Knee Pain
Knee Joint
The Knee Joint is one of the most important joints in the body. It’s a large joint made up of 3 bones – the femur, tibia and patella. It is a hinge joint – i.e. it moves in only one plane (unlike the hip and shoulder joints)
The knee joint bears the whole weight of the body therefore it is the joint most commonly affected by pain.
The Knee joint can be compared to a Car with the different parts of the joint resembling the functions of the parts of a car.
1. Synovial Fluid – The Lubricant of the Joint. This helps to keep the joint moving smoothly. When this starts to dry up with age pain and difficulty in moving the joint starts.
2. Cartilage – the Tyres of the Joint – The cartilage is the smooth tissue that covers the lower end of the femur and the upper end of the tibia (the bones that form the knee joint). It is thanks to the cartilage that the bone ends don’t rub against each other while we walk. With wear and tear of the joint, due to ageing, the cartilage starts to wear off and the underlying bone gets exposed and start to rub against each other causing pain – this is called osteoarthritis. This resembles the tyres of a car, wherein the wearing out of the tyres cannot be reversed but require changing of the tyres i.e. Knee Replacement surgery.
Surgical treatment is required when the fractured bone fragments are displaced away from each other and from their original position and when the fracture is next to a joint (like near the wrist or knee). Surgeries for fractures usually involve bringing the bone fragments back to normal position and holding them in place with screws or plates. These procedures give better chance of healing in proper position and faster than without surgery.
3. Meniscus – the Shock Absorbers of the Joint – The meniscus is a tough tissue in the knee joint in between the two bones. There are 2 menisci – one on each side of the joint – and both are the shape of crescent moons. These menisci absorb the force that gets transmitted to the knee joint while we walk. The meniscus can get injured during twisting injuries usually sustained during certain sports like football and badminton.
4. Ligaments – the Stabilizers of the Joint – The Anterior Cruciate Ligament (ACL) and the Posterior Cruciate Ligament (PCL) are 2 strong rope like tissues that hold both the bones of the knee joint (femur and tibia) together and prevent abnormal movements between them. They stabilise the joint in this manner. Twisting injuries of the joint can cause injuries to the ACL or PCL and lead to instability or giving way sensation in the joint.
Knee Pain & It’s Causes
Knee pain is a very common issue. It can happen in the older age group as well as in younger people. The causes of this pain is different in the different age groups.
The following are the different causes of Knee Pain –
1. Osteoarthritis –
(also referred to as OA knee) This is basically the wearing out of the cartilage layer of the joint leading to the uncovered bone surfaces rubbing against each other and causing pain.
This is similar to the wearing out of a car tyre.
It occurs in the older age group – usually above 50 years of age.
Diagnosis – This condition is diagnosed with simple x-rays. On an x-ray we normally see some gap in between the two bones which is where the cartilage lies (not visible on an x-ray). After the cartilage wears out the gap between the two bones disappears and both bone ends appear to rub against each other.
Treatment – OA knee progresses through 4 stages and the treatment is different for different stages.
In early stages (1, 2 and 3) surgery isn’t required.
a. Medicines include painkillers, ointments and supplements called chondroitin sulphate and glucosamine to strengthen the remaining cartilage.
b. Physiotherapy means exercises. This is the most important part of treatment of early OA knee. The whole aim is to strengthen the quadriceps muscles (the thigh muscles) so that the body weight which normally falls on the knee joint is taken by the muscle thereby offloading the joint.
The exercises for the knee joint are shown in the video attached.
Other good exercises for the knee joint are cycling and swimming.
c. Lifestyle Modifications – simple modifications in daily activities can reduce the pressure on the knee joint and pain. These include – avoidance of kneeling, squatting and sitting cross legged and minimising climbing up and down stairs.
It is always better to sit on a chair when doing activities and use Western commodes for toilet.
Treatment for Stage 4 OA of the Knee is surgical. There are 2 types of surgeries for the stage 4 OA – Total Knee Replacement (TKR) and Partial Knee Replacement (PKR or UKA).
These are explained in more detail in the attached videos and the next section.
2. Chondromalacia Patellae –
This is the most common cause of knee pain in young adults.
It is commonly seen in people in desk jobs like IT professionals as they sit for hours together without movement in the joint.
It is usually felt in the front of the knee and most commonly whole getting up after sitting for a long time.
The pain is caused by gradual softening of the cartilage leading to rubbing of the knee cap bone (patella) against the femur bone.
Another cause of discomfort is the jamming of the synovial fluid in the joint due to not moving it regularly.
Diagnosis –
X-rays help to diagnose the condition.
Treatment –
This condition never requires a surgery. Simple medications, lifestyle modifications and exercises (similar to the ones mentioned in OA knee) are usually enough.
A simple change to make while sitting at a desk is to make sure you get up every one hour and walk around for 5 minutes before sitting down to resume work.
3. Sports Injuries –
This kind of pain is again more common in younger adults.
It is a pain which occurs after a twisting injury to the joint either during sports like basketball or while dancing.
The pain is usually accompanied with swelling of the joint.
It is also associated with painful locking of the knee (if the meniscus is injured) or giving way sensation or instability (if the ACL is injured).
Diagnosis –
Sports injuries require MRIs to be diagnosed, not a simple x-ray.
Treatment –
Initially conservative treatment is tried in the form of medicines rest and gradual exercises while using a knee brace.
If the injury is severe and not improving with conservative treatment a surgery known as arthroscopy is required (also known as a keyhole surgery).
In this procedure a small incision is made in which a camera is passed to reconstruct the ACL or shave the torn meniscus.
4. Rheumatoid Arthritis –
This an autoimmune condition i.e. the immune system of the body attacks its own cells – leading to damage of the various joints of the body leading to pain and swelling.
This pain and swelling usually starts in the smaller joints of the body like those of the fingers and toes and then can progress to larger joints like the knees and hips.
It usually manifests in the mid 20s to mid 30s age.
Diagnosis –
X-rays can tell us if the joints are destroyed (similar to OA knee)
A blood test called RA Factor gives us a confirmation of whether the person is actually suffering from Rheumatoid Arthritis.
Treatment –
Treatment of RA should be done by a Rheumatologist who prescribes anti-rheumatoid medication. In severe stages where the knee or hip joints are completely destroyed an orthopaedic surgeon may have to perform a Knee or Hip replacement surgery.