Minimally invasive surgery under fluoro-navigation for anterior pelvic ring fractures

Abstract

Background: The incidence of pelvic fractures in trauma patients is reported to be 3-8.2%, with roughly half of these fractures being caused by high energy injuries with a potential for catastrophic hemorrhage and death. Indications for internal fixation of anterior pelvic ring are controversial. Because of fears of disturbing the pelvic hematoma and causing additional hemorrhage, open reduction and internal fixation of pelvic ring disruption is routinely delayed. In contrast to conventional surgery, percutaneous screw fixation is gaining popularity in the treatment of pelvic and acetabular fractures mainly because of minimal soft tissue damage, less operative blood loss, early surgical intervention and comfortable mobilization of the patient. Fluoro-navigation is a new surgical technique in orthopedic trauma surgery. This study is to investigate clinical results of fluoro-navigation surgery in anterior pelvic ring fractures.

Materials and methods: From January 2006 to October 2011, 23 patients with anterior pelvic ring fractures were treated with percutaneous cannulated screw under fluoro-navigation. There were 14 men and 9 women, with a mean age of 40.1 years (range 25-55). According to the AO and Orthopedic Trauma Association classification, there were seven A 2.1, two A 2.2, one A 2.3, six B 1.2, one B 2.1: 1, one B 2.2, one C 1.2, two C 1.3 and two C 2.3 types of fractures. Amongst these patients, 13 had posterior pelvic ring injuries, 8 had other injuries including urethral, lumbar vertebrae fractures and femoral fractures. All patients were operated when their general condition stabilized after emergency management. The mean time from injury to percutaneous screw fixation of the anterior pelvic ring fracture was 12 days (3-15 days). All the anterior ring fractures were fixed with cannulated screws by two senior surgeons. They were familiar with the navigation system and had gained much experience in the computer-assisted percutaneous placement of screws.

Results: A total of 32 screws were inserted, including 19 in the pubic ramis and 13 in the anterior acetabular columns. The average surgical time was 23.3 min/screw. The average time of X-ray exposure was 19.1 ± 2.5 s/screw. The virtual images of fluoro-navigation were compared with real-time X-rays during and after the surgery. Compared to the final position of the screw, the average deviated distance was 3.11 mm and the average trajectory difference was 2.81°. Blood loss during the operation was minimal (22.3 ml/screw). One screw (3.1%) deviated out of the fracture site during the operation. No superficial or deep infection occurred. No patient sustained recognized neurologic, vascular, or urologic injury as a result of the percutaneous screw fixation. All fractures united at the last followup.

Conclusions: Fluoro-navigation technique could become a safe, accurate, and fairly quick method for the treatment of anterior pelvic ring fractures. Standardization of the operative procedure and training are mandatory for the success of this procedure.

Keywords: Anterior pelvic ring fractures; Pelvis; acetabulum; fluoro-navigation; minimally invasive surgery; minimally invasive. fluoroscopy.

Figure 1

Anteroposterior radiograph of pelvis in a 32-year-old male showing a left fracture of the inferior public rami (a) pelvic anteroposterior, inlet, outlet, Judet views were obtained and displayed on a computer screen simultaneously (b) the real time spatial position of the guide sleeve was presented on four fluoroscopic projections. The extending blue dotted line was the virtual trajectory of the screw (c) A retrograde cannulated screw was inserted (d) Finally the screw was examined by fluoroscopy again and we used the virtual trajectory to evaluate the accuracy (e and f) The incision was about 20 mm (g) Postoperation X-ray (h)

Figure 2

Anteroposterior radiograph of a 43-year-old male with a left fracture of the anterior column of the acetabulum (a) pelvic anteroposterior, inlet, outlet, Judet views were obtained and displayed on a computer screen simultaneously (b), the real time spatial position of the guide sleeve was presented on four fluoroscopic projections. The extending blue dotted line was the virtual of the screwing trajectory (c and d). An antegrade cannulated screw was inserted (e). The incision was about 20 mm (f). Postoperation X-ray (g)

Figure 3

Average time per screw during steps of navigation surgery