The management of malalignment in hip revision surgery.

When facing revision surgery, the deformation of the femur must be considered for the important implications in the strategy of the operation and the choice of the implant. Deformation can occur in varus and retroversion, or both, in different degrees. For severe varus deformations a straightening osteotomy is generally indispensable and different types of distal fixations of the implant are necessary; in milder deformations other solutions are possible. Retroversion can be generally managed with proximally modular stems, stems without metaphyseal component, or, rarely, with a derotation osteotomy.