Aims. Minimally invasive fixation of pelvic fragility fractures is recommended to reduce pain and allow early mobilization. The purpose of this study was to evaluate the outcome of two different stabilization techniques in bilateral fragility fractures of the sacrum (BFFS). Methods. A non-randomized, prospective study was carried out in a level 1 trauma centre. BFFS in 61 patients (mean age 80 years (SD 10); four male, 57 female) were treated surgically with bisegmental transsacral stablization (BTS; n = 41) versus spinopelvic fixation (SP; n = 20). Postoperative full weightbearing was allowed. The outcome was evaluated at two timepoints: discharge from inpatient treatment (TP1; Fitbit tracking, Zebris stance analysis), and ≥ six months (TP2; Fitbit tracking, Zebris analysis, based on modified Oswestry Disability Index (ODI), Majeed Score (MS), and the 12-Item Short Form Survey 12 (SF-12). Fracture healing was assessed by CT. The primary outcome parameter of functional recovery was the per-day step count; the secondary parameter was the subjective outcome assessed by questionnaires. Results. Overall, no baseline differences were observed between the BTS and SP cohorts. In total, 58 (BTS = 19; SP = 39) and 37 patients (BTS = 14; SP = 23) could be recruited at TP1 and TP2, respectively. Mean steps per day at TP1 were median 308 (248 to 434) in the BTS group and 254 (196 to 446) in the SP group. At TP2, median steps per day were 3,759 (2,551 to 3,926) in the BTS group and 3,191 (2,872 to 3,679) in the SP group, each with no significant difference. A significant improvement was observed in each group (p < 0.001) between timepoints. BTS patients obtained better results than SP patients in ODI (p < 0.030), MS (p = 0.007), and SF-12 physical status (p = 0.006). In all cases, CT showed sufficient fracture healing of the posterior ring. Conclusion. Both groups showed significant outcome improvement and sufficient fracture healing. Both techniques can be recommended for BFFS, although BTS was superior with respect to subjective outcome. Step-count tracking represents a reliable method to evaluate the mobility level. Cite this article: Bone Joint J 2021;103-B(3):462–468

Background. The suicidal jumper's fracture of the pelvis is a special form of sacrum fractures associated with high energy trauma. The typical H-type fracture pattern runs transforaminal on both sides with a connecting transverse component between S1 and S3. Due to the high-grade instability operative treatment is imperative. Aim of this study was to compare iliosacral double screwing (2×7,3mm canulated screw with 16mm thread) with spinopelvic internal fixation. Methods. Both methods were tested on 6 synthetic and 6 anatomical pelvises. After osteotomy and alternating osteosynthesis stability was tested with a universal testing machine (Zwick) in a simulated two-leg stand. Data were generated by a 3-dimensional computer-assisted ultrasoundsystem (Zebris©) (3 translational datasets x,y,z and 3 ankles). Testing was performed after preload of 50N and two setting cycles of 100N followed by a full load cycle of 150N. ASCII-data were then transferred to SPSS for statistical analysis. Results. Both experimental series showed similar results. There was a tendancy of less displacement when iliosacral screwing was performed. However, no statistical significance could be observed between both techniques. Discussion. Although the spinopelvic internal fixation is a more rigid system, the double screwing may compensate this as it interacts in the center of the fracture. We therefore think that iliosacral double screwing is an appropriate technique for stabilisation of this special fracture type. The possibility of percutaneous osteosynthesis and of its performance in a supine position, this procedure provides essential advantages for the operative treatment of polytraumatized patients