Morphological subchondral bone tissue characteristics in knee osteoarthritis

Morphological subchondral bone tissue alterations associated with knee osteoarthritis represent a key pathogenesis link and can precede articular cartilage destruction. The study aimed to identify typical morphological and morphometric signs of osteosclerosis and osteoporosis in the subchondral zone of the femur and tibia. Analysis of 40 bone tissue fragments collected when performing knee replacement surgery in 20 patients (12 females and 8 males) aged 58–75 years with stage III–IV osteoarthritis was performed. Histological and morphometric assessment involving the use of light microscopy and microfracture index (MFI) calculation revealed significant differences in trabecular thickness, intertrabecular distance, and the degree of microdamage between the sites of sclerosis and osteoporosis. High MFI values in the zones of osteoporosis can reflect reduced subchondral bone strength. The findings confirm the diagnostic value of the subchondral zone morphometry and the prospects of using MFI as a quantitative risk criterion when planning orthopedic treatment.