Juvenile
First Rib Fracture Caused by Morning
Stretching
Lee SJ, Yie K, Chon SB.
Emergency Medicine and
Respiratory Center of Kangwon National University
Hospital and School of Medicine, Kangwon National
University, Chuncheon, South Korea.
Abstract
First rib fractures are very rare, being
primarily associated with external blunt trauma.
Related conditions, such as sudden contraction
of the neck muscle, stress fractures, and
fatigue fractures, have been reported
sporadically. These fractures are mostly related
to repetitive or explosive physical training.
However, anatomical relationships and related
injury mechanisms may cause first rib fractures
without repetitive sports activity. To present a
case of juvenile first rib fracture caused by
morning stretching without sports activity. We
present a rare case report of juvenile
atraumatic first rib fracture.
Physicians should be aware that even morning
stretching with yawning can cause a first rib
fracture in children. Awareness is important for
early recognition, and proper management is
critical for a pain-free return to normal life.
An understanding of the mechanism of atraumatic
first rib fracture is important.
INTRODUCTION
First rib fractures are very rare, being
primarily associated with external blunt trauma.
Related conditions, such as sudden contraction
of the neck muscles, stress fractures, and
fatigue fractures, have been sporadically
reported. These fractures are mostly related to
repetitive or explosive physical training.
However, certain anatomical relationships and
related injury mechanisms may cause first rib
fractures without repetitive sports
activity.
CASE REPORT
A 13-year-old boy presented to our Emergency
Department (ED) with a sudden sharp, stabbing
pain in the left shoulder and neck immediately
after stretching with a yawn in the morning. His
mother said that he woke up with his right arm
flexed pointing upward and his left arm
outstretched pointing downward. He yawned and
turned his head to the right side, and suddenly
heard a click in his neck. He had no history of
genetic disease, recent trauma, or sports
activity. He denied any child abuse and seemed
to be well nourished. On physical examination,
he had neither muscle atrophy of the shoulder
girdle nor asymmetry of the scapular region.
Although both shoulders exhibited full range of
motion, scapula retraction produced a nagging
pain in the left shoulder and medial scapular
area. There was minimal supraclavicular
tenderness. The pain was relieved somewhat by
resting. The patient felt occasional numbness in
his left upper limb when it was stretched. The
numbness was absent in the normal position.
Laboratory findings, including complete blood
cell count, electrolytes, hepatobiliary test,
renal function test, urine analysis, C-reactive
protein, and erythrocyte sedimentation rate,
were unremarkable. However, a radiograph of the
left ribs revealed a first rib fracture. Because
there was no significant neurological or
musculoskeletal complication, the patient was
treated conservatively and underwent routine
follow-up. A nonsteroidal anti-inflammatory drug
was prescribed for 3 days and effectively
alleviated the pain.
He was advised to avoid any physical
activity, including participating in physical
education classes at school. A nerve conduction
study was performed the next day in the
Neurology outpatient department; it did not
reveal any abnormal electrophysiological
finding. Two months later, the fracture site had
healed with callus formation, and the numbness
associated with limb stretching had completely
disappeared.
Atraumatic isolated first rib fracture in
juveniles is uncommon. It can be caused by
sudden muscular pulls, fatigue, or stress
fractures, or heavy mechanical loading on the
first rib. The diagnosis is made by obtaining a
careful history, finding focal tenderness
(although it was not severe in this case) on
physical examination, and performing plain
radiography. Identifying concomitant
neurovascular injury and controlling the pain
and complications is not complex in most cases.
However, the mechanism of injury should be
determined in each case. Some possible
mechanisms of juvenile atraumatic first rib
fracture follow. Matsumoto et al. suggest that
simultaneous eccentric muscle contraction of the
scalenus anterior, scalenus medius, and serratus
anterior can cause the first rib to fracture
(1). Anatomically, the scalenus muscles and the
serratus muscle insert on the superior and
inferior surfaces of the first rib,
respectively. Contraction of the scalenus
anterior pulls the lateral portion of the first
rib proximally and posterolaterally, whereas
contraction of the scalenus medius pulls the
medial portion of the first rib proximally and
medially. On the other hand, the serratus
anterior pulls the first rib posterolaterally
and inferiorly. Simultaneous contraction of
these muscles can exert a shearing force at the
groove of the subclavian artery, which is the
thinnest portion of the first rib. This
situation may not be associated with repetitive
use of the upper extremity; it can be seen with
"heading" actions, especially in laterally
bending heading of a soccer player, with
coughing, and with nervous tics in children.
Although there is no published report identical
to our case, we believe that the cause of first
rib fracture in our patient was by this
mechanism.
It has been theorized that chronic
repetitive muscle action at a younger age also
can be a cause of stress fractures of the first
rib. Vigorous sports activity and respiratory
distress require maximum increase in the
capacity of the thoracic cavity with forced
inspiration using accessory breathing muscles
such as the serratus and scalenus. Children
carrying heavy schoolbags using only one strap
are at higher risk for this situation. In
adults, on the other hand, pseudoarthrosis
formation of the costomanubrial joint of the
first rib results in limitation of "bucket
handle" motion during respiration, and this is
assumed to be associated with reduced "buffer
power" during muscular impacts, and predisposes
to stress fracture (6). Finally, child abuse
must be considered, especially in young
individuals presenting with first rib fractures.
The possible mechanisms involved in child abuse
could be direct impact force, compressive force,
shaking, or acute axial load (slamming), the
latter two of which cause indirect
fractures.
For an accurate diagnosis, considering the
possibility of first rib fracture along with
thorough history-taking and physical examination
are most important in children who have a
complaint of pain in the shoulder or neck. It
usually can be visualized on anteroposterior
chest or shoulder radiographs, mainly in the
region of the groove for the subclavian artery.
Controversies exist regarding the need for
additional imaging in this type of injury.
Although it may not be necessary for the
diagnosis, computed tomography scan is useful to
delineate the anatomy of the fracture, to rule
out pathologic lesions, and to confirm healing
at follow-up. Bone scans can assist in
determining the acuity of the fracture.
Generally, symptomatic treatment with
activity modification for 4-6 weeks and pain
control should suffice, but any hidden
neurovascular injury should be identified. The
timing of the patient's return to physical
activities depends on symptoms. Late
complications that require surgical
decompression such as brachial plexus palsy,
thoracic outlet syndrome, and Homer syndrome,
are rare but possible due to extensive callus
formation .
CONCLUSION
Physicians should be aware that even morning
stretching with yawning can cause a first rib
fracture in younger patients. Awareness is
important for early recognition, and proper
management is critical for a pain-free return to
normal life. An understanding of the mechanism,
associated findings, and prognosis of atraumatic
first rib fracture is important.
