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Etiologic factors in isolated paralysis of the serratus anterior muscle: A report of 197 cases
Etiologic factors in isolated paralysis of the serratus anterior muscle: A report of 197 cases Martti Vastamaki, MD, and Leena I. Kauppda, MD, Helsinki, Finland
One hundred ninety-seven cases of isolated paralysis of the serratus anterior muscle were analyzed to discover common etiologic factors and the mechanisms of in;ury producing this disorder. Exertion preceded 69 (35%) of the cases, and trauma caused 51 (26%) of the cases. Twenty-two (11 %) occurred after locally invasive procedures, 73 (7%) after infection, and 10 (5%) after anesthesia. Sleeping position or exposure to cold proved to be causes in a few cases. Twenty-nine (15%) of the cases were of unknown couse. Evaluation of the mechanism of the in;ury indicated that in most cases the lesion was mechanical in origin. The data suggested that the long thoracic nerve is not unusually susceptible to infectious or toxic neuropathy, as has previously been supposed. (J SHOULDER ELBOW SURG 7993;2:240-3.)
The serratus
anterior muscle receives its nerve supply from the long thoracic nerve. Lesions of this nerve produce serratus palsy leading to shoulder pain, winging of the scapula, and inability to raise the arm completely.6. 10. 1A Despite the fact that only about 350 cases have been described in the literature, the paralysis does not seem to be uncommon. Furthermore, the numerous and varied causes give the impression of the nerve being more vulnerable to paralysis than many other nerves. The majority of authors have found acute or recurrent trauma to be the most frequent cause of paralysis. ' ·ll . 13·15. 2A Furthermore, childbirth 1. A, 7, 10, lA, 23; anesthesia '2 ,22; associated and unrelated surgical operations 2 , 10, 15,22,23, 25; neuralgic amyotrophy's; toxic s, infectious,* or hereditary brachial plexus neuropathy16; (7 radiculopathy"; exposure to cold or draW; use of
'References 2, 4, 5, 8, la, 14,20,21. 23 From the Deportment of Hand Surgery, OrthopaediC Hospital of the Invalid Foundation, and the Institute of Occupational Health, Section of Ergonomics and Occupational Physiotherapy Reprint requests: Leena I, Kaupprla, MD, Lansrlmnake 6 A, SF-02160 Espoo, Finland. Copyright © 1993 by Journal 0\ Shoulder and Elbow Surgery Boord of Trustees,
1058-2746/93/$100 + 10 3211/48813
240
crutches 14; the presence of a cast 14 ; rest position 14, 18, 19; and many other causes have been mentioned as etiologic factors. A considerable number of cases have also remained without an attributed cause. We believe that the causes of the serratus paralysis need further elucidation. Therefore the aim of our study was to identify the etiologic factors in the diverse cases of this form of paralysis and to discover if there are similarities in the mechanism of the injury or events producing the lesion.
PATIENTS AND METHODS Between 1980 and 1991, 223 patients with serratus palsy were referred to the office of one of the authors (MV) or to the department of hand surgery at the Orthopaedic Hospital of the Invalid Foundation. This private hospital receives patients from all parts of Finland. All of these patients were examined by the same orthopedic surgeon (MV). Twenty-six patients with systemic disorders [such as hypothyroidism or muscular dystrophy) or damage to several nerves of the brachial plexus were omitted from the study. One hundred ninety-seven patients with isolated serratus anterior paralysis were analyzed. One hundred twenty-three (62%) of the patients were men, and 74 (38%) were women. At the onset
1. Shoulder Elbow Surg. Volume 2, Number 5
of the paralysis, their mean age was 31.6 years (range 5 to 78 years, median 29 years). In 88% of the cases the dominant side was affected. A detailed history regarding the onset of the disorder, the cause of the paralysis, hand dominance, side of the paralysis, age at the onset of the disorder, and state of health was taken at the patient's first visit to the hospital, which occurred on average 15 months after the onset of the paralysis (range from 2 weeks to 15 years, median 5 months). Previous medical records were checked for inconsistencies of history, because in some cases there might have been a tendency to change the history to obtain a better level of compensation for a work accident. The diagnosis of the long thoracic nerve lesion was confirmed in every case by electroneuromyography conducted by a senior neurophysiologist. The causes of the paralysis were classified as acute trauma, exertion, anesthesia, local invasive procedure, infection, miscellaneous, and unknown. Acute trauma was considered to be an etiologic factor if a severe blow to the shoulder region or a sudden jerk and sprain of the shoulder joint preceded the paralysis. Muscular exertion was considered as a cause if symptoms appeared after strenuous work or sport activities without any apparent injury to the shoulder region. Locally invasive procedures were considered as a cause in cases where paralysis occurred after such maneuvers, indicating direct damage to the nerve. Anesthesia was considered as a cause in other operations. Cases of paralysis after other operations were classified when the patients were under anesthesia. Patients with an infectious disease (and without any other evident cause) at the onset of the disorder were classified into one group. An unusual sleeping position and a prolonged period in cold or draft were closely associated with the onset of the paralysis in a few cases, and they were classified as "miscellaneous." Finally, no etiologic factor could be associated with the paralysis in one group of patients, and their conditions were thus classified as unknown.
RESULTS (Table) Acute trauma. Acute trauma caused the paralysis in 51 (26%) of the cases. A sudden jerk of the arm forward or backward was the most typical mechanism of injury, amounting to 15% of all the cases. Typical examples were a
Vastamaki and Kauppila
241
man who jerked his arm when trying to pull open a frozen door that suddenly gave way or a downhill skier who held onto the lift wire, which suddenly jerked. In a similar way, a secretary experienced paralysis when trying to lift an unexpectedly heavy bag from a shelf. Several athletes (e.g., a golfer, a tennis player, and a handball player) acquired the disorder after they missed the ball in a vigorous blow. A direct blow to the shoulder in conjunction with a fall or accident caused the paralysis in 22 (11 %) of the cases. Thus a fallon the outstretched arm or on the involved shoulder was a frequent occurrence causing the disorder. Exertion. Strenuous work or sport activities caused 69 (35%) of the cases. The lesion occurred when patients were fixing kitchen cupboards, painting pictures, building a house, pushing a heavy wheelbarrow, shoveling earth, carrying a heavy and/ or big object in front of themselves, and after many other laborious manual work tasks done over a period of several hours or days. The insidious onset of the paralysis was also often attributed to sport activities like weight lifting, especially lifting weights in a supine position, or to push-up exercises. Some activities to which the patient was not accustomed, such as prolonged cross-country skiing, boating, or swimming at the beginning of the season were also closely associated with the onset of several cases of paralysis. In addition to causing paralysis by acute trauma, many ball games like golf, tennis, and basketball induced the condition gradually, after a prolonged period of exertion. In four cases the paralysis was associated with childbirth. These cases were classified under the group of exertion, because all of these patients experienced the paralysis by pulling forcefully on their thighs to aid in the bearingdown maneuver during delivery. More unusual forms of straining that led to the disorder were, for example, carrying a full backpack in the army (two cases), unaccustomed walking with crutches (one case), and pulling oneself upstairs with hands on the railing (a patient who was paralyzed). Anesthesia. Ten (5%) cases of paralyses occurred after the patient was administered anesthesia. Not only general anesthesia but also spinal anesthesia was associated with development of the lesion. All these patients were in
242
J. Shoulder Elbow Surg. September/ October 7993
VastamCiki and Kauppila
Table Causes In 197 cases of serratus anterior paralysis No. of cases Percent Exertion Acute trauma Local invasive procedure Infection AnestheslO Miscellaneous Unknown Total
69 51
22 13 10
3 29 197
35.0 25.9 112 6.6 51 1.5
14.7
100.0
good physical condition and were operated on with various anesthetic agents. The operations lasted from 1 to 3 hours. In addition to the serratus anterior paralysis, no other complications were recorded in association with these pro·· cedures. Locally invasive procedures. Locally invasive procedures caused paralysis in 22 (11 %) of the cases. Operations attributed to causing the lesion were first-rib resection (10 cases), scalenotomy (three cases), mastectomy with axillary dissection (four cases), and surgical treatment of spontaneous pneumothorax (three cases). Infraclavicular plexus anesthesia also caused two cases of paralysis. This was regarded as direct damage to the nerve and therefore was classified in the same group with local operations. Infedion. Patients with some kind of infection (and without any other evident cause) at the onset of the paralysis were grouped together. However, neuritis of the long thoracic nerve seemed to be a rare cause of the disorder. Frequently, a patient with a slight illness had continued to work or train despite being ill and might have acquired the disorder by a mechanism other than infectious neuropathy. Moreover, patients with serious infections demanded lengthy bed rest, which might have caused nerve compression. Subjects with infection at the onset of the disorder complained of severe pain in the affected shoulder, perhaps indicative of neuritic cause. However, severe pain was also quite a common complaint among patients with other etiologic factors, and therefore it could not be regarded as a relioble symptom of a mononeuritis. Antibody levels were analyzed in a few cases. However, although these analyses had the potential to confirm the di-
agnosis (various common virus infections), they could not ascertain whether or not there was a manoneuritis; nar could electroneuromyography distinguish between nerve lesions resulting from infectious neuropathy or mechanical damage. Cause unknown. Twenty-nine (15%) of the patients could not associate any factor with the onset of the disorder, or the association was not strong enough to allow classification. In some cases the onset was so gradual that the condition could not be classified in any of the groups. However, electroneuromyographic studies made after the patient's first visit to the orthopaedic surgeon showed partial or complete denervation. Miscellaneous. The position of rest was the obvious reason for the paralysis in one case. A patient with back pain stayed in the hospital for 3 weeks before an operation, and most of the time he rested in a half-sitting position, supporting himself on his elbows. The paralysis was noted before surgery. Exposure to cold was associated with the onset of the paralysis in a lumberman after he had stayed for 2 hours at - 20° C. Paralysis also resulted in a man who had driven with the automobile window open on a chilly spring day. One case of apparent recurrent paralysis was included in the material. The patient suffered his first paralysis after thoracotomy. The lesion was recovered fully at the 2-year check-up, but a new and permanent paralysis occurred after a strenuous job of changing tires. There was also one case of acute bilateral paralysis of unknown cause. A family with two cases of paralysis was also included. Two brothers experienced paralysis by different mechanisms. One of the sons became paralyzed after a match of table tennis and the other during a long hospital stay for pneumonia.
DISCUSSION It has been presumed that paresis or paralysis of the long thoracic nerve results from traction on the nerve trunk when the arm is twisted and, at the same time, the head is rotated toward the other side.bln our study this was not a prominent mechanism of injury. Rather, prolonged exertion of the shoulder muscles or a forceful jerk of the arm forward or backward were to blame for most paralyses, indicating that fatigue of the shoulder muscles or a sudden movement of the
J. Shoulder Elbow Surg. Volume 2, Number 5
scapula may expose the long thoracic nerve to injury. The median age of the subjects was quite low at 29 years. Most of the cases described in the literature have also occurred in young people. Because work and sport activities are responsible for most cases, the presence of paralysis among young adults was not unexpected. Cases after miscellaneous or unknown causes also occurred mainly among young, athletic subjects, indicating that probably minorforgotten trauma may have caused the paralysis. We suspect that the nerve is not particularly susceptible to the toxic effect of anesthetics or to infectious neuropathy. On the contrary, we suggest that cases occurring when the patient is under anesthesia result from positioning of the arm during the procedure, causing compression or traction on the long thoracic nerve. The same mechanism may be involved after serious infections, when a patient is fatigued with the illness and does not move the arm often enough to avoid prolonged pressure on the nerve. During minor illnesses a patient may continue daily tasks while endurance of the serratus anterior is reduced, thus exposing the nerve to damage.
REFERENCES
Vastamaki and Kauppila
243
7. Hansson KG. Serratus mag nus paralySIS. Arch Phys Med Rehabil 1948;29: 156-61 8. Horwitz MT, Tocantins LM. Isolated paralySIS of the serratus anterior (mag nus) muscle. J Bone JOint Surg 1938,20:720-5 9. IIfred FW, Holder HG. Winged scapula: case occurring in soldier from knapsack. JAMA 1942; 120'448-9 10. Johnson H, Kendall HO. Isolated paralySIS of the serratus anterior muscle. J Bone JOint Surg [Am] 1955;37A:567 -74. 11. Llthander B, Hedler B. Serratuspares - "epldemi" bland kustjagare. Lakartldningen 1982;79'1567-9 12. Lorhan PH. Isolated paralysis of the serratus mag nus following surgical procedures: report of a case Arch Surg 1947;54:656-9. 13. Makin GJ, Brown WF, Ebers GL C7 radlculopathy. Importance of scapular winging in clinical diagnOSIs. J Neurol Neurosurg Psychiatry 1986;49:640-4. 14. Overbeck DO, Ghormley RK. ParalYSIS of the serratus mag nus muscle. JAMA 1940; 114: 1994-6 15. Pettera JE, Trojaborg W. Conduction studies of the Long thoraCIC nerve in serratus anterior palsy of different etiology. Neurology 1984;34: 1033-7. 16 Phillips LH. Familial long thoracic nerve palsy: a manifestation of brachial plexus neuropathy. Neurology 1986;361251-3. 17. Porsman 0 Serratus anterior parese som erhvervssygdom hos slagteriarbeldere Ugeskr Laeger 1977, 139:291-2. 18 Potts CS Isolated paralySIS of the serratus magnus. report of a case Arch Neural Psych 1928,20 184-6. 19 Prescott MU, Zollinger RW. Alar scapula' an unusual surgical complication. Am J Surg 1944;65.98-103. 20. Richardson JS. 1942,1 618-9
Serratus
magnus
palsy
Lancet
1. Berkhelser EJ, Shapiro F Alar scapula: traumatic palsy of serratus magnus. JAMA 1937; 108.1790-3.
21. Spillane JD Localised neUritis of the shoulder girdle' a report of 46 cases In the MEF. Lancet 1943,2:532-5
2 Fery A, Sommelet J. La paralysie du grand dentele resultat du traitement de 12 cas dont 9 operes et revue genera Ie de la litterature Rev Chlr Orthop 1987;73.27788
22 Thorek M. Compression paralysis of the long thoraCiC nerve follOWing an abdominal operation, With report of a case. Am J Surg 1926;4026-7. 23. Yastamaki M. Serratuspareesi. DuodeCim 1985; 101 969-76
3. Fiddian NJ, King RJ. The winged scapula CIIn Orthop 1984; 185:228-36 4. Foo CL, Swann M. Isolated paralySIS of the serratus anterior. a report of 20 cases. J Bone Joint Surg [Br] 1983,65B:552-6.
24. Yastamaki M. Serratus anterior paralYSIS [Abstract]. Presented at the Fifty-Sixth Annual Meeting of the American Academy of OrthopaediC Surgeons, Las Yegas, Nevada, February 24-28,1989.1989:171
5 Goodman CE, Kenrick MM, Blum MY. Long thoracic nerve palsy: a follow-up study. Arch Phys Med Rehabil 1975;56352-5.
25. Wood YE, Frykman GK Winging of the scapula as a complication of first rib resection a report of SIX cases. Clin Orthop 1980; 149: 160-3
6. Gregg JR, Labosky D, Harty M, et al. Serratus anterior paralySIS In the young athlete. J Bone JOint Surg [Am] 1979,61 A:825-31.
One hundred ninety-seven cases of isolated paralysis of the serratus anterior muscle were analyzed to discover common etiologic factors and the mechanisms of in;ury producing this disorder. Exertion preceded 69 (35%) of the cases, and trauma caused 51 (26%) of the cases. Twenty-two (11 %) occurred after locally invasive procedures, 73 (7%) after infection, and 10 (5%) after anesthesia. Sleeping position or exposure to cold proved to be causes in a few cases. Twenty-nine (15%) of the cases were of unknown couse. Evaluation of the mechanism of the in;ury indicated that in most cases the lesion was mechanical in origin. The data suggested that the long thoracic nerve is not unusually susceptible to infectious or toxic neuropathy, as has previously been supposed. (J SHOULDER ELBOW SURG 7993;2:240-3.)
The serratus
anterior muscle receives its nerve supply from the long thoracic nerve. Lesions of this nerve produce serratus palsy leading to shoulder pain, winging of the scapula, and inability to raise the arm completely.6. 10. 1A Despite the fact that only about 350 cases have been described in the literature, the paralysis does not seem to be uncommon. Furthermore, the numerous and varied causes give the impression of the nerve being more vulnerable to paralysis than many other nerves. The majority of authors have found acute or recurrent trauma to be the most frequent cause of paralysis. ' ·ll . 13·15. 2A Furthermore, childbirth 1. A, 7, 10, lA, 23; anesthesia '2 ,22; associated and unrelated surgical operations 2 , 10, 15,22,23, 25; neuralgic amyotrophy's; toxic s, infectious,* or hereditary brachial plexus neuropathy16; (7 radiculopathy"; exposure to cold or draW; use of
'References 2, 4, 5, 8, la, 14,20,21. 23 From the Deportment of Hand Surgery, OrthopaediC Hospital of the Invalid Foundation, and the Institute of Occupational Health, Section of Ergonomics and Occupational Physiotherapy Reprint requests: Leena I, Kaupprla, MD, Lansrlmnake 6 A, SF-02160 Espoo, Finland. Copyright © 1993 by Journal 0\ Shoulder and Elbow Surgery Boord of Trustees,
1058-2746/93/$100 + 10 3211/48813
240
crutches 14; the presence of a cast 14 ; rest position 14, 18, 19; and many other causes have been mentioned as etiologic factors. A considerable number of cases have also remained without an attributed cause. We believe that the causes of the serratus paralysis need further elucidation. Therefore the aim of our study was to identify the etiologic factors in the diverse cases of this form of paralysis and to discover if there are similarities in the mechanism of the injury or events producing the lesion.
PATIENTS AND METHODS Between 1980 and 1991, 223 patients with serratus palsy were referred to the office of one of the authors (MV) or to the department of hand surgery at the Orthopaedic Hospital of the Invalid Foundation. This private hospital receives patients from all parts of Finland. All of these patients were examined by the same orthopedic surgeon (MV). Twenty-six patients with systemic disorders [such as hypothyroidism or muscular dystrophy) or damage to several nerves of the brachial plexus were omitted from the study. One hundred ninety-seven patients with isolated serratus anterior paralysis were analyzed. One hundred twenty-three (62%) of the patients were men, and 74 (38%) were women. At the onset
1. Shoulder Elbow Surg. Volume 2, Number 5
of the paralysis, their mean age was 31.6 years (range 5 to 78 years, median 29 years). In 88% of the cases the dominant side was affected. A detailed history regarding the onset of the disorder, the cause of the paralysis, hand dominance, side of the paralysis, age at the onset of the disorder, and state of health was taken at the patient's first visit to the hospital, which occurred on average 15 months after the onset of the paralysis (range from 2 weeks to 15 years, median 5 months). Previous medical records were checked for inconsistencies of history, because in some cases there might have been a tendency to change the history to obtain a better level of compensation for a work accident. The diagnosis of the long thoracic nerve lesion was confirmed in every case by electroneuromyography conducted by a senior neurophysiologist. The causes of the paralysis were classified as acute trauma, exertion, anesthesia, local invasive procedure, infection, miscellaneous, and unknown. Acute trauma was considered to be an etiologic factor if a severe blow to the shoulder region or a sudden jerk and sprain of the shoulder joint preceded the paralysis. Muscular exertion was considered as a cause if symptoms appeared after strenuous work or sport activities without any apparent injury to the shoulder region. Locally invasive procedures were considered as a cause in cases where paralysis occurred after such maneuvers, indicating direct damage to the nerve. Anesthesia was considered as a cause in other operations. Cases of paralysis after other operations were classified when the patients were under anesthesia. Patients with an infectious disease (and without any other evident cause) at the onset of the disorder were classified into one group. An unusual sleeping position and a prolonged period in cold or draft were closely associated with the onset of the paralysis in a few cases, and they were classified as "miscellaneous." Finally, no etiologic factor could be associated with the paralysis in one group of patients, and their conditions were thus classified as unknown.
RESULTS (Table) Acute trauma. Acute trauma caused the paralysis in 51 (26%) of the cases. A sudden jerk of the arm forward or backward was the most typical mechanism of injury, amounting to 15% of all the cases. Typical examples were a
Vastamaki and Kauppila
241
man who jerked his arm when trying to pull open a frozen door that suddenly gave way or a downhill skier who held onto the lift wire, which suddenly jerked. In a similar way, a secretary experienced paralysis when trying to lift an unexpectedly heavy bag from a shelf. Several athletes (e.g., a golfer, a tennis player, and a handball player) acquired the disorder after they missed the ball in a vigorous blow. A direct blow to the shoulder in conjunction with a fall or accident caused the paralysis in 22 (11 %) of the cases. Thus a fallon the outstretched arm or on the involved shoulder was a frequent occurrence causing the disorder. Exertion. Strenuous work or sport activities caused 69 (35%) of the cases. The lesion occurred when patients were fixing kitchen cupboards, painting pictures, building a house, pushing a heavy wheelbarrow, shoveling earth, carrying a heavy and/ or big object in front of themselves, and after many other laborious manual work tasks done over a period of several hours or days. The insidious onset of the paralysis was also often attributed to sport activities like weight lifting, especially lifting weights in a supine position, or to push-up exercises. Some activities to which the patient was not accustomed, such as prolonged cross-country skiing, boating, or swimming at the beginning of the season were also closely associated with the onset of several cases of paralysis. In addition to causing paralysis by acute trauma, many ball games like golf, tennis, and basketball induced the condition gradually, after a prolonged period of exertion. In four cases the paralysis was associated with childbirth. These cases were classified under the group of exertion, because all of these patients experienced the paralysis by pulling forcefully on their thighs to aid in the bearingdown maneuver during delivery. More unusual forms of straining that led to the disorder were, for example, carrying a full backpack in the army (two cases), unaccustomed walking with crutches (one case), and pulling oneself upstairs with hands on the railing (a patient who was paralyzed). Anesthesia. Ten (5%) cases of paralyses occurred after the patient was administered anesthesia. Not only general anesthesia but also spinal anesthesia was associated with development of the lesion. All these patients were in
242
J. Shoulder Elbow Surg. September/ October 7993
VastamCiki and Kauppila
Table Causes In 197 cases of serratus anterior paralysis No. of cases Percent Exertion Acute trauma Local invasive procedure Infection AnestheslO Miscellaneous Unknown Total
69 51
22 13 10
3 29 197
35.0 25.9 112 6.6 51 1.5
14.7
100.0
good physical condition and were operated on with various anesthetic agents. The operations lasted from 1 to 3 hours. In addition to the serratus anterior paralysis, no other complications were recorded in association with these pro·· cedures. Locally invasive procedures. Locally invasive procedures caused paralysis in 22 (11 %) of the cases. Operations attributed to causing the lesion were first-rib resection (10 cases), scalenotomy (three cases), mastectomy with axillary dissection (four cases), and surgical treatment of spontaneous pneumothorax (three cases). Infraclavicular plexus anesthesia also caused two cases of paralysis. This was regarded as direct damage to the nerve and therefore was classified in the same group with local operations. Infedion. Patients with some kind of infection (and without any other evident cause) at the onset of the paralysis were grouped together. However, neuritis of the long thoracic nerve seemed to be a rare cause of the disorder. Frequently, a patient with a slight illness had continued to work or train despite being ill and might have acquired the disorder by a mechanism other than infectious neuropathy. Moreover, patients with serious infections demanded lengthy bed rest, which might have caused nerve compression. Subjects with infection at the onset of the disorder complained of severe pain in the affected shoulder, perhaps indicative of neuritic cause. However, severe pain was also quite a common complaint among patients with other etiologic factors, and therefore it could not be regarded as a relioble symptom of a mononeuritis. Antibody levels were analyzed in a few cases. However, although these analyses had the potential to confirm the di-
agnosis (various common virus infections), they could not ascertain whether or not there was a manoneuritis; nar could electroneuromyography distinguish between nerve lesions resulting from infectious neuropathy or mechanical damage. Cause unknown. Twenty-nine (15%) of the patients could not associate any factor with the onset of the disorder, or the association was not strong enough to allow classification. In some cases the onset was so gradual that the condition could not be classified in any of the groups. However, electroneuromyographic studies made after the patient's first visit to the orthopaedic surgeon showed partial or complete denervation. Miscellaneous. The position of rest was the obvious reason for the paralysis in one case. A patient with back pain stayed in the hospital for 3 weeks before an operation, and most of the time he rested in a half-sitting position, supporting himself on his elbows. The paralysis was noted before surgery. Exposure to cold was associated with the onset of the paralysis in a lumberman after he had stayed for 2 hours at - 20° C. Paralysis also resulted in a man who had driven with the automobile window open on a chilly spring day. One case of apparent recurrent paralysis was included in the material. The patient suffered his first paralysis after thoracotomy. The lesion was recovered fully at the 2-year check-up, but a new and permanent paralysis occurred after a strenuous job of changing tires. There was also one case of acute bilateral paralysis of unknown cause. A family with two cases of paralysis was also included. Two brothers experienced paralysis by different mechanisms. One of the sons became paralyzed after a match of table tennis and the other during a long hospital stay for pneumonia.
DISCUSSION It has been presumed that paresis or paralysis of the long thoracic nerve results from traction on the nerve trunk when the arm is twisted and, at the same time, the head is rotated toward the other side.bln our study this was not a prominent mechanism of injury. Rather, prolonged exertion of the shoulder muscles or a forceful jerk of the arm forward or backward were to blame for most paralyses, indicating that fatigue of the shoulder muscles or a sudden movement of the
J. Shoulder Elbow Surg. Volume 2, Number 5
scapula may expose the long thoracic nerve to injury. The median age of the subjects was quite low at 29 years. Most of the cases described in the literature have also occurred in young people. Because work and sport activities are responsible for most cases, the presence of paralysis among young adults was not unexpected. Cases after miscellaneous or unknown causes also occurred mainly among young, athletic subjects, indicating that probably minorforgotten trauma may have caused the paralysis. We suspect that the nerve is not particularly susceptible to the toxic effect of anesthetics or to infectious neuropathy. On the contrary, we suggest that cases occurring when the patient is under anesthesia result from positioning of the arm during the procedure, causing compression or traction on the long thoracic nerve. The same mechanism may be involved after serious infections, when a patient is fatigued with the illness and does not move the arm often enough to avoid prolonged pressure on the nerve. During minor illnesses a patient may continue daily tasks while endurance of the serratus anterior is reduced, thus exposing the nerve to damage.
REFERENCES
Vastamaki and Kauppila
243
7. Hansson KG. Serratus mag nus paralySIS. Arch Phys Med Rehabil 1948;29: 156-61 8. Horwitz MT, Tocantins LM. Isolated paralySIS of the serratus anterior (mag nus) muscle. J Bone JOint Surg 1938,20:720-5 9. IIfred FW, Holder HG. Winged scapula: case occurring in soldier from knapsack. JAMA 1942; 120'448-9 10. Johnson H, Kendall HO. Isolated paralySIS of the serratus anterior muscle. J Bone JOint Surg [Am] 1955;37A:567 -74. 11. Llthander B, Hedler B. Serratuspares - "epldemi" bland kustjagare. Lakartldningen 1982;79'1567-9 12. Lorhan PH. Isolated paralysis of the serratus mag nus following surgical procedures: report of a case Arch Surg 1947;54:656-9. 13. Makin GJ, Brown WF, Ebers GL C7 radlculopathy. Importance of scapular winging in clinical diagnOSIs. J Neurol Neurosurg Psychiatry 1986;49:640-4. 14. Overbeck DO, Ghormley RK. ParalYSIS of the serratus mag nus muscle. JAMA 1940; 114: 1994-6 15. Pettera JE, Trojaborg W. Conduction studies of the Long thoraCIC nerve in serratus anterior palsy of different etiology. Neurology 1984;34: 1033-7. 16 Phillips LH. Familial long thoracic nerve palsy: a manifestation of brachial plexus neuropathy. Neurology 1986;361251-3. 17. Porsman 0 Serratus anterior parese som erhvervssygdom hos slagteriarbeldere Ugeskr Laeger 1977, 139:291-2. 18 Potts CS Isolated paralySIS of the serratus magnus. report of a case Arch Neural Psych 1928,20 184-6. 19 Prescott MU, Zollinger RW. Alar scapula' an unusual surgical complication. Am J Surg 1944;65.98-103. 20. Richardson JS. 1942,1 618-9
Serratus
magnus
palsy
Lancet
1. Berkhelser EJ, Shapiro F Alar scapula: traumatic palsy of serratus magnus. JAMA 1937; 108.1790-3.
21. Spillane JD Localised neUritis of the shoulder girdle' a report of 46 cases In the MEF. Lancet 1943,2:532-5
2 Fery A, Sommelet J. La paralysie du grand dentele resultat du traitement de 12 cas dont 9 operes et revue genera Ie de la litterature Rev Chlr Orthop 1987;73.27788
22 Thorek M. Compression paralysis of the long thoraCiC nerve follOWing an abdominal operation, With report of a case. Am J Surg 1926;4026-7. 23. Yastamaki M. Serratuspareesi. DuodeCim 1985; 101 969-76
3. Fiddian NJ, King RJ. The winged scapula CIIn Orthop 1984; 185:228-36 4. Foo CL, Swann M. Isolated paralySIS of the serratus anterior. a report of 20 cases. J Bone Joint Surg [Br] 1983,65B:552-6.
24. Yastamaki M. Serratus anterior paralYSIS [Abstract]. Presented at the Fifty-Sixth Annual Meeting of the American Academy of OrthopaediC Surgeons, Las Yegas, Nevada, February 24-28,1989.1989:171
5 Goodman CE, Kenrick MM, Blum MY. Long thoracic nerve palsy: a follow-up study. Arch Phys Med Rehabil 1975;56352-5.
25. Wood YE, Frykman GK Winging of the scapula as a complication of first rib resection a report of SIX cases. Clin Orthop 1980; 149: 160-3
6. Gregg JR, Labosky D, Harty M, et al. Serratus anterior paralySIS In the young athlete. J Bone JOint Surg [Am] 1979,61 A:825-31.