Comparison of two surgical treatment strategies for fragility fractures of the pelvis based on early postoperative mobility outcomes using insole force sensors.

Introduction: Increasing incidences for fragility fractures of the pelvis (FFP) have been reported and surgical treatment remains demanding. While conventional screw osteosynthesis is a common method, complications may arise due to altered bone morphology in the osteoporotic pelvic bone. The iFuse implant system is a novel implant, first introduced for treatment of degenerative sacroiliac joint dysfunction, which offers promising biomechanical characteristics with potential benefits for treatment of FFP. Yet data on the use for FFP is limited. The objective of this study is to compare early postoperative mobility of patients treated with screw osteosynthesis only versus patients treated with additional iFuse stabilization based on insole force sensor gait analysis. We hypothesized that additional iFuse implantation leads to superior postoperative mobility.

Materials And Methods: In the prospective observational study, 37 orthogeriatric patients with FFP types II-IV were included. Postoperative mobility of patients treated with conventional screw osteosynthesis only (group 1) and patients with additional iFuse implantation (group 2) was compared. Mobility was examined using insole force sensors (Loadsol, Novel GmbH).

Results: Postoperative comparison of gait analysis showed no significant difference in average (APF) and maximum peak force (MPF) between group 1 (n = 19, APF 64.9% ± 13.3, MPF 76.0% ± 14.1) and group 2 (n = 18, APF 67.6% ± 9.9, MPF 78.2% ± 10.1). Gait symmetry measured by FTI (force-time integral) ratio was significantly higher in group 2 (48.5% ± 3.3) than in group 1 (44.9% ± 5.4; p = 0.023). Median Barthel Index was higher in group 2 (55) compared to group 1 (45), yet not significantly (p = 0.058). Postoperative pain levels showed no significant differences between both groups.

Conclusion: Comparison of early postoperative mobility showed similar mobility outcomes in both groups. Patients with additional iFuse implantation had a more balanced gait pattern, whereas no significance was found in peak force parameters. Additional iFuse implantation showed promising results regarding patient mobility, therefore our hypothesis was partly confirmed. In future long-term examinations with larger patient cohorts should be aimed for.