Among the largest joints of the body, the knee joint is a type of modified hinge joint which handles the way we walk, run and skip about our daily lives. It is capable of performing movements like flexion, extension and a few rotational movements. The greatest football players and athletes owe their performance to a healthy set of knees which bear about as much as 10 times the effort when some load is exerted on the upper half of the body.
The three important pillars that give the knee its strength are:
- Patella (a. k. a. knee cap)
- Femur (the thigh bone)
- Tibia (main component of lower leg bones)
These three bones articulate with each other in a unique way such that the knee is able to perform a variety of functions. The knee joint is bathed in a synovial fluid, which acts as a shock absorber and protects the knee from any unnecessary trauma or trouble. A unique joint which manages the weight bearing functions of the body while running, walking and jumping.
Apart from bones, the structure of knee is fortified by various components like tendons, ligaments, bursae, cartilage and muscles. A total of 14 muscle groups are involved in making the knee work! The combination of gliding, rotating and some restrictive mechanisms are essential to the normal functioning of the knees.
The knee is among the joints gifted with the property of mobility. Some joints are directly fused with the bone hence have a restricted form of movement. The menisci (joint compartment) and femur possess the ability to glide over each other, which gives the knee its mobility.
Where comes the gift mobility, also comes the trouble of overload and overwork. The knees are invariably an indispensable part of the musculoskeletal system and are subjected to constant stresses. Also, the knees are prone to problems because of less or no activity at all.
If you happen to overload your knees with a lot of activity with little or no variation in them, it is very likely the knee tissues will end up suffering from inflammation and injury. On the other hand, minimal activity with a sedentary lifestyle will result in degeneration of muscle tissues and make the knees weak and more prone to injuries. Apart from activity issues, the knee joint becomes vulnerable with increasing age.
Considering the above factors, the knee joints are prone to:
Posterior Cruciate Ligament (PCL) & Anterior Cruciate Ligament (ACL) Injuries -
These ligaments tend to get hurt or injured the most when subjected to excessive pivoting or sidestepping movements. Repeated injuries and trauma over a long period of time may result in hyperextensibility of the knees.
A fracture is a discontinuity or a break in the bone structure. The most common cause of fractures is trauma from an external force though in some instances, the bone may be already weakened in structure and breaks at the slightest hint of injury. These fractures are known as pathological fractures. Fractures may be as simple as a small crack in the bone to as complicated as the bony itself shattering into small pieces. The thigh bone, the upper end of the shin bone or the knee cap are susceptible to fractures. These troubles can be very painful.
It is an age related disease where the cartilage responsible for executing smooth movement of the knee joint degenerates over time. This results in decreased mobility and more friction for the knee joint to work with. Swelling and pain are commonly seen in people suffering from osteoarthritis, along with chipping of bones and cartilage around the joint.
Also known as runner's knee, this is a condition where there is abnormal contact and overload in the region between the thigh and knee cap. A runner's knee is characterized by pain in the front part of the knee. Muscle weakness or tightness around the knees often puts people at risk for this condition.
A bursa is a small sac like structure in the knee joint which contains the synovial fluid. These bursae are responsible for the smooth movement of muscles and ligament inside the knee joint. Sometimes due to trauma, infection or repetitive stress, these movements may become painful and result in inflammation of the bursae.
A type of arthritis which is autoimmune in nature, meaning the defensive cells of the body attack its own joints. This can be painful and show up as swelling, fatigue, anemia and loss of joint function.
Menisci are C-shaped compartments which help in balancing the weight around the knees. They help in cushioning the knees against repetitive trauma in most situations. However, overloading, excessive twisting and turning movements on the knee can cause meniscal tears, pieces of which can be seen floating around in the joint space. Most of these inuries can be managed conservatively, but a few rare ones may need surgery to get fixed.
A relatively rare form of trauma to the knee, excessive impact may result in total displacement of the knee from its original position. If not treated on time, knee dislocation can result in obliteration of blood supply to the joint and leg which can lead to serious complications.
Also known as patellar tendonitis, jumper's knee is characterized by pain below the knee cap. This condition is typically seen in athletes.
The quadriceps and patellar tendons can rupture either completely or partially. Again this condition is seen in athletes who jog a lot. Pain and swelling along with restriction of motion is seen.
Risk factors of knee pain:
- Poor nutrition
To diagnose these knee problems, the most commonly employed diagnostic tests include:
Your doctor will perform a series of movements using your knees to evaluate its range of motion. Simple activities which check the degree of flexion, extension and rotation of the knees are performed.
In this imaging technique, X-rays are used to create a two dimensional picture of the knee joint. X-rays are a useful method in visualizing the joint space, its alignment, signs of arthritis and bony spurs.
In times when the information provided by a knee X-ray is inadequate, knee arthrography is a useful alternative. Here, a special dye known as contrast medium is injected into the knee joint directly. After this a series of X-rays are taken to study various problems like damage due to repeated dislocations, arthritis, ligament tears and joint capsules.
A very efficient and non-invasive method of picturing the knee joint, an MRI scan uses non-ionizing radiations and magnetic field to create an image. The absence of non-ionizing radiation makes an MRI scan one of the safest methods of imaging the joint compartment. With the help of an MRI, soft tissues like muscles, tendons, blood vessels, menisci and other hard tissues can be seen with great clarity and resolution on an MRI scan.
This imaging technique works on the principle of echos created by sound waves at high frequency. A transducer like device is placed over the knee joint through which sound waves travel inside the knee joint. The difference in reflection of sound waves from various tissues are responsible for creating an image on the computer screen. A knee ultrasound is very useful in diagnosing osteoarthritis, defects of the bones and cartilage, etc. It also helps in guiding while performing fluid aspiration.
Therapy for Troubled Knees
Any therapy involves two important aspects:
This method of treatment is employed almost every time as a primary management of knee problems like . No cuts, no surgeries. A simple acronym which sums this treatment approach is RICE
R – Rest
Rest, or immobilization is an effective means of aggravating the existing knee problem any further. Complete rest should be given to the knee joint by taking a break from any strenuous activity.
I – Ice
Many say heat reduces swelling and pain. But in some instances, ice, or specifically cold helps in decreasing the signs of inflammation. Cold/ice packs applied on the affected area for 10-20 minutes twice or thrice daily controls the inflammation to a good extent.
C – Compression
The knee can be wrapped in a bandage made of crepe or any elastic material. Even knee braces are useful. It is important that the bandage should not be too tight, or the swelling will increase again. Within normal limits, compression helps to minimize swellings and provide support to the knee joint.
E – Elevation
You can place your hurt knee over something which gives more height, like a soft pillow. This helps in reducing the swelling.
- Apart from RICE, special emphasis is given on physiotherapy to help restore the normal function of the knee joint. Simple exercises are performed under the guidance of a physiotherapist.
- When the pain is a bit too intense, medications are employed by your orthopedic specialist. These can be taken either orally or be injected directly at the place of irritation. Painkillers like ibuprofen and diclofenac are the most commonly used ones. Corticosteroid injections are useful in decreasing the extent of inflammation, though they are not so efficient in the long run. Hyaluronic acid injections are beneficial in increasing joint mobility since they mimic the action of synovial fluid in joints.
- Many arthritis patients have benefited from the action of Platelet Rich Plasma injections. This plasma contains an infusion of different types of blood cells which help to control inflammation and help in healing of hurting knees.
When conventional or conservative modes of therapy are not that effective in curing knee problems, surgery is the answer. Today with advancements in medical technologies, many knee surgeries have become minimally invasive in nature which means smaller cuts and faster recoveries.
Knee surgeries are indicated in the following instances:
- Severe trouble while walking, climbing stairs and doing other activities.
- When knee pain cannot be managed by medications or physiotherapy
- To treat severe trauma to the legs
- To correct shape deformities in the knees
- The patient has been troubled with arthritis for a very long time
- To reconstruct torn ligaments
- To counter hypermobility of joints
- Recurrent knee joint dislocations
A few commonly performed surgical procedures on the knee joint are:
ACL Reconstruction Surgery:
The Anterior Cruciate Ligament is responsible for controlling excessive knee mobility and provides it with rotational stability. In instances where ACL is injured beyond repair, an ACL reconstruction surgery is performed. The injured ACL is replaced with a graft either from the patient's own body or an external source. This new graft after healing will perform the same functions as ACL, but after a rigorous period of physiotherapy.
Partial Knee Replacement Surgery:
Unlike total knee replacement, here the orthopedic surgeon will remove only the damaged parts of the knee joint like the knee cap, thigh bone or the tibia and replace them with portions made up of metal or plastic. This surgery is also known as unicompartmental knee replacement, since only a single compartment of the knee joint is involved. Osteoarthritis patients have benefited a lot from this therapy.
Total Knee Replacement Surgery:
The patients who have suffered from extensive knee damage are treated using a total knee replacement surgery. Here, all damaged parts of the knee are removed, meaning all the compartments of the affected knee are removed followed by a replacement made of metal or synthetic materials.
A minimally invasive method of executing a surgical procedure, no big cuts or complete incisions are used here. Tiny incisions are made on the skin overlying the knees. After this, tiny instruments are inserted with a camera inside the joint compartment which can be visualized on a computer screen. With this live feed, the orthopedic surgeon can easily repair damaged tissues and remove unwanted debris. The knee joint can be resurfaced and tissue tags can be taken out. This technique offers a very good post operative recovery.
As people obsessed with work or other activities, we often tend to ignore our health. Knee pain, if boiled down to its basic nature is nothing but inflammation. If the factors triggering and the root cause of inflammation are treated, knee pain can reduce drastically. Timely intervention, healthy lifestyles and regular physiotherapy can keep our knees healthy and fit.