Surgical treatment of acetabular fractures involving the anterior and posterior columns remains a challenging task. Over the recent years, ilioischial plate application has become increasingly popular as a treatment option for acetabular posterior column fractures along with posterior plate and posterior column screws [13–16]. However, the three methods are only suitable for acetabular posterior column fracture with a high fracture line (Fig. 1a, 2a-b).
There are several disadvantages when applying a posterior-approach plate for reducing acetabular fractures. First, an additional posterior approach is required. Second, the low level fracture line of the posterior column usually hampers posterior plate placement, which requires excessive soft tissue dissection. Additionally, since the displaced posterior column fracture fragment is generally rotating inward, the posterior plate mainly plays a “lift and pull” role on the posterior column fracture fragment, whereas the anterior fixation mainly produces a “push and pressure” force. Hence, anterior fixation is better suited for this scenario as per the biomechanical considerations. The three aforementioned conventional treatment methods also have certain limitations in treating low level posterior column fractures. Some authors have described inserting articular screws from the pubic bone to the anterior acetabular edge by the anterior approach to achieve fixation . However, posterior column fracture displacement is not a simple inward movement, but rotational displacement. Consequently, it is difficult to achieve an ideal control of rotation and inward displacement by placing only one screw in the “door axis” position (Fig. 2f). We observed that there was sufficient space to place a plate obliquely across the fracture line of the low level posterior column through the anterior approach. Additionally, the stability advantage over a single screw fixation was similar to that of an ilioischial plate . Furthermore, we found that the placement of oblique-ilioischial plates can be achieved only by exposing the anterior and middle fracture lines and the acetabular quadrangular region partially. Besides, this method was easier to perform when compared with the ilioischial plate technique and more conducive to protecting the local blood vessels and nerves.
In our series, the operation time, intraoperative blood loss, postoperative scores, and union time showed no significant differences with the existing literature [18–20]. This suggests that the oblique-ilioischial plate technique is a practical and effective option for acetabular low level posterior column fracture, especially in the case of acetabular fractures involving both anterior and posterior columns. Further, the method is superior to the traditional method of combining the anterior and posterior approaches. However, when applying the oblique-ilioischial plate technique, it is necessary to master the local anatomy, evaluate the patient’s condition carefully, and make a thorough preoperative plan to avoid complications such as local iatrogenic vascular and nerve injury. Largely, the indications of oblique-ilioischial plate are i) fresh acetabular fracture involving posterior column; ii) complex acetabular fracture involving the posterior column; iii) transverse fracture of the acetabular posterior column without the posterior wall. Additionally, a prerequisite as our study is that the case is suitable for the modified Stoppa approach.
There were several limitations to this study. First, the sample size was small and the follow-up duration was short. Second, the lack of a biomechanical analysis underlies the insufficient evidence supporting the superiority of the method. We also lacked sufficient experience in screw insertion in the posterior acetabular column, and we concluded that the general direction of the screw should be toward the ischial tubercle as much as possible to hold sufficient bone mass and obtain an ample insertion angle to avoid the articular cavity.
In conclusion, the oblique-ilioischial plate technique via anterior approach may be a good treatment option for acetabular fractures involving low level posterior column as it offers the advantages of reliable fixation, limited invasion, little intraoperative bleeding, and fewer complications. However, multicentric prospective control studies with larger samples are warranted to prove the safety and efficacy of the method.