1.  Introduction

According to data recently released by the World Health Organization (WHO), road traffic accidents ranked among the top 10 leading causes of death in 2011, a reality that was not existent a decade ago. The increase of road traffic involving high-energy trauma has impacted the incidence of traumatic hip dislocation [1,2]. We report a rare case of a traumatic obturator dislocation of the right hip with fracture of the ipsilateral femoral head.

2.  Case Presentation

A 34-year-old man was refered to the department of trauma and orthopedic surgery at Ibn sina University Hospital two hours after a fall from height during incident in construction. On admission, patient compained about hip pain and inability to move the right lower limb. In the physical examination, the right hip was flexed to 82^°, externally rotated, and abducted to 50^° (Figure 1).

There was neither neurovascular dificiency or associated injuries. Radiograph of the pelvic revealed obturator dislocation of the right hip with fracture of the ipsilateral femoral head (Figures 2,3).

The dislocation was reduced under general anesthesia 3 hours after the trauma. Radiograph and CT-scan showed a good reduction of the dislocation and the fracture (Figures 4-6).

Traction was applied for three weeks followed by progressive mobilization. Full weight bearing was allowed after three months. At two years’ follow-up there were no signs of osteonecrosis of the femoral head and the patient regained good function.

3.  Discussion

Hip dislocation is a disruption of the joint between femoral head and acetabulum, commonly classified according to the direction of the dislocation, either anterior or posterior [3]. Anterior dilocation is rare than posterior one (9-12 %), classified as superior (pubic), inferior (obturator) and perineal type. Obturator disocations are uncommon injury, occurring in less than 5% of all traumatic hip dilocations [4-6]. This injury occurs by flexion, abduction and externally rotation of the hip, besides road traffic accidents are the most common cause of this injury [5]. Femoral head fractures were usually reported to be located on the posterosuperior and lateral portions of the femoral head [7,8]. In our case it was a fracture of anterior femoral head with a direction on the oblique coronal plane. This injury must be reduced within 6 hours after trauma to reduce the risk of avascular necrosis [9] and traction is recommended for three to six weeks after, followed by progressive mobilization and loading [10,11]. Follow-up examination is necessary to anticipate arthritic changes and osteonecrosis of the femoral head [12].

4.   Conclusion

Obturator dislocation of the hip with ipsilateral femoral head fracture is rare. Its rarity is due to the inherent stability of the joint, its deep position in the pelvis with strong ligaments and bulky muscles around the articulation. The diagnosis and treatment are crucial in the management of these injuries.

1. The 10 Leading Causes of Death in the World, 2000 and 2012. 2013.
2. Global Status Report on Road Safety 2013.
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