Primary recurrent medial subdislocation of both patellae. Long-term review of an exceptional case of miserably malalignment syndrome

Abstract

We present a long-term review of a girl aged 11 years and 4 months with medial primary recurrent subluxation of both patellae of several months evolution associated with miserably malalignment syndrome. Not one case of medial recurrent dislocation of the patellae has been described previously. Three years previously following a jump she had suffered a right patellar luxation - self-reduced and not immobilised - followed by 10 subsequent episodes of subluxation and three more medial luxations. She could hardly walk autonomously due to persistent or habitual subluxation and patellofemoral pain, mainly in the right knee. Physical examination revealed habitual medial subluxation of both patellae, with clear medial patellar displacement, quadriceps amyotrophy and medial instability. The medial subluxation suppression test was positive. She showed excessive femoral anteversion of the hips (IR: 90º, ER: 30º), genu varum, neutral tibial torsion, patella alta, dysplastic trochlear grooves with medial condyle hipoplasia and both patellae were dysplastic (Wiberg type III). We performed a derotation subtrochanteric femoral osteotomy and bilateral proximal patellar realignment. Following surgery, bilateral stability of both sides permitted normal walking and running, as well as apprehension and the Smillie test (-), with a hip mobility of 65º ER and 50º IR. Fifteen years after the surgery the patient complains of antero-external knee pain in the right knee during prolonged walking, in getting up and down stairs and when in a prolonged sitting position, diagnosed as excessive lateral pressure syndrome.