Outcome of internal fixation for unstable pelvic fractures: a series of 30 cases

ABSTRACT

A clinical study was conducted with the aim of finding the best methods for fixing the different types of unstable pelvic ring injuries, assessing the functional outcome after the various techniques and types of implants used and the union rate of pelvic fractures. Thirty patients, 26 males and 4 females, with a mean age of 31 years underwent open reduction and internal fixation for pelvic ring injuries. The mechanisms of injury were all high-energy injuries, 11 patients were hit by motor vehicles [pedestrian accidents] [37%], 10 patients were involved in motor vehicle accidents [MVA] [33%], 3 patients had crushing injuries [10%], 3 patients fell from heights [10%], and 3 patients were involved in motorcycle accidents [10%]. Fractures were classified according to both Young [13,14] and Tile [1] classification systems. All patients were evaluated preoperatively using the st and ard radiographs AP, inlet, and outlet views, and CT scans. The operative treatment consisted of a combination of anterior and posterior fixation in 20 cases, posterior internal fixation alone was used in 5 cases and anterior external fixation was added to posterior fixation in 5 cases. Postoperatively, patients were followed-up for a mean of 12 months [range 6-24 months] and were evaluated using the Majeed score [27]. Our results revealed the following. One patient died postoperatively. Radiologically, one had a poor result, 16 patients were excellent, 11 were good, and 2 had fair reductions. The mean Majeed [27] score was 82 [range 66-95] among the 29 patients, 21 patients scored 75 points or higher [72%], and 8 patients scored between 75 and 66 [28%], and one patient died 2 weeks postoperatively. We come to the following conclusions. Unstable pelvic fractures require an aggressive and well-planned therapeutic regimen. Combined anterior and posterior internal fixation is the optimal treatment for vertically and rotationally unstable fractures. Stabilization must be tailored to the individual fracture, the surgeon must be familiar with all the techniques and able to perform them confidently. Reduction to within 10mm seems to be adequate for functional results. Anterior symphyseal diastasis is best treated by internal fixation using a single 4.5mm reconstruction plate on the superior surface of the pubic bones with either 4.5mm cortical screws or 6.5mm cancellous screws, the approach used is a Pfannenstiel approach without cutting the rectii. Fractures of the pubic rami are usually stable and do not require an extensive surgical approach, so they are best treated by anterior external fixation with posterior fixation or bed rest until patient is able to perform straight leg raising. They should be fixed when present medially, and are associated with symphyseal diastasis requiring plate fixation. Sacroiliac joint dislocations or Denis zone I sacral fractures are best treated by percutaneous cannulated 7.0mm iliosacral screws in the supine position as this allows combining anterior fixation simultaneously. Denis zone II sacral fractures can either be treated by open reduction through a posterior para-median approach in the prone position. This method is preferred, since it allows removal of bony fragments from the foramina and avoids overcompression of the foramina and hence iatrogenic nerve injuries. Alternatively, percutaneous iliosacral screws can be used, in this case they must be fully threaded to avoid overcompression of the foramina. Denis zone III sacral fractures are actually spine fractures. SI fracture dislocations are best approached anteriorly with the patient supine and fixed with two 3-4 hole 4.5mm reconstruction plates with one screw in the sacral ala, and 2 screws in the iliac side. Iliac fractures associated with vertically and rotationally unstable fractures are best treated by 4.5mm cortical interfragmentary screws between the 2 tables supported by neutralizing 4.5mm reconstruction plates through an anterior or posterior iliac approach. Sacral bars allow for vertical displacement of the hemipelvis so should be reserved for use when the surgeon is not familiar with the technique of percutaneous iliosacral screw fixation. The 3.5mm reconstruction plates should be reserved for use in thin bones, or in female patients. For stabilization of the posterior pelvic ring injuries, the supine position is preferred whenever possible, especially in polytrauma situations. Using either anterior plating of the SI joint or percutaneous iliosacral screws is recommended. Percutaneous iliosacral lag screws can be performed quickly and safely, they can restore posterior alignment and accomplish stable fixation except in very comminuted sacral fractures; therefore the need for an open posterior approach is minimized. The surgeon should decide which fracture to fix first according to the patient and the fracture. Generally, percutaneous iliosacral screw fixation in the supine position allows simultaneous anterior open reduction, as after the pelvis has been reduced both anteriorly and posteriorly, radiographic images are taken, then iliosacral screws are inserted and the anterior plate is fixed. The same is applicable with the anterior approach to the SI joint