Occult external iliac vein injury after anterior dislocation of the sacroiliac joint in adult patient.

Anterior dislocation of the sacroiliac joint, characterized by dislocation of the ilium anterior to the sacrum, is a subtype of complete posterior pelvic ring disruption. This injury occurs mostly in children. We present an adult patient with anterior dislocation of the sacroiliac joint. It was associated with numerous complications. To the best of our knowledge, it is only the second case reported in the literature.

Introduction

Fracture-dislocation of the sacroiliac joint is an important component of pelvic fractures. It is characterized by dislocation of the ilium posterior to the sacrum, which is the most frequent type of sacroiliac joint dislocation. Ilium dislocation anterior to the sacrum is rare and presents unique radiological manifestation. This distinctive injury is a subtype of complete posterior pelvic ring disruption. Several cases of anterior sacroiliac joint dislocations have occurred in children.1, 2, 3, 4 We present herein a case of anterior dislocation of the sacroiliac joint in an adult that was caused by severe violence. It was followed by complications, including an occult vascular injury after pelvic disruption that could have resulted in significant morbidity and even death.

Case report

A 38-year-old man suddenly developed pain in his pelvis after being hit by a truck. The initial assessment revealed visible subcutaneous ecchymosis in the hypogastrium and obvious scrotal swelling (Fig. 1). Plain radiography (Fig. 2) and computed tomography (Fig. 3) showed a pelvic fracture with anterior dislocation of the sacroiliac joint. After the patient's general condition was improved by the standardized advanced trauma life support protocol, he underwent urethral realignment, bladder colostomy, and drainage of the scrotal incision. The patient was stable postoperatively. He was placed in temporary skeletal traction of the tibial tubercle and prepared for the second surgery to address his pelvic fracture with internal fixation. Ten days later, however, his blood pressure suddenly dropped to 50/30 mmHg during a sneezing episode. Angiography revealed no apparent pelvic vascular damage (Fig. 4). He was then given an emergency blood transfusion and simultaneous volume expansion therapy.

Fig. 1

There was visible subcutaneous ecchymosis in the hypogastrium and obvious scrotal swelling on examination in the emergency room.

Fig. 2

Plain radiography shows a typical pelvic fracture.

Fig. 3

Computed tomography shows anterior dislocation of the sacroiliac joint.

Fig. 4

Angiography reveals no apparent pelvic vascular damage.

Physical examination revealed abdominal distension, abdominal tenderness, and rebound tenderness. Emergency laparotomy revealed a large amount of uncoagulated blood (about 4000 ml) and remnants of clotted blood (Fig. 5). Careful probing uncovered branches of a ruptured external iliac vein (Fig. 6), which was quickly repaired with 1.0 sutures (Ethicon, Johnson & Johnson, Tokyo, Japan). The patient's blood pressure then stabilized. He refused, however, to undergo open reduction internal fixation of the pelvic fracture. Skeletal traction of the tibial tubercle was therefore used successfully to reduce the sacroiliac joint (Fig. 7). The patient insisted on being discharged from the hospital 19 days later.

Fig. 5

Large amount of uncoagulated blood (about 4000 ml) and remnants of clotted blood were found during the operation.

Fig. 6

Branch of the ruptured external iliac vein was found (arrow).

Fig. 7

Postoperative, predischarge view of the patient in traction.

Discussion

Although there have been reports addressing anterior dislocation of the sacroiliac joint—wherein the ilium dislocates anterior to the sacrum instead of posterior to it—in children, there are few reports of this dislocation in adults. To the best of our knowledge, we are the first to report the anterior dislocation of sacroiliac joint in an adult patient in the English-language literature. Xue et al, in the Chinese literature, reported a pelvic fracture with this distinct dislocation in a 31-year-old man who had been hit by a car. The patient suffered from pelvic fracture with anterior dislocation of the sacroiliac joint, a pubic rami fracture, and symphysis diastasis. Associated injuries included injury of the sacral nerve, ischiadic nerve, and urethra. Open reduction and internal fixation were performed via an arc incision in the posterior sacroiliac joint combined with an anterior Pfannenstiel incision.

There is a lower incidence of combined injuries (e.g., pubic fractures) in children than in adults because of the greater plasticity of the children's pelvic bones and their thick periosteum, increased elasticity and flexibility of the symphysis pubis and sacroiliac joints, stronger ligaments, and increased capacity for energy absorption in the cartilaginous area.1, 2, 3, 4 It is not surprising, then, that anterior dislocation of the sacroiliac joint in adults is associated with more combined injuries, such as symphysis diastasis, iliac fracture, urethral injury, and occult vascular injury.

Among these combined injuries, the most important is the occult vascular injury, which may occur when the ilium is moving forward because of the impact experienced by the patient. In the present case, the ruptured branch of the external iliac vein was not apparent on angiography and so posed a serious threat to the patient. Even though we discovered this occult vascular injury and successfully rescued the patient, we have a lingering fear that it might happen again. We reported it here with the hope that other doctors could learn from our experience and be highly vigilant regarding its possibility when confronting these fractures in adults. Thus, the patient's vessels should be the primary exploration before addressing other problems as it can save the patient's life during the course of treatment.

The shortcomings and deficiencies of this case include the fact that the patient refused further surgery for internal fixation of his fracture. He was a devoutly religious man, convinced that God helped him escape death. He refused further treatment based on this belief. We therefore cannot provide complete information of this particular case. Our main goal, however, was to warn other orthopedic surgeons to be vigilant when repairing an anterior dislocation of the sacroiliac joint in adults that was caused by a high-energy injury as it can be accompanied by serious combined complications. In terms of this goal, we believe that we have been successful.

In conclusion, the incidence of anterior dislocation of the sacroiliac joint in adults can be expected to rise considering the increasing number of motor vehicles on the roads, especially in China. Emergency doctors and orthopedic surgeons should pay close attention to combined injuries, especially in regard to occult vascular injury, when confronting these fractures.