A Quantitative Assessment of the Subchondral Changes in Osteoarthritis and its Association to the Cartilage Degeneration

Summary

In order to quantify the alterations in subchrondral bone and to compare the changes with the severity of the cartilage lesions, a quantitative histological analysis of articular cartilage and subchrondral bone from osteoarthritic and normal femoral heads was performed.

The analyses were based on 12 femoral heads, seven which were osteoarthritic and five controls. Coronal sections were made and divided into four separate sites to include two weight-bearing and two non-weight-bearing. For each area the percentage volume of trabecular bone was determined by histomorphometry and the degree of cartilage degeneration was evaluated according to a histologicalhistochemical grading system.

The data obtained showed wide variations from site to site, in osteoarthritic femoral heads, with consistently more pronounced alterations in cartilage and subchrondral bone in the weight-bearing areas. Bone thickening and cartilage degeneration were distinctly increased in osteoarthritic joints, in contrast to the control group. By comparing the bony changes with the severity of the cartilage lesions, a correlation of moderate significance was found between the degeneration of the cartilage and sclerosis of the subchrondral bone.

Sections from osteoarthritic and normal canine femoral heads were obtained and divided into weight-bearing and non-weight-bearing areas. The trabecular bone area (%) and the severity of cartilage degeneration were determined by bone histo-morphology and a cartilage histological-histochemical grading system.

Bone thickening and cartilage degeneration were increased in osteoarthritic joints, when compared to normal controls with consistently more pronounced alterations in weight-bearing areas. The severity of the cartilage lesions were found to corre-late with subchrondral bone sclerosis.

Keywords

Osteoarthritis - subchrondral bone - trabecular bone area - cartilage degeneration

• REFERENCES

• 1 Radin EL, Paul IL, Tolkoff MJ. Subchondral bone changes in patients with early degenerative disease. Arthritis Rheum 1970; 13: 400-5.
• 2 Glynn LE. Primary lesion in osteoarthritis. Lancet 1977; 1: 574.
• 3 Lust G, Summers BA. Early asymptomatic stage of degenerative joint disease in canine hip joints. Am J Vet Res 1981; 42: 1849-55.
• 4 McDevitt C, Muir H. Biochemical changes in the cartilage of the knee in experimental and natural osteoarthritis in the dog. J Bone Joint Surg 1976; 58B: 94-101.
• 5 Mankin HJ, Brandt KD, Shulman LE. Workshop on the etiopathogenesis of osteoarthritis. J Rheumatol 1986; 13: 1127-60.
• 6 Arnoczky SP, Marshall JL. Degenerative joint disease I: Pathophysiology in small animal surgery. Bojrab MJ. (ed). Philadelphia: Lea & Febiger; 1981: 571-8.
• 7 Harris WH, Weinberg EH. Microscopic method of measuring increases in cortical bone volume and mass. Calcif Tissue Res; 1972; 8: 191-6.
• 8 Mankin HJ, Dorfman H, Lippiello L, Zarins A. Biochemical and metabolic abnormalities in articular cartilage from osteoarthritic human hips. J Bone Joint Surg 1971; 52 A: 424.
• 9 Radin EL, Rose RM. Role of subchondral bone in the initiation and progression of cartilage damage. Clin Orthop 1986; 213: 34.
• 10 Radin EL. Mechanical aspects of osteoarthrosis. Bull Rheum Dis 1975; -76 26: 862.
• 11 Foss MVL, Byers PD. Bone density, osteoarthrosis of the hip and fracture of the upper end of the femur. Ann Rheum Dis 1972; 31: 259-64.
• 12 Radin EL, Parker GH, Pugh JW. Response of joints to impact loading. Ill: Relationships between trabecular microfracture and cartilage degeneration. J Biomcch 1973; 6: 51-7.