Chronic osteomyelitis of the right femur after electrical burn: A case report

Abstract

Introduction and importance

Osteomyelitis is a bone infection that can occur as a rare late complication of electrical burns. It may occur in any bony part of the body where there has been an electrical burn injury. Osteomyelitis occurs several weeks or months after the initial infection, and can persist for several months or years, and is difficult to manage. To our knowledge, to date, no chronic osteomyelitis of the femur has been reported after an electrical burn injury.

Case presentation

The present case report is of a 40-year-old man who sustained a high voltage electrical burn injury involving his right upper and lower limbs as well as the posterior trunk. The estimated total body surface area burned was 20 %. He developed chronic osteomyelitis of the right femur several months after the initial injury.

Clinical discussion

The upper extremities are the sites most frequently affected by chronic osteomyelitis following electrical burns. Staphylococcus aureus is the most common causative organism, and treatment entails a combined medical and surgical approach.

Conclusion

Osteomyelitis of the long bones of the lower extremities is an uncommon complication of electrical burn injuries involving the lower limbs. We, however, advocate a high index of suspicion when faced with electrical burns of the lower extremity.

Highlights

• •Osteomyelitis is a rare complication of electrical burn injury.
• •Electricity is a devastating cause of burn injury.
• •Electrical injuries often have entry and exit wounds.
• •The upper limb and cranial vault are the most common sites of osteomyelitis following electric burns.
• •It takes several months after an electrical burn injury for osteomyelitis to occur and treatment is often very difficult.

1. Introduction

Osteomyelitis is a bone disease that refers to a progressive inflammatory process that leads to the destruction and necrosis of bones [1]. It usually occurs through one of three main mechanisms: the focus of infection, vascular insufficiency, or hematogenous spread. Trauma, including electrical burns, can be a source of contiguous spread of infection to the bone, leading to eventual osteomyelitis. This condition is usually painful and frustrating for both patients and doctors [2]. Chronic osteomyelitis is said to occur approximately six weeks after initial infection and can persist for several months or years. It is difficult to treat, requires a combination of surgical and medical treatment approaches, and can persist for many years [3].

Electricity is an uncommon but devastating cause of burn injuries, usually leading to severe complications, particularly following high-voltage injuries.

However, osteomyelitis resulting from electrical burns is a rare condition. Osteomyelitis involving the long bones of the lower extremities resulting from an electrical burn injury is even rarer. To our knowledge, no such case has been documented; therefore, we present this report.

We present a case of high-voltage electrical burn injury complicated by compartment syndrome of the right forearm that led to amputation and subsequent osteomyelitis of the right femur.

This case report is in line with the SCARE 2020 guidelines [4].

2. Case report

A 40-year-old right-handed male painter presented to us 2 h after an electrical burn injury. He was painting a commercial bank building when he misstepped on his ladder and fell into an unfenced electric transformer that was nearby, making contact with the transformer with his right forearm. He did not receive immediate first aid and was rushed to a nearby private hospital, where he received initial care before being referred to us. He was brought to the emergency room on a stretcher. He sustained an estimated 20 % burn to the total body surface area (TBSA) that affected his right arm and forearm, the posterior trunk, and the right thigh. Management commenced using the unit's burn management protocol. He is not hypertensive or diabetic and has no significant past medical history.

He had entry and exit wounds on the medial side of the elbow and the lateral part of the upper thigh, respectively, and no other associated injuries, as shown in Fig. 1. The wounds were unhealthy. The entry wound measured 8 cm by 14 cm in its widest diameter and contained exposed, nonviable muscle bellies at the common flexor origin of the forearm muscles. The exit burn wound involved approximately 4 % of his TBSA, with a central, round, full-thickness wound measuring about 10 cm by 14 cm in the widest diameter and, exposing a non-viable lateral group of thigh muscles. At presentation, he had compartment syndrome of the forearm, for which he underwent an emergency fasciotomy in the emergency room and later had debridement of all other wounds (Fig. 2). The forearm muscles appeared dusky, with doubtful viability. Subsequently, he developed wet gangrene of the right forearm and arm, which required a high above-elbow amputation of the right upper limb. Post-operatively, he became depressed and underwent sessions of psychotherapy with clinical psychologists.

Fig. 1.

Showing entry and exit wounds. Yellow arrow shows entry wound while black arrow shows exit wound. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 2.

A&B. showing the upper limb and thigh wounds after initial debridement.

He initially declined a split-thickness skin graft for his right thigh burn injury and continued with wound dressing. The dressings were done daily at the initial stage and alternated daily subsequently when the wound was cleaner. Dressings were done with 0.9 % normal saline, Bactigras®, povidone iodine solution, and honey. Wound culture yielded the growth of E. coli. The chest radiographs, the ECG and the initial X-rays of the right thigh were unremarkable. Inpatient care was continued until he was finally discharged to the outpatient clinic for follow-up after 2 months of admission. He was seen regularly at the outpatient clinic, and five months after discharge, he finally agreed to have a skin graft done for his residual wounds when he realized the wounds were not healing. The wound culture at the time of the skin graft yielded no growth. Upon discharge after the split-thickness skin graft, he defaulted from the clinic and presented again 4 months later (one year after the initial injury) with multiple discharging sinuses at the site of the skin graft on the thigh. A wound culture revealed growth of Staphylococcus aureus, and a repeat X-ray of the thigh showed clear evidence of chronic osteomyelitis (Fig. 3), as reported by the radiologist. He was informed of the nature of the pathology, and the treatment options were clearly explained to him, but he declined osteomyelitis surgery due to financial constraints. He continued with wound dressings and antibiotics and was subsequently lost to follow-up.

Fig. 3.

A&B. showing features of osteomyelitis (sequestrum) as shown by the arrows.

3. Discussion

Osteomyelitis that complicates electrical burn injuries is rare. The commonest sites of osteomyelitis following electrical injury are the upper limb and the cranial vault [5]. One case report described a 28-year-old male who sustained a 46,000-V cranial electric injury that resulted in devascularisation, necrosis, and secondary infection of the skull despite aggressive surgical debridement and antibiotic therapy [6]. Another case report described an 8-year-old boy who reported nonhealing forehead wounds for 6 months following accidental contact with a high-voltage power line [7]. Our search of the literature did not return any cases of chronic osteomyelitis of the femur resulting from an electrical burn injury, hence this case report. High-voltage electrical burn injuries in adults usually occur outdoors and are mostly related to occupation. Most victims are male electricians. Our patient, even though he is not an electrical worker, sustained his injury while working.

When the body comes into contact with electricity, the electric current completes its circuit by exiting the body from the point closest to Earth. The point from which the current enters the body is described as the entry point, whereas the point of contact with the earth is the exit point. The upper limb has been reported as the most common entry point for electrical injury [[8], [9], [10]]. However, the scalp has also been reported as a common entry point for electrical injury, though less frequently than the upper limb [5,11]. Our patient had an entry point on the right elbow and an exit point on the lateral aspect of the right thigh. The entry point, in this case, correlates with what has been previously reported.

The complications of electrical burns can occur early or late after the injury, and osteomyelitis is one of the later complications that could occur. When an electric current enters the body, the bone, being the tissue with the most resistance, takes up more of the heat. This causes burns to the periosteum, leading to ischemia and eventual osteonecrosis, which ultimately leads to osteomyelitis of the affected bone. Another possible mechanism is the contiguous spread of pathogenic organisms from the burn wound into the bone marrow, leading to infection. In cases where the patient develops sepsis, there could be a hematogenous spread of infection into the bone marrow, which may eventually lead to osteomyelitis. These factors can, individually or in combination, lead to osteomyelitis in a patient who has suffered a high-voltage electrical burn injury. Osteomyelitis complicating electrical burn injuries often occurs several months or years following the initial injury [12]. Our patient presented with features of chronic osteomyelitis about a year after the initial injury. It is difficult to accurately tell at what point he developed the infection because he was not compliant with clinic attendance. He also was unable to do serial X-rays because he had financial difficulties.

The diagnosis of osteomyelitis is based on the clinical finding of nonhealing wounds, which could be in the form of multiple sinuses with radiographic imaging features of dead bone that appear as “moth-eaten necrosis” and radiopaque sequestrum [13]. Magnetic resonance imaging (MRI) is the best imaging technique for the diagnosis of osteomyelitis, but in our practice environment, patients couldn't easily afford the cost of MRI, hence the reliance on X-rays alone for radiologic diagnosis. The radiologic features mentioned above only become obvious when almost half of the bone has become demineralized. A wound culture in our patient reported that Staphylococcus aureus was the causative organism. This is in agreement with other studies that have reported that Staphylococcus aureus is the most common cause of osteomyelitis [13].

Treatment involves a combined medical and surgical approach with long-term use of antibiotics and surgical debridement in which dead bone (sequestrum) is radically removed and then a durable soft tissue cover is provided to cover the attendant residual wound. This can be very frustrating to both the patient and the surgeon and can affect the patient's quality of life. Our patient was on antibiotics and outpatient wound care since he declined any surgical intervention. Unfortunately, he defaulted on treatment and was lost to follow-up.

4. Conclusion

Post-electrical burn osteomyelitis is an uncommon complication of an electrical burn injury that usually occurs long after the initial injury. It can occur in any bony part of the body where there has been an electrical burn injury. However, the upper limbs and skull are the most commonly reported locations. This finding of osteomyelitis in the long bone of the lower extremity should raise an increased index of suspicion when surgeons are faced with an electrical burn injury to the lower extremities.

Sources of funding

None.

Ethical approval

Our study is exempt from ethical approval.

Consent

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

Research registration

Not applicable.

CrediT authorship contribution statement

Innih A. Kadiri: Conceptualised the study. All authors participated in the literature survey, preparation, and proofreading of the final draft of the manuscript.

Declaration of competing interest

None