Knee Arthritis (Osteoarthritis)

Knee pain after the age of 50 is a common problem. This pain is almost always due to knee joint osteoarthritis. Osteoarthritis is an age related degenerative condition which can affect any joint in the body. Since knee joint is a weight bearing joint, it is more commonly affected.

What is Osteoarthritis?

As the age advances, because of the wear and tear, the natural cushion in the joint ( cartilage) is damaged. this also leads to loss of the lubricating fluid in the joint. When the cartilage is damaged, the two bones forming the joint comes in direct contact and rub with each other when ever there is movement. This rubbing leads to pain and swelling in the joint.

Gradually the pain intensity increases and range of the knee joint motion decreases. In advanced stage, there can be even joint deformity leading to abnormal alignment of the bones, partial dislocation(loss of contact)of the joint. This deformity will result in patient walking with the knees displaced outwards from the normal body axis. Another common problem associated with knee osteoarthritis is weakness of the quadriceps muscle (muscle group in front of the thigh).

Risk factors for osteoarthritis

1. Advanced age- as the age advances, the wear and tear increases
2. Over weight- this puts excess load on the knees
3. Smoking- Smoking accelerates the degenerative process
4. Female gender
5. Previous knee injury
6. Certain joint diseases like rheumatoid arthritis

Symptoms and signs.

1. Pain– Most common symptom of knee osteoarthritis is pain. The pain severity may vary from mild to severe depending on the stage of the disease. The pain is not present at rest but is initiated upon movement. Pain is also more after a period of inactivity. Hence the patients complain of pain in the morning soon after they get up from the bed and on getting up from the chair after a period of inactivity (the classic complaint of pain after watching movie). In the initial stages, the pain which increases on movement gradually improves after patient continues to walk for a distance. This improvement in pain decreases as the disease progresses and patient continues to have more pain on walking.
   In the advanced stage, the patient is unable to walk, leading to more inactivity which in turn causes weight gain and putting extra load on knee joints. This continues as a vicious cycle.
2. Stiffness– Another common complaint in knee arthritis is early morning knee stiffness. This typically lasts for about 30 minutes and gradually improves as the patient starts moving.
3. Swelling– Swelling of the knee can be an occasional complaint which is due to accumulation of the excess fluid in the joint.

How the Osteoarthritis is diagnosed?

Osteoarthritis is diagnosed based on the patients’ complaints and knee x-ray. X-ray will also help in grading the disease. Simple blood tests are usually asked for to rule out other causes of knee pain like rheumatoid arthritis, infection.

Treatment of osteoarthritis

The main goal of the treatment is to reduce the pain, improve the knee mobility and possibly slowing the degeneration process. None of the treatment can reverse the degeneration.
Not all knee osteoarthritis need knee replacement surgery. Early stages of the disease can be effectively managed by non-surgical means and effectively postpone the surgery or even avoid it.

Non-surgical treatment

Non-surgical treatment works well in early stages of knee arthritis. This mainly comprises of pain killers to control the pain and physical therapy to improve the knee movements.

1. Simple analgesic like Paracetamol, Anti-inflammatory pain killers are often prescribed for treating the knee pain. These medicines are often prescribed for not more than a week or ten days.
2. Physical therapy- Quadriceps muscle strengthening exercises are usually incorporated in the treatment. improved quadriceps muscle strength will improve stability to the knee joint and will reduce the load.
3. Weight loss- Needless to say that cutting down the excess weight will decrease the load on the knees and will improve the knee function.
4. Quit smoking- this will help in slowing down the disease progression.
5. Knee injections- There are various injection therapies for the knee joint which help in pain reduction and improved joint function.
   • Hyaluronic acid- This injection is done in to the knee joint and is an expensive treatment. The synthetic hyaluronic acid is thought to increase the lubrication of the knee joint and reduce the bon friction.
   • Platelet Rich Plasma (PRP) injection- Here a small amount of the patient’s own blood is drawn and the platelets are extracted from it. Then these platelets which are rich in growth factors are injected in to the knee joint. This will partially repair the wear and tear and will improve the joint function as well as. This is less expensive and has minimal side effects as the patient’s own blood is used.
     Both these knee injection techniques are helpful in early stages of the disease.
     Another important thing to note here is corticosteroid injections into the knee joint is no longer recommended as it will do more harm than good.
6. Genicular nerve block- Genicular nerves are the small nerves around the knee joint which are responsible for carrying pain sensations from the knee. In advanced cases where the pain in not relieved by any of the above measures, these nerves can be blocked and thus preventing from transmitting pain sensation. This procedure is often done on day care basis under local anaesthesia and will take less time.
   The genicular nerves are blocked initially with the help of numbing medicine injected under the guidance of either ultrasound or x-ray imaging. If there is significant pain relief, then a more definitive and long lasting genicular nerve ablation is planned. In this definitive treatment, a low energy current is used to numb the nerves around the knee which provides pain relief for years. The patient is able to walk immediately after the procedure and needs less recovery time.
   This treatment is much cheaper than knee replacement, less painful, has no side effects and needs no hospital admission. This treatment is offered as alternate to knee replacement when the patient is not willing for surgery or not medically fit to undergo the surgery.
7. Knee replacement- Surgical knee replacement is the first line treatment for advanced osteoarthritis. Here the diseased knee joint is replaced with artificial metallic knee joint under anaesthesia.