Diagnosis is made with reasonable certainty based on history and clinical examination. X-rays may confirm the diagnosis. The typical changes seen on X-ray include: joint space narrowing, subchondral sclerosis (increased bone formation around the joint), subchondral cyst formation, and osteophytes. Plain films may not correlate with the findings on physical examination or with the degree of pain. Usually other imaging techniques are not necessary to clinically diagnose<unk> . In 1990, the American College of Rheumatology, using data from a multi-center study, developed a set of criteria for the diagnosis of hand<unk>  based on hard tissue enlargement and swelling of certain joints. These criteria were found to be 92% sensitive and 98% specific for hand<unk>  versus other entities such as rheumatoid arthritis and spondyloarthropathies. Image:Osteo of the hand.Severe<unk>  and osteopenia of the carpal joint and 1st carpometacarpal joint. Image:Gonarthrose-Knorpelaufbrauch.MRI of<unk>  in the knee, with characteristic narrowing of the joint space. Image:Osteoarthritis left knee.Primary<unk>  of the left knee. Note the osteophytes, narrowing of the joint space (arrow), and increased subchondral bone density (arrow). Image:Damaged cartilage Danish sow.Damaged cartilage from sows. (a) cartilage erosion (b)cartilage ulceration (c)cartilage repair (d)osteophyte (bone spur) formation. Image:Primary osteoarthrosis (2) at knee joint.Histopathology of osteoarthrosis of a knee joint in an elderly female. Image:Primary osteoarthrosis (5) at knee joint.Histopathology of osteoarthrosis of a knee joint in an elderly female. Image:Health joint.In a healthy joint, the ends of bones are encased in smooth cartilage. Together, they are protected by a joint capsule lined with a synovial membrane that produces synovial fluid. The capsule and fluid protect the cartilage, muscles, and connective tissues. Image:Joint with severe<unk> .With<unk> , the cartilage becomes worn away. Spurs grow out from the edge of the bone, and synovial fluid increases. Altogether, the joint feels stiff and sore. File:Osteoarthritis.Osteoarthritis File:Osteoarthritis_--_Smart-Servier_(cropped).Bone (left) and clinical (right) changes of the hand in<unk>  Classification A number of classification systems are used for gradation of<unk> : * WOMAC scale, taking into account pain, stiffness and functional limitation. * Kellgren-Lawrence grading scale for<unk>  of the knee. It uses only projectional radiography features. * Tönnis classification for<unk>  of the hip joint, also using only projectional radiography features. *<unk>  can be classified into either primary or secondary depending on whether or not there is an identifiable underlying cause. X-ray of erosive<unk>  of the fingers, also zooming in on two joints with the typical "gull-wing" appearance. Both primary generalized nodal<unk>  and erosive<unk>  (EOA, also called inflammatory<unk>  are sub-sets of primary<unk> . EOA is a much less common, and more aggressive inflammatory form of<unk>  which often affects the distal interphalangeal joints of the hand and has characteristic articular erosive changes on x-ray.<unk>  can be classified by the joint affected: * Hand: * Trapeziometacarpal<unk>  * Wrist (wrist<unk>  * Vertebral column (spondylosis) * Facet joint arthrosis * Hip<unk>  * Knee<unk>
Osteoarthritis
Fibromyalgia
Oligoarthritis
Bunion
Osteochondropathy
Septic arthritis
Bursitis
Plantar fasciitis