The "safe zone" for infrapectineal plate-screw fixation of quadrilateral plate fractures: An anatomical study and retrospective clinical evaluation

Quadrilateral plate fractures

During the last two decades, extended scientific interest focused on quadrilateral plate (QLP) fractures as part of common acetabular fractures. The QLP corresponds to the medial wall of the acetabulum, and different fracture pattern of Letournel´s fracture types are associated with concomitant QLP fractures. Except anterior and posterior wall fractures, all other fracture types may be associated with QLP fractures. QLP fracture features include simple fracture lines up to highly comminuted fractures. A detailed preoperative analysis of these fractures is important to get a better understanding of intraoperative decision making. No consensus exists regarding the optimal classification and treatment of QLP fractures. Various operative approaches and treatment concepts exists depending on the specific QLP fracture type and the acetabular fracture type. Several new implants were development for optimal but often individual stabilization concepts. The gold-standard is still some medial buttressing during internal fixation predominantly using plates, but also screw fixation is considered an option. Additional dome impactions must be considered as an integral part in any QLP fracture analysis and stabilization.

Special contoured pelvic brim reconstruction titanium plate combined with trans-plate buttress screws (quadrilateral screws) for acetabular fractures with quadrilateral plate involvement through the anterior ilioinguinal approach

Background

Managing complicated acetabular fractures involving the quadrilateral plate (QLP) can be challenging for surgeons, especially when complicated by comminution and osteoporosis. Traditional implants do not provide sufficient fixed strength or a proper match. The new-type pre-contoured infrapectineal buttress plates may have drawbacks, such as inaccurate fitting on the medial surface of QLP and an inability to apply reversed compression force to resist medial displacement of femoral head. Therefore, the primary purpose of this study is to introduce a novel technique that utilizes a special contoured pelvic brim reconstruction titanium plate combined with quadrilateral screws to reduce and stabilize acetabular fractures involving the QLP through the ilioinguinal approach. Additionally, the secondary purpose is to evaluate both clinical effectiveness and radiological outcomes of this technique for QLP fractures.

Methods

We conducted a retrospective analysis of prospectively collected data from 48 patients (31 males and 17 females) who suffered from acute displaced fractures of the QLP and were treated between January 2012 and December 2019 using a special contoured plate combined with quadrilateral screws. The patients' mean age was 47.56 ± 11.31 years (range: 19-73 years). Fracture patterns included 20 both-column fractures, 12 anterior column and posterior hemitransverse fractures, eight T-type fractures, five transverse fractures and three anterior column fractures with the QLP affected, all of which had femoral head protrusion. Immediate postoperative reduction quality was evaluated according to Matta's criteria. Final clinical functions were assessed during follow-up using the modified Merle d'Aubigné and Harris Hip scores (HHS).

Results

The patients were followed up for an average of 48.36 ± 12.94 months (ranging from 24 to 84 months). The mean operative time was 246.08 ± 54.30 min (ranging from 178 to 397 min), and the average blood loss was 715.16 ± 263.84 ml (ranging from 400 to 2000ml). The radiological grading at postoperative stage showed anatomical reduction in 30 patients (62.50%), satisfactory reduction in 14 patients (29.17%), and poor reduction in four patients (8.33%). At the final follow-up, no re-protrusion of the femoral head was observed. In terms of functional outcome, the mean modified Merle d'Aubigné-Postel score was excellent in 26 patients (54.17%), good in 17 patients (35.42%), fair in four patients (8.33%), and poor in one patient (2.08%). The HHS was excellent in 23 patients (47.92%), good in 20 patients (41.67%), fair in four patients (8.33%), and poor in one patient (2.08%). The average HHS was 87.38 ± 7.86 (ranging from 52 to 98). Postoperative complications included lateral femoral cutaneous nerve injury in two patients, delayed wound healing and subsequent development of an inguinal hernia in one patient. Late complications were observed in two patients, with one case of heterotopic ossification and another case of post-traumatic osteoarthritis underwent hip arthroplasty within two years after surgery.

Conclusion

Our results indicate that employing the contoured plate specifically designed for QLP injuries, in conjunction with quadrilateral screws through the ilioinguinal approach, can lead to positive outcomes in the treatment of displaced acetabular fractures involving the QLP. This straightforward and efficient technique offers a viable option for surgeons who are managing complex acetabular fractures.

New screw technique for posterior column and ischial fixation from the anterior approach for acetabular fractures

Management of the ischial fragment in acetabular fractures is a considerable problem. In this report, we presented how to drill or screw around the posterior column and ischium from the anterior approach using a novel 'sleeve guide technique' and the difficulty of plating. A sleeve, drill, depth gauge and driver from DepuySynthes were prepared. The portal was about 2-3 cm inside the anterior superior iliac spine opposite to the side of the fracture. The sleeve was inserted to the screw point around quadrilateral area through the retroperitoneal space. Drilling, measuring screw length by a depth gauge and the screwing were performed through the sleeve. Case 1 used a one-third plate and case 2 used a reconstruction plate. With this technique, the approach angles to the posterior column and ischium were inclined, and plating and screw insertion could be performed with a low risk of organ injury.

Differences in fixation to young and elderly quadrilateral surfaces with anatomic quadrilateral surface plate (AQSP) based on cortical thickness morphological results

Aims

With relatively thinner cortical thickness, the management of acetabulum osteoporotic fractures in elderly patients is difficult. The aim of the research was to compare and present the morphological characteristics of the quadrilateral plate in young and elderly age groups, such as the area, and position distribution of the thin cortical thickness region, fracture lines maps, and propose a revised design plate for elderly patients based on these anatomic information.

Methods

As a retrospective research, acetabular fracture with one normal hemipelvises, including 110 men and 39 women, were collected to present the morphological characteristics of the quadrilateral region. The subjects were divided into three different age groups: Group I = 18–40 years (31.3 ± 6.6 years), Group II = 41–60 years (49.9 ± 5.3 years), and Group III ≥ 61 years (68.7 ± 6.8 years). The area of the quadrilateral surface, the area and position distribution of the thin cortical thickness region, the ratio and fracture lines maps were calculated and compared with Mimics in different groups.

Results

The thin cortical thickness/width region area (TCWRA) was significantly increased in Group III compared with Group I and Group II. The ratio of TCWRA accounted for in the quadrilateral region was also significantly increased in Group III (≥ 61 years) compared with Group I (P = 0.01) and Group II (P = 0.011). None of the subjects had a component involving the “A” zone, thirty-three thin cortical thickness regions were located in the “B” zone, and one hundred and sixteen involved both zones of the quadrilateral plate (“A + B” zone). Furthermore, there were a significant differences in the fracture line distributions in three age groups. More fracture lines of elderly patients were located at anterior part (B zone) compared with Group I and Group II.

Conclusions

It was identified the area of thin cortical thickness region increased as age grown, and fracture lines were inclined to be more distributed in “B” zone in elderly patients. To meet the demands of acetabular fixation in different age groups, cortical thickness changes in young and elderly individuals should be given special attention when the quadrilateral surface plate is designed.

Level of evidence Level IV, observational study.

How to Solve Anatomical Mismatch in Fixation of Acetabular Fractures Using an Anatomical Quadrilateral Surface Plate

The anatomical quadrilateral surface buttress plate developed for the quadrilateral surface in an acetabular fracture, a type of fracture difficult to reduce using screws and plates due to its thinness, is a useful implant that makes surgical treatment easier. However, the anatomical structure is different for each patient, and it often does not match the contour of this plate, making detailed bending difficult. Here, we introduce a simple method for controlling the degree of reduction using this plate.