It is a degenerative disease of the synovial joint characterized by focal loss of articular hyaline cartilage with proliferation of new bone and remodeling of bone contour.
(Disease of articular cartilage not bones)
➡ Commonly affects the weight-bearing joints such as the knee and hip joint.
➡ Affects woman more. (post menopausal as there is loss of estrogen)
➡ Genetic predisposition is the key factor in osteoarthritis (OA)
Pathophysiology of Osteoarthritis:
Degeneration of articular cartilage is defining feature of osteoarthritis
Normally chondrocyte are terminally differentiated cell, but in osteoarthritis
Chondrocyte differentiate further and produce nest of metabolically active cell➡ first, matrix components are produced at increased rate but in the same time major structural components of matrix are degraded (aggrecan and type II collagen)
loss of aggrecan concentration in the matrix causes the cartilage to become vulnerable to load bearing injury
Fissuring of cartilage surface➡ develop deep vertical cleft
localised chondrocyte death and cartilage thickness is reduced
Large cartilage damage and calcium pyrophosphate and calcium phosphate deposit in the abnormal cartilage
▶ Clinical feature:
➡ Pain on weight bearing activity and movement but the pain relief on rest.
➡ Early morning stiffness usually less than 15 minutes.
➡ Restricted joint movement.
➡ Swelling around joint (knee joint).
➡ Jerky gait (knee joint involvement).
➡ Patient may present with nodules in the hand (Distal interphalangeal joint & proximal interphalangeal joint) in generalized nodal OA.
➡ Patient may complain of crackling sound of the joint of walking or weight lifting, which is also heart of physical examination.
▶ Hand Nodules are usually found in later stages of OA (H/o of Knee OA+)
Heberden’s nodule- found in distal interphalangeal joint.
Bouchard’s nodule- found in Proximal interphalangeal joint.
▶ Increase calcium pyrophosphate deposition in the Knee joint can lead to pseudo-gout formation in the knee joint.
- Plain Xray
- Synovial fluid aspiration
- Rheumatoid factor
▶ What will you find in and Xray that’s suggestive of Osteoarthritis?
➡ Narrowing of joint space
➡ Subchondral cysts
➡ Subchondral osteosclerosis
➡ Joint deformity.
➡ Weight loss in obese patients
➡ Intra-articular glucocorticoids
➡ Muscle strengthening exercises.
platform academia/ Tohfa Rahman Galib