Obligatory Dislocators, Dislocation in Flexion

Abstract

Habitual dislocation of the patella or obligatory dislocation in flexion is a relatively rare condition where the patella dislocates laterally in every flexion and extension cycle and the patient has no control over the patella dislocating [1, 2]. The literature concerning obligatory dislocation of the patella is slim due to the rarity of the condition. The presentation of this condition begins mostly when the child starts to walk [3]. The condition is often well tolerated if not painful, although it may present with dysfunction and instability which leads to difficulty in running or frequent stumbling. Mainly habitual patella dislocations start to produce symptoms that are limiting the physical activity of the child at or around the start of school age. The luxation of the patella in flexion is mainly caused by too short extensor muscles, and in some cases contractures are confined to the iliotibial band, vastus lateralis, and the lateral fibers of the rectus femoris muscle [4]. This condition forms a false sulcus to the deep trochlear area that can be seen in preoperative contrast medium-enhanced CT and in the operation.