26 year old man who is a railway employee presented with left anterior knee pain and frequent dislocation of the patella since 3 months. To start with he fell down and twisted his knee while climbing down a ladder for which he visited a physician and was diagnosed to have left patella dislocation that was treated by immobilization in a long leg knee brace for 3 weeks. He had frequent anterior knee pain and frequent dislocations of the patella (probably 6) which were less painful than the primary episode and were self reducible. The patient was evaluated in the OPD, there was diffuse swelling and tenderness over medial patellofemoral joint, a positive apprehension test, no hyperlaxity and a Q-angle of 15°. Radiographs showed lateral patellar tilt, lateral patellar subluxation, sulcus angle 136° [] and Insall-Salvatti Index-1.1 []. MRI showed efussion of knee joint with tear in the MPFL at the patellar attachment. Of note, he had no other surgeries performed to the same knee. A preprocedure arthroscopy showed patellofemoral joint maltracking.\nThe patient was treated definitively with MPFL reconstruction by the technique described by us. He returned to work in 6 weeks, at 24-month follow up, Modified Crosby and Insall scale was excellent and Kujala score was 95.
The patient was an 11-year-old Caucasian boy without any relevant familiar history or comorbidity. He referred to our clinic complaining disability in walking and running with frequent falls (due to the lack of power in knee extensor mechanism). His parents said that despite the absence of pain, the functional limitation of both his knees was at the base of a serious psychological discomfort, conditioning his relationship with peers.\nOn objective examination, his lower limbs revealed mild genu valgum and tibial proximal lateral torsion. Both patellae were on the lateral aspect of the femoral condyle displacing even further during knee flexion. Femoral quadriceps function was present but this muscle was working as a flexor instead of extensor of the knee. It was observed that he was unable to actively extend both knees from the flexed position; passive range of motion (ROM) was complete and was not painful. At the upper limbs, there was a mild deficit in ROM of both elbows. There were no pathological deviation of the spine; normal clinical finding of both feet. The anterior-posterior lateral and axial knee X-rays showed bilateral, superolaterally displaced and hypoplastic patellae and reduction of the trochlear groove (, , ).\nThe extensor mechanism was studied by magnetic resonance imaging (MRI): Both quadriceps were hypotrophic with the vastus medialis enveloped over the trochlear groove which appeared flattened and dysmorphic. The patellar tendons were bilaterally lateralized and stretched. The anterior cruciate ligament could not be identified. On both sides, MRI confirmed the lateral dislocation of the patellae ().\nElbows X-ray showed a slight posterior dislocation of the radial head and absence of radioulnar synostosis. The diagnosis of CDP was confirmed. Surgical correction of the deformity was then proposed to regain walking and running function, with the aim of reduce the grade of the deformity improving the patient quality of life and his psychological well-being.