Lowering of the Patella — prevention and treatment of a rare complication during leg lengthening: a case report

Background. Changes in the level of the patella position are a well-known complication of knee replacement, reconstruction of the anterior cruciate ligament, high tibial osteotomy and consequences of injuries. However, this problem has not been disclosed in the literature in relation to distraction osteogenesis using the Ilizarov method. The aim of the study is to describe such a rare iatrogenic complication as patella baja during limb lengthening by the Ilizarov method using a clinical case as an example. Case description. In 2017, a 17-year-old teenager was injured in a head-on collision of cars at high speed. The patient was diagnosed with an open fracture of the left femur and fibula and tibia of the left leg. He was treated in another clinic using the Ilizarov apparatus for osteosynthesis of the femur, tibia and proximal osteotomy of the tibia to move the bone to fill the distal bone defect. At the end of the treatment, the patient had a moderate limitation of the knee flexion (180-80°). In 2018, the patient was admitted to our clinic due to osteomyelitis at the level of the consolidated fracture. A new resection of the osteomyelitis lesion and proximal osteotomy for bifocal osteogenesis were performed. During the treatment, limitation of knee flexion (180-120°) was developed and radiographic signs of low position of the patella were obtained. Given the progression of patella baja (the Caton-Deschamps index = 0.51), we were forced to return the patient to the operating room to restore the correct height of the patella. Conclusions. The presented clinical case emphasizes the need for a more thorough assessment of the patella height after surgical treatment on the proximal tibia using the Ilizarov method. It is also noted that it is important to conduct a control MRI, which allows for a more detailed study of the initial position of the anterior tibial tubercle. In our case, early detection of complications allowed us to achieve complete recovery without any consequences.