How to define osteoarthritisThere are several "levels" of osteoarthritis: anatomical(with presence of joint damage that is not alwaysdetectable), radiological and symptomaticMany people have radiologicallyevident but asymptomaticosteoarthritis Osteoarthritis is not necessarilysynonymous with "pain" Thus, of 100 people aged over 65:2Société Française de rhumatologie website:http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.aspINSERM (National medical research institute) web site:http://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthrose
The hips and knees are not the jointsmost commonly affectedThe spine and fingers are the most commonly affected joints.In the 65-75 year old age group, the incidence is as follows: Cervical spine: 75% Lumbar spine: 70% Hands: 60% Knee: 30% Hip: 10%It is most severe and debilitating when it affects the knees and hips,both weight-bearing jointsThe ankles, elbows and shoulders can be affected but this is lesscommon and generally occurs secondary to an earlier joint injury3 Société Française de rhumatologie website:http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp
4Cervical spine.T2 MRI.Erosive disc disease, differentstages, frontal view of lumbarspine.Hand and wrist MRI: coronal SE T1 and FSE T2 images with fat signal suppression.Patellofemoral knee osteoarthritis.Internal hip osteoarthritiswith deformation of thereinforcement cup.
Pain: the main symptom of osteoarthritis1. in the chronic phaseDuring the chronic phase, osteoarthritisprogresses very slightly or not at all Osteoarthritis pain is described asmechanical: variable, mild to moderate pain thatchanges only slowly over time arises particularly during movement/usageand is relieved by rest. tends to become worse towards the endof the day and evening little night time pain in the morning, stiffness lasts not morethan half an hour.5 Sellam J et Berenbaum F. Arthrose. Rev Prat. 2011; 61: 675-686
Pain: the main symptom of osteoarthritis2. during the acute phase: an inflammatory flare Recent change in pain intensity: sudden increase in intensity over a few days onset of night time pain which wakes the patient up morning stiffness lasting more than 30 minutes +/-mechanical pain as soon as any pressure is placed on the jointOnset of joint effusion with a low cell count, i.e. containing less than1500 elements per mm3Sometimes, presence of signs of moderate local inflammation:heat and swelling of the knee joint7 Sellam J et Berenbaum F. Arthrose. Rev Prat. 2011; 61: 675-686
Examining the jointExamination of the affected joint may show: a decrease in range of movement and/or pain when the joint is moved(distributed through most of the range of movement) course crepitus through muchof the range of movement bony swelling deformity/malalignment joint-line tenderness +/- peri-articulartenderness (hip/knee) due to secondaryperi-articular lesionsBetween osteoarthritis flares: the joint is neither swollen, nor warm8Site de la Société Française de rhumatologie :http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A1_pourquoi.aspLa Revue du Praticien, Arthrose et obésité. Jérémie Sellam and Francis Berenbaum, 2012; 62: 621-624The examination must always becomparative and, as far as theleg joints are concerned, the patient mustalso be examined in a standing position andduring walking.
Standard x-raysFirst and foremost, the imaging work-up for patients with suspectedosteoarthritis should include a comparative x-ray (for tibiofemoralcompartments weight-bearing films are required) study of thesymptomatic joint In more complex cases, it will also help rule out other joint diseases The main visible signs are: reduction in joint space width (inter-osseous distance) subchondral bone sclerosis (increased whiteness) osteophyte (mainly marginal) occasionally, the presence of lacunae calledbony cysts or geodes, and osteochondral“loose” bodies eventual development of bone attrition and deformity sometimes the radiological signs can be very discrete and even absent9 INSERM (National medical research institute) website:http://www.inserm.fr/thematiques/circulation-metabolisme-nutrition/dossiers-d-information/arthrose
10Cystic hip osteoarthritis.Oblique image hip radiographs.Fracture of the upperextremity of the femur(pertrochanteric).
11Advanced internal femorotibial kneeosteoarthritis. Standard frontal x-ray.Sample osteoarthritic knee x-rayAdvanced internal femorotibial kneeosteoarthritis. Standard oblique x-ray
Beware of the possible lack ofcorrespondence between the radiologicalfindings and the clinical symptomsThere is no direct link between the extent of the lesions seenon the x-ray and pain intensity Up to 90% of subjects aged over 50 years old are thought to presentradiological modifications whilst only 30% have clinical symptoms and signsSevere lesions may only cause occasional pain, whilst minimal damagemay be accompanied by intense painMore information can be gleaned from monitoring the progress of thelesions than from assessing radiological severity at any given timeIf the patient continues to present with pain despite appropriatetreatment, the radiological work-up should be repeated to screen forrapidly destructive osteoarthritis12 Site de la Société Française de rhumatologie :http ://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp
CT and MRI scans: how useful are they?A conventional x-ray is the gold standard examinationfor the diagnosis and follow-up of osteoarthritis inroutine practice although it does not allow directvisualisation of: cartilage damage fibrocartilage lesions (meniscus and fat pad) intra-articular inflammation These abnormalities are only screenedfor during clinical trials13Loeuille D. Quand faut-il faire une IRM dans l’arthrose des membres inférieurs ? Rev Prat. 2012; 62: 625-629Site de la Société Française de rhumatologie:http://www.rhumatologie.asso.fr/04-Rhumatismes/grandes-maladies/0B-dossier-arthrose/A0_definition.asp
14Frontal FSE T2 image of internal femorotibialosteoarthritis with stage 4 cartilage lesion ofplateau and condyle and edema of the tibialplateau and condyleKnee osteoarthritis, tibial edema andsynovial inflammation. FSE T2 sagittalslices.
MRI as a second line examination MRI can be performed as a second line examinationfor an atypical presentation: when a patient experiences mechanical pain in a joint thatappears normal on the x-ray which could potentially be anindication of pre-radiological stage osteoarthritis orepiphysial osteonecrosis a subchondral fissure Nonetheless, recourse to MRIfor osteoarthritis patients shouldbe exceptional15 Chevalier X. Arthrose du genou et de la hanche. Rev Prat Med Gen. 2007; 21: 987-991Loeuille D. Quand faut-il faire une IRM dans l’arthrose des membres inférieurs ? Rev Prat. 2012 ; 62 : 625-629
MRI, cartilage and boneUsed during clinical trials, MRI provides satisfactory explorationof the knee hyaline cartilage which varies in thickness from 1.5 to 4 mm(cartilage is thicker in men than women and varies according to height) When used for diagnostic purposes, in 35% of cases MRI shows focalcartilage lesions not evident on the x-ray Bone damage may be found with - and sometimes even before - the lossof cartilage. MRI has made a major contribution to the diagnosis of kneeosteoarthritis by making it possible to distinguish amongst the various typesof bony lesions, especially bone oedema which is not visible on standardx-rays and which is correlated with pain in patients with knee osteoarthritisMRI has made major contributions to the understanding of painmechanisms in patients with osteoarthritis17 Loeuille D. Quand faut-il faire une IRM dans l’arthrose des membres inférieurs ? Rev Prat. 2012; 62: 625-629
Conclusion A standard x-ray is the reference examinationfor patients with suspected osteoarthritis Early diagnosis of osteoarthritis could make it possibleto set up a number of preventive measures It is also hoped that, in the future, the use of biomarkers(for example type 2 collagen derivatives or hyaluronicacid) may be used to detect the first cartilage changes atan even earlier stage18 Chevalier X. Arthrose du genou et de la hanche. Rev Prat Med Gen. 2007; 21: 987-991