Old skeletons suggest widespread bone changes in OA

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Feb 20, 2004

Old skeletons suggest widespread bone changes in OA

Norwich, UK - Examination of 563 skeletons from an archaeological site

in England suggests that osteoarthritis (OA)-associated changes of the

hand, hip, and knee are related to similar changes at many sites and

that OA is a systemic disease of bone rather than a syndrome of bony

changes secondary to focal loss of articular cartilage, British

researchers report in the February 2004 issue of Arthritis & Rheumatism

[1].

" Our findings indicate that skeletal OA is more widespread in the body

than is apparent from clinical studies and are consistent with other

data suggesting that OA is a disease that is primarily dependent on

systemic predisposition to a particular type of bone response to

mechanical stress, " write Drs t , Lee Shepstone (both

University of East Anglia, Norwich, UK), and Dieppe (University of

Bristol, UK).

Perhaps, comment Drs T Felson and Tuhina Neogi (Boston University

School of Medicine, MA) in an accompanying editorial [2]. But the

enthesophytes, osteophytes, and eburnation observed by et al are

less likely to be elements of a bone disease than of a bony

proliferative response representing a particular phenotype of OA.

Osteology, the examination of bones from skeletons, offers a more

complete view of arthritic joints than that obtainable from standard

clinical or radiological examination. The skeletons in this study were

from burials between about 900 and 1850. et al examined the hip,

knee, elbow, hand, shoulder, wrist, and ankle joints for evidence of

eburnation and osteophytes and the entire skeleton for evidence of

generalized enthesophyte formation (ossification at the insertion sites

of ligaments, tendons, and joint capsules to bone).

They report, " We have found that evidence of classic OA (eburnation on

the articulating surfaces of synovial joints commonly affected by OA) is

associated with widespread skeletal changes elsewhere, including

widespread eburnation of bone and osteophyte formation, as well as

excess formation of enthesophytes. "

Most associations were similar for osteophytes and eburnation, with one

striking discrepancy. Shoulder joints had a high prevalence of

osteophytes but a relatively lower prevalence of eburnation. The

investigators suggest that this reflects a high prevalence of

rotator-cuff disease.

et al conclude that their data challenge the assumption that

idiopathic OA can be divided into monoarticular (large-joint) disease,

resulting from local injury, and generalized OA, due to a systemic

predisposition to the disease. They also question the assumption that

generalized OA involves mostly the hips, knees, and hands. " Of the

joints studied, only the ankle appeared to be spared, " they write.

Felson and Neogi point out that the idea that OA starts in the

subchondral bone has been challenged by animal experiments showing

intact subchondral bone when cartilage loss started. " Only later in OA

development did the radiographic equivalent of 'eburnation' occur, " they

note.

They also point out that age confounding could explain much of the

association reported, since the bony changes of OA and enthesophytes

both increase with age, which could not be reliably determined for many

of the skeletons.

Janis

Sources

1. J, Shepstone L, Dieppe P. Is osteoarthritis a systemic

disorder of bone? Arthritis Rheum 2004 Feb; 50(2):452-7.

2. Felson DT, Neogi T. Osteoarthritis: Is it a disease of cartilage or

of bone? Arthritis Rheum 2004 Feb; 50(2):341-344.

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org