With a "click", the orthopedic surgeon broke his own bone

Recently, an orthopedic surgeon in Henan Province broke his arm after arm wrestling with another orthopedic surgeon who was "as strong as an ox". This news became a hot search on Weibo, and netizens joked, "Is this a year-end performance boost? The hospital earns money and spends it, and doesn't take a penny home."

Left upper arm fracture | Video screenshot

From the above picture, the doctor's fracture site is in the middle of the left upper arm, that is, the middle part of the humerus. Combined with the spiral fracture line, the fracture type can be basically determined to be a spiral fracture of the humeral shaft.

However, the doctor broke the wrist, how come he broke the humerus? Did the hand of God break his humerus?

The wrist was broken, how come the humeral shaft was broken?

This has to start with why the humeral shaft breaks. The main causes of humeral shaft fractures include direct and indirect violent impacts. Direct violence to break the humerus is easy to understand, which means that the force hits the middle part of the bone from the outside of the humerus, resulting in a transverse fracture or comminuted fracture of the humerus, which is common in fights or car accidents.

The doctor in the video only clasped his hands with his opponent, and his upper arm was not directly subjected to force, which is a humeral fracture caused by indirect violence. This situation is actually more common. Usually, when falling, the hand or elbow touches the ground, and the force is transmitted upward, plus the torsion or shear force generated by the tilt of the arm, resulting in a humeral fracture. The fracture line is generally oblique or spiral. The doctor suffered a spiral fracture.

When arm wrestling, in addition to the wrist and finger muscles, the shoulder girdle muscles, forearm, upper arm muscles, and some muscle groups in the trunk are also used. The two competitive parties will try to exhaust every bit of energy and try their best to contract every muscle fiber in the upper limbs.

When the two sides are evenly matched or trying to turn the tide, one of them may exert force instantly. The explosive force generated at this time may cause the upper arm muscle groups attached to different positions of the humeral shaft to further contract strongly (such as the biceps and triceps). These muscle groups pull the humerus in different directions, and coupled with the shift of the body's center of gravity, the humeral shaft may "snap" and break, and the two ends of the fracture may separate, shift, or even rotate. Many humeral shaft fractures occur at the final stage of the "warrior contest" when the winner exerts force and tries to end this "warrior contest" with all his strength.

This is the true meaning of "breaking the wrist but breaking the humerus". It can be seen that if there is a hand of God, it is the "hand of strength" of the two orthopedic surgeons! In fact, the principle of humeral fracture caused by arm wrestling is similar to that of various throwing actions (such as soldiers throwing grenades).

After a humeral shaft fracture, upper arm pain, swelling, subcutaneous congestion, deformity, or upper limb movement disorders may occur. In addition, since the humeral shaft is located close to the radial nerve and brachial artery, fractures are likely to damage the brachial artery and radial nerve, resulting in bleeding and inability to straighten the wrist or fingers, respectively. Fortunately, nearly 90% of patients with humeral shaft fractures can recover well [1].

The front and back of the humerus | Color Atlas of the Human Body (2nd Edition)

Does arm wrestling only cause humeral shaft fractures?

In a study of closed humeral fractures, arm wrestling accounted for approximately 8% of all fractures.[2] It is not uncommon for arm wrestling to cause humeral shaft fractures, which is also the most common type of fracture caused by arm wrestling. In addition, arm wrestling can also cause fractures of the radial shaft and radial head with anterior dislocation of the forearm, as well as soft tissue injuries such as muscle strain and tendon rupture.

Since the first case of humeral fractures caused by arm wrestling was reported in 1975[3], there have been many similar cases. Many adolescents have fractured their humerus during arm wrestling, and male soldiers are particularly prone to fractures. Children, the elderly, those who are not well trained, and those with osteoporosis are more likely to fracture their humerus during arm wrestling.

Korean scholars conducted a survey on 123 young soldiers with humeral shaft fractures. The results showed that arm wrestling was the most common cause of humeral shaft fractures (accounting for 52.8%), more common than falls, and all fracture types associated with arm wrestling were spiral fractures [4].

However, due to differences in force mechanisms, the humeral fracture line caused by arm wrestling is not always spiral, and the fracture site is not always located in the middle part of the humerus. Chinese scholars have reported cases of humeral comminuted fractures and medial epicondyle avulsion fractures caused by arm wrestling [5, 6].

Figure丨wikimedia

Therefore, although arm wrestling has become a common sport or entertainment in many countries or regions, it is not a sport without risks. For those who want to participate in arm wrestling competitions, in order to reduce the risk of musculoskeletal injuries such as humeral fractures and tendon ruptures, they need to do more strength training for the upper limbs to help strengthen the muscles and bones required for arm wrestling.

If untrained people treat arm wrestling as a game, they should do it within their ability and stop when necessary to ensure safety. For children or adolescents whose musculoskeletal development is not yet complete, the elderly or patients with osteoporosis, the risk of arm wrestling is even greater. If they are not careful, they may be broken by the "hand of God".

Title image source: 4D Video

References

[1] Bounds EJ, Frane N, Kok SJ. Humeral Shaft Fractures. 2020 Aug 24. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020.

[2] Mayfield CK, Egol KA. Humeral Fractures Sustained During Arm Wrestling: A Retrospective Cohort Analysis and Review of the Literature. Orthopedics. 2018;41(2):e207-e210.

[3] Brismar B, Spangen L. Fracture of the humerus from arm wrestling. Acta Orthop Scand. 1975;46(4):707-708.

[4] Kim KE, Kim EJ, Park J, et al. Humeral shaft fracture and radial nerve palsy in Korean soldiers: focus on arm wrestling related injury. BMJ Mil Health. 2020:jramc-2019-001373.

[5] Zhu Xiangjiang, Wang Gangxiang, Pan Keliang. A case report of ulnar nerve compression caused by medial epicondyle fracture of humerus. Chinese Journal of Orthopaedics and Traumatology. 2006;19(8):1.

[6] Li Jun, Zhou Yun, Jing Juehua. A case of comminuted distal humeral fracture caused by arm wrestling. Chinese Journal of Orthopaedics and Traumatology. 2013;26(007):611-612.

Author: CHENG KT

Editor: Dai Tianyi