Age / Sex : 64 / M

Chief complaint: Inward bowing of both leg

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

(답안은 한 개만 보내주시기 바랍니다)

Courtesy: 이영한(Young Han Lee), 세브란스 병원(Severance Hospital)

Blount’s disease

Discussion

Findings:

Depression and irregularity of medial aspect of proximal metaphysis of right tibia.  

Widening of physis in right proximal tibia.

Abnormal signal intensity medial aspect of epiphysis in right proximal tibia and right distal femur.

Differential Diagnosis:

1) Developmental (physiologic) bowed legs

2) Rickets

3) Osteogenesis Imperfecta

Diagnosis: Blount’s disease

Discussion:

Blount’s disease is a local disturbance in growth of the medial aspect of the proximal tibial epiphysis. Clinically, there are two conditions of Blount’s disease; early onset or infantile and late onset or juvenile, based on the onset of clinical findings before or after 4 years of age. The standing anteroposterior radiography shows Blount's disease well. The radiographs demonstrate genu varum, abnormality of the proximal tibia consisting of depression and irregularity or fragmentation of the metaphysis posteromedially, and deficiency of the epiphysis medially. The physis may be widened medially due to arrested growth or laterally due to traction injury. It is usually unilateral or asymmetric. MR can be performed to evaluate the growth plate in Blount’s disease and to plan for the surgical correction.

Infantile tibia vara has a good prognosis, and recurrence rates of deformity are low when treated early, but in the late-onset form, juvenile type, regression does not occur and the varus deformity may worsen over time.

References:

1.     Cheema JI, Grissom LE, Harcke HT. Radiographic characteristics of lower-extremity bowing in children. Radiographics. 2003 Jul-Aug;23(4):871-80

2.     Ho-Fung V1, Jaimes C, Delgado J, Davidson RS, Jaramillo D. MRI evaluation of the knee in children with infantile Blount disease: tibial and extra-tibial findings. Pediatr Radiol. 2013 Oct;43(10):1316-26

3.     Resnick D, Kransdorf MJ, Bone and joint imaging, 3^rd edition, Elsevier Saunders, 2005, p1101-1103