Active subluxation in extension, radiological control in intercondylar eminence fractures in childhood

Twelve patients treated for intercondylar eminence fracture were controlled by a radiological Lachman test performed two and a half years after trauma. The mean differential active subluxation was 3.34 mm, corresponding to a "late hard stop" on clinical examination of the injured knee. In spite of correct reposition of the epiphyseal fragment we always found a difference between the injured and normal knee. The question of permanent damage secondary to anterior cruciate ligament (ACL) overload before intercondylar eminence fracture occurs is discussed. Surgical treatment should include careful control of ACL isometrical stretching and precise osteochondral fracture reduction, with retightening of the ACL if isometry during the last 30 degrees of extension is insufficient.