Habitual Dislocation of the Patella

Habitual dislocation of the patella (HDP) is a rare condi-tion. It presents as a lateral dislocation of the patella each time the knee is flexed, returning to the midline with extension of the knee. Habitual dislocation of the patella in children with open growth plates has usually been regarded as vastus lateralis fibrosis following multiple injections in the thigh,5,35 quadriceps fibrosis,1,17 or medial laxity of the patella.3,5,14 Many surgical procedures have been reported5,14,35 to treat it using wide lateral release, lengthening of the rectus femoris, and medial augmenta-tion, with around 80 % satisfactory results. For HDP in adults, several predisposing factors will aggravate the patel-lar instability, including trochlear dysplasia,10,21,33,34 insuffi-ciency of the medial patellofemoral ligament (MPFL),8,9,32 patella alta,2,10,31 abnormal Q-angle,18,30 and genu valgum.16 There are currently several surgical options to correct the pathophysiology of patellar dislocations, including lat-eral retinaculum release, MPFL reconstruction, trochleo-plasty, and distal realignment. Distal realignment of the patellofemoral mechanism by anteromedialization of th