Vol 43 # 2 June 2011 - Kma.org.kw

June 2011
KUWAIT MEDICAL JOURNAL 153
Letter to the Editor
Blount Disease: Bowlegs may not always be a Physiological
Ayse Esra Yilmaz 1 , Hakan Atalar 2 , Tugba Tas 1 , Nurullah Celik 1
1
Department of Pediatrics, Fatih University, Faculty of Medicine, Ankara, Turkey
2
Department of Orthopedics, Fatih University, Faculty of Medicine, Ankara, Turkey
Kuwait Medical Journal 2011; 43 (2): 153
Bowing of the lower extremities is common and is a
frequent cause for orthopedic referral [1] . The role of the
physician is to determine if the bowing is physiological
or pathological. Among the most common causes
of bowlegs are developmental bowing, congenital
bowing, tibia vara (Blount disease), neurofibromatosis,
osteogenesis imperfecta, rickets, campomelic dysplasia,
and achondroplasia [2] .
A 16-month-old girl was referred to our clinic
with bowing of legs. She had received Vitamin D
prophylaxis and there was no history of trauma or
a similar disease in family. Physical examination
revealed that her anterior fontanel was closed, and
there were no pathological findings in the legs except
for bowing. Serum Ca, inorganic phosphate and
alkaline phosphatase were normal.
X-ray examination revealed varus deformity of
both knee joints in lower extremities. Considering the
age of the patient, and the possibility of a physiological
bowing, the patient was advised to come for another
examination after six months. The patient was
brought for the next examination 11 months later.
Physical examination revealed that O-bain deformity
progressed, while varus deformity of knee joints was
apparent, being more prominent in the right knee joint.
Inclination towards the medial was apparent on the
side of the metaphysis facing the epiphysis and was
more prominent on the right. The patient was started
on orthosis with a diagnosis of Blount disease.
Tibia vara or Blount disease is an orthopedic
problem that may cause growth retardation, believed
to result from abnormal stress on the postero-medial
proximal tibial physis. Aberrant epiphyseal growth
pattern develops due to abnormal stress, which leads
to typical varus angulation. The predisposing factors
are listed as starting to walk early, obesity, and being
of African-American origin. Early diagnosis and
treatment of the disease is critical for prevention of
progressive worsening [1] . The diagnosis is made by
antero-posterior radiograph of both legs. Radiography
reveals genu varum, abnormal proximal tibia due
to depression, irregularity or fracture at the posteromedial
metaphysis, and deficiency of the medial
epiphysis. While the developmental bowing is typically
symmetrical, Blount disease usually develops on one
side or asymmetrically. Metaphyseal-diaphyseal angle
measurement is significant for both diagnosis and
differential diagnosis from developmental bowing.
Magnetic resonance imaging is used in Blount disease.
Primarily orthosis should be preferred for treatment of
children under four years of age and at early stages of
the disease. However, at a later stage, tibial and fibular
osteotomy is generally done [3] . As a consequence, early
diagnosis and treatment is important in Blount disease,
which is a progressive disorder. We believe that
pediatric physicians should take Blount disease into
consideration when examining cases with childhood
bowlegs.
REFERENCES
1. Tolo VT. The lower extremity. In: Morrissy RT, Weinstein
SL, editors. Lovell and Winter’s pediatric orthopaedics.
Vol II. 4th ed. Philadelphia, Pa: Lippincott- Raven, 1996;
1047-1075.
2. Jugesh I, Chee J, Leslie E, Grissom L, Harcke H.
Radiographic characteristics of lower extremity bowing
in children. RadioGraphics 2003; 23:871-880.
3. Langenskiold A. Tibia vara: a critical review. Clin
Orthop Rel Res 1989; 246:195-207.
Address correspondence to:
Dr Yilmaz AE, MD, Department of Pediatrics, Fatih University, Faculty of Medicine, Alparslan Turkes Caddesi No: 57, 06510, Ankara, Turkey. Tel: +
90 312 203 55 55, Ext: 5074, Fax: + 90 312 221 36 70, E-mail:aysesra@yahoo.com