Periarticular osteopenia, erosions at the margins of joints, synovial hypertrophy, subchondral cysts and sclerosis, joint space narrowing.
The knee is the most commonly affected large joint.
Septic arthritis
Pus or organisms on arthrocentesis.
Although acute bacterial infections are usually rapidly destructive and thus tend not to alter epiphy-seal growth, infantile osteomyelitis may accelerate development of the affected epiphysis.
Legg-Calvé-Perthes disease
The femoral head is enlarged (coxa magna) and the epiphysis is flattened and deformed from AVN.
Coxa magna develops during the reparative stage.
Status post hip dislocation
Coxa magna with normal architecture.
Accelerated growth of the affected side occurs after successful relocation of a previously small proximal femoral epiphysis. Necrosis of the femoral head is more common than coxa magna.
Hemophilia
Soft-tissue swelling, periarticular osteopenia, epiphyseal overgrowth. Later stages progress to joint space narrowing, marginal osteophyte formation. Synovium is decreased in T1- and T2-weighted signal intensity on MRI.
Turner syndrome
Small medial tibial plateau with hypertrophy of the medial femoral condyle (Kosovicz sign).
Short stature, shortening of the fourth metacar-pals, radiocarpal angulation, cervical ribs, Scheuer-mann disease, Madelung deformity.
Hypochondroplasia
Large proximal femoral epiphyses with broad metaphyses and short femoral neck.
Mild form of short-limbed dwarfism. Between the spectrum of achondroplasia to normal. Spinal stenosis.
Hemihypertrophy
Unilateral hypertrophy.
Increased incidence of embryonal tumors, Wilms tumor, neuroblastoma, and hepatoblastoma.
Klippel-Trenaunay syndrome
Uneven enlargement of the parts of the affected limb, including the epiphysis.
Triad of unilateral capillary hemangioma, v arices, and localized gigantism with overgrowth of the skeleton and soft tissues.
Fig. 5.42a–c Juvenile idiopathic arthritis. Epiphyseal overgrowth at the proximal femur in a child with JIA. (a) Enlarged epiphysis of the proximal femurs with erosions on T1-weighted imaging (b) and erosions (arrow in c) and rice bodies on proton-density fat-saturated imaging.Fig. 5.43a, b Blount disease. (a) Tibia vara. (b) Double echo steady state (DESS) MRI shows bone bridge (arrow) on the medial side of the tibia and reactive changes in the lateral physis of the distal femur.Fig. 5.44 Macrodystrophia lipomatosa of the middle finger.Fig. 5.45a, b Macrodystrophia lipomatosa with hypertrophy of fat around the index finger and thumb on T1-weighted (a) and fat-suppressed T2-weighted (b) MRI.Fig. 5.46a–c Dysplasia epiphysealis hemimelica (Trevor disease). Radiograph (a) and CT (arrow in b) show ossific excrescence projecting offthe lateral aspect of the distal femoral epiphysis in an 8-year-old. (c) T2-weighted MRI shows cartilage cap (arrow).
Table 5.31 Epiphyses: generalized overgrowth
Diagnosis
Findings
Comments
Hyperthyroidism
Cone-shaped epiphyses.
Advanced skeletal maturation. Premature closure of cranial sutures. Brachydactyly.
Acromegaly
Epiphyses are enlarged but normal in shape.
Accelerated skeletal growth with delay in closure of growth plates. Widened joint spaces from increased amount of cartilage. Spadelike appearance of hands and feet.
Polyostotic fibrous dysplasia with precocious puberty (McCune-Albright syndrome)
Multifocal fibrous dysplasia. Advanced bone age, pathologic fractures, and pseudarthrosis.
Triad of fibrous dysplasia, precocious puberty in girls, skin pigmentation mainly in the trunk and proximal limbs. Two to three percent of patients with fibrous dysplasia. Bone involvement tends to be asymmetric.
