Cement augmentation of sacroiliac screws in fragility fractures of the pelvic ring-A synopsis and systematic review of the current literature.

BACKGROUND: Fragility fractures of the pelvis (FFP) show a notable rise in prevalence. Minimally invasive surgical fixation of FFP is increasingly advocated for its obvious advantages with reference to early mobilization and weight bearing. Concerns regarding the holding power of osteosynthetic materials in osteoporotic bone led to the development of cementing techniques. However, the role of cement augmentation in the surgical treatment of FFP has yet to be defined. Therefore, the aim of this study was to conduct a systematic review of the current literature concerning studies that are comparing the performance of cement augmented versus non-augmented sacroiliac (SI) screws.

METHODS: We conducted a systematic literature review from 01/01/2000 onwards. Inclusion criteria were randomized controlled studies, case series (n>3), biomechanical studies and reviews, comparing augmented and non-augmented SI screws. Only papers in German or English language were included.

RESULTS: Out of 1247 initial hits, eleven studies met the inclusion criteria. Out of those, six were biomechanical studies and five were clinical case series. Most biomechanical studies showed cement augmented screws to have a greater mechanical stability, both regarding pull-out force and resistance to cyclic loading. The five case studies reported on a total of 98 patients with 122 screw fixations. Three cases of cement leakage into neuroforamina occurred, however, none of these patients showed clinical symptoms.

CONCLUSION: In clinical case series, cement augmentation of SI screws appears to be a safe surgical technique without relevant complications and biomechanical studies demonstrate greater pull-out forces of augmented SI screws but no advantage in regard of cyclic loading. Hence, applicability of the mechanical testing results on the clinical situation are debatable. So far, there are neither retrospective nor randomized controlled studies comparing the performance of cemented and non-cemented SI screws in FFP. Therefore, the clinical benefit of SI screw cement augmentation is unclear and their use remains experimental.