"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 peopleaged less than 45 But it affects 65% of people aged over 65.This doesnt mean that all these are actuallyin pain, because osteoarthritis can be clinicallysilent 80% of people in the over 80 age grouphave osteoarthritis Although age is the primary risk factor,there are many others of varying importance2Société Française de rhumatologie website:http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.aspInserm (National medical research institute) websitehttp://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthrose
The hips and knees are not the mostcommonly affected jointsThe spine and fingers are the most commonlyaffected jointsIt is most severe and debilitating when itaffects the knees and hips, both of whichare weight-bearing jointsWhile more uncommon, shoulderosteoarthritis is also very debilitatingThe ankles and elbows can be affected butthis is less common and tends to occur after jointand/or bone injury3Société Française de rhumatologie website:http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp
4Flexor tenosynovitis in zone IV. MRI of both hands via the MCP, gadolinium-enhancedTI-weighted sequences and fat signal saturation in axial slices (prayer position).Synovitis: synovial membrane enhancement.Internal and external femorotibialosteoarthritis. Knee CT-arthrography.Hip-femoral osteoarthritis. Right hip arthrography,frontal image.Cervical spine. T2 MRI.
Risk factors for osteoarthritisMain risk factors Age Excess weight and obesity Mechanical constraints (intensesport, some professions) Heredity Female gender, menopause Osteonecrosis Leg bone malalignement Estrogen deficiency Metabolic syndrome Advanced hip osteoarthritis causedby spondylarthritis or rheumatoidarthritis5Société Française de rhumatologie website:http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A1_pourquoi.aspNational health insurance website:http://www.ameli-sante.fr/arthrose-de-la-hanche/facteurs-de-risques-arthrose-de-la-hanche.htmlhttp://www.ameli-sante.fr/arthrose-du-genou/facteurs-de-risque-arthrose-du-genou.htmlINSERM (National medical research institute) websitehttp://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthroseOther risk factors Injury: cruciate ligament rupture,meniscectomy (surgical removal ofmeniscus) Metabolic diseases (chondro-calcinosis, genetic hemochromatosis) Infectious diseases involving the bone Rheumatoid arthritis sequellae
Weight and osteoarthritis: a complicatedrelationshipIn overweight patients and especially in the obese, the jointsare exposed to mechanical constraints which tend topromote the development of osteoarthritis, particularly in thekneesHowever: Obesity has a "dose-related" effect: the risk of knee osteoarthritisincreases by 15% for every point increase in the BMI. The risk ofknee osteoarthritis therefore increases with weight It is important to note that finger joint osteoarthritis is morecommon 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/m2Société Française de rhumatologie website:http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A1_pourquoi.aspSellam J, Berenbaum F. Arthrose et obésité. Rev Prat 2012;;62::621-624.
When mechanical constraint promotesosteoarthritisMechanical constraint is a risk factor for osteoarthritis,particularly in the kneeThe knee is a complex joint and weight must be evenlydistributed and not excessive. The risk factors for kneeosteoarthritis 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 loadsINSERM (National medical research institute) websitehttp://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthroseOther risk factors for osteoarthritis include an untreatedsprain or a joint fracture
Knee osteoarthritis, injury and surgery There are two forms of injury which play a particularlyimportant role in the onset of knee osteoarthritis : Sprain with ligament tear, creating knee instability, Meniscus damage8 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 riskof 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 factorfor osteoarthritis: Studies have reported that 5 to 10 years after meniscectomy, theincidence 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 inanimalsPatellofemoral knee osteoarthritis.
Physical exercise and osteoarthritis When not practiced to excess, physical exerciseis not a risk factor for osteoarthritis The risk factors are considered to be: Top-level sports with the risk of injury: footballand rugby for the knees Repetitive excessive load-bearing Repeated microtrauma (workers regularly usinga jack hammer: elbow osteoarthritis) Some professions placing excessive pressure onthe knees (tiler, carpet-fitter, mason, painter anddecorator, gardener, etc.)9Société Française de rhumatologie website:http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp
Heredity and osteoarthritis People with a parent or sibling who has osteoarthritisare at higher risk of developing the disorder The proof: there are families in which the proportion of adultsaged over 50 with osteoarthritis is much higher thanin the general population concordance of osteoarthritis is more commonin identical than non-identical twins however, these genetic factors have been demonstratedmainly for hip or hand osteoarthritis.10Société Française de rhumatologie website:http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.aspINSERM (National medical research institute) websitehttp://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthrose
11MRI of both hands and wrists: SE T1 sagittal images.Hip osteoarthritis surrounding the hip.
Other risk factors Gender and hormonal status: post-menopausal womenare at higher risk of hip, knee or hand osteoarthritis thanmen of a similar age Differences in long bone length increase the risk of hiposteoarthritis but it may also affects subjects aged lessthan 5012http://www.ameli-sante.fr/arthrose-de-la-hanche/facteurs-de-risques-arthrose-de-la-hanche.htmlhttp://www.ameli-sante.fr/arthrose-du-genou/facteurs-de-risque-arthrose-du-genou.html
ConclusionOsteoarthritis is a strongly age-associated conditionThe most commonly affected joints are the spine(back bone) and handsOsteoarthritis is most debilitating when it affects thehip or kneeOverweight patients are at higher the risk ofdeveloping osteoarthritis, particularly in the kneesNormal physical exercise is not a risk factor (if noinjuries are sustained)Post-menopausal women are at higher risk of hip orknee osteoarthritis than men of a similar ageAn unstable knee and leg malalignement are riskfactors for the development of knee osteoarthritis13
14Lumbar canal stenosis,posterior lumbar facet jointosteoarthritis, sagittal imageof lumbar spine.Hand and wrist MRI: coronalimage, SE T1 sequence withsuppression of fat signal andinjection of gadolinium.Primary osteoarthritis,CT-arthrography.Advanced internalfemorotibial kneeosteoarthritis. MRI T2 images.