Posterior pelvic ring injury of straddle fractures: Incidence, fixation methods, and clinical outcomes

Straddle fracture, a superior and inferior ramus fracture of both sides, is generally treated conservatively. However, posterior pelvic ring injury is often associated with straddle fracture, leading to unstable pelvic bone fracture that requires surgical treatment. The present study reports the clinical and radiological outcomes of straddle fracture with posterior pelvic ring injury. This study included 73 patients (41 men, 32 women) with a straddle fracture injury. The injury mechanism, injury severity score (ISS), accompanying injuries, presence of posterior pelvic ring injury, and fixation methods for the pelvic fracture were analyzed, and outcomes were evaluated functionally and radiologically. Of the 73 patients, 56 (77%) had a posterior pelvic ring injury and 7 died. In 43 patients, the posterior pelvic ring injuries constituted unstable pelvic injury and were treated surgically. The fixation method was determined based on the severity of the posterior pelvic injury. The patients’ mean ISS was 24.7 points. Radiological evaluation of surgical outcomes in 43 patients revealed the outcomes as anatomic in 20, nearly anatomic in 14, moderate in 5, and poor in 4, whereas functional evaluation revealed the outcomes as excellent in 21, good in 9, fair in 7, and poor in 6. Posterior pelvic ring fracture can accompany straddle fractures, which may lead to pelvic injury instability. Thus, special attention is required for patients with a straddle fracture.