What is the difference between Osteoarthritis and Osteoporosis and does one cause the other?

What is the difference between Osteoarthritis and Osteoporosis and does one cause the other?

Osteoarthritis (wear and tear arthritis)

Arthritis can be crudely defined as the “inflammation” of a joint. Osteoarthritis results from the pathological loss of cartilage within a joint that is associated with swelling, pain, stiffness, and loss of optimal function of the juncture. It usually gets gradually worse over time and excessive use will worsen the symptoms. 

The articular cartilage that covers the end of the bones and allows for normal smooth pain free mobility of the joint is worn away, exposing underlying bone which results in bone-on-bone articulation with associated severe pain, swelling and stiffness. When the joint is moved there is characteristic “crepitus” which can be felt. This is caused by bone rubbing on bone rather than smooth cartilage which should line both sides of the joint giving friction free movement.

Ball and socket osteoarthritis
Maintained articular cartilage shown as a space between the ball and socket of the hip – cartilage is invisible to the X-ray
Osteoarthritis and Osteoporosis
Complete loss of cartilage (arthritis) with absent space between ball and socket

Treatment of osteoarthritis is a sequential process depending on the severity of the cartilage loss. Early osteoarthritis can be treated symptomatically with pain killers (paracetamol) and anti-inflammatory drugs (ibuprofen) as well as general measures such as weight loss, gentle exercise to keep muscles conditioned and physiotherapy. Orthopaedic surgery is a last resort and usually involves replacing the affected joint with a prosthetic joint replacement.

Osteoporosis

This is defined as the pathological loss of bone mineral density predisposing the person to fractures with minimal trauma (pathological fractures). The most commonly seen fractures linked to osteoporosis include hip, wrists and vertebral fractures.  Osteoporosis is usually a disease of older age groups and tends to affect women more commonly than men. 

Osteoporosis diagram
Osteoporosis comparison

The causes of Osteoporosis include:

  • Family history
  • Early menopause (females)
  • Vitamin D deficiency
  • Certain drugs
  • Lack of weight bearing exercises
  • Heavy smoking and drinking

In reality, a diagnosis of osteoporosis should ideally be before a pathological fracture occurs, but, the fracture often precipitates the investigation diagnosis and treatment of osteoporosis.  Diagnosis is by means of a special scan called a DEXA scan (Dual Energy X-ray Absorptiometric scan). This quantifies how “dense” the bones are and gives a probability of having a fracture. Bones with lower density have a higher risk of breaking.

Treatment of osteoporosis is usually aimed at prevention and early recognition. This can be diagnosed and managed by an endocrinologist using drugs called bisphosphonates, hormone replacement therapy, if indicated, Vitamin D replacement and moderate weight bearing exercise. Reversal of all causes is vital if possible. 

If a fracture occurs, the orthopaedic surgeon is involved in managing the fracture and getting the person back to full function. 

In the case of osteoporosis prevention is far better than cure.

Are Osteoarthritis and Osteoporosis linked? 

The short answer is No. But a person who has osteoarthritis may also have osteoporosis and vice versa. However, the one does not cause the other. 

For more information on managing these conditions, contact us on https://www.midlandsorthopaedics.co.za/contact-us/.