There are a number of conditions which can cause knee pain. The most common cause of knee pain is arthritis. “Arthritis” means inflammation of a joint, but in general it describes any condition which causes damage to the cartilage.
What is Cartilage ?
The bone ends of a joint are covered with a smooth material called cartilage. The cartilage cushions the bone and allows the joint to move easily without pain. Without it, bones would grind together.
What are the causes of knee pain?
- INFLAMMATORY ARTHRITIS : Osteoarthritis is the most common cause of knee pain in patients over 40 years of age. It is seen in many people as they age, although it may begin when they are younger as a result of injury or overuse. Although any joint may be involved, osteoarthritis is more common in weight-bearing joints such as the knee, hip, and spine than in the wrist, elbow, and shoulder joints. The cartilage covering the bone ends gradually wears away. Bone growths called "spurs" develop in osteoarthritic joints. The joint inflammation causes pain & swelling. Continued use of the inflamed joint produces pain.
- PATELLOFEMORAL SYNDROME : This is the most common cause knee pain in patients below 40 years. Tracking of patella or knee cap is abnormal in these patients and they experience pain while going up or downstairs & while squatting.
- NFLAMMATORY ARTHRITIS :Knee pain is usually associated with pain and swelling in other joints. There may be constitutional symptoms like fever, body-ache, morning stiffness, etc.
Examples of this type of arthritis are Rheumatoid Arthritis, soriatic Arthritis, Ankylosing Spondylitis, Acute Rheumatic Fever, etc.
- INFECTIVE ARTHRITIS :Examples of this type of arthritis are Septic and Tubercular Arthritis. Septic Arthritis is the most dangerous type which needs urgent diagnosis and treatment. Otherwise it could lead to septicaemia and a permanently damaged joint.
- TRAUMATIC KNEE PAIN :Knee pain may be due to injuries to the knee which can lead to Meniscal Tears, Cruciate Ligament Tears, Chondral Cartilage Tears or Fractures. Meniscal tears usually result from a twisting injury and the knee becomes painful and swollen. Patient gives history of clicking sensation. It may need Trimming of meniscus or meniscectomy which can be done with the help of key-hole surgery or Arthroscopy.
Cruciate Ligament Tears result in unstable knees and patient has difficulty in running or taking sudden turns. Many of them will improve with quadriceps strengthening exercises but if disability persists or in athletes Anterior Cruciate Ligament Reconstruction will be needed.
- Neoplasm or Tumors :Tumors may be the cause of knee pain in any age group but are rare. Benign tumors are more common in young patients whereas malignant tumors are more common in middle age and older age groups. In malignant tumors there may be constitutional symptoms like fever, night sweats, body-aches etc.
How common is osteoarthritis of the knee?
40% of people over 70 years suffer from Knee Osteoarthritis (OA). 80% of patients with Knee OA have some degree of limitation of movement, and 25% cannot perform their daily activities.
Patients with Knee OA experience decrease in quality of life.
What are the symptoms of knee osteoarthritis ?
Initially patients complaint of pain and stiffness of the joint especially after a period of inactivity or while climbing stairs or getting up from squatting position. The pain may be felt in the front, the back or the sides of the knee. Later on, the mobility of the patient reduces and pain is felt even at rest and sleep gets disturbed. There may be other symptoms such as swelling, painful limp, giving way, locking or reduced walking distance. The leg gradually becomes deformed and may be either bow-legged or knock-kneed.
Treatment of osteoarthritis
Aims of treatment are
- Reduction of pain
- Improvement of function
- Stop/ retard progression of the disease
- Correction of deformity
Nonsurgical treatment of knee arthritis
- Behavioural and Environmental Changes
- It may be easier for you to cycle than to walk
- Exercise in water may be much easier than on dry land
- Doing little & often is better than overdoing too much at a time
- Toilet seats, low chairs and bed can be raised
- It is better to take showers than baths
- Use of a walking aid can make a big difference in walking
- Loose weight if you are overweight
- Physical and Mechanical Interventions
- Heat application before exercise and cold applications after exercise will reduce inflammation
- Walking aids will reduce the loading on the knee while walking
- Knee braces and wedged shoes have been shown to be helpful in some cases
Physiotherapy aims to restore function to the maximum degree possible through exercises increasing the range of movement in the joint and improving muscle strength.
- Pharmacological Management
Simple pain-killers like paracetamol may be helpful in relieving pain initially, but if you have to take pain killer daily for a long period, it is best to consult your doctor to avoid the side effects of the pain-killer.
Topical analgesic creams may occasionally help relieving the pain temporarily.
Intra-articular injections of steroid and Sodium Hyaluronate may improve symptoms in mild and moderate degrees of arthritis.
Pharmacological approaches provide symptomatic relief from pain but can not cure or arrest the progression of the disease.
- Do not stand for more than 10 minutes; instead use a high stool or take frequent rests.
- Limit stair climbing; take the elevator, escalator, or ramp.
- Avoid bending and squatting; keep items at waist level
- Avoid low beds, chairs, and toilets; elevate them when possible
What you can do?
- Exercise - the right kind of exercise can slow down the disease, very important in keeping the cartilage from breaking down and causing more stiffness and pain
- It is better to exercise for a short time frequently than for a long time only once in a while
- Protect your joints from injury and stress
- Use heat on joints before exercise for 15-20 minutes
- Use ice on joints after exercise for 15-20 minutes
What are the indications of surgery?
- Progressive limitation in activities
- Failed medical therapy
- Gross deformities and laxities of joints
- Gross symptoms
What are the surgical options?
In cases of mild to moderate osteoarthritis when there is normal alignment, arthroscopic washout and debridement may be helpful in relieving the symptoms. It helps therapeutically if there is a degenerative meniscal tear which can be trimmed and any loose bodies may be removed or the washout may be palliative in relieving pain by diluting the inflammatory material. Arthroscopy usually relieves symptoms temporarily for somewhere between 6 months to 2 years.
Osteotomy is done to correct deformity by removing or adding triangular wedges of bone. It is useful in preventing deterioration of joints in early osteoarthritis due to a pre-existing deformity such as a bowleg. This procedure will reduce pain but will not eliminate it altogether.
- Total Knee Replacement
Treatment of Choice for end stage arthritis whether it is due to osteoarthritis, rheumatoid arthritis or post-injury.
- Gross symptoms