Anterior Cruciate Ligament Changes in Human Joint in Aging and Osteoarthritis

Objective—The development and patterns of spontaneous aging-related changes in the anterior cruciate ligament (ACL) and their relationship to articular cartilage degeneration are not well characterized. The aim of this study was to investigate the types and temporal sequence of agingrelated ACL changes and establish the correlation with cartilage lesion patterns at all stages of OA development in human knee joints without prior joint trauma. Methods—Human knee joints (n=120; 65 donors; age 23-92) were obtained at autopsy and ACL and cartilage were graded macroscopically and histologically. Inflammation surrounding the ACL was assessed separately. Results—Histological ACL substance scores and ligament sheath inflammation scores increased with aging. Collagen fiber disorganization was the earliest and most prevalent change. The severity of mucoid degeneration and chondroid metaplasia in the ACL increased with development of cartilage lesions. A correlation between ACL and cartilage degeneration was observed, especially in the medial compartment of the knee joint.