Three-Dimensional Digital Surgical Planning and Rapid Prototyped Surgical Guides in Bernese Periacetabular Osteotomy

Figures

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  Figure 1. Radiographs of the pelvis (AP in (a) and Lequesne view in (b)) showing signs of hip dysplasia.

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  Figure 2. MRI (coronal cut) of the right hip showing dysplasia and a hypertrophic labrum torn at its base.

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  Figure 3. The pelvis with positioned osteotomes and the extruded guide (in green).

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  Figure 4. Images of the acetabular fragment in different projections (rotations).

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  Figure 5. Images of the acetabular fragment superimposed to the pelvis after rotation and space repositioning.

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  Figure 6. Image of the repositioned acetabular fragment, femur, and pelvis, with the ray casting technique, to simulate the transparency of the structures as in radiographs. The center edge angle (a) and Tönnis angle (b) were measured in both hips.

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  Figure 7. Final guide printed in ABS plastic (pelvic and abdominal faces).

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  Figure 8. Surgical guide held in place (iliac fossa) with a reduction clamp, and a perfect fit can be noticed.

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  Figure 9. Picture of a straight osteotome inserted into the pubic slot ready to be driven through the bone. Notice the screw securing the guide to the bone.

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  Figure 10. Fluoroscopic images of the iliac and posterior column osteotomes being driven through the bone (a) and the extension of the posterior column cut up to the ischium cut (b).

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  Figure 11. Picture of the acetabular fragment repositioned in space. Note that the planned rotation of the fragment is 5.9° in the longitudinal axis, 28° in the anterior-posterior axis, and 14° in the laterolateral axis.

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  Figure 12. Measurement of the center edge angle (a and b) and the Tönnis angle (c and d), for both the planned (a and c) and actual radiographs (b and d). The obtained center edge angle is equal to as planned, and the Tönnis angle is 2° less than as planned.