Augmented stabilization of a rare geriatric "open book"-injury, using a cement augmented internal fixator - a case report.

BACKGROUND: Pelvic ring injuries in elderly patients, particularly in the context of low-energy trauma, typically involve posterior ring structures due to underlying osteopenia or osteoporosis. However, symphyseal disruptions are extremely rare in this population. Pelvic ring injuries in elderly patients are increasingly common due to demographic changes, often resulting from low-energy falls. We present a unique case of a 77-year-old morbidly obese female with a Type B1.1 pelvic ring injury (APC-2, according to Young & Burgess classification), characterized by an open book lesion with no posterior fracture. Given the patient's body habitus and reduced bone quality, a minimally invasive internal fixator spine system was implanted and augmented with polymethylmethacrylate (PMMA) cement to enhance fixation strength and allow early mobilization.

CASE PRESENTATION: A 77-year-old female (BMI: 36 kg/m2) presented with a rare isolated Type B1.1 pelvic ring injury (Fig. 1A) following a domestic fall. After emergency stabilization using an external fixator, in a secondary definitive surgery a subcutaneous internal fixator was implanted bilaterally in a minimally invasive fashion. To improve fixation in the osteoporotic supra-acetabular bone, the screws were cement-augmented using PMMA. The patient showed good postoperative recovery, early mobilization, and stable radiographic outcomes at 6 weeks follow-up.

CONCLUSION: This case illustrates the feasibility and benefit of cement-augmented internal fixator of the pubic symphysis with a rare case of an "open-book" injury in elderly, obese female patient. Cement augmentation may offer additional pull-out strength in patients with reduced bone quality, facilitating early mobilization and avoiding complications related to implant loosening.