A syndrome characterized by dwarfism, bowed legs,
saber shins, mental retardation, mild involvement of the arms, and dural
Anterior Bowing of the Legs with Dwarfism;
Toxopachyosteose Diaphysaire Tibio-Peroniere (French).
Unknown but rare. A total of 47 cases had been reported
in the literature between 1954 and 2000.
Presumed autosomal or X-linked dominant
inheritance. Most cases appear to have been sporadic and the relatively
small number of familial cases suggests incomplete penetrance.
The pathogenesis is unknown. Assumed to be a
primary metabolic abnormality of bone.
Clinical features consistent with the syndrome.
Radiological examination is characteristic (anterior bowing of tibiae and
fibulae, with cortical hyperostosis on the concave side of the curvature,
slight bowing of the radius, ulna and humerus). Inconsistent radiological
findings include squaring of the iliac wings, low position of the fifth
lumbar vertebra in relation to the ilia, horizontal sacrum, kyphoscoliosis, and
dural calcification. Alkaline phosphatase is normal or raised; bone biopsy
Short stature is the most constant manifestation
(males averaging 151 cm [59.4 inches] and females 142 cm [56 inches]).
Features include anterior bowing of tibiae (saber shins) and lateral
bowing of femora (usually bilateral), occasional mild bowing of ulna,
radius, and humerus, and delayed ambulation in childhood. Of those affected,
20% have mental retardation of variable severity. Kyphoscoliosis is
present in approximately 30% of cases. Age at diagnosis has ranged from 2
weeks to 94 years. The skeletal deformities do not seem to progress during adult
life. Normal life expectancy.
Detailed clinical history and physical
examination must be performed to determine the progression of the syndrome and assess the presence of unrelated
medical conditions. Evaluate pulmonary function if kyphoscoliosis present
(chest radiography, spirometry, arterial blood gases).
Careful patient positioning and transfer from the stretcher to the operating room table
(patients seem to have an increased propensity to bone fracture following
minor trauma). If the kyphoscoliosis is significant, the use of regional anesthetic
technique may not be applicable. Technical difficulties may be
experienced because of lower spinal abnormalities and the risk of dural
puncture is increased. The laryngeal inlet may be smaller than normal for
age. A range of endotracheal tubes of sizes smaller than normal should be
Sedative premedication may be
beneficial in patients with mental retardation. No specific pharmacological
Maffucci Syndrome: Rare disorder characterized by
skeletal dysplasia. The age of onset can be at birth or not until early
childhood. It primarily affects long bones and cartilage. Limb shortening,
bowing of the long bones, and/or short stature may occur.
Camptomelic Syndrome: A congenital disorder characterized
by short stature along with bowing and an unusual angular shape of the legs. The shoulder and the
pelvic skeletal structures are often abnormal. Individuals affected with
this syndrome usually present with 11 pairs of ribs instead of 12. ...