Fact-sheet: Avascular necrosis of medial condyle - Blount disease
- Blount's disease
- Deforming tibial osteochondrosis
Updated on 04/19/2018 at 8:07 AM
View all RADEOS cases associated with this fact-sheet
Definition
Growth disturbance of the medial tibial metaphysis resulting in progressive deformity of the proximal tibia
2 forms: infantile and adolescent
Etiology: unknown
Predisposing factors: early walking, obesity, Black ethnicity
Clinical features
Limb deformity
Radiography
Depression and irregularity of the medial aspect of the tibial metaphysis: "beak" appearance
Depression of the medial tibial epiphysis (small and irregular)
Overall depression of the medial tibial plateau assessed using the Drennan metaphyseal-diaphyseal angle: > 11° indicates probable Deforming tibial osteochondrosis
Compensatory hypertrophy of the medial femoral condyle
Secondary genu varum
CT
Similar to standard radiography
MRI
Hypertrophy of the medial growth cartilage (good compensation for the metaphyseal tibial growth defect) and good vascularization of this cartilage favor a benign form
Management
No collapse of the tibial growth cartilage (hypertrophy, compensating for bony collapse): elevation surgery of the medial tibial plateau
Collapse of the growth cartilage: valgus osteotomy
Classification
Langenskiold classification (juvenile form)
Guides treatment
Based on the persistence (or destruction) of the physis