It is important to diagnose osteoarthritis because there are more than a hundred types of arthritis and many of them have different types of treatments.

Diagnosis of osteoarthritis, whether it be of the knee, hip, spine, or hands,  is simply made from the history of the symptoms and clinical evaluation.

The gradually progressive symptoms of osteoarthritis like pain in the affected joint, which gets worse the more you use the joint, and stiffness leading to limitation of movement lasting no longer than thirty minutes will already make the doctor suspect this condition. Again, advanced age and swelling of the joint will make him pin the diagnosis.

Physical examination is important in coming to a diagnosis. Pain on movement of the joint and restricted range of joint movement are common signs of osteoarthritis, The further guidelines to diagnose osteoarthritis are simple:

  • Imaging (Radiological) tests are done to view the bones directly and
  • Blood tests are done to diagnose the cause of osteoarthritis.

Imaging (Radiology tests)

X-rays are the most useful tests in osteoarthritis diagnosis though many a time you will not need one when the symptoms are classic.

Key features of OA that radiology helps to detect are joint space narrowing, subchondral sclerosis, and osteophytosis.

Plain x-ray

The degenerated cartilage does not show on the x-ray, but a diagnosis of osteoarthritis is suspected when you see

  • The reduced joint space between the two bones
  • Increased bone formation around the joint called subchondral (beneath the cartilage) sclerosis
  • Formation of subchondral cysts
  • Presence of spurs or osteophytes

Plain x-ray is, however, relatively insensitive to changes of early osteoarthritis.

Magnetic resonance imaging (MRI)

MRI is usually not required to diagnose osteoarthritis, but it can help to view the soft tissues such as cartilage, tendons, muscles, and the neighboring bones.

This will help to see changes typical of osteoarthritis both in early and advanced cases. It helps to understand the history of the disease and in drafting the future course of therapies.

MRI can accurately help to view both bones and soft-tissue joint structures. It can help to see bone marrow changes and cartilage loss, both of which are early OA changes that are not visible on radiographs.

Laboratory tests

These tests do not help in the diagnosis of osteoarthritis but are required to diagnose the causes of secondary osteoarthritis such as diabetes, gout, and bleeding disorders.

  • Blood tests will help to identify the causes of osteoarthritis and also rule out rheumatoid arthritis.
  • Joint fluid analysis. The doctor inserts a needle into the affected joint and withdraws fluid from the joint (Arthrocentesis). This fluid is then inspected for evidence of gout, any other infection, or inflammation.