Erlacher-Blount syndrome

Syndrome characterized by osteochondrosis, which affects the upper tibial epiphysis in children, causing progressive bowing of one or both legs in childhood. In the infantile type, the deformity appear before the age of 8 years and is usually bilateral; otherwise there is normal development, except for some overweight. The bowing is evident as an abrupt angulation with the apex laterally, just below the knee. The changes may appear as a developmental exaggeration with sloping epiphysis and beaklike recurving metaphysis. In the adolescent type, a similar deformity may occur in one side after the age of 8 years. Most cases are sporadic but involvement of successive generations has been recorded. Blount's is the familial type, transmitted as an autosomal recessive trait.

In 1922 Philipp Erlacher documented progressive deformity of the upper end of the tibia, using the term "tibia vara" in his text. Blount in 1937 reported 13 children with a form of bow legs which he termed "osteochondrosis deformans tibiae". The condition was the consequence of deformation of the upper medical tibial epiphyses and metaphyses but the aetiology was unknown. Blount retained a life-long interest in the disorder, and in 1966, 30 years after his original paper he wrote a review of the condition in the authoritative Current Practice of Orthopaedic Surgery. Carroll Glenn Barber (born 1895) in 1939 and 1942 further advanced the concept of this syndrome.

Although Erlacher-Blount syndrome is supposedly rare, the infantile form is common amongst the indigenous population of South Africa. Indeed, in a 10-year period, more than 300 affected children were treated in the Barangwanath Hospital, Johannesburg (Bathfield and Beighton 1978).

We thank Mats Geijer, M. D., Iowa, USA, for information submitted.

• P. Erlacher:
  Deformierende Prozesse der Epiphysengegend bei Kindern.
  Archiv für orthopädische und Unfall-Chirurgie, München, 1922, 20: 81-96.
• W. P. Blount:
  Tibia vara: osteochondrosis deformans tibiae.
  Journal of Bone and Joint Surgery, Boston, 1937, 19: 1-29. Tibia vara: osteochondrosis deformans tibiae.
  Current Practice of Orthopaedic Surgery, 1966. Volume 3, page 141. Mosby Co., St. Louis, Illinois.
• C. G. Barber:
  Osteochondrosis deformans tibiae. Nonrachitic bow leg in children.
  American Journal of Diseases of Children, Chicago, 1942, 64: 831-842.
• C. A. Bathfield, P. H. Beighton:
  Blount disease. A review of etiological factors in 110 patients.
  Clinical Orthopaedics and Related Research, Philadelphia, 1978, 135: 29-33.