Our sports medicine specialists are board certified and highly trained in their fields. Our team members work together to treat your sports injuries. We offer nonsurgical and surgical treatments as well as minimally invasive procedures to treat a wide range of sports-related medical conditions.
Knee cartilage overview
Cartilage is a rigid yet flexible connective tissue found in many areas of the body, including your joints. Articular cartilage coats areas of bone that are in close proximity to each other. It is found at the ends of your femur (thigh bone), tibia (leg bone) and on the underside of your patella (kneecap).
Articular cartilage is important because it provides a smooth surface for your bones to guide, acts as a shock absorber and protects bones from the pressure of your body weight. However, it does not have its own blood supply and must rely on the fluid in your joint (called synovial fluid) for its nutrients. Because of this, articular cartilage has limited ability to heal itself if damaged.
Knee cartilage injury
Cartilage injuries are common. In fact, more than half of people who undergo knee surgery for an unrelated injury are found to have cartilage injuries as well. Athletes who participate in twisting and pivoting sports such as football, soccer and basketball are particularly at risk. A cartilage injury can occur along with another knee injury, such as an anterior cruciate ligament, or ACL, tear or it can occur on its own. Cartilage can also be injured from years of accumulated wear and tear. Symptoms of a cartilage tear may include pain, swelling, locking, catching and decreased range of motion.
Treatment of cartilage injury
There are a number of treatment approaches to cartilage injuries including nonsurgical, minimally invasive surgery (arthroscopy) and open surgery (arthrotomy). The approach your doctor recommends will depend on the size of your injury and your activity level. Nonsurgical treatment may include physical therapy, knee bracing, anti-inflammatory medication and injection into the joint with cortisone or hyaluronic acid. Surgical options available at OHSU range from minimally invasive arthroscopic surgery to larger open surgeries to replace the damaged cartilage. The type of surgery recommended will depend on a number of factors including the size of your injury, your expectations and goals, the overall condition of your knee, and if there is any damage to the underlying bone.
If you have been given a diagnosis of osteoarthritis, cartilage repair surgery will likely not be recommended as this damage is often too extensive to be repaired. In other words, we are able to treat small potholes in the road, but if the whole road needs re-paving, knee replacement surgery may be a better option.
Common cartilage surgeries performed at OHSU
Two small incisions are made just below your kneecap and a thin fiber optic camera is inserted. This allows us to visualize the inside of the knee joint, then trim and smooth the damaged cartilage. Removing the damaged tissue allows for healthy cartilage to potentially fill in the defect.
Microfracture surgery is also done arthroscopically. First, the damaged cartilage is removed. Then, small holes are poked into the bone below, bringing new cells to the area which will eventually go on to grow new scar cartilage. Though this new type of cartilage is not quite as strong as your normal cartilage, it does serve to put a cover on the “pothole” which helps to improve many people’s symptoms.
Autologous chondrocyte implantation
Another approach to cartilage repair involves replacing damaged cartilage with new cartilage that essentially matches the other cartilage in your knee.
ACI is a two-step procedure. In the first step, new cartilage cells are grown. During the second step, these new cartilage cells are implanted in your body.
First, healthy cartilage tissue is removed from a non-weight-bearing area of your bone. This step is done as an arthroscopic procedure. This tissue, which contains healthy cartilage cells, or chondrocytes, is then sent to the laboratory and the cells are cultured and increase in number over a three- to five-week period. During the second step, an open surgical procedure, or arthrotomy, is then done to implant the newly grown cells.
Osteochondral allograft transplantation
If a cartilage defect is too large for the above surgeries to be effective and/or if there is damage to the underlying bone, we may recommend use of donor cartilage and bone to replace your injured cartilage and bone. This is done through a small open incision in your knee. A thin piece of bone with the overlying cartilage attached is press-fit inside your knee. We work with an excellent tissue bank to ensure we have access to high-quality grafts screened for diseases and contamination.
Doctors at the OHSU Sports Medicine Clinic offer a full range of treatments for injuries of the knee, including ACL tears.
The best treatment for you depends on several factors including how recently your injury occurred, what concurrent injury you may have sustained and what your goal are for post treatment function. Our goals are to treat your pain, improve your function, reduce your newly acquired risk of degenerative joint disease and prevent additional future injuries.
The knee is a complex joint made up of principally three bones which are stabilized with several ligaments that interact to hold these bones in close proximity and dissipate stress. These ligaments work to allow you to turn, pivot and jump while protecting your cartilage (meniscus and hyaline). In concert these structures protect us from gravity. Four ligaments act to stabilize the knee joint while performing both simple tasks like walking down stairs and complex tasks like gliding over moguls while skiing. One of these ligaments, the ACL, is particularly vulnerable to injury while landing from jumps, twisting or hyper extending your knee.
Injury of the ACL is often associated with immediate pain, swelling and instability, but not in all cases. After a week or so of recovery and proper rehabilitation, some people may not notice many symptoms. However, untreated or improperly rehabilitated ACL injuries can become associated with chronic joint instability and an increased likelihood of further injury, particularly damage to cartilage and meniscus. This can occur even in the absence of symptoms.
At your first appointment, your doctor will have reviewed your history, including any past and current injuries, obtain images and review your personal expectations. Your answers give the doctor detailed information about your goals and the potential to return to full function, as well as the risk of further injury. This helps determine how urgent and what types of treatments will be most likely to get you back to a pre-injury level.
Conservative (non-surgical) treatment
Treatment of a torn or injured ACL depends on your degree of injury, symptoms and activity level. Non-surgical treatment for an ACL injury includes rehabilitation exercises and education to reduce swelling and restore motion. This often includes a program of physical therapy and instruction on how to strengthen the area and your core muscles to reduce the risk of future knee instability.
Surgery for ACL injuries often involves replacing the torn ACL, as this ligament will not heal on its own. Minimally invasive techniques for ACL reconstruction can include replacing the ligament with a tissue graft. Several graft options are available and recommendations on graft types are based on a variety of factors such as your age, activity level, goals and health history. OHSU provides all graft options available and our surgeons have extensive experience with ACL injuries and the appropriate treatment required. We specialize in repairing ACL injury in patients with repeat injury, sometimes called “revision” ACL surgery.
After surgery and rehabilitation, your risk of re-rupturing a reconstructed ACL should be equal to injuring a normal ACL. Exercises to reduce the risk of ACL injury to either knee will be part of your post-surgery rehabilitation recommendations and physical therapy prescription.
New implant for ACL tears
OHSU offers a less-invasive new implant to treat ACL (anterior cruciate ligament) tears. The Bridge-Enhanced ACL Restoration Implant —or BEAR Implant — is the first FDA-approved medical technology to help heal a torn ACL.
In the standard treatment, called reconstruction, the ACL is replaced with a donor tendon or with a healthy tendon from another part of the leg. It can require two surgical sites.
The BEAR Implant keeps the ACL in place and serves as a bridge as the torn ends heal back together. It uses one surgical site.
Advantages of the BEAR Implant include:
- The body heals its own ACL while keeping the knee’s natural anatomy.
- The procedure is less invasive than reconstruction surgery, which often requires a second surgical site.
- As the ACL heals, the body absorbs the Bear Implant, usually within eight weeks.
- In small studies, patients had more hamstring strength two years after surgery compared with those who had reconstruction.
- OHSU has one of the few doctors in the state to offer the implant.
In arthroscopic knee surgery, your surgeon uses a tiny camera and small instruments to diagnose and fix problems inside the joint. Arthroscopy can help us diagnose and treat many problems, including torn cartilage, torn ligaments and unstable joints. It can also help us decide if knee replacement is a good option for you.
At OHSU, the latest cutting-edge research is helping us bring you new treatments and cures for bone and joint injuries and disease.
In arthroscopy, your doctor looks inside the joint with a tiny camera to diagnose and treat joint problems. With shoulder arthroscopy, the doctor can see inside the shoulder without making a large incision. The latest cameras provide higher resolution, so this procedure is even more effective. If needed, our shoulder specialists can perform complex surgery through the scope.
Your doctor may recommend arthroscopy for shoulder problems including:
- Damaged cartilage
- Shoulder instability
- Torn ligaments or tendons
- Torn rotator cuff
- Bone spur or inflammation around the rotator cuff
- Shoulder impingement syndrome
In arthroscopy, your doctor looks inside a joint with a tiny camera. Small instruments are used to repair joint problems. The camera gives your surgeon a clear view inside the hip without making a large incision. With the newest high-resolution cameras, this procedure has become even more effective for diagnosing joint problems. Doctors can even perform complex surgery through the scope.
You may be a candidate for hip arthroscopy if you are active but have painful hips, and if your doctor believes there is a chance to preserve the cartilage in your hip. If you have hip arthroscopy, you might not need hip replacement surgery, or might not have it as soon.
Ligament sprains or tears are among the most common knee injuries. If you participate in certain sports such as soccer, football or basketball you are even more likely to injure your ligaments.
If you have injured your ligament, you may need surgery to regain full function of your knee. Whether you need surgery depends on several factors, including the severity of your injury and your activity level. Most of ligament repairs can be done arthroscopically, using a tiny camera to perform surgery through a small incision in the knee. This makes it easier to recover quickly and return to sports or other activities.
New implant for the treatment of medial knee osteoarthritis
OHSU offers the first FDA-cleared implantable shock absorber to treat mild to moderate cases of medial knee osteoarthritis (OA). It is the first and only device of its kind for people with symptomatic medial knee OA, who are not candidates for total knee replacement.
How it works
As the knee extends and the foot strikes the ground, the shock absorber compresses and reduces stress force on the knee by more than 30% with every walking step. As the knee flexes, the device relaxes and allows normal, smooth walking movement.
During the clinical trials for the device, successful MISHA™ Knee System patients were often able to resume high-level activities that they previously lost due to pain. They were able to return to work, play sports, and be more active and thus healthful.
Advantages of the MISHA™ Knee System include:
- It is an outpatient procedure.
- Unlike joint replacement surgery, NO bone, ligament, or cartilage is removed,
- Allowing future treatment options and limiting recovery requirements.
- After surgery you are permitted to stand normally and walk without restrictions.
- A brace and crutches may be helpful for a few days.
Is MISHA™ right for you or one of your patients?
OHSU is now evaluating candidates for this procedure. For more information, see our Patient Assessment for MISHA™ Knee System to help determine who is a good candidate for MISHA.
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OHSU accepts most insurance plans. View OHSU's Billing and Insurance page
PSU team doctor
OHSU's Sports Medicine program is the official team doctor for Portland State University athletics.