Anatomy Study Of Lateral-rectus Approach To Acetabular Fracture And Its Clinical Use

Background:Acetabulum fractures is caused by a severe trauma, its incidence is lower than other fracture. With the development of our country, the scale of industry and the number of motor vehicles are increasing, which make the high-energy injuries of acetabulum become more common. This is the one of reason leading to the increased incidence rate of acetabular fracture; The incidence of acetabular fractures in the elderly caused by osteoporosis is on the rise with an ageing population typically in modern society. All of these will make the orthopaedic surgeon pay more attention on acetabular fracture. However, the position of acetabulum is deep and the structure of the bone is complex which make the treatment of the fracture become a major challenge for orthopaedic surgeons.The treatment of acetabular fracture has changed from conservation treatment to open reduction and internal fixation, the process was formed through long-term exploration. Letournel developed the acetabular fracture classification according to the characteristic of the bone.For his study, The effect of open reduction and internal fixation of the displaced acetabular fracture is satisfactory. Letournel had make a significant contribution for acetabular fracture treatment.With the further study of anatomy and classification of acetabular fracture, the approach of treat acetabular fracture got rapid development. A retrospective analysis, 204 cases’ X-ray image of acetabular fractures made by Matta and his colleagues,show that an concept of roof-arc angle which provide a criterion to treat acetabular fracture by conservation treatment or by open reduction and internal fixation way. Simultaneously, Various approaches are successively applied in the treatment of acetabulum fracture, just like the Kocher-langengbeck approach which mainly used to treat the posterior wall or column fractures of acetabulum, the ilioinguinal approach which mainly used to treat the anterior column fractures of acetabulum. In addition, Using the Stoppa approach, had been used to treat ventral hernia at the beginning, to treat the acetabular fracture was advocated by Cole and Bolhofner. There are many other approaches for treatment of acetabular fracture, such as anterior iliofemoral approach, extensile acetabular approach, Y type approach, combined anterior and posterior approach and so on. All these approaches promote the treatment of acetabular fracture. There are many shortcomings in these approaches. For instance, Long-time learning curve, or leading a larger incision, or limiting the reduction effect. even more than that, bring about the complication of heterotopic ossification and neurovascular injury. In acetabular fracture, the correct choice of the surgical approach is mandatory to achieve accurate reduction and to avoid complications.Management of acetabular fractures involving the anterior column has become more challenging ad complex fracture patterns with involvement of the quadrilateral plate, medial displacement of the femoral head and significant impaction of the superomedial joint surface have increased in incidence. For the visualization, disimpaction and fixation of a fracture of the dome of the acetabulum with less surgical morbidity than has been associated with the ilioinguinal approach, orther approached have been described. However, an inadequate view or difficulty with residual articular incongruities detected on post-operative CT scans. Based on the cadaver specimen of Chinese adult, a new surgical approach is proposed to treat acetabular fractures for the aims of reducing time of operation and peri-operative bleeding. Through this approach, anatomical reduction of acetabular fractures which not involves posterior wall can be achieved by a minor incision. We supposed that this approach can obtain a good effect when it applied in clinical.Objectives:1.Based on the cadaver specimen of Chinese adult, define the tissue layers of the lateral-rectus approach, understanding the position of the blood vessels, nerves, and bony structures, and define the factors at risk in the surgical field and adjacent relationship of important neurovascular structures, provide anatomical basis for clinical application by anatomical study of lateral-rectus approach. We focused more attention on the exposure of the quadrilateral plate and medial of the posterior column, where we should be care of the soft tissue.2.For the purpose of using lateral-rectus approach to treat acetabular fractures. To explore the clinical effect and surgical operating points of lateral-rectus approach by retrospective for the internal fixation of acetabular fractures with anterior column and posterior semi-transverse and displacement of both anterior and posterior column. Providing a new approach for the treatment of complex acetabular fracture.Methods:1.Dissections were conducted on five human cadaver specimens(3 males,2 females). For each cadaver, an dissection was conducted on the right side of the abdominal wall to be acquainted with the anatomy. While on the contralateral side the lateral-rectus approach was used to simulate the surgical procedure to expose the pelvic ring. The lateral-rectus approach was divided into 3 windows. In this study, we observed neurovascular structures in one window which located between peritoneum and external iliac blood vessels, and in the another window is located between external iliac blood vessels and iliopsoas. Such as iliolumbar vessels, corona mortis vessels,obturator nerve, obturator vessels; Measured the distance from obturator nerve and obturator vessels to linea iliopectinea and the distance from corona mortis vessels to symphysis.2. From January 2012 to June 2014, in The Third Affiliated Hospital Of Southern Medical Univesity,26 patients with acetabular both-column fractures and anterior column and posterior semi-transverse fractures were surgically managed through the lateral-rectus approach. Based on inclusion criteria and exclusion criteria to choice object of study. They were 18 males and 8 females, with an average age of 42 years(from 19 to 61 years). According to Judet-Letournel classification, There were 17 anterior column plus posterior hemitransverse fractures,9 both-column fractures,8 cases involving the limb fracture. All these fractures were treated through the lateral-rectus approach, in the horizontal position with general anesthesia. The pre-bended plate was placed in interior pelvic ring to fix the anterior wall, anterior column and quadrilateral plate in direct sight. Then, the posterior column was exposed and fixed with antegrade lag screw. The follow-up was 4、12 weeks,6 momth,1 years, and the anteroposterior radiograph of pelvis and the X-ray examination of the fractured hip was performed.Results:1. The incision length of lateral-rectus approach was 9.0±0.7cm. Through the window between peritoneum and external iliac blood vessels, and the anther window between external iliac blood vessels and iliopsoas, the pubic symphysis, the front of pelvic brim, medical side of posterior column and quadrilateral plate can be revealed fully. The important blood vessels and nerves inside the window can be exposed under the direct sight. Obturator vessels and never were the most important structures at risk. The distance from the midpoint of obturator artery to line terminalis by retraction is 29.8±0.9mm, The distance from the obturator canal entrance of obturator artery to line terminalis is 19.1 ±1.1 mm. The distance from the midpoint of obturator vein to line terminalis by retraction is 39.5± 1.8mm, The distance from the obturator canal entrance of obturator vein to line terminalis is 20.2±1.1mm. The distance from the obturator canal entrance of obturator never to line terminalis is 18.1±0.9 mm, The distance from the starting point of inferior epigastric vascular to the sheath of rectus is 6.5±0.4cm.2.There were 37 causes of acetabular fractures treated by lateral-rectus approach. According to the inclusion criteria and exclusion criteria, There were 26 causes of anterior column plus posterior hemitransverse fractures and both-column fractures included. All the cases underwent the operation successfully. The lateral-rectus approach is 8cm-10cm, an average of 9.5cm. Operative time was ranged from 45minutes to 133minutes, with an average of 77 minutes. The intraoperative bleeding ranged from 150 ml to 700 ml, with an average of 430 ml. According to the Matta radiological evaluation postoperatively, anatomical reduction of acetabular fracture was 16cases,6 cases satisfactory reduction, discontented reduction was 4 causes, The rate of excellent and good was 84.6%. All patients were followed up for 6 to 18 months, the median follow-up time was 12 months, and all patients achieved bone union (rang 6 to 10 weeks, average 8 weeks). According to the modified Merle d’Aubigne and Postel scoring system,15 cases were excellent,8 good, and 3 fair after operation. The rate of excellent and good was 88.5%. During the follow-up time, there were no postoperative complications, such as fixator breakage, wound infection, femoral vessels and nerve injury, heterotopic ossification, traumatic osteoarthritis and so on.Conclusions:1.Before clinical applying lateral-rectus approach to treat acetabular fracture, cadaver dissection is important to minimize surgical risk. In this study, we obtain clear anatomical data through a single incision. The area of pubic symphysis, pelvic brim, medial side of posterior column and quadrilateral plate can be exposed clearly through that two windows. By doing this operation, we obtain nerve, vessel and orthpeadic structure measurement data which will provide reliable anatomical data for carrying out lateral-rectus approach to treatment of acetabular fractures.2.It achieved a satisfactory effect by using the lateral-rectus approach to treat acetabular fractures which were belong to anterior column plus posterior semi-transverse fractures and both-column fractures. The lateral-rectus approach is an ideal surgical approach for treatment of acetabular fractures. There are many advantages by using the lateral-rectus approach, The first is that using an 10cm incision to reset and fix the anterior and posterior column fractures providing an less injury than ilioinguinal approach does. The second point, the treatment of comminuted fracture of quadrilateral plate can be applied in direct sight, simultaneously, the plate is placed in the medial side of the quadrat to prevent the fracture block movement. Thirdly, Achieving the fixation of the anterior column fractures, then the posterior column was exposed and fixed with antegrade lag screw. By this way, we can reduce the damage and risk of complication. Fourthly, the horizontal position is conducive to anesthesia. Finally, the longitudinal incision can reduce the injury of femoral neurovascular and lateral femoral cutaneous nerve. The lateral-rectus approach is an ideal surgical approach for treatment of anterior column fractures of acetabulum, but it is a prior choice for treatment of acetabular fracture which is not involve the posterior wall.