[Fixed posterior subluxation with lateral rotation of the knee joint caused by congenital dislocation of the patella in combination with aplasia of the posterior cruciate ligament. Case report and review of the literature].

Congenital dislocation of the patella is very rare. In this anomaly, the patella is dislocated to the side of the lateral femoral condylus and cannot be repositioned manually. Diagnosis is often made by clinical examination and observation of an abnormal gait. We describe the long-term course of treatment in a young girl with fixed posterior subluxation with lateral rotation of the knee joint caused by congenital dislocation of the patella in combination with aplasia of the posterior cruciate ligament. These anomalies of the knee joint were corrected incrementally. First, recentralization of the patella was performed by open surgery. Subsequently, distraction of the shortened ischiocrural muscles and the posterior capsules and ligaments was conducted. This is the first case to be described, to the best of our knowledge, of a patient with congenital dislocation of the patella in combination with aplasia of the posterior cruciate ligament. We describe the successful treatment of such a fixed posterior subluxation and lateral rotation of the knee joint.