A case report on 2 cases of closed scapular fractures caused by low-voltage alternating current shock

Scapular fractures caused by domestic low-voltage alternating current (220 V, 50 Hz) electrical injury are rare and can be easily missed or misdiagnosed in emergency clinical practice. This report presents 2 such cases and, through a pooled analysis of relevant literature, summarizes and analyzes the underlying mechanism, key points for early diagnosis, and treatment strategies for this rare injury pattern. The aim is to enhance clinical awareness of this condition and to provide a reference for early recognition and standardized management.

At the instant of electrical current passage through the upper limb, both patients experienced an intense shock, followed immediately by severe shoulder pain and restricted upper limb movement. Upon presentation, despite only minor cutaneous injuries, both patients reported intense pain localized to the scapular region. This discrepancy between the relatively mild superficial findings and the severity of their symptoms caused considerable confusion and concern, with fear of an invisible severe injury.

Computed tomography imaging confirmed scapular fractures in both patients.

After excluding the risk of potential systemic injuries, both patients underwent conservative management comprising sling immobilization, analgesia, and progressive rehabilitation exercises.

Following 6 weeks of treatment, both patients reported satisfaction with the therapeutic effect, and at the 6-month follow-up, they demonstrated complete functional recovery of the shoulder joint.

Even in the absence of visible entry or exit cutaneous lesions, the intense tetanic muscle contractions induced by low-voltage electrical shock can be sufficient to cause scapular fractures. For patients presenting with shoulder pain following low-voltage alternating current electrical injury - regardless of skin integrity - clinicians should maintain a high index of suspicion for this rare injury so as not to miss the diagnosis.