Knee Pain

Oh My Aching Knee!

Ever since we transitioned from walking on fours to our now bipedalism, humans have been affected by knee pain.

First, what is bipedalism? It comes the term biped /ˈbaɪpɛd/, meaning "two feet" (from the Latin bis for "double" and pes for "foot").  Bipedalism is a form of terrestrial locomotion means of its two rear limbs or legs.  Thank you Wikipedia.

Yeah baby!  Technical stuff there!

According to the Mayo Clinic and John Hopkins Medicine, knee pain is one of the most common complaints that affects people.

Ok now that we established that humans walk on 2 legs and we have a pair of knees and they ache sometimes, now what?

Since there are roughly 8 billion people on earth, I think it is safe to say we have about 8 billion reasons why it would be good to know how it works.

Below is a typical anatomy of the knee:

image courtesy of https://www.urmc.rochester.edu

• It is made up of the lower end of the thighbone (femur), the upper end of the shinbone(tibia), and the kneecap(patella);
• The ends of the bones are covered with cartilage, which serves as protection from friction as we move;
• You can find a wedge shaped structure in between the thigh bone and the shin bone, termed as the meniscus, which cushions impact and absorbs all the jarring motions we give to our knees (shock absorber); 
• The knee is encapsulated by a synovial membrane that produces fluid. This fluid in our knees (synovial fluid) is the WD40 to hinges--it greases them up good and keeps them moving smoothly;
• The surrounding membrane are a set of ligaments and muscles to keep the knee stable while on the go. 

Now that we know how it looks like, and a bit of how it works, what causes the pain?

Common causes 

1. Injuries - it can range from a simple soft tissue inflammation due to sprains, to a torn ligament, to fracture of the bones 
2. Biomechanical - muscle imbalances (one muscle is weaker or stronger than the other), tightness (yes, a bit of flexibility always helps), and alignment problems 
3. Arthritis - there are several forms of this, with osteoarthritis being the most popular, infamous for its "wear and tear" title
4. Infection - commonly caused by bacteria, and to some extend, by tuberculosis (when tuberculosis escapes the lungs and spread to other parts of the body, it can also affect joints--this is now called TB of the joints or TB arthritis
5. Masses - don't panic! masses or tumors do not always equate to cancer. However, this is a broad term which encompasses both benign and malignant kinds. Either way, they can still cause pain because it can impinge on neighboring structures or increase pressure on the affected area

Risk factors 

1. Excess weight - need I say more.  The heavier you are the more load you place on your joints;
2. Previous injury - If you had a knee injury chances are that knee injury will have some degree of discomfort or even pain;
3. Certain sports - Any sports that applies torque, has impact, pressure or twisting movement (yes as Pinoys love basketball, knee injuries loves pinoy ballers)
4. Aging - unlike wine, knees do not get better with age

Not all knee pain is serious.  However some injuries and medical conditions can lead to increasing pain, joint damage and even disability.  It's best that you visit your friendly neighbourhood orthopaedist or orthopaedic surgeon just to be sure.

What will your doctor do to find out what's wrong?

Aside from your usual physical examination, your doctor might ask you to undergo a few tests to guide them in their diagnostics.  

• Laboratory work up - to look for possible presence of infection, metabolic problems, and tumor related stuff

• Imaging modalities:

• X-Ray - ye olde reliable usually looks like this.  By far X-Ray is the cheapest option in imaging modalities.

                                                           

• Ultrasound - this is especially wonderful for those bumps and lumps you feel around your knee



image courtesy of : https://www.slideshare.net/sahilchaudhry89?utm_campaign=profiletracking&utm_medium=sssite&utm_source=ssslideview

• MRI or magnetic resonance imaging - as compared to an X-ray, an MRI is able to show the soft tissue structures (ligaments, meniscus, muscles) surrounding the bones. this is the better option if fracture is not the main suspect.

• CT scan or computed tomography scan  - similar to an MRI, but this is the better option if one is considering the bony parts to be affected rather than the soft tissues. why not just plain x-ray if you can visualize the bones with it?  Because this imaging is best for occult (hidden) fractures and estimating sizes of small masses found on bones. The devil is in the details ladies and gents.

• Arthroscopy - nothing beats an ocular inspection.  However, you wouldn't want anyone to open your knee up just to find out what's wrong. Arthroscopy is minimally invasive, as a very small incision is made while a doctor inserts the probe (as huge as the diameter of the body of an ordinary ballpoint pen) to find out what's wrong with your knee. Therefore, this can also be categorized under treatment, as arthroscopy can be both diagnostic and therapeutic. 

Once your physician finds out what's wrong, they can recommend the appropriate treatment.

The treatments can be divided into conservative and invasive (surgery).

Conservative. Depending on your affliction, conservative treatment may start with analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), and physical therapy for basic pain relief. Disease-modifying anti-rheumatic drugs (DMARDs), antibiotics and anti TB drugs can address pain due to rheumatoid arthritis and infections, respectively. 

Surgery. If all else fails (conservative treatment, I mean), maybe its time to consider surgical treatment for the resolution of symptoms. Depending on the cause of your knee pain, surgical intervention may involve:

• Arthroscopy - addresses meniscal and ligamentous tears, and mild cartilage problems
• Total knee replacement (for severe arthritic causes)
• Debridement (to remove infected tissues and pus

There are minimally-invasive treatment aside from surgery that could alleviate major knee pain out there such as corticosteroid injection, Hyaluronic acid supplement injection and platelet rich plasma (PRP) injections.

Your best bet for a pain-free knee is consulting a board certified orthopaedic surgeon.

Best of health!

Sources:

1. https://orthoinfo.aaos.org

2. https://www.arthritis-health.com

3. https://www.mayoclinic.org/

4. https://www.hopkinsmedicine.org

5. https://en.wikipedia.org