Case report

The following images show a case of congenital genu recurvatum diagnosed at second trimester of a pregnancy. Additionally the fetus had a large ventricular septal defect and a maternal uterine septum was also present. The uterine septum was probably a contributing factor of the fetal congenital genu recurvatum, causing restriction of mobility of the fetal lower limbs, despite of the concomitant polyhydramnios.

Genu recurvatum or back knee deformity is rarely reported prenatally. It is characterized by hyperextension of the knee, limited flexion and forward curvature of the lower extremities. The findings can be detected prenatally during second and third trimester of pregnancy. Postural congenital genu recurvatum is associated with oligohydramnios and breech presentation contributing to the leg"s hyperextension due to the pressure of the myometrium on the fetus in the diminished fetal environment. Abnormal laxity of fetal ligaments can also contribute to the congenital genu recurvatum.

Three varieties of the congenital genu recurvatum exist: 1. congenital genu recurvatum with isolated hyperextension of the knees; 2. congenital genu recurvatum with subluxation of tibia; 3. congenital genu recurvatum with anterior dislocation of the knees.

The congenital genu recurvatum may be an isolated finding or associated with some syndromes (for example Ehlers Danols syndrome, Marfan syndrome, or Larsen syndrome). Arthrogryposis multiplex congenita, spastic cerebral palsy and cervical myopathy are other conditions associated with the genu recurvatum.

Postnatal management of the congenital genu recurvatum is conservative. Surgical treatment is the last option.

Images 1, 2: The image 1 shows uterine septum which probably contributed to the finding of the congenital genu recurvatum. The image 2 shows large ventricular septal defect at the level of the four-chamber view of the heart.

 

Images 3, 4, 5, and 6: The images represent 3D scans of the fetus with the genu recurvatum.

 

 

Image 7: The image shows postnatal appearance of the newborn with the genu recurvatum.