Osteoarthritis of the Anterior Cruciate Ligament and Medial Tibial Plateau: A Cadaveric Study

The objective of this study was to analyze morphometric anatomy and damages with aging in cadaveric knee specimens specific to the cruciate ligaments, the articular cartilage of the tibial plateau, and the menisci. Morphometric analyses to cadaveric anatomy of the knee were performed using Image-Pro (R) software on 3 age populations: <70 years old, 70 to 79 years old, and >= 80 years old. An average thickness of the cruciate ligaments was assessed with 5 circumferential measurements per specimen using nylon thread. Percent degeneration of the tibial plateau's articular cartilage and coverage by menisci was assessed with surface area measurements. The articular cartilage of the medial tibial plateau in >= 80 years old specimens showed a 1.7-fold increase in surface area degeneration (mm(2)) compared to 70 to 79 years old specimens (P < 0.05). The medial meniscus also experienced degenerative changes with aging, which were expressed as decreases in tibial plateau coverage. The anterior cruciate ligament (ACL) experienced substantial degenerative thinning with aging. The 70 to 79 years old specimens had a 1.2-fold (10.5%) decrease in average ACL circumference (mm) compared to the <70 years old specimens (P < 0.001). The >= 80 years old specimens had a 1.24-fold (19%) decrease in ACL circumference compared to the <70 years old specimens (P < 0.001). ACL thinning during aging may be leading to substantial articular cartilage and menisci degeneration given the cruciate ligaments are a primary restraint that combats shearing forces at the knee joint.