Morbus van Neck

Ischiopubic synchondrosis asymmetry (also known as van Neck-Odelberg disease) is characteristic enlargement of one of the ischiopubic synchondroses. It is largely considered an anatomic variant of skeletal developmental, given that it is a common and usually asymptomatic finding.

However, some cases are thought to be symptomatic and may correspond to MR findings that suggest a stress reaction .

Epidemiology

Occurs in all children before puberty during fusion of the pubic and ischial bones .

Clinical presentation

Most cases of ischiopubic synchondrosis asymmetry are observed in asymptomatic patients. Symptomatic cases are described as presenting with groin or buttock pain in ambulatory, pre-pubertal children

Pathology

Ischiopubic synchondrosis asymmetry is much more common on the side of the weight-bearing non-dominant foot, with the differences in ossification thought to result from asymmetric mechanical forces .

Radiographic features

Recognition of an entity as a normal variant is important for radiologists when interpreting a pediatric pelvic radiograph. One of the key questions to ascertain is whether the region is painful or not:

• if asymptomatic and there is no concerning antecedent history: it is unlikely to represent a sinister pathology other than just a developmental variant
• if symptomatic or if the there is concerning antecedent history: it could still be a developmental variant although other important differential considerations should also be considered

Ischiopubic synchondrosis can be avid on bone scintigraphy and FDG PET/CT.

Differential diagnosis

On imaging alone, the condition can mimic many other pathological entities including:

• stress fracture 
• osteomyelitis: ischiopubic osteomyelitis
• post-traumatic osteolysis
• bone tumor

The preceding clinical history is crucial in image interpretation.

History and etymology

The condition is named after M van Neck and A Odelberg who initially described these findings in 1924 .

Siehe auch:

• Osteomyelitis
• Aseptische Knochennekrose
• Stressfraktur

und weiter:

• Morbus van Neck
• Os ischii
• Auftreibung der Osteochondrosis ischiopubica