Untreated Bleeding in the Joints
The most common place for a person with hemophilia to bleed is the space inside his joints. Bleeding into joints or muscles causes the most long-lasting problems. This section tells how these problems arise. Fortunately, with the treatments we have today, long-lasting problems or crippling do not have to happen.
How joints are damaged by bleeding
A joint is the space where two bones meet. Together, the bones and joint bend and straighten body parts. For example, the knee is the joint that lets us bend and straighten our leg.
Certain kinds of joints are called synovial joints. A synovial joint is one that has a clear fluid inside of it called synovial fluid. This fluid makes the ends of the bones slide over each other smoothly. By keeping the bone ends from rubbing against each other, the synovial fluid protects the bones from wear and tear. It is like the way oil in a car's engine keeps the pistons running smoothly.
Our shoulders, elbows, wrists, hands, knees, ankles, and feet all have synovial joints. Our spine, ribs, skull, and pelvis do not. In a person with hemophilia, the synovial joints are the ones damaged most often.
Blood flowing into the space in the synovial joint causes damage to the joint. If this happens often enough, it causes crippling arthritis. The person will not be able to use the joint without a lot of pain. To show how this happens, we will look at a normal knee joint and compare it to one that has bled over and over. This picture shows the inside of a normal knee joint. Find the parts of the joint in the picture as you read about them below.
Joint cartilage - a smooth layer of body tissue which covers and protects the ends of the bones in a joint.
Ligaments - strong bands of body tissue which connect and support two bones or cartilages. Ligaments keep a joint from moving too far out of line (dislocating).
Synovial capsule - a tough, elastic casing which surrounds and protects the entire joint. The synovial membrane lines the inside of the synovial capsule.
Synovial membrane - the membrane lining the inside of the joint capsule. It does not cover the cartilage at the end of the bones. The synovial membrane contains many small blood vessels and makes the synovial fluid.
Muscle - body tissue that can contract and relax to move itself or other body tissue.
Tendon - the tough band of tissue that attaches a muscle to a bone.
Muscles, tendons, and ligaments work together to support a joint and make it stronger. Weak joints will have more bleeding into the synovial capsule than strong ones. This is because weak joints do not have as much support or protection. Regular exercise will keep joints strong.
Bleeding in the joint starts from breaks in the tiny blood vessels of the synovial membrane. These breaks may be caused by an injury such as hitting your knee. In a person with severe hemophilia, they may happen without a clear cause. Blood starts to leak into the synovial space.
Early signs of a joint bleed are a bubbling or tingling feeling or a feeling of heat in the joint. The bleeding will stop if the person takes factor right away. The sooner the bleeding is stopped, the less damage will be done to the joint.
This picture shows joint that has just started bleeding.
This picture shows a joint bleed that hasn't been treated.
Here the bleeding continues because the person did not take factor. It may stop when the joint space is filled up. By this point, the capsule has been stretched and the ends of the bones are out of place. It hurts a lot. Some signs that bleeding has being going on in a joint for some time are swelling, heat, stiffness, and pain. Bending the knee may be the only position the person can bear. However, this position causes even more stiffness. If the joint stays in a bent (flexed) position too long, it will be hard to straighten.
A joint bleed that has gone this far still needs factor. Other medical care and physical therapy (PT) may also be needed to help with the pain and stiffness.
This picture shows a knee joint with synovitis and the beginning of arthritis.
Without factor, the bleeding goes on until the space is filled with blood. The knee looks swollen and spongy. The blood inside the joint makes the synovial lining overgrow and get thick. The lining grows more blood vessels, which makes it likely to bleed again. A cycle begins that is hard to stop. Untreated bleeding leads to the growth of more blood vessels in the joint which leads to more bleeding. This problem with the synovial lining is called synovitis.
The joint may seem to get better after time, but the damage has been done. Your body sends cells called macrophages into the synovial space to break down the blood. The synovial space becomes filled with iron, broken down blood, and scar tissue. As this happens, the space between the bones becomes smaller and smaller. The ends of the bones are less lubricated and protected. The synovial membrane gets thicker and thicker.
The macrophages that break down the blood in the joint don't stop there. They begin to attack and break down the smooth cartilage on the ends of the bones. The cartilage becomes ragged and pitted. The ends of the bones soften. It becomes very painful to move the joint. Ligaments and tendons that were stretched during bleeds now become slack from not being used.
The knee joint in this picture has been totally destroyed by arthritis.
The joint and bones are slowly destroyed. The cartilage continues to erode away. The unprotected ends of the bones begin to spread out. As the ends of the bones shift, they rub together. This causes intense pain when you move. Bending the knee becomes almost impossible since the joint contains so much scar tissue.
The joint wastes away. What is left is a painful condition called degenerative arthritis. The knee is too stiff and painful to move easily. The muscles become weak from not being used. This makes them more likely to bleed.
It is a vicious cycle. When a joint bleed is not quickly or completely treated, the joints and bones are damaged. The muscles weaken, then more bleeding occurs. The end result is crippling. If this happens, physical therapy or surgery may help.
People with hemophilia can avoid this painful cycle by:
- learning to tell the first signs of a joint bleed.
- taking factor right away, before the joint fills with blood.
- exercising to make the muscles that protect their joints stronger. A physical therapist can help plan an exercise program.
- Research suggests that any bleeding into a joint causes damage. For this reason, it is recommended that children with severe hemophilia be given prophylactic treatment. This means they take factor several times a week to keep the level of factor in their blood high enough to prevent most bleeding.