**6. Distal femoral epiphysis lesion**

A rare type of neonatal femoral fracture is the epiphysiolisthesis of the distal femoral epiphysis. The knee joint presents with effusion, there is limited movement of the affected limb, like a type of pseudoparalysis. The neonate is restless and bathing and dressing are difficult because of the reactions of the neonate. Diagnosis is obscure and septic arthritis of the neonate must be differentiated from epiphysiolisthesis. The distal femoral epiphysis ossification nucleus appears in infancy, but it is a small one and separation is not easily appearent on plain X-rays. Plain X-rays may appear with a minimal disruption of the metaphyseal corner. Ultrasound examination is helpful but cannot confirm diagnosis, as the fluid collection of the effusion may be a sign of infection. MRI examination will reveal the translation of the epiphysis. On MRI the hematoma is well demarcated with the separation of the epiphysis in the growth plate (**Figures 15**–**17**).

#### **Figure 15.**

*Distal femoral epiphysiolisthesis Salter type 1, with calcification from the periosteal elevation. MRI demonstrates the hematoma and the periosteal elevation.*

#### **Figure 16.**

*Distal femoral epiphysiolisthesis Salter type 1, with calcification from the periosteal elevation. MRI demonstrates the hematoma and the periosteal elevation.*

#### **Figure 17.**

*Distal femoral epiphysiolisthesis Salter type 1, with calcification from the periosteal elevation. MRI demonstrates the hematoma and the periosteal elevation.*

The distal femoral epiphysis is the most important for the proper growth of the limb, so the lesion must be diagnosed early in order to reduce the epiphysis. It is a Salter Harris type 1 or 2 lesion. The limb is immobilized in a light cast, incorporating the foot. If properly reduced, then growth of the limb may not be affected. The neonate must be followed for the next years to confirm the leg length equality. There have been reported cases with reduction and stabilization using K-wires. These injuries may create severe leg length discrepancy (LLD) and it is important for them to be evaluated by a pediatric orthopedic surgeon [43–48].
