1) Injury involving growth cartilage
Growth cartilage is more vulnerable to stress than bone structures.
Acute traumatic or chronic low-intensity injuries can damage the growth plate.
Injuries to the growth plate can be direct,
indirect or both.
Acute injuries
Epiphyseal fractures are of great importance in the context of traumatic injuries,
corresponding to approximately 18% of all fractures that occur in children.
In children,
fractures can directly affect or extend to the growth plate,
a site two to five times weaker than the surrounding bone structures,
and occur more frequently in the upper extremities.
The Salter-Harris classification divides the fractures according to their radiographic appearance into five types.
(Fig 2)
Radiographs are usually sufficient for the diagnosis of fractures in children; however,
in some cases,
it is necessary to perform CT or MRI for greater anatomical detail and to establish a definitive treatment.
Avulsion fractures occur due to secondary trauma caused by sudden and disproportionate muscular effort,
with acceleration and deceleration movements and jumps.
Pelvic processes appear between the ages of 13 and 15 and fuse between 16 and 24 years.
The clinic is of immediate and localized acute pain; it is associated inability to support weight,
active movement and weakness.
The bony fragment can be palpable when it affects the anterior superior iliac spine.
Plain radiographs confirm the avulsion and the degree of displacement.
The anterior superior iliac spine (ASIS) is a bony protrusion on the anterior margin of the iliac crest.
The sartorius and tensor muscles of the fascia lata are inserted in this site; they are the cause of avulsion injuries.
The ASIS ossifies between 13 and 15 years,
merges with the iliac crest at 20 years.
In the imaging studies (X-ray,
CT or MRI) an avulsed bone fragment is observed,
usually unilateral,
so the contralateral comparison is recommended.
(Fig.
6)
The anterior inferior iliac spine (AIIS) the rectus femoris is inserted,
the ossification begins between 13 and 14 years of age,
it is completed between 16 and 18 years of age.
On radiographs,
the bone fragment adjacent to the AIIS is seen,
with better visualization in the lateral or frog projection.
MRI is useful in cases of non-fossilized processes or when the diagnosis is not clear according to the radiographs.
(Fig.
7-8)
Chronic injuries
Chronic or overuse injuries are caused by repetitive microtrauma that exceeds the healing capacity of the tissues.
They usually have an insidious onset,
depending on the intensity and duration of physical activity.
Growth cartilage,
articular cartilage,
and apophyseal insertions are the sites that are affected by children.
Stress fractures,
osteochondritis and traction apophysitis,
are more frequent in adolescents.
Little Leaguer’s Shoulder is an injury due to repetitive and excessive use,
causes the rupture of the vessels located in the primary spongy metaphysis of the proximal humeral bone,
is observed in baseball pitchers between the ages of 11 and 16,
presents with pain in the lateral part of the shoulder.
In the radiographs abnormal thickening and irregularity of the epiphysis are observed,
the magnetic resonance is useful because,
in addition to seeing the thickening of the epiphysis,
bone edema of the metaphysis is identified with increased intensity on T2-weighted,
with hypointensity on the T1-weighted.
(Fig 9)
Little Leaguer’s Elbow is caused by valgus tension on the elbow joint,
causes avulsion of the medial epiphyseal plate (growth plate).
The term has been extended to include a series of anomalies that affect the elbow of adolescents since the immature process of the medial epicondyle is the weakest link.
It is characterized by pain in the medial epicondyle,
which limits athletic performance.
X-rays may be normal or show a widening of the epiphysis.
MRI demonstrates edema of the bone marrow within the medial epicondyle,
in some cases of the common flexor tendon and paratendinous soft tissues.
(Fig 10)
Sever's disease or calcaneal apophysitis is a prevalent cause of heel pain in young athletes.
It usually occurs bilaterally.
It consists of an inflammatory process of the growth plate of the calcaneus bone.
In radiographs it is generally not visible,
in MRI it presents as bone edema of the calcaneal process.
(Fig.
11)
The Sinding-Larsen-Johansson disease is a traction apophysitis located in the lower pole of the patella,
is considered tendinopathy.
It manifests as focal pain in the lower part of the patella and is self-limiting.
Imaging studies such as radiographs or MRI are useful to exclude other diagnoses such as a patellar fracture.
(Fig.
12)
Osgood-Schlatter disease is caused by constant and intense tension of the patellar tendon.
It affects girls between 8 and 12 years old,
and children between 10 and 15 years old.
It begins with insidious pain in the anterior part of the knee that is exacerbated by physical activity.
MRI identifies changes in signal intensity of the patellar tendon and tibial tubercle.
(Fig 13)
Finally,
the ossification center of the tibial tuberosity fuses and the symptoms become self-limiting.
Osteochondritis dissecans of the knee is a frequent cause of pain,
and dysfunction children and adolescents,
occur more often in athletes.
The etiology is uncertain; it is associated with repetitive microtrauma lesions of the secondary epiphysis,
ischemia,
genetic factors and in some cases as a failure of the process of endochondral ossification.
The diagnosis can be performed with radiographs.
However,
MRI is better to evaluate the integrity and degree of cartilage damage.
(Fig 14-15)
2) Injury joints,
tendons,
and ligaments
Osteitis pubis is a common pathology in high-performance athletes,
consists of an aseptic inflammatory process of the pubic symphysis bone,
and can affect the soft tissues,
tendons,
and adjacent muscles.
The probable etiology is due to the mechanism of repetitive stress with microtrauma that affects the stability of the symphyseal joint.
Magnetic resonance imaging shows bone edema of the asymmetric or bilateral pubic symphysis,
edema of the soft tissues and periarticular muscles.
(Fig 16)
Traumatic lateral patellar dislocation is a common pathology in athletes when performing sports activity.
Traumatic dislocation is associated with rupture of medial ligament structures,
and in most cases it presents hemarthrosis.
MRI is the most specific image method for assessing injured structures.
The findings can be hemarthrosis,
bone edema of the medial patellar facet and the lateral femoral condyle,
osteochondral lesions of the patellar aspect and rupture of the medial patellofemoral ligament.
(Fig 17)
The glenohumeral joint is the most susceptible to presenting dislocations.
The dislocations may be earlier in most cases or later.
Anterior glenohumeral dislocation is caused by external rotation and abduction by excessive external force.
The humeral head displaces the anteroinferior surface of the glenoid,
with impaction of the superior posterolateral surface in the anteroinferior glenoid rim.
The resulting lesions are called Bankart,
which is the rupture of the anterior glenoid labrum and may be accompanied by a fracture of the bone portion.
Hill-Sachs lesion is a wedge-shaped defect of the posterolateral humeral head,
is associated with bone edema.
(Fig 18 and 19)
Imaging studies such as X-rays,
tomography or MRI scans can identify this type of injury.
Posterior glenohumeral dislocation is frequently associated with intense muscle contraction.
The humeral head moves backward in an internal rotation while the arm is abducted.
The McLaughlin lesion (reverse Hill-Sachs) and the reverse Bankart lesion are characteristics of posterior dislocation.
The diagnosis is based mainly on tomography or magnetic resonance,
X-rays can go unnoticed these injuries.
(Fig 20)
The SLAP lesion is a tear of the upper labrum,
which can extend to the anterior and posterior surfaces.
They usually occur due to intense and sudden traction.
The clinical diagnosis is difficult; patients refer to insidious and unspecific pain.
Currently,
up to 10 different types of SLAP lesions have been described.
MRI is the image study with higher sensitivity and specificity for the evaluation of glenoid labrum lesions.
An increase in labrum intensity with biceps involvement is observed.
(Fig 21)
Lesions of the anterior cruciate ligament occur more frequently in adolescents than in children.
Occurs when an excessive load of knee valgus is applied in flexion with external rotation of the tibia or internal femur.
Magnetic resonance findings include fiber discontinuity,
angle loss,
abnormal hyperintensity,
anterior tibial translation,
and contusions of the bone marrow in the lateral femoral condyles and tibial plateaus.
(Fig 22)
The meniscus tears may accompany rupture of the anterior cruciate ligament and appear isolated,
in children and adolescents may be associated with a discoid meniscus.
The medial meniscus breaks more frequently.
MRI is the image study of choice to evaluate meniscus injuries.
(Fig 23)
3) Bone fracture
Fractures are the most common injuries in childhood and usually occur in the context of sports practice.
Acute fractures are caused by a force mechanism that exceeds the ability of the bone to resist it. Fractures can be classified according to the type of extension in the bone (complete or incomplete,
displacement (translation,
angulation or rotation) and its associated complications (exposed fracture,
extension to a joint or with dislocation).
Clavicle,
supracondylar fractures of the humerus and forearm usually occur in contact sports or indirect forces due to falls with the extension of the arm or hand.
Fractures of the ankle and tarsal bones are the result of a torsional force or direct trauma.
X-rays are the image study of the first choice for its diagnosis.
4) Spine
Low back pain is a common symptom in young athletes,
usually affects gymnasts,
wrestlers or dancers,
because they exert an excessive axial load,
with flexion and extension.
Spondylolysis is the fracture of the pars interarticularis of the vertebral body.
Spondylolisthesis is the sliding of a vertebra on a lower one.
(Fig 28)
The disc protrusions can occur in young athletes; however the mechanism is not clarified,
it is suggested as factors to develop disk herniation,
acute trauma and degenerative changes by repetitive microtrauma.
(Fig 29)