Short-term mobility in low-energy pelvic ring fractures after conservative treatment

Background: The growing population of elderly people is leading to a rising number of pelvic ring fractures. These often involve combinations of pubic branch and sacrum fractures, as seen in lateral compression type 1 (LC1) and 2 (LC2) fractures or more precisely classified as fragility fractures of the pelvis (FFP). The combined impact on the anterior and posterior ring brings the risk of prolonged pain, resulting in decreased mobility and increased complications. Given the higher multimorbidity of this population, surgical treatment poses a greater risk of intra- and post-operative complications. Hence, the management and treatment of this particular type of fracture remain challenging. Methods: A retrospective data analysis of 41 patients (F/M; 27/14) treated conservatively for low-energy LC1 or LC2 fractures was performed between 2017 and 2020. The fractures were classified using Rommens' FFP classification. The primary outcome was mobility at 2 and 6 weeks, assessed through chart analysis and phone interviews. To determine factors influencing patient outcomes fracture consolidation was assessed via X-ray analysis. As a secondary outcome logistic regression and decision tree analyzes were conducted. Results: The mean age at the time of fracture was 79.8 +/- 12.5 (SD) years. Thirty-two patients regained mobility (F/M; 25/7) after 2 weeks. Another 7 patients were mobile after 6 weeks (F/M; 2/5). Two male patients did not regain mobility. Male sex emerged as the sole independent predictor of non-mobility at 2 weeks (p = 0.0037). Age, BMI, pubic branch fracture dislocation >5 mm, analgesic use of opiates, corticosteroid therapy, alcohol and smoking showed no association with mobility recovery. Fracture consolidation was observed in 73.2 % of patients (F/M; 21/9), while one female had no consolidation. Ten patients (F/M; 5/5) were lost to follow-up. Conclusions: Our study shows that LC1 (FFP IIb, IIc) and LC2 (FFP IIIc, IVb) fractures can be effectively treated conservatively, with successful remobilization within 6 weeks. The only independent negative predictor of early mobilization was male sex. Pubic branch displacement >5 mm did not affect the outcome. Therefore, conservative management proves to be a viable option for low-energy LC1 or LC2 fractures. Level of Evidence: IV (retrospective study).