Post-traumatic bilateral posterior hip dislocations with femoral head fracture on one side and acetabular fracture on the other side: a very rare presentation

Abstract

Hip dislocations are common orthopaedic emergencies which need early intervention to have a better outcome. They usually occur as a result of high energy trauma with motor vehicle accidents being the most common cause followed by fall from height. Posterior hip dislocation is more common than anterior. However, bilateral hip dislocations are rare compared with unilateral. Here we report our case with bilateral posterior hip dislocation with one side having head of femur fracture and contralateral side acetabulum fracture. Both hips were reduced under general anaesthesia on the same day of the trauma. Staged definitive treatment was carried out. The patient had an early recovery with no complications. This case represents an unusual, type of injury resulting from a high speed motor vehicle accident. Early diagnosis, immediate resuscitation and reduction of the hip joints followed by a careful and planned definitive treatment is necessary to have a better outcome.

Background

Post-traumatic hip dislocation are not so rare injuries which have a very high morbidity and mortality. The most the most common type of hip dislocation is the posterior type, constituting 85%–90% of hip dislocations. However, bilateral hip dislocation is rare, amounting to only 1.25% of all hip dislocations.¹ Asymmetrical hip dislocations are rarer and account for roughly 0.01%–0.02% of all joint dislocations.² These high energy injuries are usually associated with injuries like acetabular or proximal femoral fractures. It is very crucial to evaluate the patient for such associated injuries.^{3 4} Early diagnosis and immediate reduction must follow to prevent future complications like avascular necrosis (AVN), stiffness and secondary arthritis of the joint.³ We present our case and management strategy which would give some insight to the readers about how to tackle such once-in-a-lifetime rare case.

Case presentation

A 25-year-old male presented to the casualty with alleged history of road traffic accident. The mechanism of injury was such that he was thrown over from a speeding motorcycle. He was brought to the casualty with multiple abrasions all over the body and soft tissue injury of the face. On examination, his Glasgow Coma Scale was 15/15 with stable vitals, his left lower limb appeared to be shortened more than the right side and both hips were locked in a flexed attitude. There were no neurovascular deficits and no associated long bone fractures. The patient did not have any other significant injury except for facial soft tissue injury and fractured mandible. The patient was then resuscitated and shifted for X-rays of the pelvis, chest and other trauma screening radiographs. His X-rays revealed left hip posterior dislocation with acetabulum fracture and right hip posterior dislocation with a bone fragment in the joint. The patient was immediately taken up for reduction under general anaesthesia. Reduction of both the hip joints was easy however, the hips were highly unstable on both sides. Bilateral proximal tibial skeletal traction was applied and a 3D CT scan was performed post reduction. CT scans showed left hip posterior dislocation with undisplaced transtectal acetabular fracture with grossly displaced posterior wall acetabular fractures and the right hip posterior dislocation with head of femur fracture (Pipkin’s type 2). Staged definitive treatment was executed. He is currently under regular follow-up and has asymptomatic recovery.

Investigations

Along with the standard radiographs for pelvis, a 3D CT scan was asked for better understanding of the pattern of these injuries and better preoperative planning (figures 1–3A, B).

Figure 1.

Pelvis with both hips and upper half of femur, radiographs revealing bilateral hip dislocation with left acetabular fracture.

Figure 2.

3D CT scan showing the left hip posterior dislocation with undisplaced transtectal acetabular fracture (yellow ring) with grossly displaced posterior wall acetabular fractures (yellow arrow).

Figure 3.

(A) 3D CT scan showing left hip posterior dislocation with grossly displaced posterior wall acetabular fractures (yellow arrow). (B) 3D CT scan showing right side posterior hip dislocation with head of femur fracture (Pipkin’s type 2) (yellow arrow).

Differential diagnosis

Very rarely, anterior hip dislocation on one side and posterior dislocation on the contralateral side has been described in the literature. In an anterior dislocation of the hip joint, an obvious mass will be palpable anterior to the hip joint. In our case, a palpable mass was felt posterior to the hip joint.

Treatment

The right hip fracture dislocation was addressed with safe surgical dislocation and head fragment was fixed with Herbert’s headless screws. Three days following the first surgery, the left hip was approached by Kocher-Langenbeck approach and the posterior wall fragments were reduced and fixed with screws and buttressed with a reconstruction plate (figure 4). Since the anterior column fracture was undisplaced and also the patient had bilateral hip injuries, which required him to be confined to bed for 4–6 weeks, it was decided not to fix the anterior column on the same day in order to reduce surgical morbidity. Postoperatively, the patient was put on deep vein thrombosis (DVT) prophylaxis. In bed, gradual range of movement of bilateral hip joint was initiated to prevent any myositis ossificans. He was started on walker-assisted gait training after 6 weeks.

Figure 4.

Postoperative radiographs showing the femoral head and acetabular fixation with concentric reduction of hip joints.

Outcome and follow-up

The patient has been under regular follow-up. At 9 months postoperative follow-up, the patient has been full weight bearing without any pain or limp. His latest radiographs of the pelvis revealed union of the fractures and no evidence of any AVN of the femoral head (figures 5–7).

Figure 5.

Latest follow-up radiographs showing union of fracture and no evidence of avascular necrosis of the femoral head.

Figure 6.

Latest follow-up radiographs showing union of fracture and no evidence of avascular necrosis of the femoral head.

Figure 7.

Clinical image showing the patient’s ability to bear full weight on both the lower limbs without any obvious lurch.

Discussion

Hip joint inherently is a very stable joint as a result of which the dislocation of the hip joint is not commonly encountered. Therefore, the hip dislocates only when there is a high energy trauma.⁵ Among all the dislocations, hip dislocation amounts to about 2%–5%, of which, 93% of dislocations are posterior and the rest anterior dislocation. However, bilateral dislocation of the hip joint is very rare, accounting for only 1.25% of the hip dislocations.^{2 4} The pattern of injury is attributable to the position of the lower limbs at the time of the injury.¹ Our patient was thrown over from a speeding motorcycle with posterior-directed forceful impact on both knees. At the time of presentation, both his hips were in a flexed and adducted attitude. One must look out for other associated injuries like acetabular fracture, femoral head fractures, femoral neurovascular injury, sciatic nerve injuries, intrapelvic injuries, femur and patella fracture in such high energy trauma.⁵ Such patients have to be screened as per the advanced trauma life support protocol and necessary radiographs must be taken at the earliest.¹ Positioning a patient with bilateral hip dislocation may be difficult for taking Judet radiographic views.⁶ There is no need for a CT scan prior to the reduction of the dislocation; however, a CT screening of the hip can be done if the patient needs any other part to be screened to rule out solid organ injury or head injury. Ideally, a 2 mm (thin slice) CT scan has to be asked after the reduction of the joint to look out for any loose bodies or acetabular or femoral head fractures, and also as an aid for better surgical planning.^{1 4 7}

Early diagnosis and reduction are the most important prognostic factors for a hip dislocation. The risk of developing AVN is directly proportional to the duration of the head being outside the joint and also repeated attempts of reducing the joint increases the risk for developing AVN.^{1 3} Thus, it is necessary to attempt reduction with adequate general anaesthesia. The ideal recommended duration for joint to be reduced is within 6 hours.⁵ The risk of developing AVN is 6%–27% for early reduction and for delayed reduction it is 48%.⁸ Also associated femoral head fractures would increase the risk of AVN. A prompt and early reduction followed by early staged fixation of the associated fracture is very essential to have a better outcome. Postreduction skeletal traction may or may not be needed depending on the stability of the hip joint. In our case, following the hip reduction, the patient was put on the skeletal traction as both the hips were highly unstable. On day 3 of admission, he underwent femoral head fixation and on day 5 he underwent fixation of the acetabular fracture.

Following definitive treatment, the initiation of weight bearing is still highly debatable. Many studies favour early mobilisation and weight bearing to minimise the complications like AVN, stiffness and myositis. However, there are many studies which declare that there is no relation of AVN, stiffness with respect to delayed mobilisation.⁵ There is no standard recommendation for the duration of rest following reduction; however, most common followed is 4–6 weeks of rest.^{4 5} In our case, the patient was confined to bed for a period of 4–6 weeks; however, in bed, gentle hip mobilisation was initiated and he was under mechanical and chemical prophylaxis for DVT. At 6 weeks, walker-assisted gait training was initiated. Subsequently, the patient has to be followed up regularly to look out for features of AVN or secondary osteoarthritis. Pain is the most common presenting complaint of AVN and it needs evaluation in the form of X-rays and MRI or bone scan.¹

Our patient has been under regular follow-up and is asymptomatic for the last 9 months. As per the literature review, similar cases of bilateral hip dislocation have been published but most of them are associated with acetabular fracture.^{1 4} The uniqueness of our case is that the femoral head fracture on the right side and acetabulum fracture on the left side adds on to more complex type of injury which warrants a good resuscitation, preoperative planning and a good surgical team for having a good outcome. In conclusion, traumatic bilateral hip dislocations are very rare injuries which need an early and prompt reduction, proper preoperative planning, staged definitive treatment and gradual rehabilitation for a better outcome in the long run.

Learning points.

• Bilateral hip fracture dislocations are rare injuries caused by a result of very high energy trauma.

• A prompt and an early reduction under general anaesthesia followed by detailed radiographical evaluation of the injury pattern is very much essential for having a better outcome.

• Staged definitive treatment has to be planned, taking the patients’ general health status into consideration.

• Slow and gradual rehabilitation protocol has to be followed to minimalise any postoperative complications.

• The patient has to be counselled regarding the delayed presentation of avascular necrosis of the femoral head, secondary osteoarthritis and the need for regular evaluation.