**2. Clinical features**

The most common cause of injury in acetabular fractures is road traffic accidents and fall from a height [1, 2]. Usually acetabular fractures are associated with other major visceral injuries. There are very few literature available on the relationship of non-orthopedic injuries associated with acetabular fractures. Even though most of the acetabular fractures are caused due to axial compression along the femur, driving the femoral head into the acetabulum [3]. In a study on patients with combined pelvic and acetabular fractures, Dalal et al. reported 27% with traumatic brain injuries, even though there was relatively low rate of abdominal injuries [4]. According to him, some of the causative energy of the injury pattern is distributed to long bones before it reaches pelvis and torso, thus producing lower extremity fractures. Most of the posterior wall or column fractures are caused by axial forces transmitted to the acetabulum by knee and femur with the hip in adducted and flexed position—Dashboard injury. The other fracture pattern is caused by direct lateral compression force transmitted through the trochanter or indirect axial force along the femur in extended position of hip joint [5, 6]. In yet another study, it was noted that axial load pattern of injuries were associated with lung injury, retroperitoneal haematoma, traumatic brain injury and lower extremity fractures whereas incidence of genito-urinary injury, hepatic and splenis injury, pelvic vascular injury are more associated with lateral compressive type of acetabular fracture [7].

Life threatening injuries like head injury, abdominal and other visceral injury must get priority in the initial evaluation of acetabular fracture. Other skeletal injuries, like fractures of patella-ipsilateral shaft of femur, tibial plateau fractures and knee ligamentous injury are also looked into. The lower limb will be flexed, adducted and internally rotated in posterior dislocation of hip which is usually associated with posterior wall or column fracture whereas it will be in abducted, extended and externally rotated in anterior dislocation. Lateral displacement of the anterior superior iliac spine on the affected side might give clue regarding central fracture dislocation of hip. Local injuries including skin, open acetabular fractures and perineum and scrotal injury must be excluded. A closed degloving injury of the subcutaneous tissue which is detached from the underlying fascia—Morel-Lavele lesion must be looked into because of the risk of high infection and wound healing in post-operative period. These lesions are not apparent initially but become evident later [8]. A careful neurological examination to rule out sciatic and common peroneal nerve injury should be done. There are isolated reports of injury to iliofemoral artery associated with high anterior column fracture and superior gluteal artery injury in displaced fracture into the greater sciatic notch. Hence, high index of suspicion should be there to rule out vascular injury of the ipsilateral lower limb [9, 10].

Sometimes acetabular fracture can produce profuse bleeding and shock. According to Letournel and Judet "the cause of shock relates to severity of trauma and to hemorrhage from the fracture site and often from other visceral lesions. The respective part played by the various elements producing the shock may be difficult to apportion" [4]. According to Dalal et al. patients with acetabular fractures needed lower transfusion rate than with pelvic fractures. But in yet another study out of 16 acetabular fracture, 2 fracture required embolization compared to 9 of the 100 pelvic fractures. The transverse and posterior wall fractures often require blood transfusion. Both column fractures, T-shaped fracture, fracture with extension into the sciatic notch and those fracture associated with pelvic injury are more likely to have greater blood loss and may need blood transfusion [11].
