Monday, March 22, 2010

OSTEOARTHRITIS

Today I am going to give certain details of the disease process for a lay man to understand In this post the journey to complete understanding of osteoarthritis and its treatment starts with as to how normal joints work, what happens to them in osteoarthritis and which of the body joints are more likely to develop osteoarthritis.

Osteoarthritis is the commonest form of arthritis or joint disease and is a very important cause of pain and disability in advancing years of life. Some degree of osteoarthritis will develop in everyone in old age .Osteoarthritis has no effect on longevity of persons affected with this disease, but can be quite debilitating in terms of limiting activities and diminishing overall quality of life.


How Healthy Joints Work

Joints are parts of body where one bone meets the other and movement occurs such as elbow, knee, hip and ankle. Backbone or spine also has large numbers of small joints, which allow us to move our neck, and back in all possible directions. Ends of bone which meet each other at joint are covered by cartilage. Cartilage is white, smooth, glistening material and is very specialized which functions as a cushioning material and a shock absorber so that hard bones do not rub against each other, and the cartilage also reduces friction during joint movement since its surface is very smooth. In fact no man made material can match the low friction and shock absorbing properties of healthy cartilage in the joint.


Cartilage is made up of tough fibres of a protein called collagen - Enmeshed in these fibres of collagen are the large molecules of another protein called proteoglycan. Proteoglycan molecules contain lot of water in their interior. Water keeps on moving in and out of the domain of proteoglycan molecules almost like water being sucked in and squeezed out of sponge. This property of ability to exchange water so easily gives an elastic characteristic to the cartilage. Collagen fibres give desired strength and proteoglycan molecules allow reversible compression. The combined structure thus makes up for the tough but not too rigid quality needed for this very specialized tissue.



The bone ends with cartilage covering are enclosed in a membrane called synovium. The synovium releases a slippery fluid know as synovial fluid and this fluid further reduces the friction between moving surfaces capped with cartilage and ensures that the joint moves easily and smoothly. The synovial fluid or joint fluid formed by synovial membrane is a special type of fluid that behaves like fluid when the joint is being moved and during walking when the joint is loaded its character changes to something like jelly to act as an additional shock absorber. The synovial fluid nourishes the cartilage. The cartilage has no blood vessels and relies on synovial fluid moving in and out to provide nutrients and take away the waste products.


Ends of bone, cartilage and synovium are further enclosed in a layer of tissue called capsule. Capsule is a thick and strong tissue but is capable of stretching when joint moves. The combination of bone ends with cartilage covering, synovium and capsule is the joint. The joint is further covered by muscles and tendons, which support the joint and also provide the power to move the joint.

What Happens in Osteoarthritis

In osteoarthritis changes occur both in the cartilage and the synovial fluid.The synovial fluid changes in character and composition and it loses its characteristic capacity to behave in a jelly like manner and act as a shock absorber when the joint is loaded. The cartilage therefore has to sustain more load and impact.


At the same time the cartilage also undergoes subtle changes in chemical composition in a way that proteoglycans decrease and water content increases. As a result the collagen fibrils become disrupted and disorganized. The cartilage has now become soft due to disorganization of tight collagen fibrils, and also swollen due to increased water content. It has thus become less resistant to forces gradually develops cracks or fissures, breaks into fragments usually known as fibrillations, becomes thin and completely disappears in places.


Over a period of time most or all of the cartilage covering at the end of bone may disappear. This is seen on x-ray as gradual decrease and then disappearance of joint space. The loss of cartilage leaves the bone end exposed. Similar changes occur on both sides of the joint and therefore now instead of cartilage moving against cartilage, a situation develops where bone is moving against bone. These changes abolish smooth and frictionless movement at the joint. The broken pieces of cartilage and bone fragments lie in the synovial fluid and this irritates synovial membrane to produce more fluid. This fluid, of course, is not of the same composition and physical character as the normal synovial fluid. The joint swells up due to excessive fluid in it.


Bone rubbing against bone, stretching of joint capsule due to excessive fluid and increased friction in the joint, all three elements produce pain and difficulty in moving the joint. This is perceived as stiffness in the joint as the increased effort required to move the joint. Along with this, the range of joint movements becomes less. The bone ends gradually become misshapen and develop bony spurn at the margins called osteophytes. With advancing disease a part of the end of bone may be extensively rubbed of and this produces severe deformity of the joint. The joint deformity is most easily seen at the knee joint. In advanced osteoarthritis of knee the leg does not remain straight but bends to one side commonly towards inside producing bow leg deformity or sometimes bends outwards to produce knock-knee deformity.


Most common joints affected by it are Knee, Hip, Spine and Hands.


Physical therapy can be used to improve strength in the muscles, splinting to support the joint during inflammation, Taping and elecrtic modalities to reduce pain and swelling.



Readers comments are welcome and also if you want me to write about any disorder which you are intrested to know please let me know.

Sunday, January 17, 2010

What is Repetitive Strain Injury?

The Repetitive Strain Injury is called with diffrent names, computer related injuries, cumulative trauma disorder.

The term "repetitive strain injury (RSI)" and "cumulative trauma disorder (CTD) mean the same thing - a muscle that has been used so frequently, doing the same motion, that is has become injured

Muscles are the reason we can move - when a muscle pulls on a bone, the bone moves. When the bone moves, we can walk, lift our arms, turn our head, wiggle a finger or a toe, in fact it even takes a muscle to blink an eye. Our bodies have 300 pairs of muscles for a total of 600 muscles.

All muscles have similar characteristics
•all muscles pull - they never push
•muscles go in a straight line, not around corners
•muscle originate on one bone and cross over a joint
•muscles merge into fibers called tendons
•the muscle tendon attaches to a bone
•when the muscle pulls the tendon, the bone moves


Muscles are made of many small fibers all lying next to each other, in some cases there are thousands of fibers, merging into the tendon. Each individual fiber works exactly the same way - it contracts and pulls on the tendon. Depending on the amount of strength needed to perform a task, a variety of the fibers will contract (shorten and pull) causing the action to occur. With this amazing system we have the strength to pick up a feather - or a heavy weight. The more fibers contracted, the greater strength expended.

There is a phenomenon called "muscle memory". When a muscle is contracted repeatedly, the brain registers it as needing to be shorter, and it changes the "set-point" of the muscle, making it shorter. Likewise, when a person stretches on a regular basis, the brain registers the change and lengthens the muscle. This lengthening releases the tension on the insertion points of the muscle, and eliminates pain that is caused by the short muscle, or its tendon, pulling on the bone.

When you do the same motion over and over, contracting the muscle continuously, several things happen:
1.The muscle fiber responds to "muscle memory" and permanently changes the muscle to the new shortened length. When this happens a problem occurs because the origination point and the insertion point remain the same, but the muscle is now too short to easily make the distance, so tension is placed on the muscle. While the tension can be at either end, it is more frequently felt at the insertion point at, or just over, the joint.

2.As the muscle fiber is contracting, but the insertion points remain the same, the fiber may tear, causing pain in the muscle.

3.The tendon may begin to tear away from the bone. When this happens the body sends bone cells to the area to hold onto the tendon. The build-up of bone cells forms a "spur". Nothing will stop the growth of the spur while the tendon is being pulled away from its insertion point.

4.If you try to remove the spur, without first releasing the muscle's tension on the bone, it will either quickly return, or the tendon will tear. This is commonly seen when the calf muscles are putting strain onto the Achilles tendon. As the muscles tighten, the tendon is pulled away from the heel, and a spur is formed on the back of the heel.

5.In the case of muscles that insert onto the spine, the vertebre are pulled out of alignment, and pressure is placed on the spinal cord and nerves. While there are many muscles that cause this problem, it is clearly seen in the case of the psoas (pronounced "so-as") muscle. The psoas originates on the lumbar (low back) vertebre, goes around the inside of the hips, and inserts into the front of the thigh bone. When the muscle contracts normally, you bend over or lift your leg. However, when the muscle is shortened by muscle memory, the lumbar vertebre are pulled forward, and the spinal cord is pressed by the moving vertebre. You now have low back pain.

6.Muscles can also trap a nerve, causing pain far from the site of the spasm. This is clearly seen in the case of the muscles of the neck, the scalenes. When the scalenes are in spasm they trap the bundle of nerves that become the nerves of the arm and hand. While the spasm is in the neck muscle, the pain and numbness is felt in the wrist and fingers. Until the spasm is released in the neck, the pain in the hand will not go away.

7.Tight muscle tendons can also trap a nerve, causing the burning pain and tingling common with nerve damage. This is most clearly seen when the flexor (forearm) muscles are contracted, causing the tendons to become taut, and the nerve to the hand is trapped by the tendons. You have all the symptoms of carpal tunnel syndrome, but all you actually are experiencing is the result of muscle tension impinging on a nerve.

8.When a muscle is pulling tightly on a joint, it is common for the joint to become stiff. Many people are told to strengthen the muscles that move the joint - but this is exactly the opposite of what actually needs to be done. The muscles need to be stretched, not strengthened. This is often seen in all the major joints - especially the shoulders, hips, knees and elbows. People will be told to lift weights, squeeze balls, cycle, or exercise to strengthen the muscles that move the joint. As they continue to contract the muscle even further, the joint becomes less and less mobile, and the person is told they have "arthritis", "bursitis", or they may even tear a tendon or ligament.

Repetitive Strain Injury can, and does, happen to muscles throughout the body. Every muscle spasm has its own referred pain area, frequently far from the source of the spasm. The spasms are commonly called "trigger points".