Clinical application of a minimally invasive cement-augmentable Schanz screw rod system to treat pelvic ring fractures.

PURPOSE: The purpose of this study is to analyze the results using the USS fracture MIS system (DePuy Synthes) to treat instable pelvic ring fractures. As its outstanding feature, it is the only Schanz screw and rod system at present that combines angular stability, perforation/fenestration of the screws for cement-augmentation, a variable screw length, and a large screw diameter.

MATERIALS AND METHODS: Retrospective investigation of 134 pelvic ring fractures treated in 2012-2013. Twenty-five patients obtained the abovementioned implant. Besides baseline characteristics of the included patients and the surgical procedure, a clinical/radiological follow-up of six months was analyzed.

RESULTS: Dividing the collective into two groups, I high-energy trauma and II fragility fracture of the pelvis, the following results were recorded: group I: ten patients, six male, age 48.4 ± 19.7 years. Mean ISS 41 ± 22.5, fracture classification: AO/OTA type 61 B1 /C1 /C3  = 1/5/4. Operative treatment: three transiliac internal fixator, seven iliolumbar fixation, one implant was cement-augmented. Group II: 15 patients, 14 female, age 77.5 ± 10.1 years. Fracture classification according to Rommens: FFPII /III /IV  = 6/1/8. Operative treatment: eight transiliac internal fixator, seven iliolumbar fixation, 14 implants were cement-augmented. Overall surgical side complications: 16%. Radiological examination: correct positioning of all ilium screws. Follow-up after six month (16 patients): all showed fracture consolidation. One ilium screw was broken close to the connecting clamp.

CONCLUSION: The investigated Schanz screw rod system is a suitable implant to broaden the established procedures to stabilize dorsal pelvic ring fractures.

TRIAL REGISTRATION: The study is registered at the Clinical Trial Registry University of Regensburg (Number Z-2017-0878-3).