HOW ARTHRI­TIS HAP­PENS

EQUUS - - Eq In Brief -

To un­der­stand how arthri­tis de­vel­ops, con­sider first the func­tion and com­po­nents of a typ­i­cal limb joint: The ends of long bones are cov­ered by ar­tic­u­lar car­ti­lage, which is made up of 80 per­cent wa­ter. The re­main­der is col­la­gen and long chains of pro­teins called pro­teo­gly­cans, which

In­flam­ma­tory en­zymes pro­duced in re­sponse to an in­jury break down syn­ovial fluid, which pro­vides lu­bri­ca­tion within the joint space, mak­ing it thin­ner and less pro­tec­tive.

give car­ti­lage stiff­ness to with­stand shear­ing forces as the joint moves. Ar­eas of higher mo­tion in the joint have higher lev­els of pro­teo­gly­cans. Ar­tic­u­lar car­ti­lage com­presses and ex­pands un­der pres­sure from the bones each time the joint flexes, forc­ing wa­ter and other flu­ids in and out, keep­ing the tis­sues hy­drated and healthy.

Even rou­tine ac­tiv­ity might cause minute dam­age and small amounts of in­flam­ma­tion within a joint. Usually, the body makes the needed re­pairs quickly and ef­fec­tively. If the in­sults are too se­vere or repet­i­tive, how­ever, these heal­ing pro­cesses may be over­whelmed, start­ing the cas­cade of events that leads to arthri­tis.

In­flam­ma­tory en­zymes pro­duced in re­sponse to an in­jury break down syn­ovial fluid, which pro­vides lu­bri­ca­tion within the joint space, mak­ing it thin­ner and less pro­tec­tive. Mean­while, col­la­gen and pro­teo­gly­cans are lost, re­duc­ing the car­ti­lage’s abil­ity to retain wa­ter. If the process is not in­ter­rupted with rest or med­i­cal in­ter­ven­tion, the dam­age mounts and the joint fills with in­flam­ma­tory flu­ids, lead­ing to the pres­sure, pain and stiff­ness that are the hall­marks of arthri­tis. Left unchecked, this cy­cle can tear or erode car­ti­lage to the ex­tent that bone ends rub painfully against each other. This is an ad­vanced case of os­teoarthri­tis, also called de­gen­er­a­tive joint dis­ease.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.