Risk Factors Of Osteoarthritis

There are certain subpopulations who are more vulnerable to develop osteoarthritis than others. Women tend to develop more severe degenerative arthritis on X-ray than men as a group. They also tend to develop more osteoarthritis of the hands and knee osteoarthritis.

These differences are of a genetic nature rather than environmental (see Ref. 2, p. 29). There is an age dependent increase of frequency of being affected with osteoarthritis, with symptoms getting symptomatic around age 45 and peaking at about age 65. There seems to be a plateau beyond the age of 70, perhaps because of less mobility.

There are biomechanical factors such as obesity, which is a clear risk factor for weight dependent joints like hips and knees. Malalignment problems such as genu valgus (knock-knees) or genu varus (bowleggedness) are also associated with development of premature osteoarthritis of the knee.

There are some cases where deposits of calcium crystals, such as calcium pyrophosphate dihydrate (CPPD) and basic calcium phosphate(BCP), are deposited in joints.

CPPD deposits are often present in severe knee joint osteoarthritis in elderly women and if proven by joint aspiration may be the first sign that the person has pseudogout. If BCP is found, this explains a severe destructive form of osteoarthritis and this has been described in elderly women as the "Milwaukee shoulder" (Ref. 1, p. 465). The BCP crystals cause the lining of the joint to release inflammatory prostaglandins and cells, which leads to joint destruction.

In this image a 77-old woman had a shoulder dislocation and irregular calcification from pseudogout. An MR image showed a large joint effusion, resorption and deformity of the humeral head, and also a complete rupture of the rotator cuff. It is extremely difficult for an orthopedic surgeon to return such a shoulder back to normal function.

Disclaimer:

This outline is only a teaching aid to patients and should stimulate you to ask the right questions when seeing your doctor. However, the responsibility of treatment stays in the hands of your doctor and you.

References:

1. The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999. Chapter 52.

2. ABC of rheumatology, second edition, edited by Michael L. Snaith , M.D., BMJ Books, 1999.

3. EL Cain et al. Clin Sports Med 2001 Apr;20(2):321-342.

4. B. Sears: "Zone perfect meals in minutes". Regan Books, Harper Collins, 1997.

5. Goldman: Cecil Textbook of Medicine, 21st ed.(©2000)W.B.Saunders

6. Ferri: Ferri's Clinical Advisor: Instant Diagnosis and Treatment, 2004 ed., Copyright © 2004 Mosby, Inc.

7. Rakel: Conn's Current Therapy 2004, 56th ed., Copyright © 2004 Elsevier

Last Modified: March 16, 2012