Windhager et al. treated periacetabular sarcomas with a custom prosthesis (Howmedica, Germany). The size of the prosthesis was generated from 3-D CT reconstructions with resection margins defined by the surgeon. He reported satisfactory results with less complications than with arthrodesis, pseudoarthrosis, or saddle prosthesis.
Major surgical drawback: prosthesis needs to be exact fit as it is pre-ordered and made of precise measurements from 3-D Computed Tomography models.
Massive allografts/autografts and composite allografts.
Some proponents have had success with these techniques, but major complications are somewhere in the 25-35% range.
Which led to the development of the saddle prosthesis.