Osteochondritis dissecans of the lateral tibial condyle associated with agenesis of both cruciate ligaments.

Osteochondritis dissecans is a rare cause of painful knees in children. Only 10 cases of lateral tibial condyle involvement have been reported in the literature. Congenital agenesis of both cruciate ligaments has been described even less, and its prevalence is unknown. The authors report an atypical association of osteochondritis dissecans of the tibia with congenital absence of both cruciate ligaments. A 12-year-old male soccer player presented with a painful right knee. Magnetic resonance imaging revealed the diagnosis. The child was treated conservatively. At 18-month follow-up, radiographs showed osseointegration of the osteochondritis dissecans, and the patient had resumed normal athletic activity without pain. To the authors' knowledge, this is the only report describing such an association. The authors discuss the possible etiology of osteochondritis dissecans associated with agenesis of the cruciate ligaments and highlight the possibility of this association when osteochondritis dissecans of the tibia is diagnosed in a child with a painful knee. In this patient, the strain due to anteroposterior instability may have been the cause of osteochondritis. Conservative treatment should be considered in this setting.