Congenital absence of the anterior cruciate ligament (ACL) is an extremely rare condition (0.017 per 1000 live births) . It has been reported as an isolated entity [1, 14] or associated with other abnormalities such as congenital femoral deficiency, fibular hemimelia, scoliosis, hip dysplasia, and dysplasia of the tibial intercondylar eminence [4, 9, 10, 14]. It was first reported by Giorgi  in 1956 in a radiographic study, and since then, several case reports have been published [4, 11]. Most reports describe patients with no complaints of instability (despite having positive objective instability tests) but pain due to osteoarthritis of the medial femorotibial joint .
HSS Journal, an academic peer-reviewed journal published three times a year, February, July and October. The Journal accepts and publishes peer reviewed articles from around the world that contribute to the advancement of the knowledge of musculoskeletal diseases and disorders.