Module 69, General Medical Level

This 2 year and 9 month old male presented for evaluation of a worsening valgus deformity of his right knee. Thirteen months ago, his mother states the patient complained of some right leg pain and a limp, unassociated with recognized trauma. The pain and limp resolved over a number of weeks. Mom has noticed a progressive cosmetic deformity of the leg without any complaints of pain or functional limitation in running or walking. At the time of the initial injury, the patient was examined by his doctor but there was no history of injury and the problem was not considered to be significant; therefore, no x-rays were performed to document the possibility of a fracture. On physical examination moderate to severe genu valgum of 25 degrees of the right knee and 5 degrees of genu valgum of the left knee was noted. The right knee had full, painless range of motion without ligamentous instability. The left iliac crest was higher than the right. There was no significant rotational deformity noted at the hip, knee or ankle. On gait examination, patient was able to walk and run without tripping or displaying a functional deficit. Standing AP films of the bilateral lower extremities revealed a tibial femoral angle of 17 degrees of the right knee.

Question 69A

During this age period the knees normally are growing into more valgus alignment.

Question 69B

The fact that this valgus deformity is unilateral makes it very unlikely to be a normal variation.

Question 69C

Blount's disease of the knee may be causing this angular deformity.

Question 69D

The lack of trauma in this history is uncommon for this type of history and complaint.

Question 69E

Valgus knee deformity can be an early sign of a bone dysplasia.