in high demand sports like soccer, football, and basketball are more likely to injure their anterior cruciate ligaments.
If you have injured your anterior cruciate ligament, you may require surgery to regain full function of your knee. This will depend on several factors, such as the severity of your injury and your activity level.
- Knee Surgery in Minnesota
- ACL/Meniscus Injury
- Partial vs. Total Knee Replacement
- Knee Replacement Surgery
- Partial Knee Replacement
- Minimally Invasive Knee Surgery
- Custom Knee Replacement (Visionaire)

Anatomy
Three bones meet to form your knee joint: your thighbone (femur), shinbone (tibia), and kneecap (patella). Your kneecap sits in front of the joint to provide some protection.
Bones are connected to other bones by ligaments. There are four primary ligaments in your knee. They act like strong ropes to hold the bones together and keep your knee stable.
Collateral Ligaments
These are found on the sides of your knee. The medial collateral ligament is on the inside and the lateral collateral ligament is on the outside. They control the sideways motion of your knee and brace it against unusual movement.
Cruciate Ligaments
These are found inside your knee joint. They cross each other to form an “X” with the anterior cruciate ligament in front and the posterior cruciate ligament in back. The cruciate ligaments control the back and forth motion of your knee.
The anterior cruciate ligament runs diagonally in the middle of the knee. It prevents the tibia from sliding out in front of the femur, as well as provides rotational stability to the knee.
Normal knee anatomy. The knee is made up of four main things: bones, cartilage, ligaments, and tendons.
Description
About half of all injuries to the anterior cruciate ligament occur along with damage to other structures in the knee, such as articular cartilage, meniscus, or other ligaments.
Injured ligaments are considered “sprains” and are graded on a severity scale.
Grade 1 Sprains. The ligament is mildly damaged in a Grade 1 Sprain. It has been slightly stretched, but is still able to help keep the knee joint stable.
Grade 2 Sprains. A Grade 2 Sprain stretches the ligament to the point where it becomes loose. This is often referred to as a partial tear of the ligament.
Grade 3 Sprains. This type of sprain is most commonly referred to as a complete tear of the ligament. The ligament has been split into two pieces, and the knee joint is unstable.
Partial tears of the anterior cruciate ligament are rare; most ACL injuries are complete or near complete tears.
Cause
The anterior cruciate ligament can be injured in several ways:
- Changing direction rapidly
- Stopping suddenly
- Slowing down while running
- Landing from a jump incorrectly
- Direct contact or collision, such as a football tackle
Several studies have shown that female athletes have a higher incidence of ACL injury than male athletes in certain sports. It has been proposed that this is due to differences in physical conditioning, muscular strength, and neuromuscular control. Other suggested causes include differences in pelvis and lower extremity (leg) alignment, increased looseness in ligaments, and the effects of estrogen on ligament properties.
Symptoms
When you injure your anterior cruciate ligament, you might hear a “popping” noise and you may feel your knee give out from under you. Other typical symptoms include:
- Pain with swelling. Within 24 hours, your knee will swell. If ignored, the swelling and pain may resolve on its own. However, if you attempt to return to sports, your knee will probably be unstable and you risk causing further damage to the cushioning cartilage (meniscus) of your knee.
- Loss of full range of motion
- Tenderness along the joint line
- Discomfort while walking
Treatment
Treatment for an ACL tear will vary depending upon the patient’s individual needs. For example, the young athlete involved in agility sports will most likely require surgery to safely return to sports. The less active, usually older, individual may be able to return to a quieter lifestyle without surgery.
Nonsurgical Treatment
A torn ACL will not heal without surgery. Depending upon a patients age and activity level, surgery may not be necessary to get them back to their desired activities.
Bracing- Your doctor may recommend a brace to protect your knee from instability. To further protect your knee, you may be given crutches to keep you from putting weight on your leg.
Physical therapy- As the swelling goes down, a careful rehabilitation program is started. Specific exercises will restore function to your knee and strengthen the leg muscles that support it.
Surgical Treatment
Rebuilding the ligament. Most ACL tears cannot be sutured (stitched) back together. To surgically repair the ACL and restore knee stability, the ligament must be reconstructed. Your doctor will replace your torn ligament with a tissue graft. This graft acts as a scaffolding for a new ligament to grow on.
Grafts can be obtained from several sources. These sources include the patellar tendon, hamstring tendons or quadriceps tendon. Donor tissue is also sometimes used. Dr. O’Keefe most often utilizes quadriceps tendon graft tissue for ACL reconstruction. The graft is strong, can be harvested in multiple sizes and causes minimal morbidity at the donor site. This also minimizes the chance of pain in the front of the knee with deep knee bending or squatting. Ultimately, graft choice will depend on the patient and this will be discussed at your visit.
Because the regrowth takes time, it may be six months or more before an athlete can return to sports after surgery.
Surgery to rebuild an anterior cruciate ligament is done with an arthroscope using small incisions. Arthroscopic surgery is less invasive. The benefits of less invasive techniques include less pain from surgery, less time spent in the hospital, and quicker recovery times.
Rehabilitation
Whether your treatment involves surgery or not, rehabilitation plays a vital role in getting you back to your daily activities. A physical therapy program will help you regain knee strength and motion.
If you have surgery, physical therapy first focuses on returning motion to the joint and surrounding muscles. This is followed by a strengthening program designed to protect the new ligament. This strengthening gradually increases the stress across the ligament. The final phase of rehabilitation is aimed at a functional return tailored for the athlete’s sport.
Meniscus Tears Overview
Anatomy
Three bones meet to form your knee joint: your thighbone (femur), shinbone (tibia), and kneecap (patella).
Two wedge-shaped pieces of cartilage act as “shock absorbers” between your thighbone and shinbone. These are called meniscus. They are tough and rubbery to help cushion the joint and keep it stable.


Description
Menisci tear in different ways. Tears are noted by how they look, as well as where the tear occurs in the meniscus. Common tears include bucket handle, flap, and radial.
Sports-related meniscus tears often occur along with other knee injuries, such as anterior cruciate ligament tears.
Types of meniscus tears:
(Left) Bucket handle tear. (Right) Flap tear.
(Left) Radial tear. (Right) Degenerative tear.
Cause
Sudden meniscus tears often happen during sports. Players may squat and twist the knee, causing a tear. Direct contact, like a tackle, is sometimes involved.
Older people are more likely to have degenerative meniscus tears. Cartilage weakens and wears thin over time. Aged, worn tissue is more prone to tears. Just an awkward twist when getting up from a chair may be enough to cause a tear, if the menisci have weakened with age.
Symptoms
You might feel a “pop” when you tear a meniscus. Most people can still walk on their injured knee. Many athletes keep playing with a tear. Over 2 to 3 days, your knee will gradually become stiff and swollen.
The most common symptoms of meniscus tear are:
- Pain
- Stiffness and swelling
- Catching or locking of your knee
- The sensation of your knee “giving way”
- You are not able to move your knee through its full range of motion
Without treatment, a piece of meniscus may come loose and flip into the joint. This can cause your knee to slip, pop, or lock.
Doctor Examination
Physical Examination and Patient History
After discussing your symptoms and medical history, your doctor will examine your knee. He or she will check for tenderness along the joint line where the meniscus sits. This often signals a tear.
One of the main tests for meniscus tears is the McMurray test. Your doctor will bend your knee, then straighten and rotate it. This puts tension on a torn meniscus. If you have a meniscus tear, this movement will cause a clicking sound. Your knee will click each time your doctor does the test.
Imaging Tests
Because other knee problems cause similar symptoms, your doctor may order imaging tests to help confirm the diagnosis.
X-rays. Although x-rays do not show meniscus tears, they may show other causes of knee pain, such as osteoarthritis.
Magnetic resonance imaging (MRI). This study can create better images of the soft tissues of your knee joint, like a meniscus.


Treatment
How your orthopedic surgeon treats your tear will depend on the type of tear you have, its size, and location.
The outside one-third of the meniscus has a rich blood supply. A tear in this “red” zone may heal on its own, or can often be repaired with surgery. A longitudinal tear is an example of this kind of tear.
In contrast, the inner two-thirds of the meniscus lacks a blood supply. Without nutrients from blood, tears in this “white” zone cannot heal. These complex tears are often in thin, worn cartilage. Because the pieces cannot grow back together, tears in this zone are usually surgically trimmed away.
Along with the type of tear you have, your age, activity level, and any related injuries will factor into your treatment plan.
Nonsurgical Treatment
If your tear is small and on the outer edge of the meniscus, it may not require surgical repair. As long as your symptoms do not persist and your knee is stable, nonsurgical treatment may be all you need.
RICE. The RICE protocol is effective for most sports-related injuries. RICE stands for Rest, Ice, Compression, and Elevation.
- Rest. Take a break from the activity that caused the injury. Your doctor may recommend that you use crutches to avoid putting weight on your leg.
- Ice. Use cold packs for 20 minutes at a time, several times a day. Do not apply ice directly to the skin.
- Compression. To prevent additional swelling and blood loss, wear an elastic compression bandage.
- Elevation. To reduce swelling, recline when you rest, and put your leg up higher than your heart.
- Non-steroidal anti-inflammatory medicines. Drugs like aspirin and ibuprofen reduce pain and swelling.
Surgical Treatment
If your symptoms persist with nonsurgical treatment, your doctor may suggest arthroscopic surgery.
Knee arthroscopy is one of the most commonly performed surgical procedures. In it, a miniature camera is inserted through a small incision (portal). This provides a clear view of the inside of the knee. Your orthopedic surgeon inserts miniature surgical instruments through other portals to trim or repair the tear.
Illustration and photo show a camera and instruments inserted through portals in a knee.
- Partial meniscectomy- In this procedure, the damaged meniscus tissue is trimmed away.
- Meniscus repair- Some meniscus tears can be repaired by suturing (stitching) the torn pieces together. Whether a tear can be successfully treated with repair depends upon the type of tear, as well as the overall condition of the injured meniscus. Because the meniscus must heal back together, recovery time for a repair is much longer than from a meniscectomy.
(Left): Close-up of partial meniscectomy.
(Right): A torn meniscus repaired with sutures.
Once the initial healing is complete, your doctor will prescribe rehabilitation exercises. Regular exercise to restore your knee mobility and strength is necessary. You will start with exercises to improve your range of motion. Strengthening exercises will gradually be added to your rehabilitation plan.
For the most part, rehabilitation can be carried out at home, although your doctor may recommend physical therapy. Rehabilitation time for a meniscus repair is about 3 months. A meniscectomy requires less time for healing — approximately 3 to 4 weeks.
Recovery
Meniscus tears are extremely common knee injuries. With proper diagnosis, treatment, and rehabilitation, patients often return to their pre-injury abilities.
ACL/Meniscus Surgery in Minneapolis, MN
Specializing in minimally invasive surgery, Dr. Patrick O’Keefe provides the highest quality orthopedic care to patients suffering from knee pain in the Minneapolis area. Dr. O’Keefe is renowned for his state-of-the-art treatment of osteoarthritis and rheumatoid arthritis. For more information about knee replacement surgery, schedule an appointment with Dr O’Keefe at his Blaine, Coon Rapids, or Otsego offices at (763) 441-0298.