The posterior approach to the pelvic ring continues to be associated with a high postoperative infection risk despite studies to the contrary [2
]. We set out to define the risk of deep surgical site infection using a larger cohort of unstable pelvic injuries (Type C) operated on by a group of surgeons trained in a specific technique and to determine if infectious complications led to the need for secondary reconstructive procedures.
We recognize limitations of our study. First, we had no set indications for treating with open reduction and internal fixation through the posterior approach and no specific treatment protocol for those patients having this treatment. Although the surgeons favored the posterior approach for treating unstable posterior pelvic ring injuries, the number of patients treated with alternative approaches for stabilization of the posterior ring resulting from injury pattern, patient factors, or conditions of the posterior soft tissue envelope is not known for the entire series of patients. Furthermore, we had no protocol for type and duration of perioperative antibiotics and these data were not compiled for this study. Second, we had only short-term followup. All patients included were operated on within 21 days of injury and followed for at least 3 months postoperatively. It is possible some late infections would not have been diagnosed in patients with short-term followup, especially in the setting of internal fixation. Third, we did not determine if infections affected the subsequent course of the patient. Open reduction and internal fixation reportedly decreases the incidence of nonunion and malunion after a pelvic fracture [29
] and reduces disability [14
] with a higher percentage of satisfactory results [29
]. Anatomic reconstruction of the pelvic ring may be important, but other factors can influence patient-reported pain, function, and ability to return to work [8
]. Therefore, we cannot comment on the impact of soft tissue complications on patient-reported results of the injury. Finally, we did not evaluate reductions and/or subsequent loss of reduction and therefore we cannot comment on whether the increased risk of infection is warranted in comparison to closed reduction and internal fixation.
Using the technique described, the posterior approach to an unstable posterior pelvic ring was associated with an infection rate of 3.4%. This rate is much less than that reported by Goldstein et al. [12
] or Kellam et al. [22
] in the early era of pelvic open reduction and internal fixation. These authors attributed the higher infection rates to prolonged operating times or a crushing mechanism of injury. Our rate also falls in the middle of those reported in other smaller series and is lower than that reported for the addition of spinopelvic fixation to sacral fractures (13%) or spinopelvic dissociations (16%) [1
]. It approximates the rate in large series of operatively treated acetabulum fractures (2.3% to 4.9%) [24
]. Because this series includes a wide variety of injuries and surgeons of differing experience from a spectrum of practice environments, we believe the rate reported likely represents a realistic expectation for this approach performed by individuals trained in pelvic surgery who deem the posterior soft tissue appropriate for an open procedure.
No additional soft tissue reconstructive procedures other than surgical excision, débridement, and closure were required as a result of the approach. Of those developing an infection, five of eight (62.5%) underwent some change in the pelvic fixation during treatment of the infection.
Previous studies have appropriately focused attention on the status of the soft tissues after pelvic fractures. Appropriate nursing care, an anatomic-based approach, identification and treatment of soft tissue degloving injuries [15
], débridement of severely contused or necrotic tissue at surgery, and changes in fixation technique may all account for the improvement in soft tissue complications. A careful overall evaluation of the patient and soft tissues will help in making appropriate choices regarding techniques for reduction and fixation of posterior ring injuries. A posterior approach as described for open reduction and internal fixation of posterior pelvic ring injuries has a 3.4% deep surgical site infection rate and no major soft tissue complications occurred in this study. The authors continue to advocate the use of the posterior approach when necessary for reduction of posterior pelvic ring injuries in patients without a severely compromised posterior soft tissue envelope.