Knee Pain

Besides spinal conditions, knee pain is one of the most common ailments of the musculoskeletal system (10). Problems with the knee can be classified into three categories (1):

1)    poor mechanics or overuse of the knee joint,
2)    traumatic injury from events such as sports and falls, and
3)    problems due to arthritic changes in the joint.



1. Patellofemoral Syndrome ( Knee Cap Pain )

Poor mechanics of the knee joint and the associated stress upon the soft tissues of the knee is by far the most common cause of non-traumatic pain. The most common part of the knee affected by this is the patella or knee-cap. Often the patella does not move smoothly or does not move sufficiently on the femur during bending of the knee causing abnormal stresses upon the tendons cartilage and ligaments. Symptoms consist of vague pain in, around or under the knee cap. This is called Patellofemoral Syndrome (PFS) (1,2,3,10).

The problem usually originates when there are imbalances in the quadriceps muscles of the thigh which attach to and move the patella (3).  The inner and outer thigh muscles become out of sync with each other and the patella moves out of it’s normal groove in the femur (thigh bone) causing irritation and pain. Pain is often experienced during activity such as stair climbing, running, jumping or getting up after prolonged sitting (3).

PFS can result from a number of factors such as pelvic/hip imbalance and over pronation of the feet (3).  There are a number of effective treatments and the role of your health practitioner is to help you via hands-on treatment and appropriate self management such as appropriate excercises. Treatment may include adjustments to the pelvis and lower back, prescribing orthotics to realign the feet, strengthening and proprioceptive exercises, acupuncture and soft tissue release to the muscles around the knee and thigh.  The knee can also be taped to draw the patella inward, and advice on modifying activity and using ice after exercise may be useful (4,5)).

In most cases, PFS responds well to conservative care and exercise (4,5).

Repetitive Knee Strain - Overuse Injury

Imbalances in other muscle groups that attach to the knee can also lead to pain and dysfunction. As an example, the muscles on the inside of the thigh when strained and tight can cause pain on the medial or inside of the knee.

Lower back problems especially in the sacroiliac joints, are one of the main reasons for imbalances in the muscles associated with knee movement and subsequent knee problems (3). Foot problems that cause gait abnormalities such as pronation, are another cause of mechanical knee pain (2).

Treatment for mechanical or overuse injuries to the knee may involve helping to improve balance of the muscles, movement to the patella and other joints of the knee, and look to see if there are any other musculoskeletal issues that may affect the knee (3,10).

2. Trauma

Traumatic injuries often occur during sports that involve running and jumping, such as football and basketball, and with activities such as skiing, soccer and hockey that require change of direction driven through knee movement (10). When the knee is stretched or twisted beyond the strength of the ligaments that hold the joint together, tearing of these tissues can occur causing a sprain. The muscles that move the knee can also be torn during injury causing a strain or pull of the muscle. As with a sprain, a muscle strain can vary from a minor injury that requires little care to a severe injury requiring surgery(10).

The knee also contains two special "cartilages" - the menisci - between the tibia and the femur that provide for smooth movement and cushioning. These cartilages can also be torn during trauma and often require surgical repair or removal if damaged severely. Traumatic knee injuries can cause severe pain and swelling and may require immediate evaluation and attention.  In any case, it is important to stabilise the injured joint and ice if possible until you can get the injury evaluated. For further information see sporting injuries.

3. Arthritic Changes

If poor mechanics or traumatic injuries are not corrected at an early age, the tissues of the knee joint especially the cartilage will eventually begin to wear out. As a result the bones rub upon one another and changes such as bone spurs can occur. This painful condition is often progressive with age (1). Treatment may involve medications such as NSAIDS (non-steroidal anti-inflammatory drugs). There is some evidence that nutritional substances such as Glucosamine, Chondroitin and Fish oils can be helpful in the long term management (8,9). People can often help themselves by keeping their weight down, doing exercises especially in the pool, and wearing cushioned shoes or insoles (6).

References:

1. CushJJ, Kavanaugh A, Stein CM (2015). RheumaKnowlegy. ICD9 code:270.0. www.rheumaknowledgy.com
2. Magee DJ (2008). Orthopedic Physical Assesment Ed 5. pg 972-1012. Saunders Elsevier. ISBN-13:978-0-7216-0571-5 (2) Page P, Frank C, Lardner R, (2010) Assessment and treatment of Muscle Imbalance. The Janda Approach. Human Kinetics. ISBN10:0-7360-7400-7
3. Page P, Frank C, Lardner R, (2010) Assessment and treatment of Muscle Imbalance. The Janda Approach. Human Kinetics. ISBN10:0-7360-7400-7
4. Lack S, et alProximal muscle rehabilitation is effective for patellofemoral pain: a systematic review with meta-analysis. Br J Sports Med 2015;49:1365-1376
5. Barton CJ, et al The ‘Best Practice Guide to Conservative Management of Patellofemoral Pain’: incorporating level 1 evidence with expert clinical reasoning Br J Sports Med  2015;49:923-934 
6. Buttgereit F, Burmester GR, et al. Non-surgical management of knee osteoarthritis:where are we now and where do we need to go? RMD Open 2015
7. Dwyer, L, Parkin-Smith GF, Brantingham JW et al , Manual and manipulative therapy in addition to rehabilitation for osteoarthritis of the knee: assessor-blind randomized pilot trial. J Manipulative Physiol Ther. 2015 Jan;38(1):1-21.e2. doi: 10.1016/j.jmpt.2014.10.002. Epub 2014 Nov 20.
8. Singh J, Noorbaloochi S, MacDonald R et al (2015). Chondroitin for osteoarthritis. Cochrane Database of Systemic Reviews. 10.1002/14651858.CD005614.pub2
9. Towheed T, Maxwell L, Anastassiades Tp et al, Glucosamine therapy for treating osteoarthritis 2005.
Cochrane Database of Systemic Reviews. DOI: 10.1002/14651858.CD002946.pub2
10. Brukner P, Karim K (2012). Clinical Sports Medicine 4th Ed. McGrath-Hill Education. ISBN:9780070998131.