Trabecular bone strength patterns at the proximal tibial epiphysis.

The longitudinal compressive strength of trabecular bone from the human proximal tibial epiphysis was investigated in 12 autopsy specimens using multiple penetration tests with a small diameter indentor. Strength profiles were visualized by three-dimensional computerized reconstruction as a function of location on the resection surfaces. There were large variations of the maximal values between individuals, but the patterns obtained were remarkably uniform. The medial condyle showed the highest peak value in all but one knee with a mean medial-to-lateral peak value-ratio of 1.7. At the medial condyle the high strength area was relatively large with peak values being obtained centrally and anteriorly; the lateral condyle showed a more restricted, posteriorly localized area of high strength. Beneath the menisci, bone strength gradually decreased toward the margins of the condyles; likewise, bone strength decreased to reach very low values at the intercondylar region. There was a significant reduction of bone strength with the distance from the subchondral resection surface. This reduction was most pronounced at the high strength areas.