PMC6140273_01
Preoperative plain radiographic (a) and computed tomographic (b, c) images of the pelvis. Coronal computed tomographic image shows a screw pressing the bladder wall (white dotted circle). White arrow indicates a fracture of the superior aspect of the obturator foramen.
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fig1
Anteroposterior pelvic radiography revealed migration of the acetabular cup into the pelvis with destruction of the medial wall of the acetabulum (Figure 1(a)). Computed tomography (CT) showed extensive destruction of bone at the anterior and medial aspects of the acetabulum and a migrated cup screw compressing the bladder wall (Figure 1(b)). The migrated cup was also pushed anteriorly and in contact with the femoral vessels (Figure 1(c)).
Images from the bone model used for preoperative planning. (a) A bone defect is seen at the acetabulum. (b) We rehearsed the iliac osteotomy and slid the ilium distally (black arrow). (c) The trial cup was placed in the acetabulum.
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fig2
Next, we cut the anterior part of the iliac bone and slid it distally and fixed it at the iliac crest with screws and small reconstruction plates (Figures 2(b) and 3(b)).
PMC6140273_02
Images from the bone model used for preoperative planning. (a) A bone defect is seen at the acetabulum. (b) We rehearsed the iliac osteotomy and slid the ilium distally (black arrow). (c) The trial cup was placed in the acetabulum.
CRIOR2018-9015727.002.jpg
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fig2
Next, we cut the anterior part of the iliac bone and slid it distally and fixed it at the iliac crest with screws and small reconstruction plates (Figures 2(b) and 3(b)).
Postoperative radiograph at immediately after surgery (a) and at final follow-up (b).
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fig3
An additional long reconstruction plate bridging the pubis and the iliac bone was inserted to support the medial wall of the acetabulum (Figure 3(b)). A plain radiograph at final follow-up showed her limb length discrepancy was 5 mm and revealed no evidence of implant migration (Figure 3).
Reconstructed computed tomographic image (a). The dotted line indicates the osteotomy line of the iliac bone. The slid bone is fixed by two screws (1) and a small plate (2), and (3) indicates the reconstruction plate. Cross-sectional computed tomographic image (b).
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fig4
Bone union at the osteotomy site was observed on postoperative plain radiographs and CT images, and there was no evidence of aseptic loosening of the cup (Figure 4).