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Case
An otherwise healthy 29-year-old man presented to the ED for evaluation of right arm pain. He had been throwing a baseball when he felt acute onset of severe pain in his right shoulder and became unable to use his arm. Radiographs of the humerus were obtained (Figure a and b).
Fracture of the Humerus
A thrower’s fracture is a rare fracture pattern characterized by a spontaneous fracture of the mid to distal third of the humeral diaphysis during an attempted throwing motion. It was first described by Wilmoth in a case report published in 1930.1 Understanding the proposed mechanism and complications of injury are important for proper work-up and management in the ED.
Fractures of the humerus in young adults are typically the result of high-energy direct trauma. So how does the humerus fracture from throwing a baseball? The most commonly proposed mechanism is an excessive torque during the cocking and acceleration phases of the throwing motion.2-5 This can be visualized as a pitcher’s arm maximally cocked back prior to forward acceleration. During the transition into the acceleration phase, internal rotation is abruptly initiated by the subscapularis, pectoralis major, and latissimus dorsi.6,7 The distal humerus continues to externally rotate due to the momentum generated by the cocking phase, while the proximal humerus violently internally rotates, creating a torsional force on the humerus at the insertion of these muscles and a fulcrum for potential fracture.8 Spiral fractures are the most commonly seen fracture pattern, which correlates with this proposed mechanism.9
Thrower’s fractures are most commonly reported in men in their 20s and 30s who are less seasoned athletes.10,11 These individuals are potentially at greater risk due to the lack of compensatory humeral cortical hypertrophy from repetitive throwing10,12 coupled with a less refined throwing motion.13 Additionally, up to 75% of patients experience prodromal throwing pain at the impending fracture site,11 which suggests that a primary insult such as a stress fracture may also predispose patients to this fracture pattern.
Once a fracture is suspected, a neurovascular assessment should immediately be performed, because concurrent radial nerve injuries have been reported in an average of 11.8% of mid-distal humeral fractures.14 Fractures with associated radial nerve deficits should not be reduced without an orthopedic consultation. Most radial nerve injuries are the result of neuropraxia, which usually resolves spontaneously, and attempted reduction may result in worsening nerve damage.14,15 Additionally, the orthopedist may consider late exploration if no spontaneous nerve recovery occurs within 3 to 6 months.16 Thrower’s fractures with or without associated radial nerve palsies are typically treated conservatively with a hanging cast, which has shown similar results to orthopedic fixation.10,17 The emergency physician should feel comfortable not ordering additional imaging to search for a pathological fracture, unless plain films suggest otherwise.
1. Wilmoth CL. Recurrent fracture of the humerus due to sudden extreme muscular action. J Bone Joint Surg.1930;12(1):168-169.
2. Miller A, Dodson CC, Ilyas AM. Thrower’s fracture of the humerus. Orthop Clin North Am. 2014;45(4):565-569.
3. Weseley MS, Barenfeld PA. Ball throwers’ fracture of the humerus. Six case reports. Clin Orthop Relat Res. 1969;64:153-156.
4. Chao SL, Miller M,Teng SW. A mechanism of spiral fracture of the humerus: a report of 129 cases following the throwing of hand grenades. J Trauma. 1971;11(7):602-605.
5. Polu KR, Schenck RC Jr, Wirth MA, Greeson J, Cone RO 3rd, Rockwood CA Jr. Stress fracture of the humerus in a collegiate baseball pitcher. A case report. Am J Sports Med. 1999;27(6):813-816.
6. Jobe FW, Moynes DR, Tibone JE, Perry J. An EMG analysis of the shoulder in pitching. A second report. Am J Sports Med. 1984;12(3):218-220.
7. Pappas AM, Zawacki RM, Sullivan TJ. Biomechanics of baseball pitching. A preliminary report. Am J Sports Med. 1985;13(4):216-222.
8. Sabick MB, Torry MR, Kim YK, Hawkins RJ. Humeral torque in professional baseball pitchers. Am J Sports Med. 2004;32(4):892-898.
9. Klenerman L. Fractures of the shaft of the humerus. J Bone Joint Surg Br. 1966;48(1):105-111.
10. Ogawa K, Yoshida A. Throwing fracture of the humeral shaft. An analysis of 90 patients. Am J Sports Med. 1998;26(2):242-246.
11. Branch T, Partin C, Chamberland P, Emeterio E, Sabetelle M. Spontaneous fractures of the humerus during pitching. A series of 12 cases. Am J Sports Med. 1992;20(4):468-470.
12. Tullos HS, Erwin WD, Woods GW, Wukasch DC, Cooley DA, King JW. Unusual lesions of the pitching arm. Clin Orthop Relat Res. 1972;88:169-182.
13. Bingham EL. Fractures of the humerus from muscular violence. U S Armed Forces Med J. 1959;10(1):22-25.
14. Shao YC, Harwood P, Grotz MR, Limb D, Giannoudis PV. Radial nerve palsy associated with fractures of the shaft of the humerus: a systematic review. J Bone Joint Surg Br. 2005;87(12):1647-1652.
15. Bishop J, Ring D. Management of radial nerve palsy associated with humeral shaft fracture: a decision analysis model. J Hand Surg Am. 2009;34(6)991-996.
16. Niver GE, Ilyas AM. Management of radial nerve palsy following fractures of the humerus. Orthop Clin North Am. 2013;44(3):419-424.
17. Kaplan H, Kiral A, Kuskucu M, Arpacioglu MO, Sarioglu A, Rodop O. Report of eight cases of humeral fracture following the throwing of hand grenades. Arch Orthop Trauma Surg. 1998;117(1-2):50-52.
Case
An otherwise healthy 29-year-old man presented to the ED for evaluation of right arm pain. He had been throwing a baseball when he felt acute onset of severe pain in his right shoulder and became unable to use his arm. Radiographs of the humerus were obtained (Figure a and b).
Fracture of the Humerus
A thrower’s fracture is a rare fracture pattern characterized by a spontaneous fracture of the mid to distal third of the humeral diaphysis during an attempted throwing motion. It was first described by Wilmoth in a case report published in 1930.1 Understanding the proposed mechanism and complications of injury are important for proper work-up and management in the ED.
Fractures of the humerus in young adults are typically the result of high-energy direct trauma. So how does the humerus fracture from throwing a baseball? The most commonly proposed mechanism is an excessive torque during the cocking and acceleration phases of the throwing motion.2-5 This can be visualized as a pitcher’s arm maximally cocked back prior to forward acceleration. During the transition into the acceleration phase, internal rotation is abruptly initiated by the subscapularis, pectoralis major, and latissimus dorsi.6,7 The distal humerus continues to externally rotate due to the momentum generated by the cocking phase, while the proximal humerus violently internally rotates, creating a torsional force on the humerus at the insertion of these muscles and a fulcrum for potential fracture.8 Spiral fractures are the most commonly seen fracture pattern, which correlates with this proposed mechanism.9
Thrower’s fractures are most commonly reported in men in their 20s and 30s who are less seasoned athletes.10,11 These individuals are potentially at greater risk due to the lack of compensatory humeral cortical hypertrophy from repetitive throwing10,12 coupled with a less refined throwing motion.13 Additionally, up to 75% of patients experience prodromal throwing pain at the impending fracture site,11 which suggests that a primary insult such as a stress fracture may also predispose patients to this fracture pattern.
Once a fracture is suspected, a neurovascular assessment should immediately be performed, because concurrent radial nerve injuries have been reported in an average of 11.8% of mid-distal humeral fractures.14 Fractures with associated radial nerve deficits should not be reduced without an orthopedic consultation. Most radial nerve injuries are the result of neuropraxia, which usually resolves spontaneously, and attempted reduction may result in worsening nerve damage.14,15 Additionally, the orthopedist may consider late exploration if no spontaneous nerve recovery occurs within 3 to 6 months.16 Thrower’s fractures with or without associated radial nerve palsies are typically treated conservatively with a hanging cast, which has shown similar results to orthopedic fixation.10,17 The emergency physician should feel comfortable not ordering additional imaging to search for a pathological fracture, unless plain films suggest otherwise.
Case
An otherwise healthy 29-year-old man presented to the ED for evaluation of right arm pain. He had been throwing a baseball when he felt acute onset of severe pain in his right shoulder and became unable to use his arm. Radiographs of the humerus were obtained (Figure a and b).
Fracture of the Humerus
A thrower’s fracture is a rare fracture pattern characterized by a spontaneous fracture of the mid to distal third of the humeral diaphysis during an attempted throwing motion. It was first described by Wilmoth in a case report published in 1930.1 Understanding the proposed mechanism and complications of injury are important for proper work-up and management in the ED.
Fractures of the humerus in young adults are typically the result of high-energy direct trauma. So how does the humerus fracture from throwing a baseball? The most commonly proposed mechanism is an excessive torque during the cocking and acceleration phases of the throwing motion.2-5 This can be visualized as a pitcher’s arm maximally cocked back prior to forward acceleration. During the transition into the acceleration phase, internal rotation is abruptly initiated by the subscapularis, pectoralis major, and latissimus dorsi.6,7 The distal humerus continues to externally rotate due to the momentum generated by the cocking phase, while the proximal humerus violently internally rotates, creating a torsional force on the humerus at the insertion of these muscles and a fulcrum for potential fracture.8 Spiral fractures are the most commonly seen fracture pattern, which correlates with this proposed mechanism.9
Thrower’s fractures are most commonly reported in men in their 20s and 30s who are less seasoned athletes.10,11 These individuals are potentially at greater risk due to the lack of compensatory humeral cortical hypertrophy from repetitive throwing10,12 coupled with a less refined throwing motion.13 Additionally, up to 75% of patients experience prodromal throwing pain at the impending fracture site,11 which suggests that a primary insult such as a stress fracture may also predispose patients to this fracture pattern.
Once a fracture is suspected, a neurovascular assessment should immediately be performed, because concurrent radial nerve injuries have been reported in an average of 11.8% of mid-distal humeral fractures.14 Fractures with associated radial nerve deficits should not be reduced without an orthopedic consultation. Most radial nerve injuries are the result of neuropraxia, which usually resolves spontaneously, and attempted reduction may result in worsening nerve damage.14,15 Additionally, the orthopedist may consider late exploration if no spontaneous nerve recovery occurs within 3 to 6 months.16 Thrower’s fractures with or without associated radial nerve palsies are typically treated conservatively with a hanging cast, which has shown similar results to orthopedic fixation.10,17 The emergency physician should feel comfortable not ordering additional imaging to search for a pathological fracture, unless plain films suggest otherwise.
1. Wilmoth CL. Recurrent fracture of the humerus due to sudden extreme muscular action. J Bone Joint Surg.1930;12(1):168-169.
2. Miller A, Dodson CC, Ilyas AM. Thrower’s fracture of the humerus. Orthop Clin North Am. 2014;45(4):565-569.
3. Weseley MS, Barenfeld PA. Ball throwers’ fracture of the humerus. Six case reports. Clin Orthop Relat Res. 1969;64:153-156.
4. Chao SL, Miller M,Teng SW. A mechanism of spiral fracture of the humerus: a report of 129 cases following the throwing of hand grenades. J Trauma. 1971;11(7):602-605.
5. Polu KR, Schenck RC Jr, Wirth MA, Greeson J, Cone RO 3rd, Rockwood CA Jr. Stress fracture of the humerus in a collegiate baseball pitcher. A case report. Am J Sports Med. 1999;27(6):813-816.
6. Jobe FW, Moynes DR, Tibone JE, Perry J. An EMG analysis of the shoulder in pitching. A second report. Am J Sports Med. 1984;12(3):218-220.
7. Pappas AM, Zawacki RM, Sullivan TJ. Biomechanics of baseball pitching. A preliminary report. Am J Sports Med. 1985;13(4):216-222.
8. Sabick MB, Torry MR, Kim YK, Hawkins RJ. Humeral torque in professional baseball pitchers. Am J Sports Med. 2004;32(4):892-898.
9. Klenerman L. Fractures of the shaft of the humerus. J Bone Joint Surg Br. 1966;48(1):105-111.
10. Ogawa K, Yoshida A. Throwing fracture of the humeral shaft. An analysis of 90 patients. Am J Sports Med. 1998;26(2):242-246.
11. Branch T, Partin C, Chamberland P, Emeterio E, Sabetelle M. Spontaneous fractures of the humerus during pitching. A series of 12 cases. Am J Sports Med. 1992;20(4):468-470.
12. Tullos HS, Erwin WD, Woods GW, Wukasch DC, Cooley DA, King JW. Unusual lesions of the pitching arm. Clin Orthop Relat Res. 1972;88:169-182.
13. Bingham EL. Fractures of the humerus from muscular violence. U S Armed Forces Med J. 1959;10(1):22-25.
14. Shao YC, Harwood P, Grotz MR, Limb D, Giannoudis PV. Radial nerve palsy associated with fractures of the shaft of the humerus: a systematic review. J Bone Joint Surg Br. 2005;87(12):1647-1652.
15. Bishop J, Ring D. Management of radial nerve palsy associated with humeral shaft fracture: a decision analysis model. J Hand Surg Am. 2009;34(6)991-996.
16. Niver GE, Ilyas AM. Management of radial nerve palsy following fractures of the humerus. Orthop Clin North Am. 2013;44(3):419-424.
17. Kaplan H, Kiral A, Kuskucu M, Arpacioglu MO, Sarioglu A, Rodop O. Report of eight cases of humeral fracture following the throwing of hand grenades. Arch Orthop Trauma Surg. 1998;117(1-2):50-52.
1. Wilmoth CL. Recurrent fracture of the humerus due to sudden extreme muscular action. J Bone Joint Surg.1930;12(1):168-169.
2. Miller A, Dodson CC, Ilyas AM. Thrower’s fracture of the humerus. Orthop Clin North Am. 2014;45(4):565-569.
3. Weseley MS, Barenfeld PA. Ball throwers’ fracture of the humerus. Six case reports. Clin Orthop Relat Res. 1969;64:153-156.
4. Chao SL, Miller M,Teng SW. A mechanism of spiral fracture of the humerus: a report of 129 cases following the throwing of hand grenades. J Trauma. 1971;11(7):602-605.
5. Polu KR, Schenck RC Jr, Wirth MA, Greeson J, Cone RO 3rd, Rockwood CA Jr. Stress fracture of the humerus in a collegiate baseball pitcher. A case report. Am J Sports Med. 1999;27(6):813-816.
6. Jobe FW, Moynes DR, Tibone JE, Perry J. An EMG analysis of the shoulder in pitching. A second report. Am J Sports Med. 1984;12(3):218-220.
7. Pappas AM, Zawacki RM, Sullivan TJ. Biomechanics of baseball pitching. A preliminary report. Am J Sports Med. 1985;13(4):216-222.
8. Sabick MB, Torry MR, Kim YK, Hawkins RJ. Humeral torque in professional baseball pitchers. Am J Sports Med. 2004;32(4):892-898.
9. Klenerman L. Fractures of the shaft of the humerus. J Bone Joint Surg Br. 1966;48(1):105-111.
10. Ogawa K, Yoshida A. Throwing fracture of the humeral shaft. An analysis of 90 patients. Am J Sports Med. 1998;26(2):242-246.
11. Branch T, Partin C, Chamberland P, Emeterio E, Sabetelle M. Spontaneous fractures of the humerus during pitching. A series of 12 cases. Am J Sports Med. 1992;20(4):468-470.
12. Tullos HS, Erwin WD, Woods GW, Wukasch DC, Cooley DA, King JW. Unusual lesions of the pitching arm. Clin Orthop Relat Res. 1972;88:169-182.
13. Bingham EL. Fractures of the humerus from muscular violence. U S Armed Forces Med J. 1959;10(1):22-25.
14. Shao YC, Harwood P, Grotz MR, Limb D, Giannoudis PV. Radial nerve palsy associated with fractures of the shaft of the humerus: a systematic review. J Bone Joint Surg Br. 2005;87(12):1647-1652.
15. Bishop J, Ring D. Management of radial nerve palsy associated with humeral shaft fracture: a decision analysis model. J Hand Surg Am. 2009;34(6)991-996.
16. Niver GE, Ilyas AM. Management of radial nerve palsy following fractures of the humerus. Orthop Clin North Am. 2013;44(3):419-424.
17. Kaplan H, Kiral A, Kuskucu M, Arpacioglu MO, Sarioglu A, Rodop O. Report of eight cases of humeral fracture following the throwing of hand grenades. Arch Orthop Trauma Surg. 1998;117(1-2):50-52.
