C T g k b a he purpose of this final chapter is to present interesting cases requiring creative or demanding solutions for acropelvic unit (SPU) fixation from several busy spinal reonstruction practices. The pathology represented ranges rom infection, trauma, and degenerative disease to complex pinal deformity and tumor reconstruction. Considering the ide spectrum of pathology, the vast array of instrumentaion available, and the number of possible fixation points in he SPU, it is not surprising that many surgical options are vailable. Although the author’s (M.O.B.) predilection is for liac fixation in any situation requiring adjunctive sacropelvic nit fixation beyond S1, it is not always required. Depending n the biomechanics of the reconstruction, the available soft issue coverage, previous surgery, and available bone stock, ones 1, 2, or 3 fixation may be sufficient for a particular case. Inadequate fixation of the SPU can result in nonunion, instruentation failure, and deformity. Therefore, in this biomechanially challenging environment, more instrumentation rather han less may be better as a rule of thumb when considering xation to the SPU. Concerns regarding prominent distal hardare or sacroiliac joint irritation ought not to deter the spinal econstruction surgeon from utilizing this valuable anatomic eal estate to achieve immediate postreconstruction stabilization f the lumbosacral spine. Iliac fixation can always be removed if t is too prominent or if postoperative complaints develop, sugesting sacroiliac joint irritation. In the author’s experience