Case report: a case of single-sided shoulder blade fracture resulting from an electrical shock

Abstract

Electric shock injuries, a category of severe industrial accidents, often entail the risk of multi-organ damage. In the present unique case report, the infrequent occurrence of a right scapular fracture stemming from an electric shock accident is described. A male patient in his early 30s accidentally received an electric shock while working, resulting in pain in the right upper limb and shoulder. Although he had no obvious external injuries, physical examination revealed a decrease in muscle strength in the right upper limb. Following magnetic resonance imaging and computed tomography, a comminuted fracture of the scapula was diagnosed. The patient received emergency symptomatic treatment, including pain relief, anti-infection measures, and nutritional support for the myocardium, and subsequent orthopaedic surgical intervention for fracture fixation. The patient recovered well after surgery, with muscle strength gradually returning. This report documents the rarely-described occurrence of non-traumatic unilateral scapular fractures following an electric shock. Medical practitioners should be aware of the wide range of potential injuries, including fractures, when evaluating patients with electric shock injuries.

Introduction

Electric shock injuries occur when an electric current passes through the body, and can range from mild to severe depending on the voltage and current. Mild electric shocks typically cause superficial burns or skin pain, while moderate electric shocks can result in serious internal injuries or cardiac arrest. Severe electric shocks can be fatal. Even mild or moderate electric shocks may lead to complications, such as muscle spasms, irregular heartbeats, or nerve damage. ¹

In the USA, more than 20 000 people are reported to be hospitalized each year due to electric shock injuries, accounting for 4–6.5% of all burn unit admissions and resulting in more than 1 000 deaths. In developing countries, electric shock injuries are the leading cause of occupational injuries, with an incidence rate ranging between 21% and 27%. ² Falling after an electric shock is common and may lead to fractures. The most common electric-shock related skeletal injury is posterior dislocation of the shoulder joint, often accompanied by a fracture. ³

Electric shock injuries to the human body may have severe consequences, particularly electric shock fractures, which can affect multiple parts of the body, such as the back, hips, shoulders, and wrists.^4–9 Electric shocks may cause not only fractures but also skin burns, motor and sensory nerve deficits, dislocations, and other complications. ⁷ Several studies have stressed the importance of further research into the mechanisms, frequency, and patterns of electric shock fractures, as well as improving the effectiveness of identifying, diagnosing, and treating these injuries.^5,10 Previous reports have described a 6-year-old girl who experienced a distal radial buckle fracture after a 230V electric shock, ⁹ a 12-year-old boy who sustained bilateral distal radial fractures after a household electric shock, ⁸ a 41-year-old male who experienced a femoral neck fracture following a 300V direct current electric shock, ¹¹ and a 20-year-old male who experienced bilateral femoral neck fractures after an accidental 440V direct current electric shock. ¹² These cases illustrate that electric shocks of any voltage may lead to serious consequences that require urgent medical intervention and appropriate treatment strategies.^9,13 Furthermore, electric shocks may also cause rare scapular fractures.^14–16

In the present case, the patient experienced a rare nontraumatic scapular fracture after an accidental electric shock at work. Such a condition is rarely reported in the literature, highlighting the importance of detailed assessments for patients with electric shock injuries.

Case report

In March 2024, a male patient in his early 30s experienced an electric shock while working, which caused his right hand to be immobilized and resulted in pain in his right upper limb and shoulder. He was rescued by a colleague after approximately 10 min. The patient reported experiencing weakness and palpitations in addition to pain. However, he did not experience any dizziness, headache, loss of consciousness, difficulty breathing, or urinary or faecal incontinence during the entire incident. There were no secondary injuries, such as a result of falling or hitting an object.

Upon arrival at the hospital, the patient's temperature, pulse, respiration rate, and blood pressure were all within normal ranges. The patient reported pain in the right upper limb and shoulder, with a Medical Research Council manual muscle strength grading assessment of level 4 (where grade 0 = no contraction and grade 5 = normal muscle strength), indicating that the muscles could move against some resistance but were below normal level. The emergency physician conducted a comprehensive physical examination and found no obvious entry or exit wounds from electric shock or other significant abnormalities.

The emergency doctor immediately provided the patient with symptomatic supportive treatment, and completed relevant tests, including routine blood, liver and kidney function, myocardial infarction marker, blood gas analysis, coagulation function, and electrocardiogram tests. The results showed no obvious myocardial damage or organ dysfunction in the patient, but the pain in the right upper limb and shoulder continued.

After admission, the patient's vital signs and condition were reassessed. His vital signs were stable, but the right upper limb muscle strength remained at level 4, indicating a need for further treatment. The patient underwent a magnetic resonance imaging (MRI) scan of the shoulder joint, which provided detailed information regarding muscle and tendon injuries and suggested the possibility of a scapular fracture (Figure 1). A subsequent computed tomography (CT) scan with 3D reconstruction clearly showed the specific morphology and displacement of the fracture (Figure 2). These imaging results provided important evidence for the development of a treatment plan.

Figure 1.

Series of magnetic resonance images of the shoulder joint of a male patient in his early 30s who presented with pain in the right upper limb and shoulder following an electric shock, showing: (a) a partial tear of the supraspinatus tendon, characterized by an elevated signal intensity within the adjacent muscle tissue, suggesting an inflammatory process and the presence of oedema; (b) a discontinuity within the fibres of the infraspinatus tendon, suggesting a potential tear, and a noticeable irregularity in the integrity of the scapula, which may be indicative of an underlying fracture; and (c and d) widespread hyperintensity in the muscle tissues surrounding the shoulder joint, indicative of inflammatory changes or oedema, and an abnormal configuration in the scapula, which prompted further investigation to rule out any structural abnormalities (all indicated by red arrows).

Figure 2.

Computed tomography (CT) scan of the shoulder joint with three-dimensional (3D) reconstruction from a male patient in his early 30s who presented with pain in the right upper limb and shoulder following an electric shock, showing: (a) the location and direction of the fracture line (arrow); (b) the displacement of the fracture fragments (arrow); (c) a 3D reconstructed stereoscopic view of the scapular fracture, facilitating its comprehension; and (d) detailed information on the fracture and surrounding anatomical structures, providing precise reference information for surgical procedures.

Based on the MRI and CT results, the doctor diagnosed multiple fractures of the right scapula and multiple muscle and tendon injuries. Due to the severity of the condition, the patient was transferred to the orthopaedic department for surgical treatment. After systematic preoperative evaluation, he was treated with open reduction and internal fixation. In assessing the surgical treatment for scapular fractures, the study by Rollo et al. ¹⁷ offered significant insights, highlighting complex fractures and soft tissue injuries as primary indications for surgery. In the present case, the patient's scapular comminuted fractures and muscle-tendon injuries, resulting from an electrical shock, aligned with surgical criteria that would aid in functional recovery and pain reduction.

After follow-up, the patient was pain-free in his right shoulder. He had returned to full activity and was satisfied with his level of function. He was stable with an acceptable range of motion and was able to carry out daily activities.

This case report did not require approval by the institutional review board, due to local regulations and the nature of the case. Patient data were deidentified for this report, and written informed consent was obtained from the patient to publish any potentially identifiable images or data. Ethical guidelines were strictly followed to ensure that the privacy and rights of the participant were fully protected. The reporting of this study conforms to CARE guidelines. ¹⁸

Discussion

In the present case, despite experiencing an electric shock, the patient did not experience significant myocardial damage or organ failure. This may have been attributed to multiple factors: first, the duration of contact was relatively brief, and the timely power cut by a colleague minimized potential cardiac injury; secondly, the path of the current did not directly involve the heart, reducing the risk of myocardial damage; and finally, the patient's young age and previous good health may have provided better physiological compensation, helping to alleviate the effects of the shock.

There were several potential causes of the scapula fracture in the present case. First, the muscles of the shoulder girdle, including the supraspinatus, infraspinatus, small round muscle, and large round muscle, originate from the scapula and cross the shoulder joint to attach to the humerus. These muscles are responsible for stabilizing and moving the shoulder joint to maintain normal function. During electric shock, intense muscle contractions due to the current passing through the body can lead to abnormal forces being exerted on the scapula. In particular, the powerful contractions of large and small round muscles may generate shear forces at the lower edge of the scapula, which is structurally weaker and more prone to fracture. Secondly, the scapula has different thicknesses and strengths across its anatomy, with the lower and inner margins being thinner and more susceptible to fracture under the influence of greater muscle tension during a strong contraction. Furthermore, the spine and outer margins of the scapula are thicker, more robust, and able to withstand greater forces. Finally, intense muscle contractions during an electric shock may be accompanied by heat effects generated by the current, potentially causing temporary functional loss or structural damage in the affected area, thus increasing the risk of fracture. This heat effect may further exacerbate the fragility of the local tissue and contribute to fracture.

Given the anatomy and muscle attachment patterns of the shoulder girdle, it may be inferred that during electric shock, intense muscle contractions, particularly in the deltoids and rotator cuff muscles, could lead to fractures in the weaker area of the scapular inferior margin. Additionally, because the scapular inferior margin is a critical area for force transmission, the abnormal concentration of force caused by electric shock may increase the risk of fracture in this region.^16,19

A review of the published literature on fractures caused by electric shock revealed that, although there have been a few reported cases of fractures caused by electric shock, including fractures of the scapula and other sites, the present case report provides a more detailed analysis of the mechanisms of injury. The scapular fractures caused by muscle contraction were detailed through MRI and CT scans, which are uncommon in the literature. In addition, the possible influence of the thermal effects of electrical current on fracture risk is highlighted, which has not been fully explored in previous studies. The present report not only enriches the existing literature, but also provides new insights and support for clinicians in diagnosing and treating electroshock fractures.

Conclusion

The present finding that an electric shock injury can result in a scapular fracture provides important clinical lessons and implications. First, it highlights the need for a comprehensive evaluation of the skeletal system in patients with electric shock injuries, even if there is no obvious history of trauma. Hidden fractures in areas such as the scapula, which may result from strong contractions of the shoulder girdle muscles, must be promptly identified and managed through careful clinical examination and appropriate imaging studies.

Furthermore, the present case emphasizes the multisystem effects of electric shock, including in the heart, muscles, and skeletal system. Although the patient in the present case did not exhibit signs of myocardial damage or organ failure, this did not mean that potential widespread harm from electric shock could be ignored. Comprehensive evaluation and treatment approaches must be taken for patients with electric shock, including symptomatic supportive care, protection of organ function, and necessary surgical interventions.^20–22

The present case serves as a reminder of the importance of preventing electric shock injuries. In the workplace, safety education should be intensified, awareness of the hazards of electric shock should be increased, and effective preventive measures, such as using insulated protective equipment, following safe operating procedures, and conducting regular equipment maintenance checks, should be implemented to reduce the occurrence of electric shock injuries.^23–27

Finally, long-term follow-up and management of patients with electric shock injuries are equally important. Due to the potential for delayed complications, such as chronic pain, functional impairment, or psychological trauma, a multidisciplinary team approach involving emergency physicians, specialists from various fields, rehabilitation experts, and mental health professionals is required to provide comprehensive diagnosis, treatment, rehabilitation plans, and psychological support for patients.

Supplemental Material

sj-pdf-1-imr-10.1177_03000605241279803 - Supplemental material for Case report: a case of single-sided shoulder blade fracture resulting from an electrical shock

Supplemental material, sj-pdf-1-imr-10.1177_03000605241279803 for Case report: a case of single-sided shoulder blade fracture resulting from an electrical shock by Hai-rui Chen, Yong-dong Ren, Nian-dan Hu, Rui Wang and Wen-qiang Li in Journal of International Medical Research