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Metaphyseal Dysplasia

Case

Can anyone give me a differential diagnosis for these xrays?

A four year old male child, with a valgus deformity of both knees, procurvatum and varus of the lower tibiae. he has broadening of the wrists (distal forearm). All the joints show a full range of painless movements, and the child has no problems apart from the deformity.

The spine and pelvis look normal to me, and while the hip, upper tibial and lower tibial epiphyses look abnormal, the lower femoral epiphysis looks normal to me.

The parents are 'sure' that this deformity has been there for only one year. How much I can rely on them I am not sure.

what is this condition?

mangal parihar

Bombay, India

I finally got some time to go down to the library and read up some radiology books (yes those big fat tomes are better than the internet sometimes). One good internet source for these kind of cases is the Online Mendelian
Inheritance in Man http://www3.ncbi.nlm.nih.gov/Omim/

The first thing I noticed was that my initial message revealed my mistake in using the term epiphysis in a loose/interchangeable fashion with epiphyseal plate/space. I now realise that the terms epiphysis (epiphyseal ossification center), epiphyseal plate / space / cartilage, and metaphysis should not be used interchangeably

From my reading it seems that the differential is limited to (on radiological grounds)
1. Metaphyseal Chondrodysplasia, Schmid type
2. Vit D resistant type of rickets

Metaphyseal chondrodysplasia is most likely because - the epiphyseal ossification centers are normal, the round bones of the hand appear normal, the spine is normal. In rickets the epiphysial ossification centers as well as the small bones of the hand & foot are likely to be affected.
Having said that, rickets needs to be ruled out by a metabolic work-up, since the two conditions are very often confused radiologically.

It's not a spondylo-anything because the spine is normal.

Unlikely to be an epiphyseal dysplasia of any type because in that case the epiphyseal centers would be irregularly ossified.

Given below are the notes I made while reading, to clear my ideas on this.
Iit might be useful to others. Most of it is from the title mentioned in the first line, with a point or two from other texts

mangal parihar

(editor's note - the following notes have also been copied to the Comments page

NOTES___________________________________________________

Essentials of caffeys pediatric x-ray diagnosis
silverman and kuhn, year book medical publishers 1996
pgs 836 to 899

Metaphyseal chondrodysplasia, type schmid
Mild manifestations, moderate, progressive shortening of stature, bowed legs.
Before epiphyseal union, radiographic examination discloses widening, cupping, and defective irregular mineralisation of the metaphyses of the tubular bones that is much less severe than in the jansen type.
Occasionally bony spicules passing into the epiphysis from the metaphysis, may be seen.
None of the disorganised metaphyseal clcification that occurs in the jansen type.
The round bones of the wrists and ankles and the epiphyseal ossification centers are not affected. Confusion with the radiographic changes of vitamin d resistant rickets often occurs.

Spondylo-metaphyseal dysplasias
involvement of the axial skeleton (platyspondyly, sail vertebra, ballooning of disc spaces, pelvic changes)

Multiple epiphyseal dysplasia and other epiphyseal dysplasias
The most common form is the Fairbank type.
Patients come for poor growth, problems with walking or joint pains, but rarely before 2 years of age.
Diagnosis is radiographic. Ossification centers are late in appearance, small and irregularly mineralised. Usually symmetrical. at maturity, affected bone ends may become distorted as after osteochondroses.
Osteoarthritic changes are frequent in adults.
Verterbral bodies may show mild end plate deformities. Carpal and tarsal bones are also affected.

Meyer dysplasia, isolated bilateral hip involvement
Ribbing type is milder than the Fairbank type and is often referred to as the Flat epiphysis type to differentiate from the Small epiphysis type of fairbank

Pseudoachondroplasia
A special form of spondyloepiphyseal dysplasia. Short limbed rhizomelic dwarfism of late onset (2 - 4 yrs of age)
Mild to moderate spinal deformity, normal craniofacial structure slight irregularities of vertebral end plates worsen with time epiphyseal ossification centers are small and irregularly mineralised,

Spondyloepiphyseal dysplasia tarda
Short trunk dwarfism. Vertebral bodies flattened

Rickets
Normally sharply defined provisional zone of calcification fades out indistinctly into the soft tissue density of the adjacent epiphyseal cartilage. In rickets the space between the metaphysis and its poorly calcified epiphysis is deepened.
In the shaft a diffuse rarefaction develops, with coarsening of the trabecular architecture. Greenstick fractures and radiolucent transverse bands resembling stress fractures may occur.
Epiphyseal ossification centers in the carpal and tarsal bones are similar to those in the shafts - margins disappear and the spongiosa becomes osteopenic and even invisible in severe cases.
The first evidence of healing is a reappearance of the provisional zone of calcification. As healing progresses, the metaphysis becomes mineralised from the shaft toward the epiphysis, ultimately resulting in radiographic
continuity of the shoft with the provisonal zone of calcification.

Vitamin D resistant rickets
The several forms of Vitamin D resistant and Vitamin D dependant rickets often dmonstrate marked lower-limb bowing in addition to metaphyseal changes resembling those in metaphyseal chondrodysplasias.

Renal Rickets
is often associatied with a chalky appearance of the bones as well as auxiliary signs of hyperparathyroidism theat are related to the retention of phosphate by the damaged kidney