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/m2
 Obesity > 30 kg/m2
 Morbid obesity > 40 kg/m2
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
13

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.