29 year old woman who is a daily wage worker presented to the outpatient department (OPD) with right anterior knee pain since 4 months. She felt a popping sensation in her right knee after slipping from the foot board of a bus while running to catch it 4 months ago. After this episode, she had severe pain and was unable to move her knee. She was then taken to a quack, after a local manipulation and massaging by him she was relieved of acute symptoms but had persistent knee swelling and mild knee pain. Patient returned to her daily activities the next day with minimal knee pain and difficulty in knee movements. She had similar episodes frequently (around 8) episodes since then, particularly during stair climbing, squatting and while boarding or trying to get down a running bus. The patient was evaluated in the OPD, she had severe anterior knee pain, tenderness over medial patellofemoral joint, a positive apprehension test, no hyperlaxity. Her Q-angle was 18°. Radiographs showed lateral patellar tilt, bony fragment in the medial patellofemoral joint, lateral patellar subluxation, Insall-Salvatti Index-0.91, sulcus angle 133°. Magnetic resonance imaging (MRI) showed effusion of knee joint with tear in the MPFL at the patellar attachment, osteochondral defect in the lateral patellar facet and an osteochondral fragment in the medial patellofemoral joint. Of note, she had no other knee surgeries performed to the same knee. An arthroscopy showed chondromalacia of patella, patellofemoral joint maltracking and an osteochondral fracture of lateral facet of patella [].\nThe patient was treated definitively with MPFL reconstruction by the technique described by us. Her pain resolved in 3 weeks, she returned to her daily routine in 6 weeks after surgery and at 24-month followup, Modified Crosby and Insall scale was good and Kujala score was 88.
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.