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Brachial plexus injury in snowboarding
ARTICLE IN PRESS BRACHIAL PLEXUS INJURY IN SNOWBOARDING T. OGAWA, N. OCHIAI and Y. HARA From the Department of Orthopaedic Surgery, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences and University Hospital, University of Tsukuba, Tsukuba, Japan
This paper reports three cases of brachial plexus injury which occurred during snowboarding. Journal of Hand Surgery (British and European Volume, 2006) 31B: 6: 661–662 Keywords: brachial plexus, injury, snow boarding
Brachial plexus injuries commonly occur as a result of motorcycle and motor vehicle accidents (Pino and Colville, 1989). The injury is also, occasionally, seen in football players and wrestlers (Clancy et al., 1977; Roland, 1949). This paper reports three cases of brachial plexus injury which occurred during snowboarding, a sport not previously identified with brachial plexus injury.
Case 2 A 23 year-old female snowboarder suffered a dislocation of her left shoulder in a fall on a gentle slope. Her shoulder was reduced in the local Accident and Emergency department without anaesthesia. The whole of her left upper extremity was anaesthetic before and after the shoulder reduction. The following day, she complained of motor paralysis, numbness and pain in her left upper extremity. She could not move the shoulder, elbow or hand. Very slight but painful sensation remained only in each finger tip. On manual muscle testing, the trapezius exhibited level 5, the latissimis dorsi, pectoralis major and infrasupinatus level 1 and the muscles distal to the deltoid level 0 motor strength. She had no Horner’s sign. Tinel’s testing was entirely negative. Radiography, MRI and CT showed no abnormality. Eleven days after injury, electrophysiological examination revealed degenerated patterns in the muscles innervated by all branches of the infraclavicular brachial plexus. However, very low amplitude sensory nerve action potentials were detected both in the median and ulnar nerves. The injury was diagnosed as a lesion in continuity of the infraclavicular part of brachial plexus and was treated conservatively. She recovered completely by 34 months after injury.
CASE REPORTS Case 1 A 24 year-old male snowboarder fell on a moderately steep slope. His neck was in left lateral flexion and his right upper extremity was pinned against his body at the time of injury (Fig 1). He was unconscious for a few seconds just after the injury. He then experienced numbness in the whole of the right upper extremity and was unable to move his shoulder and elbow. On examination, 7 days after the injury, sensation of the right upper limb was normal but muscle strength of the deltoid, infraspinatus, biceps and brachioradialis muscles was level 1 on manual muscle testing (Medical Research Council, 1954). Radiography, MRI and CT showed no abnormality. The injury was diagnosed as a postganglionic lesion in continuity of C5, 6 and was treated conservatively. Seven months after injury, the motor paresis had disappeared and the deltoid, infraspinatus, biceps and brachioradialis muscles had regained level 5 strength on manual muscle testing.
Fig 2 Probable mechanism of injury in case 2. The hand hit the snow with the shoulder internally rotated, hyperextended and hyperabducted causing shoulder dislocation, as a consequence of which the infraclavicular brachial plexus was stretched by the dislocating humeral head.
Fig 1 Probable mechanism of injury in case 1. The head and shoulder are forcibly separated. 661
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Fig 3 Probable mechanism of injury in case 3. The rider’s position on the board was such that, during a fall, he landed with his right hand behind him and his shoulder internally rotated, hyperextended and hyperabducted causing anterior shoulder dislocation. The dislocating humeral head pushed up and stretched the infraclavicular brachial plexus.
Case 3 A 56 year-old man snowboarder suffered a dislocation of his right shoulder in a fall onto his right hand, with the right elbow and shoulder hyperextended, on a gentle slope. His shoulder was reduced in the local Accident and Emergency department without anaesthesia. He was unable to move his elbow and hand and the whole of his right upper extremity was numb before and after the reduction. On examination 3 days after the injury, he had no sensory loss but several muscle strengths were reduced. On manual muscle testing, the deltoid, pectoralis major, infraspinatus and biceps exhibited level 1, triceps and flexor carpi radialis level 3 and all other muscles of the upper limb level 0 motor strength. Sensation was not anaesthetic. He had no Horner’s sign. Tinel’s testing was entirely negative. Radiography showed no abnormality. The injury was diagnosed as an infraclavicular brachial plexus lesion in continuity and was treated conservatively. Muscle strength was recovered from proximal to distal. All muscles had recovered normal strength by 3 months except the finger intrinsic muscles, which only recovered 5 months after the injury.
DISCUSSION Hand injuries make up 3% to 15%, spinal injuries 1% to 13% and peripheral nerve injuries less than 1% of reported skiing and snowboarding injuries (Krivickas and Wilbourn, 2000). Injury to the upper extremities in snowboarding is a result of impact with the snow when the boarder falls. The rider’s position on the board is such that, during a fall, especially during a heel turn, he tends to land squarely on his buttocks. This differs from skiing, in which the skier usually falls forward (Kim et al., 2004; Milton, 1954). The full impact of a snowboarding fall is usually absorbed by the upper extremities and the force can be transmitted to any point along the upper limbs. The mechanism of injury in case 1 was forcible widening of the shoulder–neck angle: when his head
THE JOURNAL OF HAND SURGERY VOL. 31B No. 6 DECEMBER
2006
struck the snow with the arm alongside the body, most of the strain was borne by the upper cervical nerve roots. In cases 2 and 3, we believe that the shoulder dislocations were a result of a mixture of abnormal movements of internal or external rotation, hyperextension and hyperabduction. Case 2 remembered that her left upper extremity was caught behind her (Fig 2) and case 3 fell down onto his buttocks, with his right hand behind him and the right elbow and shoulder hyperextended (Fig 3). We believed that their shoulders dislocated as a result of enforced internal rotation, hyperextension and hyperabduction. If the shoulder dislocates as a result of enforced external rotation and abduction, an isolated lesion of the axillary nerve may occur. But if the shoulder dislocates as a result of enforced internal rotation and abduction, the brachial plexus may be stretched and bent caudally over the humeral head. Minor trauma, such as shoulder dislocation in a fall from one’s own height, is extremely unlikely to cause nerve rupture or avulsion. In contact sports, such as rugby, hockey and skiing, there are a few reports of nerve rupture or avulsion (Koehle et al., 2002). In the three cases of injury while snowboarding reported in this paper, the degree of recovery confirms that the injured nerves were in continuity. The reason for the nerve injuries being relatively minor is, probably, that the speed of the fall in all three cases was slow and the impact occurred with snow. However, a more severe brachial plexus injury could occur during snowboarding if travelling at high speed on a steep slope, in a fall from a greater height or on impact with another snowboarder. References Clancy WG, Brand RL, Bergfield JA (1977). Upper trunk brachial plexus injuries in contact sports. American Journal of Sports Medicine, 5: 209–216. Kim DH, Murovic JA, Tiel RL, Kline DG (2004). Infraclavicular brachial plexus stretch injury. Neurosurgical Focus, 16: 1–6. Koehle MS, Lloyd-Smith R, Taunton JE (2002). Alpine ski injuries and their prevention. Sports Medicine, 32: 785–793. Krivickas LS, Wilbourn AJ (2000). Peripheral nerve injuries in athletes: a case series of over 200 injuries. Seminars in Neurology, 20: 225–232. Medical Research Council (1954). Peripheral nerve injuries. Medical Research Council Special Report Series, 282: 1–8. Milton GW (1954). The circumflex nerve and dislocation of the shoulder. The British Journal of Physical Medicine, 17: 136–138. Pino EC, Colville MR (1989). Snowboard injuries. American Journal of Sports Medicine, 17: 778–781. Roland B (1949). Traction injuries of the brachial plexus in adult. The Journal of Bone and Joint Surgery, 31B: 10–16. Received: 19 April 2005 Accepted after revision: 17 August 2006 Takeshi Ogawa, Department of Orthopaedic Surgery, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences and University Hospital, University of Tsukuba 11-1 Tennodai Tsukuba, 305-8575, Japan. Tel.: +81 29853 3219; fax: +81 29853 3162. E-mail: [email protected]
r 2006 The British Society for Surgery of the Hand. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhsb.2006.08.010 available online at http://www.sciencedirect.com
This paper reports three cases of brachial plexus injury which occurred during snowboarding. Journal of Hand Surgery (British and European Volume, 2006) 31B: 6: 661–662 Keywords: brachial plexus, injury, snow boarding
Brachial plexus injuries commonly occur as a result of motorcycle and motor vehicle accidents (Pino and Colville, 1989). The injury is also, occasionally, seen in football players and wrestlers (Clancy et al., 1977; Roland, 1949). This paper reports three cases of brachial plexus injury which occurred during snowboarding, a sport not previously identified with brachial plexus injury.
Case 2 A 23 year-old female snowboarder suffered a dislocation of her left shoulder in a fall on a gentle slope. Her shoulder was reduced in the local Accident and Emergency department without anaesthesia. The whole of her left upper extremity was anaesthetic before and after the shoulder reduction. The following day, she complained of motor paralysis, numbness and pain in her left upper extremity. She could not move the shoulder, elbow or hand. Very slight but painful sensation remained only in each finger tip. On manual muscle testing, the trapezius exhibited level 5, the latissimis dorsi, pectoralis major and infrasupinatus level 1 and the muscles distal to the deltoid level 0 motor strength. She had no Horner’s sign. Tinel’s testing was entirely negative. Radiography, MRI and CT showed no abnormality. Eleven days after injury, electrophysiological examination revealed degenerated patterns in the muscles innervated by all branches of the infraclavicular brachial plexus. However, very low amplitude sensory nerve action potentials were detected both in the median and ulnar nerves. The injury was diagnosed as a lesion in continuity of the infraclavicular part of brachial plexus and was treated conservatively. She recovered completely by 34 months after injury.
CASE REPORTS Case 1 A 24 year-old male snowboarder fell on a moderately steep slope. His neck was in left lateral flexion and his right upper extremity was pinned against his body at the time of injury (Fig 1). He was unconscious for a few seconds just after the injury. He then experienced numbness in the whole of the right upper extremity and was unable to move his shoulder and elbow. On examination, 7 days after the injury, sensation of the right upper limb was normal but muscle strength of the deltoid, infraspinatus, biceps and brachioradialis muscles was level 1 on manual muscle testing (Medical Research Council, 1954). Radiography, MRI and CT showed no abnormality. The injury was diagnosed as a postganglionic lesion in continuity of C5, 6 and was treated conservatively. Seven months after injury, the motor paresis had disappeared and the deltoid, infraspinatus, biceps and brachioradialis muscles had regained level 5 strength on manual muscle testing.
Fig 2 Probable mechanism of injury in case 2. The hand hit the snow with the shoulder internally rotated, hyperextended and hyperabducted causing shoulder dislocation, as a consequence of which the infraclavicular brachial plexus was stretched by the dislocating humeral head.
Fig 1 Probable mechanism of injury in case 1. The head and shoulder are forcibly separated. 661
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Fig 3 Probable mechanism of injury in case 3. The rider’s position on the board was such that, during a fall, he landed with his right hand behind him and his shoulder internally rotated, hyperextended and hyperabducted causing anterior shoulder dislocation. The dislocating humeral head pushed up and stretched the infraclavicular brachial plexus.
Case 3 A 56 year-old man snowboarder suffered a dislocation of his right shoulder in a fall onto his right hand, with the right elbow and shoulder hyperextended, on a gentle slope. His shoulder was reduced in the local Accident and Emergency department without anaesthesia. He was unable to move his elbow and hand and the whole of his right upper extremity was numb before and after the reduction. On examination 3 days after the injury, he had no sensory loss but several muscle strengths were reduced. On manual muscle testing, the deltoid, pectoralis major, infraspinatus and biceps exhibited level 1, triceps and flexor carpi radialis level 3 and all other muscles of the upper limb level 0 motor strength. Sensation was not anaesthetic. He had no Horner’s sign. Tinel’s testing was entirely negative. Radiography showed no abnormality. The injury was diagnosed as an infraclavicular brachial plexus lesion in continuity and was treated conservatively. Muscle strength was recovered from proximal to distal. All muscles had recovered normal strength by 3 months except the finger intrinsic muscles, which only recovered 5 months after the injury.
DISCUSSION Hand injuries make up 3% to 15%, spinal injuries 1% to 13% and peripheral nerve injuries less than 1% of reported skiing and snowboarding injuries (Krivickas and Wilbourn, 2000). Injury to the upper extremities in snowboarding is a result of impact with the snow when the boarder falls. The rider’s position on the board is such that, during a fall, especially during a heel turn, he tends to land squarely on his buttocks. This differs from skiing, in which the skier usually falls forward (Kim et al., 2004; Milton, 1954). The full impact of a snowboarding fall is usually absorbed by the upper extremities and the force can be transmitted to any point along the upper limbs. The mechanism of injury in case 1 was forcible widening of the shoulder–neck angle: when his head
THE JOURNAL OF HAND SURGERY VOL. 31B No. 6 DECEMBER
2006
struck the snow with the arm alongside the body, most of the strain was borne by the upper cervical nerve roots. In cases 2 and 3, we believe that the shoulder dislocations were a result of a mixture of abnormal movements of internal or external rotation, hyperextension and hyperabduction. Case 2 remembered that her left upper extremity was caught behind her (Fig 2) and case 3 fell down onto his buttocks, with his right hand behind him and the right elbow and shoulder hyperextended (Fig 3). We believed that their shoulders dislocated as a result of enforced internal rotation, hyperextension and hyperabduction. If the shoulder dislocates as a result of enforced external rotation and abduction, an isolated lesion of the axillary nerve may occur. But if the shoulder dislocates as a result of enforced internal rotation and abduction, the brachial plexus may be stretched and bent caudally over the humeral head. Minor trauma, such as shoulder dislocation in a fall from one’s own height, is extremely unlikely to cause nerve rupture or avulsion. In contact sports, such as rugby, hockey and skiing, there are a few reports of nerve rupture or avulsion (Koehle et al., 2002). In the three cases of injury while snowboarding reported in this paper, the degree of recovery confirms that the injured nerves were in continuity. The reason for the nerve injuries being relatively minor is, probably, that the speed of the fall in all three cases was slow and the impact occurred with snow. However, a more severe brachial plexus injury could occur during snowboarding if travelling at high speed on a steep slope, in a fall from a greater height or on impact with another snowboarder. References Clancy WG, Brand RL, Bergfield JA (1977). Upper trunk brachial plexus injuries in contact sports. American Journal of Sports Medicine, 5: 209–216. Kim DH, Murovic JA, Tiel RL, Kline DG (2004). Infraclavicular brachial plexus stretch injury. Neurosurgical Focus, 16: 1–6. Koehle MS, Lloyd-Smith R, Taunton JE (2002). Alpine ski injuries and their prevention. Sports Medicine, 32: 785–793. Krivickas LS, Wilbourn AJ (2000). Peripheral nerve injuries in athletes: a case series of over 200 injuries. Seminars in Neurology, 20: 225–232. Medical Research Council (1954). Peripheral nerve injuries. Medical Research Council Special Report Series, 282: 1–8. Milton GW (1954). The circumflex nerve and dislocation of the shoulder. The British Journal of Physical Medicine, 17: 136–138. Pino EC, Colville MR (1989). Snowboard injuries. American Journal of Sports Medicine, 17: 778–781. Roland B (1949). Traction injuries of the brachial plexus in adult. The Journal of Bone and Joint Surgery, 31B: 10–16. Received: 19 April 2005 Accepted after revision: 17 August 2006 Takeshi Ogawa, Department of Orthopaedic Surgery, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences and University Hospital, University of Tsukuba 11-1 Tennodai Tsukuba, 305-8575, Japan. Tel.: +81 29853 3219; fax: +81 29853 3162. E-mail: [email protected]
r 2006 The British Society for Surgery of the Hand. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhsb.2006.08.010 available online at http://www.sciencedirect.com