Giuseppe Selva. M.D., Pediatric Orthopaedic Research Fellow

S. Jay Kumar, M.D., Attending, Orthopaedic Surgery

August 29, 1995





Diastrophic dwarfism is a rare skeletal dysplasia first defined by Maroteaux and Lamy in 1960. More than 200 cases have been described in literature (most from the U.S. and Finland).

The major clinical features of diastrophic dysplasia are:

  1. severe short-limb short stature
  2. cleft palate (27-59% of cases)
  3. typical ear deformity (cauliflower deformity in 85% of cases)
  4. progressive deformities and contractures of joints (100% of cases)
  5. progressive hip dysplasia (dysplasia 70% of cases; dislocation 22% of cases)
  6. typical hand deformities (100% of cases)
  7. severe clubfoot (almost 100% of cases)
  8. progressive spinal curvatures (Lumbar lordosis 100% of cases, scoliosis 80% of cases)
  9. Early degenerative changes in joints (100% of cases)
Genetic features:

1. Lethal form (death soon after birth because of cardio- respiratory insufficiency)

2. Diastrophic variant (mild form with only some features)


The combination of marked limitation of motion of all major joints together with a tendency to dislocation and subluxation characterize this disease. Some authors believe there are 2 forms of DTD: the lax and the stiff type.

Virtually every joint is likely to develop stiffness. This is due to the severe deformities of bones (epiphyseal and metaphyseal) as well as soft tissue contractures.

Progressive dislocation of the hip, patella, radial head are often observed.

Hip dislocation and hip dysplasia have been reported, respectively in 22% and 70% of patients. Delayed femoral head appearing, coxa valga or, on the contrary, coxa vara are common findings.

Valgus deformity of the knees, associated to flexion contracture, is another common finding.

Clubfeet are another diagnostic feature occurring in almost every patient. Clubfeet are usually very stiff and require surgical correction. Particular findings are the adducted forefoot with a severe inward curvature of the metatarsals .

Hand deformities are essential for diagnosis and they are present in almost 100% of cases. Hands are short and broad and deviated because of the ulnar shortness. PIP joint stiffness is in contrasts with the hypermobility of the thumb that is abducted over a short first metacarpal ("hitch-hiker" deformity).

Non-progressive lumbar lordosis is present in all patients and it is probably related to flexion contractures of the hips. Cleft vertebral laminae are common in both cervical and lumbar spine. Interpediculate narrowing occurs in 75% of patients but spinal stenosis is unusual because pedicles are not short, the posterior arch is relatively normal.

Scoliosis or kyphoscoliosis occur in 80% of patients. These curves usually onset during the first 2 years of life and they are not due to primary vertebral deformities. They must be carefully monitored because of the potential progression (usually during adolescence). Most authors suggest an aggressive orthotic treatment and early spine fusion.

Diastrophic dwarfs do not present atlo-axial instability or foramen magnum stenosis. In some cases their C-spine develops progressive kyphosis secondary to wedging of the lower cervical vertebrae. Progression of this deformity can lead to neurologic deficits and death unless the patient undergoes posterior or anterior and posterior spinal fusion.

The whole spine should be carefully monitored since the first year of life.


Literature data are not enough to evaluate the orthopaedic treatment of this disease.

Prevention and treatment of contractures, dislocations as well as spinal and foot deformities should be the goal of the orthopedist.


O.A. female. DOB 2-6-91. Product of a normal gestation. Two healthy half-sisters.

At birth:

Walking age: 17 months (with some flexion of hips and knees)

Cauliflower deformity of ears occurred in the first weeks of life.

Cervical kyphosis with C3-C4 deformity and instability since first year of life. No neurologic involvement. Several MRIs (91-93) have shown no spinal cord compression despite a somehow worsening of radiographs.

Progressive genu valgum and increased flexion contractures of knees and hips are now compromising the walking ability of the patient.


Feet: bilateral taping and serial casts. PMLR on the left foot (at age 9 months). Phelps braces. Feet are now plantigrade but with some residual deformity.


MRI C-spine. Hip arthrograms. Extension osteotomies for hip and knees.

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