Osteoarthritis risk factors

1. and

present

Osteoarthritis risk factorsOsteoarthritis risk factors

2. "Osteoarthritis, why me?"
You have told your patient that he/she has osteoarthritis.
He/she is asking both you and him/herself "Why me?".
The main risk factor is age:
Osteoarthritis affects only 3% of people
aged less than 45
But it affects 65% of people aged over 65.
This doesn't mean that all these are actually
in pain, because osteoarthritis can be clinically
silent
80% of people in the over 80 age group
have osteoarthritis
Although age is the primary risk factor,
there are many others of varying importance
2
Société Française de rhumatologie website:
http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp
Inserm (National medical research institute) website
http://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthrose

3. The hips and knees are not the most
commonly affected joints
The spine and fingers are the most commonly
affected joints
It is most severe and debilitating when it
affects the knees and hips, both of which
are weight-bearing joints
While more uncommon, shoulder
osteoarthritis is also very debilitating
The ankles and elbows can be affected but
this is less common and tends to occur after joint
and/or bone injury
3
Société Française de rhumatologie website:
http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp

4. 4
Flexor tenosynovitis in zone IV. MRI of both hands via the MCP, gadolinium-enhanced
TI-weighted sequences and fat signal saturation in axial slices (prayer position).
Synovitis: synovial membrane enhancement.
Internal and external femorotibial
osteoarthritis. Knee CT-arthrography.
Hip-femoral osteoarthritis. Right hip arthrography,
frontal image.
Cervical spine. T2 MRI.

5. Risk factors for osteoarthritis
Main risk factors
Age
Excess weight and obesity
Mechanical constraints (intense
sport, some professions)
Heredity
Female gender, menopause
Osteonecrosis
Leg bone malalignement
Estrogen deficiency
Metabolic syndrome
Advanced hip osteoarthritis caused
by spondylarthritis or rheumatoid
arthritis
5
Société Française de rhumatologie website:
http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A1_pourquoi.asp
National health insurance website:
http://www.ameli-sante.fr/arthrose-de-la-hanche/facteurs-de-risques-arthrose-de-la-hanche.html
http://www.ameli-sante.fr/arthrose-du-genou/facteurs-de-risque-arthrose-du-genou.html
INSERM (National medical research institute) website
http://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthrose
Other risk factors
Injury: cruciate ligament rupture,
meniscectomy (surgical removal of
meniscus)
Metabolic diseases (chondro-
calcinosis, genetic hemochromatosis)
Infectious diseases involving the bone
Rheumatoid arthritis sequellae

6. Weight and osteoarthritis: a complicated
relationship
In overweight patients and especially in the obese, the joints
are exposed to mechanical constraints which tend to
promote the development of osteoarthritis, particularly in the
knees
However:
Obesity has a "dose-related" effect: the risk of knee osteoarthritis
increases by 15% for every point increase in the BMI. The risk of
knee osteoarthritis therefore increases with weight
It is important to note that finger joint osteoarthritis is more
common in obese patients!
6
Body Mass Index calculation (BMI)
Overweight if BMI = 25-29.9 kg/m
2
Obesity > 30 kg/m
2
Morbid obesity > 40 kg/m
2
Société Française de rhumatologie website:
http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A1_pourquoi.asp
Sellam J, Berenbaum F. Arthrose et obésité. Rev Prat 2012;;62::621-624.

7. When mechanical constraint promotes
osteoarthritis
Mechanical constraint is a risk factor for osteoarthritis,
particularly in the knee
The knee is a complex joint and weight must be evenly
distributed and not excessive. The risk factors for knee
osteoarthritis are therefore:
7
Being overweight or, especially, obese
leg bone malalignement (genu varum [bow legs] and genu valgum
[knock-knees])
Knee instability caused by ligament rupture (cruciate ligaments)
Surgical removal of a meniscus (meniscectomy)
Repeatedly carrying excessive loads
INSERM (National medical research institute) website
http://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthrose
Other risk factors for osteoarthritis include an untreated
sprain or a joint fracture

8. Knee osteoarthritis, injury and surgery
There are two forms of injury which play a particularly
important role in the onset of knee osteoarthritis :
Sprain with ligament tear, creating knee instability,
Meniscus damage
8
Société Française de rhumatologie website:
http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp
Cruciate ligament surgery will not totally prevent the risk
of osteoarthritis after these types of injury:
Experience shows that while surgery reduces this risk,
it nonetheless remains high
Conversely, meniscus removal is a major risk factor
for osteoarthritis:
Studies have reported that 5 to 10 years after meniscectomy, the
incidence of osteoarthritis was much higher in the operated knee
(21% versus 5% on the non-operated side). Furthermore,
meniscectomy is an excellent model of induced osteoarthritis in
animals
Patellofemoral knee osteoarthritis.

9. Physical exercise and osteoarthritis
When not practiced to excess, physical exercise
is not a risk factor for osteoarthritis
The risk factors are considered to be:
Top-level sports with the risk of injury: football
and rugby for the knees
Repetitive excessive load-bearing
Repeated microtrauma (workers regularly using
a jack hammer: elbow osteoarthritis)
Some professions placing excessive pressure on
the knees (tiler, carpet-fitter, mason, painter and
decorator, gardener, etc.)
9
Société Française de rhumatologie website:
http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp

10. Heredity and osteoarthritis
People with a parent or sibling who has osteoarthritis
are at higher risk of developing the disorder
The proof:
there are families in which the proportion of adults
aged over 50 with osteoarthritis is much higher than
in the general population
concordance of osteoarthritis is more common
in identical than non-identical twins
however, these genetic factors have been demonstrated
mainly for hip or hand osteoarthritis.
10
Société Française de rhumatologie website:
http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp
INSERM (National medical research institute) website
http://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthrose

11. 11
MRI of both hands and wrists: SE T1 sagittal images.
Hip osteoarthritis surrounding the hip.

12. Other risk factors
Gender and hormonal status: post-menopausal women
are at higher risk of hip, knee or hand osteoarthritis than
men of a similar age
Differences in long bone length increase the risk of hip
osteoarthritis but it may also affects subjects aged less
than 50
12
http://www.ameli-sante.fr/arthrose-de-la-hanche/facteurs-de-risques-arthrose-de-la-hanche.html
http://www.ameli-sante.fr/arthrose-du-genou/facteurs-de-risque-arthrose-du-genou.html

13. Conclusion
Osteoarthritis is a strongly age-associated condition
The most commonly affected joints are the spine
(back bone) and hands
Osteoarthritis is most debilitating when it affects the
hip or knee
Overweight patients are at higher the risk of
developing osteoarthritis, particularly in the knees
Normal physical exercise is not a risk factor (if no
injuries are sustained)
Post-menopausal women are at higher risk of hip or
knee osteoarthritis than men of a similar age
An unstable knee and leg malalignement are risk
factors for the development of knee osteoarthritis
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14. 14
Lumbar canal stenosis,
posterior lumbar facet joint
osteoarthritis, sagittal image
of lumbar spine.
Hand and wrist MRI: coronal
image, SE T1 sequence with
suppression of fat signal and
injection of gadolinium.
Primary osteoarthritis,
CT-arthrography.
Advanced internal
femorotibial knee
osteoarthritis. MRI T2 images.