Borrelli et al. firstly reported the cases of pelvic crescent fracture-dislocation, and all patients were fixed with hollow screws and plates through posterolateral approach [6-7]. For the treatment of type Ⅱ CFD, the main surgical method is ORIF by anterior or posterior approach. The advantages of anterior approach surgery are completely expose, accurately anatomical reduction and immediately stabilize the sacroiliac joint, but the disadvantages are major surgical incision, long operation time, severe soft tissue damage, and L5 and S1 nerve root injury [16-18]. However, the posterior approach surgery has superiority in exposing the posterior structure of the iliac bone, reducing blood vessel and nerve injury, the enough space for placing plate and anatomical reduction of fractures besides the reduction of sacroiliac joint [6-8,11, 19]. ORIF will cause more intraoperative bleeding, greater surgical trauma, and a relatively higher incidence of postoperative incision complications, which also affects the efficacy of surgery.
In recent years, minimally invasive techniques for closed reduction and percutaneous fixation of pelvic fractures have made great progress [21-24]. On the basis of the Day classification, we tried to apply percutaneous sacroiliac joint screws plus posterior iliac screws to treat type II CFD, achieving the purpose of minimally invasive treatment [25]. In this study, we found that PCSIF has less surgical trauma, less intraoperative blood loss, shorter operation time and lower infection rate than traditional methods. But the shortcomings were that the quality of sacroiliac joint reduction was unguaranteed and the placement of screws required frequent X-ray confirmation. There was no significant difference between the two groups in terms of postoperative Matta score. The mean Majeed score at the last follow-up in Group A was higher than that in Group B. However, the difference was not statisticall significant and might be related to the small number of patients.
The key to the treatment of type II CFD with percutaneous cross screw internal fixation is reduction, so it is necessary to select the appropriate case. The patients with crescent fracture rupture, abnormal sacral anatomy, and dissatisfied with closed reduction are not suitable for this operation. In the order of fixation, the sacroiliac joint is fixed first, and then the percutaneous posterior iliac screw is used to fix the iliac fracture. The fluoroscopic examination should be repeated to ensure the guide pin inserts correctly. Piston-like movements should be done during the insertion of the guide pin to feel the guide pin walking in the iliac bone. The more mistakes in placing the guide pin, the more likely the screw will loosen and shift.
There were several limitations in this study. First, this was a retrospective study, and selection bias was unavoidable. Second, the data in this article came from a single center and the amount of data was limited. Third, the follow-up time was relatively short. Furthermore, there was no comparison of anterior approach and posterior approach surgery. It is necessary to expand the sample size in future studies for further comparison. Therefore, a further investigation with a larger sample size and a prospective randomized controlled design are needed.