Ultrastructural changes in cartilage after intra-articular administration of osmium tetroxide and the sodium salts of fish oil fatty acids (Varicocid).
A clinical and experimental study was carried out on knee joints of rabbits and in humans. In one knee joint of each rabbit 0.3 ml 1% osmic acid or 0.3 ml 5% Varicocid was injected, the remaining uninjected joints serving as controls. The animals were killed after 1 and 24 hours, 15, 45 and 90 days. Study with the electron microscope after osmic acid injection revealed necrosis of the chondrocytes in the superficial layer and upper middle zone. The articulations injected with Varicocid exhibited only slight lesions of the chondrocytes in the upper layer, consisting of dilated rough endoplasmatic reticulum, mitochondria lacking matrix and christae; the electron density of the layer seemed to be diminished. Biopsy of the non-weight-bearing cartilage of the lateral femoral condyle was performed in 4 patients with Rheumatoid Arthritis and arthritis of the knee in the onset stage. Two of these patients received one intra-articular injection of 10 ml 1% osmic acid, 5 ml 2% xylocaine and 50 mg hydrocortisone and the other 2 patients 6 ml 5% Varicocid. Biopsy of the cartilage in the areas adjacent to the site of the first biopsies 1 and 3 1/2 months after treatment with osmic acid and 2 and 3 1/2 months after treatment with Varicocid showed in the first two cases necrosis of the chondrocytes in the superficial layer and upper middle zone of the articular cartilage and depletion of the mucopolysaccharides in the ground substance, revealed by PAS and alcian blue staining. No lesion of the knee joint cartilage was observed in the other two cases. In view of the results obtained, chemical synovectomy with Varicocid can be considered as having received further support.