A case report of the management and the outcome of a complete epiphyseal separation and dislocation with left anterior column fracture of the acetabulum.

INTRODUCTION: Femoral head and neck fractures in children are uncommon, accounting for fewer than 1% of all pediatric fractures and fewer than 8% of all hip fractures. Furthermore, traumatic transphyseal hip fracture is rare to present in daily practice especially when associated with an acetabular fracture. PRESENTATION OF THE CASE: A twelve years old boy, not known to have any chronic illnesses, presented to the emergency department as a case of polytrauma after a road traffic accident. Signs of left hip dislocation were discovered upon physical examination. X-rays and CT scans, revealed a complete transphyseal posterior dislocation and a left anterior column fracture of the acetabulum with a minimal displacement. Within five hours, the patient underwent open reduction and internal fixation by two cannulated screws. The acetabular fracture was managed conservatively. After six months, there were clear signs of osteonecrosis of the femoral head. DISCUSSION: A high-energy trauma in children and adolescents can lead to simultaneous epiphyseal and acetabular fractures which are associated with a poor prognosis. The age seems to play a role as patients older than ten years have a higher risk of developing AVN after sustaining a hip dislocation regardless of the time of intervention.
CONCLUSION: Epiphyseal fracture with dislocation of the femoral head is rare among children and adolescents, especially when associated with an acetabular fracture. AVN in such cases can develop, and it represents a challenge to orthopedic surgeons due to the poor prognosis and the future functional limitations of the joint.

Introduction

The rates of lower limb fractures or dislocations are relatively uncommon among children. It is even more infrequent to face a case of a hip dislocation with a concomitant acetabular fracture [1], [2]. Since traumatic transphyseal hip fractures are rare, the published data related to them are scarce. However, such fractures can lead to a permanent deformity of the hip joint [3]. The goals of treatment in the aforementioned injuries are early anatomic reduction, maintenance of reduction until complete healing, and minimization of any associated complications. In this study, we present the management along with the follow-up findings of a rare case of proximal femoral epiphysiolysis with a posterior dislocation of the femoral head and a concomitant acetabular fracture.

Case report

A twelve-year-old boy, not known to have any chronic illnesses, was an unrestrained frontal passenger in an automobile when it rolled over after a collision into another car. The patient presented to our emergency department at King Saud Medical Complex as a case of poly-trauma. After resuscitation and assessment, he was conscious, alert and oriented. The patient only recalled the rollover and did not remember how his injuries exactly occurred. Upon the secondary survey, there was shortening, external rotation of left lower limb, and tenderness of the left hip joint. The patient had a decreased and painful range of motion. The distal neurovascular status of the left lower limb was intact. Radiological assessment, including x-rays and computed tomography (CT) scans, revealed a complete transphyseal posterior dislocation and a left anterior column fracture of the acetabulum with a displacement of less than five millimeters (Fig. 1). After seeing the radiographic studies, we believe that the mechanism of injury was a high impact on the knee with the hip flexed more than 90°.

Figure 1

X-ray and C-scan showing complete transphyseal separation and dislocation of the femoral head associated with anterior column fracture of left acetabulum.

Due to the difficulty of closed reduction of the dislocated hip, the patient was prepared for an emergency operation and was given prophylactic antibiotics prior to surgery. After five hours from the accident, he was shifted to the operating room and placed in a lateral position on the OR table. Under general anesthesia, the patient underwent an open reduction through a Kocher-Langenbeck approach. The surgery was meticulously performed as none of the nerves or vessels were injured during the superficial or deep dissection. The damage was minimized to the surrounding soft tissues, including the quadratus femoris, to avoid compromising the blood supply from the medial circumflex femoral artery. The internal fixation was maintained by two cannulated 6.5 mm screws (Figure 2, Figure 3). Multiple C-arm radiographic images of different views were taken during surgery and immediately after the insertion of the two cannulated screws to confirm proper reduction and fixation. There were no intra-operative complications or breach of sterility. The acetabular fracture was managed conservatively since the displacement was less than five millimeters.

Figure 2

Post-operative AP and lateral X-ray views revealing the fixation with the two cannulated screws.

Figure 3

Axial and coronal CT cuts demonstrating a well reduced epiphysis.

Post-operatively, the patient was doing well, as he had no complications and did not develop any neurovascular deficits. He was kept on skin traction for one week and was instructed not to bear weight on the left lower limb.

The patient was seen in the clinic after one month, two months, four months, and six months and radiographic assessments were performed each time (Fig. 4). The last visit revealed clear signs of osteonecrosis of the femoral head. After ten months from his surgery, the patient was readmitted for a removal of the cannulated screws (Fig. 5) and at the same admission a magnetic resonance imaging (MRI) of the left hip was performed confirming the presence of avascular necrosis (AVN). Since that time, the patient has been followed-up on regular basis for his AVN and managed in a similar manner to that of Perthes disease. He has been exercising the thigh muscles as instructed by the physiotherapist in our hospital and prescribed paracetamol for his pain. So far, these measures have caused noticeable relief and the patient is now living a normal life despite the occasional pain and the limitation when playing sports.

Figure 4

X-ray images of the left hip after one month, four months and six months respectively.

Figure 5

A post-operative X-ray image of the left hip taken after removing the two cancellous screws.

Discussion

Children and adolescents are prone to develop hip dislocations with even a minimal trauma due to their relatively cartilaginous acetabulum and their generalized ligamentous laxity [4]. In 75% to 92% of the cases, the femoral head dislocates posteriorly [5], [6]. The position of the hip at the time of accident plays a major role since an adducted hip that sustains a forceful impact, as in dashboard injuries, would dislocate posteriorly [7]. We believe that this was the case in our patient because at the time of their car's first impact into another vehicle, he was a frontal seat passenger. A high-energy trauma in this group of patients can lead to simultaneous epiphyseal and acetabular fractures which are associated with a poor prognosis [8].

The incidences of AVN after a hip dislocation in pediatrics varied widely ranging between zero and 92% [9]. In this regard, a recent systematic review and meta-analysis emphasized on the reduction of a traumatic dislocated hip within 12 from the time of injury to prevent AVN since the odds ratio of AVN can reach up to 5.63 following a delayed reduction (after 12) [10]. Nonetheless, published scientific evidence stated that the dislocations of the hip should be reduced within the first six hours, making this case a real emergency. The majority of authors agreed upon the paramount importance of an early reduction, even within the six-hour period, to minimize the risk of AVN as every hour matters in preventing this catastrophic complication [4], [7], [11].

Despite the early intervention, our patient developed AVN of the femoral head. The age seems to play a role as patients older than ten years have a higher risk of developing AVN after sustaining a hip dislocation regardless of the time of intervention [10], [12]. Furthermore, Mohammad et al. [8] reported a similar case which ended up with an AVN in a fifteen year-old boy.

In the literature, treatment choices in similar cases generally involve open reduction and internal fixation. However, some authors have presented closed reduction as the preferred treatment choice in certain circumstances [6]. In pediatric patients who develop AVN, a future surgery, like total hip arthroplasty, is usually inevitable; however, the variety of options in terms of conservative management should be considered first to delay surgical intervention and thus further revisions [5], [13].

Conclusion

Epiphyseal fracture with dislocation of the femoral head is rare among children and adolescents, especially when associated with an acetabular fracture. AVN in such cases can develop despite the early intervention and it represents a challenge to orthopedic surgeons due to the poor prognosis and the future functional limitations of the joint.

Conflicts of interest

None.

Funding

The study was not funded by any party.

Ethical Approval

From the research center at King Saud Medical City, Riyadh, KSA.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of the journal on request.

Author contribution

Jesus Palencia: study concept and design, data collection, writing parts of the paper, revising the manuscript.

Saud Alfayez: data collection and interpretation, writing parts of the paper, submitting and revising the manuscript.

Firas Serro: data collection and interpretation, writing part of the paper, revising the manuscript.

Jamal Alqahtani: data collection and interpretation, reviewing the paper.

Hani Alharbi: data collection, reviewing the final manuscript.

Hamed Alhinai: data interpretation, literature review.

Guarantor

Jesus Palencia.