Multiple Epiphyseal Dysplasia Workup

Updated: Aug 26, 2015
  • Author: Ashish S Ranade, MBBS, MS, MRCS; Chief Editor: Dennis P Grogan, MD  more...
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Workup

Laboratory Studies

The initial diagnosis of multiple epiphyseal dysplasia (MED) is typically based on clinical and radiographic features, though molecular genetic testing is available. Molecular genetic testing has a role in confirming the clinical diagnosis and in establishing a prenatal diagnosis. [14, 22]

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Imaging Studies

Imaging studies that may be relevant to the evaluation of MED include the following:

  • Radiography
  • Magnetic resonance imaging (MRI)
  • Radioisotopic bone scanning

However, bone scanning, MRI, and ultrasonography are not necessary to confirm the diagnosis of MED.

Radiography

Although the cervical spine is not typically involved, the acquisition of flexion-extension radiographs may be prudent if surgery is being considered. Radiographs of major joint areas show a delay in the appearance of ossification centers in the long tubular bones. The epiphysis is small, fragmented, and irregular. In rare instances, metaphyseal irregularities and streaking may be seen. These changes are most pronounced in the hip and the knee. (See the image below.)

Radiograph shows alignment of the lower extremitie Radiograph shows alignment of the lower extremities.

Hip

Irregularities of the femoral head are evident by the first year of life. The secondary center of ossification in the femoral head may appear as late as 30 months of age. Epiphyseal fragmentation is evident by 10 years of age. [23] Increased fragmentation of the capital epiphysis is associated with an early onset of osteoarthritis. [24]  Coxa vara may be seen in some patients. Avascular necrosis (AVN) may be superimposed on the typical changes observed in MED. AVN is associated with changes such as metaphyseal cysts and the crescent sign. [25]  Acetabular involvement occurs in MED. (See the image below.)

Anteroposterior (AP) radiograph of the pelvis show Anteroposterior (AP) radiograph of the pelvis shows bilateral hip changes.

Knee

Radiographic changes in the knee (see the image below) are typically described as those noted before or after the epiphyses close.

Anteroposterior (AP) radiographs of the knee shows Anteroposterior (AP) radiographs of the knee shows characteristic changes of multiple epiphyseal dysplasia (MED).

Changes before epiphyseal closure include the following:

  • Irregularity and segmentation of epiphysis
  • Widening of the joint space and angular deformity (eg, genu valgum)

Changes after epiphyseal closure include the following:

  • Shallow femoral trochlear groove (seen in >50% of patients)
  • Early-onset osteoarthritic changes
  • Depression of the lateral tibial plateau
  • Genu valgum
  • Multiple loose bodies

The presence of genu varum or valgum with loose bodies and premature osteoarthritis warrants radiographic evaluation of other joints. The clinician should keep in mind the possibility of MED. Double-layered patellae have been described with MED. [21] Both knees are typically involved. A double-layered patella has anterior and posterior components.

Investigators have described a relationship between the shape of the femoral trochlear groove and the rate at which osteoarthritis develops. Three types of grooves have been described: shallow, normal, and an inverted V. [26] The most common finding in this study was a shallow femoral trochlear groove, which was recorded in 56.5% of 31 patients, followed by irregularity of the articular surface, which was seen in 43.5%.

Foot and ankle

Foot and ankle findings (see the images below) include the following:

  • Valgus deformity of the distal tibia
  • Hypoplasia of the tarsal bones
Anteroposterior (AP) radiographs of the feet. Anteroposterior (AP) radiographs of the feet.
Lateral radiographs of the right and left feet. Lateral radiographs of the right and left feet.

Shoulder

Shoulder findings include the following [16] :

  • Minor epiphyseal involvement
  • Severe involvement (hatchet head group) - Malformed humeral head; broad metaphysis; bowing of the proximal shaft; hypoplasia of the glenoid

Elbow

Elbow findings include the following:

  • Cubitus valgus
  • Osteochondral loose bodies

Hand

Hand findings include the following:

  • Ivory epiphyses
  • Short phalanges and metacarpi (variable feature)

Spinal

Spinal findings include the following:

  • Schmorl nodes and endplate irregularities (rare)
  • Scoliosis (rare)

Magnetic resonance imaging

In a report on young patients, MRI findings included irregular and delayed ossifications of the epiphyses. [27] The articular cartilage had a normal appearance, and no edema was observed. Neither joint effusion nor loose bodies were noted. Conventional radiography and MRI showed that the ossified parts of the epiphyses had similar shapes. Findings in the menisci and ligaments were unremarkable. MRI and conventional radiography provided the same information about the epiphysis in young patients with MED.

In the same report, both T1- and T2-weighted MRI showed a homogeneous hyperintensity of the epiphyses in patients aged 16-18 years. MRI also showed homogeneously thick cartilage without clefts. However, plain radiography showed a defect in these cases. MRI did not depict osteochondritis dissecans or any free bodies. The ligaments and menisci were normal. The authors inferred that MRI did not give any additional information about the cause of the complaints in these adolescent patients.

In young children, MRI of the hip joint reveals irregularity of the proximal femoral epiphyses, diffusely decreased signal intensity, and a typical garland formation of the epiphyseal plate.

Radioisotopic bone scanning

Radioisotopic bone scans can be used to diagnose AVN superimposed on MED.

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Diagnostic Procedures

Arthrography has been used to evaluate the hip joint in children. In young individuals with MED, the articular surface of the joint is intact.

Hip arthroscopy has been used to treat acute and semiacute pain in MED. Hip arthroscopy has shown the involvement of hip in the form of chondral avulsion fractures, loose bodies, labral tears, femoral head/acetabular chondromalacia, and chondral flaps. [28]

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Histologic Findings

Intracytoplasmic inclusions are seen in MED. These are similar to but not as severe as those observed in pseudoachondroplasia. Abnormal organization of the growth plate is a clinically significant finding of MED. Other histologic findings are disordered columns of cartilaginous cells, clefts, and areas of degeneration in the matrix. [29] Some changes are seen in the metaphysis.

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