Background

Vertebral fractures (VF) are among the most common injuries, mainly affecting the thoracic and lumbar regions (T12 or L1) [1, 2]. The prevalence is growing with age, achieving the maximum in the population over 70 years (20%) [3]. While high energy injury is the most common mechanism, it must be noted that other mechanisms may also result in a vertebral fracture (VF) [4]. One of the less obvious mechanisms involves the tetanic muscle spasm caused by an electric shock [5]. Although the vast majority of fractures in this mechanism are not caused by the electric injury itself but rather by a subsequent fall, one must be vigilant when examining the patient after low-voltage (LV) shock. Herein, we describe the first case of multiple VF following a muscle spasm resulting from LV trauma.

Case presentation

A 22-year-old male patient, with no prior medical history, was admitted to the trauma ward of the Department of Surgery after suffering an electric shock by the guitar combo amplifier. The patient suffered a full-body spasm for a few seconds, after which he unplugged the amplifier and asked his mother to call an ambulance. The patient remained conscious and did not have a fall after the electric shock.

Clinical examination revealed a second-degree burn on the fifth finger of the right hand (3 × 5 mm) and a minor burn on the thumb of the left hand. The patient reported pain in the interscapular region but the clinical examination did not reveal any other pathologies. X-ray, however, revealed compression fractures of Th3–Th5 (Fig. 1). Following these findings, a CT scan was performed confirming the presence of compression fractures of the aforementioned vertebrae; the spinal cavity was intact (Fig. 2). Transthoracic echocardiography revealed no pathology.

Fig. 1
figure 1

X-ray of thoracic vertebrae revealing Th3–5 compression fractures (yellow arrows)

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Fig. 2
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CT scan showing multiple compression fractures of thoracic vertebrae

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Following the radiological findings, neurological and neurosurgical consultations were performed. The neurosurgeon recommended MRI to rule out injuries to the spinal cord and ligaments. MRI revealed a compression fracture of the 3rd (T3: A3; according to AO thoracolumbar classification system), 4th (T4: A3), 5th (T5: A1) and 6th (T6: A1) thoracic vertebrae. In addition, MRI detected also a small compression of the 2nd thoracic vertebra (T2: A1) and lesions of interspinous ligaments Th2–Th5 (Fig. 3). Based on the MRI results, conservative treatment using a cervico-thoracic support corset (Miami JTO) (Fig. 4.) was prescribed. The posterior ligamentous complex (PLC) was, according to MRI scans, intact. Neurological examination did not reveal any neurological deficit (N0). The analgesic therapy along with rehabilitation resulted in verticalization of the patient on day + 11 after a standing X-ray proving no deterioration of fractures nor progression of kyphosis. The patient was discharged on day + 12.

Fig. 3
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MRI scan confirming multiple compression fractures of thoracic vertebrae

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Fig. 4
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Patient in a cervico-thoracic support corset (Miami JTO)

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At the follow-up visit 1 month after the injury, the patient complained of moderate pain in the back; an X-ray was performed but no kyphotisation was present. MRI scan at 2.5 months was confirmed the reparative changes of the Th2–Th6 fractures without any sign of a spinal injury; therefore, a decision was made to withdraw a corset and commence rehabilitation, which lasted for 2.5 months and resulted in the full restoration of the movement and eased the pain.

Discussion

The VF resulting from electric shock are mainly connected with high voltage (HV) electricity and concomitant falling from the height [6]. The muscle spasm following the spontaneous LV electric shock, as opposed to electric shock therapy-induced fracture [7], is an extremely rare mechanism of injury.

The literature review provided only a handful of such cases, none of which included multiple VF.

Brink and Leeuwen [8] reported a similar case of lumbar burst fracture due to a muscle spasm following an LV shock, while Putti et al. [9] described a C5 fracture. Vincenti et al. [10] reported 2 more cases of VF associated with an electric shock. An overview of related papers is presented in Table 1.

Table 1 List of publications describing vertebral fractures resulting from low-voltage electric shock
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Several cases of bone fractures following LV trauma have been described in the literature. The most common fractures involved humerus and scapula [11] with the forearm being the third most common [12, 13].

Contrary, the incidence of bone injuries after a HV shock is much higher [5]. The mechanism usually involves contact with HV wires; however, iatrogenic VF following electric shock therapy [7] or cardioversion [14] have been described. Besides, tasers used by police can also cause muscle spasms resulting in VF [15].

Conclusions

Albeit vertebral fractures caused by LV injury are extremely uncommon, clinicians should always consider this diagnosis in patients after an LV shock, especially when clinical symptoms are present. Quick and accurate diagnosis is the key element of full recovery. Therefore, we strongly recommend performing X-ray and CT scans in adult patients with symptoms; in children, we recommend performing X-ray and MRI scan.