This gentleman had central fracture dislocation of his left hip that was initially treated non-operatively resulting in persistent central dislocation of the femoral head with gap non-union of the acetabulum.

On analysis of the 3D model, it was realized that the patient had deficiency of posterior wall and the central part of the acetabulum with impression fracture of the femoral head. The bone model also revealed that the acetabulum orientation had changed into retroversion.

The alternate strategies considered were :-

Figure 1 : Protrusion Ring being placed on the fratured acetabulum model	Figure 2 : Side view showing the areas that require grafting.

Figure 1 : Acetabular cup placed on the fractured hip joint	Figure 2 : Side view of the Acetabular Cup strategy highlights the graft requirement

a. use it as bone graft to reconstruct the major posterior wall deficiency
b. to use iliac crest graft to fill up the medial wall defect
c. place acetabular cup in proper orientation on the graft bed

In plan A, there is more dependence on metal as compared to other options. In plan C the patient's own tissues from the local area was used. This also reduced the cost of the surgery but also improve the quality of results. In plan B, the literature shows that may fail over a period of time compared to autograft that was used in plan C giving a longer lasting result.

After, analyzing different options with the help of bone-model the best surgical plan that was devised was to use plan C.

The exact extent of machining and positioning of the femoral head graft was made easy by working with the bone model.

Using the bone graft it was realized that the difficulties in this case would be to bring down the center of acetabulum to its correct level and orientation in 3D will require extensive exterior and medial wall post grafting and this was helped by mock surgery on the bone model.