Tag Archives: Knee

Causes of Knee Osteoarthritis.


Knee (Photo credit: mariandy_gizfel)

I have talked about the extraordinary and disturbing number of knee joints that are being replaced by artificial joints. There are 600,000 knee replacements every year in the US at a yearly cost of $9 Billion. They have doubled over the last decade. (OECD iLibrary 2011). They are expected to double again in the UK over the next 2 decades! (Lancet 380:1768 2012).

Age is a factor. 70% of those 65+ show radiological evidence of osteoarthritis in at least one knee or hip joint. (J. Orthop. Res. 7:15 2012)

But one of the major causative factors is obesity. 69% of knee operations may be attributed to obesity in Croatia (Ljec. Vjesn. 131:22 2009). If all overweight and obese people were to reduce weight by only 5Kg., or until their  BMI was within the normal range, 24% of OA knee surgical cases could be avoided.! (Int. J. Obes. Relat. Metab. Disord. 25(5):622 2001). Some surgeons do not operate until the patient has reduced his BMI. A BMI of 40 is considered inoperable!

Another major cause of osteoarthritis of the knee, which is rarely discussed, is inactivity. The synovial fluid of the joints is viscous and cannot function unless the joint is put under pressure. 40% of men with knee osteoarthritis are couch potatoes (Northwestern Univ. News Aug. 2011). Lower extremity muscle weakness is a risk factor for knee osteoarthritis (Arthrit. & Rheum. 41(11):1951 1998). Low muscle strength is strongly associated with knee pain, (Ann. Rheum. Dis. 57:588 1998) and muscle weakness may be an im portant factor in the pathogenesis of osteoarthritis. (Rheum. Dis. Clin. N. Am. 25(2):283 1999).  Such patients require not only rehabilitation after the operation  but “prehabilitation”, to increase necessary muscle strength,  before the operation!

Age-standardised disability-adjusted life year...

Age-standardised disability-adjusted life year (DALY) rates from Osteoarthritis by country (per 100,000 inhabitants). (Photo credit: Wikipedia)

Man is the most destructive animal that has ever existed on the planet and efforts are being made to protect animal and plant species. However there seems little effort to protect the human species from the man made destruction of human health.

We are already at a point where we have to be treated to give us sufficient minimal health in order that we can be treated.

Jumper’s and Runner’s Knee

English: Medial view of the knee showing anato...

English: Medial view of the knee showing anatomical features. (Photo credit: Wikipedia)

In my one of my previous blogs the content referred to the dramatic increase knee replacements, mainly due to osteoarthritis, which creates a huge burden on health systems.

The causes are multifactorial, which include previous injury, obesity and possibly genetic influences. (Dr. Sofat, RFS Newsletter 46:4 2013).

Age is also a factor with the majority of people over 60 showing evidence of osteoarthritis in at least one joint. At over 65 (a shocking) 70% of hips or knees show radiological evidence of osteoarthritis! (J. Orthop. Res. 7:15 2012)

But the increased number of knee replacements cannot be explained by population growth and obesity epidemic alone. The recent increase is likely to be related to the growing prevalence of sport-related knee injuries. (J. Bone Joint Surg. Am. 94(3):201 2012)

Injury:   An injury in younger years can lead to osteoarthritis in later years. Kneeling for long periods can cause injury. Housemaid’s Knee (Bursitis), (swelling in front of the kneecap) or Clergyman’s Knee, (swelling below the kneecap), seem to be relatively harmless (Mailonline May 2013).

Jumper’s Knee:  Jumping causes sudden pressure to the knee joint of 9-11 times body weight.  20% of jumping athletes have Jumper’s Knee (Performance, June 2009). In volleyball the prevalence of jumper’s knee is high, up to 40-50%!  Symptoms increase slowly and are often unreported especially as athletes with tendon pain perform substantially better in jump tests compared to asymptomatic controls!  “Jumper’s Knee Paradox”. (B.J.S.M. 47(8):503 2012)

Runner’s Knee: Whereas in jumper’s knee, high stresses on the knee are the main causative factor, runner’s knee is caused by repeated micro-trauma. (Angelfire March 2002).    25-65% of runners suffer from runner’s knee. There is a significant increase with increasing duration per week, but training pace has no impact on the incidence of chronic knee lesions. (Eur. J. Radiol. 58:286 2006).  In Singapore up to 50% of runners have runner’s knee (HealthXchange).  However, long distance running per se does not increase the risk of osteoarthritis. (J. Am. Osteopath. Ass. 106(6):342 2006).

English: Jogging at Cranny Good for your healt...

English: Jogging at Cranny Good for your health, but sore on the joints. (Photo credit: Wikipedia)

Jogging is excellent and popular exercise, but decades of jogging especially after 50 can cause problems. Not only overuse, but muscular imbalance can be a source of injury. (Walk Jog Run May 2012).  Cross training has been seen to be beneficial as prevention of injury.   Barefoot running reduces joint movement and work done at the knee and may provide potential benefits for the management of knee pain and injury. (Br. J. Sports Med. 47:387 2013)

It is unfortunate that sport related knee injuries are too often ignored, thus compounding the damage.  While the percentage of jumpers and runners that develop jumper’s knee or runner’s knee are disturbing and sport related knee injuries are on the increase, early injuries, although important, are nevertheless not the major cause of knee osteoarthritis in later life.