Microscopic Changes in the Articular Cartilage

To characterize cartilage degradation, Mankin et al [53] developed a histologic grading scale that ranges from 0 (normal cartilage) to 14 (severe degradation). Scoring reflects the loss of structural organization (0-6), cellular characteristics (0-3), loss of safranin-O staining (0-4) and tidemark integrity (0-1). More recently, a new histopathologic grading system has been proposed by Osteoarthritis Research Society International (OARSI) [67]. With normal cartilage as grade 0, OA severity is divided into six grades. Grades 1 to 4 involve changes in articular cartilage, and grades 5 to 6 involve the subchondral bone as well. It is important to note that both grading systems are histologic, assessed at a particular location. A patient may have severely degraded cartilage in the weight-bearing regions (Mankin score, Ms >10; OARSI grade >4), yet still have near-normal cartilage in non-weight-bearing regions (Ms <5; OARSI grade 1-2), however severe the patient's OA.

The stages in cartilage degradation can readily be seen in histologic sections, graded according to the Mankin score (53). In control cartilage (Ms = 1, OARSI = 0) obtained from the femoral heads of patients who had fractured the neck of the femur, aggrecan is evenly distributed throughout the cartilage, as indicated by safranin-O (Fig. 1.6A) and Alcian blue (Fig. 1.6E) staining. Loss of aggrecan in the superficial zone, as shown by loss of safranin-O staining (Fig. 1.6B), is the first indication of OA (Ms = 3-4, OARSI = 1). At this stage, the collagen network remains intact, on the basis of positive sirius-red staining (Fig. 1.6F). Aggrecan loss leads to reduced resistance to mechanical loading and to damage to the collagen network. The stage that follows is erosion of

Mankin score = 1

Was this article helpful?

0 0
Arthritis Relief and Prevention

Arthritis Relief and Prevention

This report may be oh so welcome especially if theres no doctor in the house Take Charge of Your Arthritis Now in less than 5-Minutes the time it takes to make an appointment with your healthcare provider Could you use some help understanding arthritis Maybe a little gentle, bedside manner in your battle for joint pain relief would be great Well, even if you are not sure if arthritis is the issue with you or your friend or loved one.

Get My Free Ebook

Post a comment