Pathobiology of articular cartilage in trapeziometacarpal osteoarthritis. I. Regional biochemical analysis.

Abstract

Biochemical analysis was performed on hyaline cartilage from four distinct quadrants in surgically harvested osteoarthritic thumb trapeziometacarpal joints and both normal and osteoarthritic cadaver specimens. Chondromalacic surfaces in the palmar contact areas of arthritic specimens were characterized by preferential loss of glycosaminoglycan, retention of collagen, and a shift in glycosaminoglycan subspecies as indicated by an increasing chondroitin sulfate/keratan sulfate ratio. In contrast, articular cartilage from the dorsal portion of arthritic joints biochemically resembled that from both the adjacent normal surfaces of the scaphoid and trapezoid facets and normal postmortem specimens. No significant difference was noted between the biochemical profiles of osteoarthritic surgical specimens and arthritic cadaver specimens. Such selective glycosaminoglycan depletion localized to the contact areas of the joint suggests an interdependent relationship between mechanical factors and biochemical matrix degradation in production of the cartilage lesion of trapeziometacarpal osteoarthritis.