A boy with bilateral hip pain

Clinical History

We describe a case of young boy with limping gait and bilateral hip pain. Skeletal survey and routine blood analysis were done. Subsequent radiographs of lumbar spine and pelvis were performed to reach to the final diagnosis.

Imaging Findings

A thirteen-year-old boy presented with pain in bilateral hips and limping since one year. Principal abnormalities on examination were short stature with particular shortening of the spine in relation to the limbs but no obvious kyphosis or scoliosis was seen. He had painful limitation of hip movements. Routine blood tests were normal. Skeletal survey was done. Radiographs of anteroposterior and lateral lumbar spine views shows (Fig 1a, b) platyspondyly (flattened vertebral bodies) with characteristic superior and inferior "humping" seen better on lateral view. Anteroposterior radiograph of pelvis involving both the hip joints reveals (Fig 2) expansile femoral head and neck shortening with areas of sclerosis and lucency, mild coxa vara and evidence of premature osteoarthritis beginning in young adulthood.

Discussion

Spondyloepiphyseal dysplasia tarda (SEDT) belongs to osteochondrodystrophies result from structural defects in type II collagen (3) refers to deformed vertebrae and distorted epiphyseal ends of long bones(1, 2). SED tarda, the X-linked recessive condition occurs only in male subjects and generally becomes evident between the ages of 5 and 10 years because of impaired spinal growth, in addition autosomal dominant and autosomal recessive forms also occur. Patients with SEDT have disproportionately short stature with a short trunk. At birth, affected males are normal in length and achieve normal body proportions. Progressive joint and back pain with osteoarthritis ensues. They have normal motor and cognitive milestones. The extremities and face are normal. The cardinal radiographic features of spine are platyspondyly with mounds of dense bone in the central and posterior parts of the superior and inferior vertebral end plates (1,2).Odontoid hypoplasia or os odontoideum may cause atlantoaxial instability, but is more common in the congenital type (5).Molecular genetic testing reveals a mutation in SED locus (chromosomal locus Xp22.2-p22.1) in >80% of affected males with a clinical diagnosis(3). Such genetic testing is available on research basis only. The differential diagnosis of spondyloepiphyseal dysplasia tarda may be confused with Legg Calve Perthes disease. However in spondyloepiphyseal dysplasia tarda the involvement is symmetrical, while in bilateral perthes disease involvement is asymmetric with one hip more radiographically affected than the other. Mucopolysaccharidoses type IV (Morquio-Brailsford disease) shows coxa valga, corneal clouding, cardiac and visceral involvement, atlantoaxial instability. In Multiple epiphyseal dysplasia there is no significant vertebral changes, Mild end plate changes but intervertebral disc spaces are well preserved (4).

Differential Diagnosis List

Final Diagnosis

Spondyloepiphyseal dysplasia tarda (SEDT)

URL:	https://eurorad.org/case/3492
DOI:	10.1594/EURORAD/CASE.3492
ISSN:	1563-4086