You’re not alone in your questions. We know that osteonecrosis is the death of bone tissue. But spontaneous osteonecrosis (SON) is sudden, unexpected, and without known cause.

Some recent reports point to a possible increase in this condition in adults over age 60. At first doctors thought it was linked with arthroscopic surgery to remove a torn meniscus. But then five new cases were reported in patients who had meniscus degeneration but no surgery.

It appears that age-related wear and tear on the meniscus may be the start of the problem. But there are still many questions about what’s going on. For example, in one study of five patients, symptoms of knee pain were identified as medial meniscal degeneration.

At the time of the diagnosis, there were no changes in the bone seen on an MRI. The patients were all treated with physical therapy, exercise, and noninflammatory drugs. Two months later the symptoms increased. A second MRI showed osteonecrosis of the knee.

What happened in those two months between MRIs? Doctors just aren’t sure yet but further studies may offer some insight into SON.

Incomplete healing of a torn mensicus is usually found by having a second arthroscopy.

The surgeon makes one or more puncture holes in the skin and inserts a long, thin needle called a cannula into the joint.

Tiny tools can be passed through the cannula including a miniature TV camera to take a look inside the joint. What the surgeon sees as an incomplete healing of meniscal tears is a cleft or gap at the site of the tear. It may go down 10 to 50 percent of the thickness of the meniscus.

A gap of more than 50 percent is a nonhealed repair. A second operation is often needed in such cases.

For more information on this subject, call The Zehr Center for Orthopaedics at 239-596-0100 or visit www.zehrcenter.com. The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of a visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.

There are several benefits to this type of surgery. First of all, only a few small puncture holes are needed to slip the surgical tools into the joint. No large scars are needed. The back of the knee doesn’t have to be opened to tie the sutures. Healing time is shorter.

There’s less risk of damaging nerves or blood vessels with arthroscopy. The risk of infection is also less. The disadvantages may be just coming to light.

The first long-term studies are being reported. After about 10 years of using special devices that allow for an all-inside or all-arthroscopic repair, it’s clear that the repair is incomplete for many patients. A second operation may be needed to repair or remove the re-injured meniscus.

For more information on this subject, call The Zehr Center for Orthopaedics at 239-596-0100 or visit www.zehrcenter.com. The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of a visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.

Well, there’s some truth to your statement but there are many factors in between those two points. First it depends on how severe the damage is to your anterior cruciate ligament (ACL). A minor tear can be treated with rehab. This is especially true if you’re not an athlete or exercising at intense levels.

Studies do show a tendency toward cartilage damage in unstable knees. This means the ACL is deficient and not doing its job. The joint slides around more than it should, putting stress on the meniscus and other joint cartilage. Under the increased load, wear and tear on the meniscus could end up in a tear.

Only one study has been done that shows the need for a total replacement (TKR) after ACL injury without repair. A small group of olympic athletes in the former East Germany were treated without surgery and returned to training. Doctors followed them 35 years later and found out that all of them had a torn meniscus. Half had a total knee replacement.

Long-term studies of everyday average people with an unrepaired ACL have not showed these kinds of results. They do report an increased pattern of osteoarthritis in the unstable (unrepaired) knees. The risk of a TKR is present but not a certainty.

For more information on this subject, call The Zehr Center for Orthopaedics at 239-596-0100 or visit www.zehrcenter.com.The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.

Meniscal transplantation is in the works. It’s not done by all surgeons but it’s being studied by some. There are many questions left to answer before using this operation on a routine basis.

For example how much meniscus is really needed? What’s the best way to prepare donated tissue? How should it be put into the knee? How long does it last? What problems come up soon after the operation compared to years later?

Right now this method of meniscal “repair” is used in young patients who have already had the entire meniscus taken out. Pain and joint degeneration are the basic criteria for this treatment method. There’s about a 60 percent success rate. This means about 40 percent (four out of 10) of patients have a failed transplantation.

For more information on this subject, call The Zehr Center for Orthopaedics at 239-596-0100 or visit www.zehrcenter.com.The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.

The most likely cause for this is a torn meniscus. If the outer curve of the meniscus is torn, the inner portion can get stuck in the notch or opening for the ligaments. The terms “trick knee” or “locked knee” are used to describe the condition.

Usually the knee can still bend but can’t straighten. Sometimes the inner portion of the meniscus can slip back into place. Then the knee seems to work fine again. A minor injury can displace the torn cartilage again.

Most surgeons advise repairing a small tear before another injury tears it completely. Have an orthopedic doctor take a look soon.

For more information on this subject, call The Zehr Center for Orthopaedics at 239-596-0100 or visit www.zehrcenter.com.The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.

There are two menisci between the shinbone (tibia) and thighbone (femur) in the knee joint. (Menisci is plural for meniscus.) The C-shaped medial meniscus is on the inside part of the knee, closest to your other knee. (Medial means closer to the middle of the body.) The U-shaped lateral meniscus is on the outer half of the knee joint. (Lateral means further out from the center of the body.)

The meniscus is thin but has a wedge shape when viewed from the side. The outer edge of the meniscus is thicker than the central part. There’s more blood supply to the outer edge. The inside or central part of the meniscus doesn’t have a blood supply. It gets its nutrients from the synovial fluid inside the joint.

The thicker wedge of the medial meniscus is attached to the joint capsule and ligaments. The thinner central portion is free to move in and out slightly during normal knee motion. Both parts of the meniscus work to give the knee joint a smooth fit and easy movement. Both functions are needed for the kinds of loads the knee holds up under.

Without a lot of blood vessels, injury results in pain but doesn’t cause swelling. A locking sensation or even “giving way” of the leg can occur when the meniscus is torn.

For more information on this subject, call The Zehr Center for Orthopaedics at 239-596-0100 or visit www.zehrcenter.com.The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.

The meniscus is a C-shaped piece of cartilage in the knee joint. It helps the joint move smoothly and acts as a shock absorber. It can also help transfer the load through the joint.

The knee joint has two menisci (plural), the medial (inner portion) and lateral (outer portion). When the outer edge of the cartilage is torn, it looks like a crescent-shaped moon or bucket handle.

At one time it was thought the meniscus didn’t have any real function. A tear would result in surgery to remove the whole thing. Later scientists found this treatment led to joint damage and early arthritis. Now most surgeons prefer to repair the tear or just take out the torn section.

For more information on this subject, call The Zehr Center for Orthopaedics at 239-596-0100 or visit www.zehrcenter.com.The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.

A loose body is a piece of tissue from within a joint that has somehow become dislodged and floats freely in the joint. It can get caught between the joint when it moves, causing the joint to pop, click, catch, or even lock up. There are several conditions in the knee that can be sources of a loose body. A loose body can form if a section of the meniscus has torn loose, either from trauma or degeneration. A bone chip from a fracture can also become a loose body.

Another possible source for a loose body is osteochondritis dessicans (OCD), a condition in which a piece of cartilage and the underlying bone have been damaged. In some cases, the damaged fragment separates from the bone and floats freely within the joint. The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments.

The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic. For more information on this subject, visit http://www.zehrcenter.com

  The meniscus is a tough, rubbery pad between the shinbone (tibia) and thighbone (femur) in the knee joint. There are actually two menisci inside the knee. The C-shaped medial meniscus is on the inside part of the knee, closest to your other knee. The U-shaped lateral meniscus is on the outer half of the knee joint. 

The meniscus protects the knee by spreading out pressure and forces on the knee. Without it, these forces are concentrated to a smaller area, which puts more wear and tear on the joint. The meniscus also improves knee stability by forming a socket on the top surface of the tibia. This socket gives added support where the femur bone joins the knee.

The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic. For more information on this subject, visit www.zehrcenter.com.