PMC5632487_01
Anterior-posterior radiograph of the hip. Enlargement of the acetabular fossa is shown (black arrow).
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fig1
An anteroposterior plain radiograph of the hip indicated enlargement of the acetabular fossa of the affected hip (Figure 1).
T1-weighted axial magnetic resonance image of the left hip joint. The extra-articular herniation sac is indicated by the arrowhead.
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fig2
A large extra-articular tumour-like lesion appeared to be connected to the inferomedial joint capsule (Figure 2).
Arthro-computerised tomography scan of the left hip joint. The extra-articular herniation sac is indicated by the arrowhead.
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fig3
Arthrography and computed tomography (CT) images of the left hip joint also revealed a honeycomb appearance of the lesion (Figure 3).
Histological section with haematoxylin and eosin staining. Clustered chondrocytes were observed in hyaline cartilage tissue (arrow).
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fig4
Histopathological examination confirmed the diagnosis of a synovial osteochondromatosis (Figure 4).
Excised osteochondromas.
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fig5
Osteochondromas in the herniation sac were easily and completely removed manually (Figure 5).
T1-weighted coronal magnetic resonance image at 1 month after surgery. There was no sign of avascular necrosis of the femoral head. The herniation sac had diminished in size (arrow).
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fig6
The herniation sac diminished in size, with no apparent contents (Figure 6).
PMC5632487_02
Arthrography of the hip. There are many loose bodies in the left hip joint (honeycomb appearance: arrow).
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fig7
Arthrography showed a honeycomb appearance around her left hip joint (Figure 7).
T1-weighted axial image of extra-articular loose bodies (arrow) adjacent to the iliopsoas muscle and the femoral vessels (asterisk).
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fig8
Upon MR imaging, axial images of the left hip joint revealed intra-articular and extra-articular mass lesions, one of which was located adjacent to the femoral vessels (Figure 8).
Excised osteochondromas of case 2.
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fig9
Osteochondromas existing in the iliopsoas muscle were completely excised by bluntly splitting the muscle and herniation sac (Figure 9).