gms | German Medical Science

Objectives: In fragility fractures of the pelvis (FFP), fractures of the posterior pelvic ring are nearly always combined with fractures of the anterior pelvic ring. When a surgical stabilization of the posterior pelvis is performed, a stabilization of the anterior pelvis is also recommended. It is not clear whether conventional plate osteosynthesis is a valid option in patients with osteoporotic bone.

Methods: We retrospectively reviewed medical charts and radiographs of all patients with a FFP, who underwent a plate osteosynthesis of the anterior pelvic ring between 2009 and 2019. Patient demographics, patient characteristics, properties of the osteosynthesis, complications and revision surgeries were documented. Single plate osteosynthesis (SPO) at the pelvic brim was compared with double plate osteosynthesis (DPO) with one plate at the pelvic brim and one plate anteriorly. We hypothesized that the number and severity of complications in DPO are lower than in SPO.

Results and Conclusion: 48 patients with a mean age of 76,8 years were reviewed. In 37 cases, SPO was performed, in 11 cases DPO. Eight out of 11 DPO were performed in patients with FFP Type III or IV. We performed significantly more DPO when the instability was located at the level of the pubic symphysis (p=0.025). More patients with a chronic FFP (Surgery > 1 month after Trauma) were treated with DPO (p=0.07). Infra-acetabular screws were more often inserted in DPO (p=0.056). Screw loosening (SL) was seen in the superior plate in 45% of patients. There was no SL in the anterior plate. There was more SL in SPO (51%) than in DPO. SL was seen near to the pubic symphysis in 19 of 22 patients, who had SL after SPO and in all 3 patients, who had SL with DPO. There was no SL in DPO within the first month postoperatively. We performed revision osteosynthesis in 6 patients (6/48), all belonged to the SPO group (6/37). The presence of a bone defect, unilateral or bilateral anterior pelvic ring fracture, post-operative weight-bearing restrictions, osteosynthesis of the posterior pelvic ring, and the presence of infra- or supra-acetabular screws did not significantly influence screw loosening in SPO or DPO.

In Conclusion, there is a high ratio of SL in plate fixation of the anterior pelvic ring in FFP. In the vast majority, SL is located in the pubic bone. DPO is associated with a lower ration of SL, less severe SL and a later onset of SL. Revision surgery is less likely in DPO.

In FFP, we recommend DPO instead of SPO for fixation of fractures of the anterior pelvic ring, which are located in or near to the pubic symphysis.