Biochemical and magnetic resonance imaging features of cartilage in primary osteoarthritis / 中华风湿病学杂志

ABSTRACT

Objective To investigate the morphological and biochemical changes of primary knee joint osteoarthritis of guinea pigs and study its initial pathogenesis. To study the appearance of magnetic resonance imaging (MRI) in early stages of cartilage degeneration and to evaluate its values. Methods Thirty female Hartley guinea pigs were divided into postnatal 1, 3 and 6 months groups with 10 animals in each group. The degeneration of knee joint cartilage was observed. The proteoglycan (PG) and estradiol (ET) in serum were measured and the concentration of hydroxyproline (HOP), uronic acid (UA) and water ratio (WR) in articular cartilage were determined. Guinea pigs were scanned with magnetic resonance imaging ,using a 1.5T ASC-NT Gyroscan unit (Philips) magnet with 16 cm coil. Gradient echo sequences and spin echo sequences were performed in the sagittal planes at postnatal 1, 3, 6 months. Then signal intensity and thickness of cartilage were measured. The proteoglycan level was measured biochemically and histochemically. Results Degeneration of knee joint cartilage was seen in guinea pigs of 3 months old. The level of serum ET and cartilage WR were increased with age, while the value of serum PG and cartilage UA were decreased with age. The cartilage thickness and signal intensity were decreased significantly in treated knees compared with postnatal 1 month knees (P