Diseases of musculoskeletal system

4. Degenerative bone diseases

Osteoarthritis

ILOs

• Recognizing definition, pathophysiology, clinical features and treatment of osteoarthritis.

* Definition:- Degenerative disease affecting large joints (weight-bearing).- Age: usually old ages.

* Etiology:1. Primary osteoarthritis: - It is of unknown cause.- It affects the elderly.- It occurs in a normal joint.2. Secondary osteoarthritis: - Occurs on top of an intra-articular or extra-articular bone diseases e.g congenital hip dysplasia, malunion of a fracture or bowing legs ….

* Pathogenesis:- The central part of the articular cartilage undergoes cracklings & some pieces separate into the joint cavity & the underlying bone becomes exposed.- The peripheral parts of destructed cartilage proliferate & ossify osteophytes.- Synovial membrane, capsule & ligaments undergoes inflammation.

* Symptoms:

• Pain and stiffness in the joints are the most common symptoms. The pain is often worse after exercise.

• The phrase "morning stiffness" refers to the pain and stiffness you may feel when you first wake up in the morning. Stiffness usually lasts for 30 minutes or less.

• During the day, the pain may get worse when you're active and feel better when you are resting. After a while, the pain may be present when you are resting. It may even wake you up at night.

• Some people might not have symptoms, even though x-rays show the changes of OA.

* Signs and tests:

- A physical exam can show:• a cracking (grating) sound with the joint

movement. (called crepitation)• Joint swelling (bones around the joints may

feel larger than normal)• Limited range of motion• Tenderness when the joint is pressed• Normal movement is often painful

* Pathological features:The affected joints are: large joints, usually singly e.g. knee or hip…The affected joint shows;- The synovial membrane and peri-articular tissue show chronic non-specific inflammation and fibrosis.- Degenerated central parts of articular cartilage.- Osteophytes: bony projections along joint margins

• Complications:1- joint disability1* Treatment:1. Analgesics and anti-inflammatory drugs.2. Joint replacement in severe disabling cases.