- Email: [email protected]
Bilateral scapular fractures from low-voltage electrical injury
CASE REPORT electrical injury, scapular fracture; fracture, scapular, from electrical injury
Bilateral Scapular Fractures from Low.Voltage Electrical Injury Bilateral, charactez~stically distributed fractures of the scapula occv/r from low-voltage electrical injury due to tetanic muscle contraction involving the upper extremities and shoulder girdles. We present the case of a 43-year-old man who sustained bilateral scapular fractures after exposure to a 440-volt, 60 cycle-per-second current passing briefly through his upper extremities. Conservative management, consisting of shoulder immobilization, analgesia, and progressive physical therapy, led to healing of the fractures over six weeks with essentially normal shoulder function after a follow-up period of six months. The absence of an associated fall or other direct trauma should not dissuade the physician from the diagnosis of scapular fractures in electrical injury. [Beswick DR, Morse SD, Barnes AU: Bilateral scapular fractures from low-voltage electrical injury, Ann Emerg Med 11:676-677, December 1982.]
David R. Beswick, MD* Steven D. Morse, MD* Anne U. Barnes, MD* Philadelphia, Pennsylvania From the Division of Emergency Medicine* and the Department of Surgery,t The Medical College of Pennsylvania, Philadelphia, Pennsylvania. Address for reprints: Steven D. Morse, MD, Division of Emergency Medicine, The Medical College of Pennsylvania,3300 Henry Avenue, Philadelphia, Pennsylvania 19129.
INTRODUCTION Fractures of the shoulder girdle m a y occur as a complication of electrical injury.t-4 While such injuries are more likely if the victim suffers associated direct trauma, as in a fall from a height, 1 a high index of suspicion is required to avoid overlooking similar injuries unassociated with direct trauma. Bilateral fracture of the scapula, an unusual complication of electrical injury, has been reported only once in the literature. 4 Presented is a case not associated with direct trauma.
CASE REPORT A 43-year-old man, employed as a serviceman for a vending machine company, presented after sustaining exposure to a 440-volt, 60 cycle-per-second current. On the day of injury the patient neglected to turn off the electrical supply to a machine prior to repairing it. His left hand accidentally came into contact with uninsulated wiring while his right hand was firmly affixed to the metal shell of an adjacent machine. His hands became frozen to the areas, and the patient, remaining quite lucid, noted "stiffening" of his shoulders and involuntary arching of his neck and upper back. After several seconds the patient reported feeling a "snapping sensation" in his shoulders. A witness shut off the power supply and estimated the patient's exposure to current to be 30 to 60 seconds. After the shock, the patient did not fall and sustained no direct trauma. He immediately noted bilateral shoulder pain and inability to abduct his arms. He denied back or mid-back pain, chest pain, and problems with strength or sensation in his hands or lower extremities. On physical examination the patient was alert and oriented. Blood pressure was 140/90 m m Hg, pulse was 88 beats per minute and regular, and respirations were 16/min and unlabored. Temperature was 36.9 C orally. No entry or exit burns were present. The cervical and thoracic spines were nontender, and there was full active range of motion of the neck. Cardiopulmonary examination was normal. There was m a r k e d tenderness over the trapezius muscles, the bodies of the scapulae, and the shoulder girdle mus-
11:12 December 1982
Annals of Emergency Medicine
676/53
ELECTRICAL INJURY Beswick, Morse & Barnes
Figs. 1 & 2. Symmetric fractures of the right and left scapulae (arrows). culature bilaterally. No edema was noted. The patient could not abduct either shoulder, complaining of pain with each effort. Neurologic examination revealed no evidence of any deficits in the hands or lower extremities. The peripheral pulses were symmetric and of normal amplitude and contour in both the hands and the lower extremities. Electrocardiogram was normal, as were radiographs of the cervical and thoracic spine. Shoulder and chest films revealed bilateral comminuted fractures of the scapulae involving the body and the base of the glenoids (Figures 1 and 2). The patient was hospitalized for one week and developed no visceral abnormalities. His fractures were treated conservatively with shoulder immobilization, analgesia, and physical therapy, and gradually healed, leaving him with no limitation of shoulder motion after follow-up of six months.
DISCUSSION Fractures of the scapula are uncommon. They usually result from direct trauma, such as motor vehicle accidents, falls, or homicidal injuries. Other associated injuries are common,
54/677
often involving the thorax and craniospinal axis. s Fractures from electrical injury unassociated with direct trauma also are uncommon, and are frequently missed clinically. 1 Posterior shoulder dislocation and posterior fracture-dislocation involving the surgical neck of the humerus, while unusual, have received attention in victims of electrical shock. 2'~ O'Flanagan 2 and Ansorge3 each described a case of bilateral posterior fracture-dislocations of the shoulders as a result of low-voltage electrical injury. There are 18 muscle attachments, either by origin or insertion, on the scapula that exert various magnitudes of force in different directions. 6 The simultaneous tetanic contraction of these m u s c l e groups m a y lead to stress and subsequent fractures in the subglenoid area and through the body of the scapula. It is a matter of conjecture whether maximal stress forces or the intrinsic properties of the bone account for the characteristic distribution of the fractures in this entity. Tarquino et al 4 described the first case of pure bilateral scapular fractures from accidental low-voltage electrical injury. The absence :of direct trauma and the distribution of fracture lines are similar in their case and ours. The mechanism of injury is probably similar in both cases.
Annals of Emergency Medicine
The diffuse tenderness of the shoulder girdle musculature that our patient manifested made clinical diagnosis of this entity challenging. A high index of suspicion by the emergency physician and appropriate roentgenographic studies were required for timely, accurate diagnosis and institution of appropriate management. This rarely reported entity responds well to conservative, nonoperative therapy consisting of shoulder girdle immobilization, progressive physical therapy, and necessary analgesia.
REFERENCES t. Cooper MA: Electrical injuries. Current Topics II in Emergency Medicine 1:1-5, 1981. 2. O'Flanagan PH: Fracture due to shock from domestic electricity supply. Injury 6:244-245, 1975. 3. Ansorge VD: Die duppelseitige hintere Schultergelenksluxationsfrakfur als Fulge eines Starkstromunfalles. Zbl Chirurgie 105:465-467, 1980. 4. Tarquino T, Weinstein ME, Virgilio RW: Bilateral scapular fractures from accidental electric shock. J Trauma 19:132-133, 1979. 5. McGahan JP, Rab"GT, Dublin A: Fractures of the scapula. J Trauma 20:880-884, 1980. 6. Anderson JE (edl: Grant's Atlas of Anatomy, ed 7. Baltimore, Williams and Wilkins, 1978, Figs. 6-28 through 6-46.
11:12 December 1982
Bilateral Scapular Fractures from Low.Voltage Electrical Injury Bilateral, charactez~stically distributed fractures of the scapula occv/r from low-voltage electrical injury due to tetanic muscle contraction involving the upper extremities and shoulder girdles. We present the case of a 43-year-old man who sustained bilateral scapular fractures after exposure to a 440-volt, 60 cycle-per-second current passing briefly through his upper extremities. Conservative management, consisting of shoulder immobilization, analgesia, and progressive physical therapy, led to healing of the fractures over six weeks with essentially normal shoulder function after a follow-up period of six months. The absence of an associated fall or other direct trauma should not dissuade the physician from the diagnosis of scapular fractures in electrical injury. [Beswick DR, Morse SD, Barnes AU: Bilateral scapular fractures from low-voltage electrical injury, Ann Emerg Med 11:676-677, December 1982.]
David R. Beswick, MD* Steven D. Morse, MD* Anne U. Barnes, MD* Philadelphia, Pennsylvania From the Division of Emergency Medicine* and the Department of Surgery,t The Medical College of Pennsylvania, Philadelphia, Pennsylvania. Address for reprints: Steven D. Morse, MD, Division of Emergency Medicine, The Medical College of Pennsylvania,3300 Henry Avenue, Philadelphia, Pennsylvania 19129.
INTRODUCTION Fractures of the shoulder girdle m a y occur as a complication of electrical injury.t-4 While such injuries are more likely if the victim suffers associated direct trauma, as in a fall from a height, 1 a high index of suspicion is required to avoid overlooking similar injuries unassociated with direct trauma. Bilateral fracture of the scapula, an unusual complication of electrical injury, has been reported only once in the literature. 4 Presented is a case not associated with direct trauma.
CASE REPORT A 43-year-old man, employed as a serviceman for a vending machine company, presented after sustaining exposure to a 440-volt, 60 cycle-per-second current. On the day of injury the patient neglected to turn off the electrical supply to a machine prior to repairing it. His left hand accidentally came into contact with uninsulated wiring while his right hand was firmly affixed to the metal shell of an adjacent machine. His hands became frozen to the areas, and the patient, remaining quite lucid, noted "stiffening" of his shoulders and involuntary arching of his neck and upper back. After several seconds the patient reported feeling a "snapping sensation" in his shoulders. A witness shut off the power supply and estimated the patient's exposure to current to be 30 to 60 seconds. After the shock, the patient did not fall and sustained no direct trauma. He immediately noted bilateral shoulder pain and inability to abduct his arms. He denied back or mid-back pain, chest pain, and problems with strength or sensation in his hands or lower extremities. On physical examination the patient was alert and oriented. Blood pressure was 140/90 m m Hg, pulse was 88 beats per minute and regular, and respirations were 16/min and unlabored. Temperature was 36.9 C orally. No entry or exit burns were present. The cervical and thoracic spines were nontender, and there was full active range of motion of the neck. Cardiopulmonary examination was normal. There was m a r k e d tenderness over the trapezius muscles, the bodies of the scapulae, and the shoulder girdle mus-
11:12 December 1982
Annals of Emergency Medicine
676/53
ELECTRICAL INJURY Beswick, Morse & Barnes
Figs. 1 & 2. Symmetric fractures of the right and left scapulae (arrows). culature bilaterally. No edema was noted. The patient could not abduct either shoulder, complaining of pain with each effort. Neurologic examination revealed no evidence of any deficits in the hands or lower extremities. The peripheral pulses were symmetric and of normal amplitude and contour in both the hands and the lower extremities. Electrocardiogram was normal, as were radiographs of the cervical and thoracic spine. Shoulder and chest films revealed bilateral comminuted fractures of the scapulae involving the body and the base of the glenoids (Figures 1 and 2). The patient was hospitalized for one week and developed no visceral abnormalities. His fractures were treated conservatively with shoulder immobilization, analgesia, and physical therapy, and gradually healed, leaving him with no limitation of shoulder motion after follow-up of six months.
DISCUSSION Fractures of the scapula are uncommon. They usually result from direct trauma, such as motor vehicle accidents, falls, or homicidal injuries. Other associated injuries are common,
54/677
often involving the thorax and craniospinal axis. s Fractures from electrical injury unassociated with direct trauma also are uncommon, and are frequently missed clinically. 1 Posterior shoulder dislocation and posterior fracture-dislocation involving the surgical neck of the humerus, while unusual, have received attention in victims of electrical shock. 2'~ O'Flanagan 2 and Ansorge3 each described a case of bilateral posterior fracture-dislocations of the shoulders as a result of low-voltage electrical injury. There are 18 muscle attachments, either by origin or insertion, on the scapula that exert various magnitudes of force in different directions. 6 The simultaneous tetanic contraction of these m u s c l e groups m a y lead to stress and subsequent fractures in the subglenoid area and through the body of the scapula. It is a matter of conjecture whether maximal stress forces or the intrinsic properties of the bone account for the characteristic distribution of the fractures in this entity. Tarquino et al 4 described the first case of pure bilateral scapular fractures from accidental low-voltage electrical injury. The absence :of direct trauma and the distribution of fracture lines are similar in their case and ours. The mechanism of injury is probably similar in both cases.
Annals of Emergency Medicine
The diffuse tenderness of the shoulder girdle musculature that our patient manifested made clinical diagnosis of this entity challenging. A high index of suspicion by the emergency physician and appropriate roentgenographic studies were required for timely, accurate diagnosis and institution of appropriate management. This rarely reported entity responds well to conservative, nonoperative therapy consisting of shoulder girdle immobilization, progressive physical therapy, and necessary analgesia.
REFERENCES t. Cooper MA: Electrical injuries. Current Topics II in Emergency Medicine 1:1-5, 1981. 2. O'Flanagan PH: Fracture due to shock from domestic electricity supply. Injury 6:244-245, 1975. 3. Ansorge VD: Die duppelseitige hintere Schultergelenksluxationsfrakfur als Fulge eines Starkstromunfalles. Zbl Chirurgie 105:465-467, 1980. 4. Tarquino T, Weinstein ME, Virgilio RW: Bilateral scapular fractures from accidental electric shock. J Trauma 19:132-133, 1979. 5. McGahan JP, Rab"GT, Dublin A: Fractures of the scapula. J Trauma 20:880-884, 1980. 6. Anderson JE (edl: Grant's Atlas of Anatomy, ed 7. Baltimore, Williams and Wilkins, 1978, Figs. 6-28 through 6-46.
11:12 December 1982