Imaging of pediatric musculoskeletal trauma: Age-specific considerations and challenges

Abstract

Pediatric musculoskeletal trauma differs significantly from adult injuries due to the dynamic and evolving nature of the growing skeleton. The presence of open growth plates (physes), secondary ossification centers, and a more elastic bone structure contributes to unique injury patterns and imaging findings in children. Proper interpretation of pediatric imaging requires an in-depth understanding of age-specific anatomy, biomechanics, and normal developmental variants. This review provides a comprehensive overview of pediatric bone physiology and fracture types, including the Salter-Harris classification, special pediatric fractures, elbow ossification, avulsion injuries, and conditions related to repetitive stress. Additionally, we address the critical topic of non-accidental trauma, underscoring the radiologist’s role in early detection. Through an anatomical and pathophysiological lens, this paper explores the challenges and strategies for accurate diagnosis in pediatric trauma imaging.

Key Words: Musculoskeletal; Trauma; Pediatric; Children; Computed tomography; Magnetic resonance imaging; X-ray

Core Tip: Pediatric musculoskeletal trauma presents unique imaging challenges due to growth plates, ossification centers, and elastic bone structure. Accurate diagnosis requires knowledge of age-specific anatomy, developmental variants, and injury patterns. This review highlights fracture classifications, special injuries, and non-accidental trauma, emphasizing the radiologist’s critical role in early, precise evaluation.

INTRODUCTION

Pediatric musculoskeletal trauma poses unique diagnostic challenges as the developing skeleton is structurally and physiologically different from that of adults. The presence of open growth plates, evolving ossification centers, and a more elastic bone structure leads to distinctive injury patterns such as greenstick, buckle, and physeal fractures that require careful interpretation. Developmental variants can further complicate assessment by mimicking or obscuring pathology. In this context, imaging is central not only for identifying common and complex fractures but also for detecting overuse syndromes, apophyseal avulsions, and injuries related to non-accidental trauma (NAT). Selecting the most appropriate modality is particularly important in children, where reducing radiation exposure and considering age-specific anatomy and biomechanics must guide decision-making. This review addresses these challenges by examining pediatric bone physiology, fracture classifications and variants, imaging approaches to both acute and chronic injuries, and the expanding role of advanced techniques such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) in improving accuracy and safety in pediatric trauma care[1,2].

PEDIATRIC BONE ANATOMY AND THE SALTER-HARRIS CLASSIFICATION

Pediatric bones are in a constant state of development, characterized by the presence of growth plates, or physes, which lie between the metaphysis and epiphysis. These physes represent the weakest part of a growing bone, making them vulnerable to trauma[1]. The Salter-Harris classification system, used exclusively in pediatrics, categorizes physeal fractures into five types based on the involvement of the physis and surrounding structures[2]. The first being, type I fractures, which involves a separation through the physis alone. Radiographically (for example in distal tibial physeal separations), these fractures display a widened physis, occasionally with periosteal reaction during healing. Type II fractures extend through the physis and metaphysis, while type III fractures affect the physis and epiphysis. Type IV injuries traverse all three zones, metaphysis, physis, and epiphysis, posing a higher risk of growth disturbance, and as a result may demonstrate healing complications such as radiographically visible physeal bony bridging. Finally, type V fracture, which often goes unnoticed during initial imaging, is a compression or crush injury to the physis that can carry a poor prognosis due to growth arrest (Figure 1)[2,3].

Figure 1 Fractures according to the Salter Harris classification. The top left one represents a non-fractured pediatric bone. Type 1: Split/Separated physis; Type 2: Above the physis (involving the metaphysis); Type 3: Below the physis (involving the epiphysis); Type 4: Through the physis (involving both the metaphysis and epiphysis); Type 5: “smashed” physis (i.e. compression injury)[3]. Citation: Skalski M. Salter-Harris illustrations. Case study, Radiopaedia.org 2014. Copyright ©The Authors 2014. Published by Radiopaedia. The authors have obtained the permission (Supplementary material).

SPECIAL SALTER-HARRIS VARIANTS

This section will elaborate on unique Salter-Harris variants. To begin, slipped capital femoral epiphysis (SCFE) is a Salter-Harris type I fracture of the proximal femur, characterized by a posterior and inferior displacement of the femoral head relative to the metaphysis through the physis[4]. SCFE presents with widening and irregularity of the proximal femoral growth plate, with misalignment seen on reference lines drawn through the metaphysis and epiphysis (Figure 2)[5].

Figure 2 The Klein line is traced along the outer edge of the femoral neck and should normally pass through part of the lateral capital epiphysis. On the right side, the green line shows the expected, normal course of the Klein line. On the left side, the red line is abnormal, as it barely makes contact with the capital epiphysis[5]. Citation: Lustosa L. Slipped capital femoral epiphysis (SCFE). Case study, Radiopaedia.org 2023. Copyright ©The Authors 2023. Published by Radiopaedia. The authors have obtained the permission (Supplementary material).

The second is the Tillaux fracture, a type III physeal fracture, which is unique to adolescents. It involves the anterolateral epiphysis of the distal tibia and results from asymmetric physeal closure[6,7]. The lateral portion, which closes last, remains vulnerable to shear stress (Figure 3)[8].

Figure 3 Tillaux fracture. A: Salter-Harris III fracture of anterolateral aspect of distal tibial epiphysis, minimally displaced; B: Computed tomography performed to rule out occult fractures with none demonstrated[8]. Citation: Glick Y. Tillaux fracture. Case study, Radiopaedia.org 2017. Copyright ©The Authors 2017. Published by Radiopaedia. The authors have obtained the permission (Supplementary material).

Lastly, the triplane (or triplanar) fractures occur in the distal tibia and are seen exclusively in adolescents. Since physeal closure begins medially, the still-open lateral physis becomes vulnerable to this injury. They are generally considered a variant of Salter–Harris type IV fractures[9]. These fractures have three distinct components: A vertical (sagittal) fracture through the epiphysis, a horizontal (axial) fracture across the physis, and an oblique (coronal) fracture through the metaphysis[10]. Although most common at the distal tibia, triplane fractures have occasionally been described at other sites where physeal closure initiates asymmetrically, such as the distal radius, proximal tibia, and distal femur[9-11]. These fractures are best evaluated with CT or multiplanar imaging since this provides precise multiplanar and three-dimensional assessment of the articular surface and fracture geometry, which are critical for surgical planning (Figure 4)[12].

Figure 4 This is a triplane fracture (fracture across 3 planes). A: Sagittal (orange arrow), axial (green arrow); B: Coronal (blue arrow) fracture. The coronal fracture can be seen on the sagittal view in the image on the right[12]. Citation: Al Salam H. Triplanar fracture. Case study, Radiopaedia.org 2015. Copyright ©The Authors 2015. Published by Radiopaedia. The authors have obtained the permission (Supplementary material).

PEDIATRIC-SPECIFIC ANATOMY AND ELBOW IMAGING

The pediatric elbow contains six secondary ossification centers, which appear in a predictable sequence: Capitellum, radial head, internal (medial) epicondyle, trochlea, olecranon, and external (lateral) epicondyle (mnemonic: CRITOE-1, 5, 7, 10, 10, 11)[13,14] (Table 1). This pattern, along with patient age, helps distinguishnormal developmental variants from actual pathology.

Table 1 Ossification occurs in a typically predictable order (Mnemonic: CRITOE: 1, 5, 7, 10, 10, 11).

Ossification centers	Average age that ossification occurs
Capitellum	1 year (ossifies first)
Radial head	5 years
Internal (medial) epicondyle	7 years-always ossifies before the trochlea
Trochlea	10 years
Olecranon	10 years
External (lateral) epicondyle	11 years (ossifies last)

Normal elbow imaging landmarks include the anterior humeral line, which should bisect the middle third of the capitellum in children older than 2.5 years[15]. In younger children, it intersects the anterior third due to the eccentric ossification (Figure 5)[16]. The radial head-capitellar line should pass through both the radial head and the capitellum in all views (Figure 6)[17,18].

Figure 5 Anterior humeral line along the anterior humeral cortex. On a normal elbow, the AHL should pass through the middle third of the humeral capitulum[16]. Citation: Benoudina S. Anterior humeral line. Case study, Radiopaedia.org 2015. Copyright ©The Authors 2015. Published by Radiopaedia. The authors have obtained the permission (Supplementary material).

Figure 6 Radial head-capitellar line[18]. Citation: Benoudina S. Radiocapitellar line. Case study, Radiopaedia.org 2015. Copyright ©The Authors 2015. Published by Radiopaedia. The authors have obtained the permission (Supplementary material).

Another important sign is the “fat pad sign”. The posterior fat pad is normally not visible on lateral elbow radiographs, as it lies within the olecranon fossa (intercondylar depression)[19]. A visible bulbous appearing posterior fat pad is considered pathologic and is strongly suggestive of an intra-articular fracture, even if no fracture line is seen on the X-ray (Figure 7)[20].

Figure 7 Fat pad sign (right arrow)[20]. This image shows some effusion, which has displaced both the anterior (left arrow) and posterior fat pads. Citation: Hellerhoff. Fat pad sign: Ventral fat pad bowed and dorsal fat pad visible in a case of a nondisplaced fracture of the radius head which is not visible directly. Copyright ©The Authors 2026. The authors have obtained the permission (Supplementary material).

Instead, the anterior fat pad can be seen normally but it’s usually a thin small arch (thin lucent arc in the normal elbow). A joint effusion may elevate the anterior fat pad making it more prominent, often described as having a “sail sign” appearance[21,22].

COMMON ELBOW FRACTURES

Supracondylar fractures are the most common elbow fractures in children, typically resulting from a fall on an outstretched hand[23,24]. The Gartland classification (Table 2) is used for the classification of supracondylar humeral fractures which categorizes them according to the degree and direction of displacement, as well as whether the cortex remains intact. It is specifically used for extension-type supracondylar fractures and does not typically apply to the uncommon flexion-type fractures[25].

Table 2 Gartland classification.

Type	Description	Subtypes
I	Undisplaced or minimally displaced (< 2 mm)	Ia: Undisplaced in both projections; Ib: Minimal displacement, medial cortical buckle, anterior humeral line intersects capitellum
II	Displaced but with intact cortex	IIa: Posterior angulation, intact posterior cortex, anterior humeral line does not intersect capitellum; IIb: Rotatory or straight displacement, fracture ends remain in contact
III	Completely displaced	IIIa: Complete posterior displacement, no cortical contact; IIIb: Complete displacement with soft tissue gap (bone ends separated by soft tissue)
IV	Displaced, unstable in flexion and extension, periosteal disruption (diagnosed intra-operatively)	NA

NA: Not available.

Lateral condyle fractures, the second most common elbow fracture, involve the extensor tendon insertion site and may show entrapment or nonunion due to displacement[26]. Medial epicondyle fractures are frequently associated with elbow dislocation, and intra-articular entrapment of the fragment may be misinterpreted as trochlear ossification[27].

PHYSIOLOGY AND FRACTURE PATTERNS IN PEDIATRIC BONES

Pediatric bones differ structurally from adult bones in several important ways. They have a relatively thinner cortex, a stronger periosteum, and greater elasticity, which allows them to deform under load rather than fail completely[28,29]. These unique biomechanical properties give rise to a spectrum of incomplete fracture patterns not typically seen in adults, most notably greenstick, bowing, and buckle (torus) fractures.

Greenstick fractures are incomplete injuries of long bones and are most commonly observed in children under the age of 10, usually involving the mid-diaphysis of the forearm or lower leg[30,31]. They occur when bending forces are applied such that the convex cortex fails while the concave surface remains intact, producing a cortical breach on only one side of the bone. These forces may be longitudinal, as in a fall on an outstretched hand, or perpendicular, as in a direct blow. Radiographs typically show mid-diaphyseal involvement with associated angulation and bowing. The fracture takes its name from the characteristic appearance of a green twig breaking incompletely when bent (Figure 8)[30-33].

Figure 8 Incomplete fracture (cortical breach of only volar side) of the middle third of radius with mild dorsal angulation[30]. Citation: Kahveci S. Greenstick fractures-radius. Case study, Radiopaedia.org 2021. Copyright ©The Authors 2021. Published by Radiopaedia. The authors have obtained the permission (Supplementary material).

Bowing fractures represent another distinct pattern, characterized by plastic deformation of long bones without a discrete fracture line. They are almost exclusively seen in children, most often involving the radius and ulna but occasionally the fibula or other long bones[34]. In these injuries, low-force bending can temporarily deform the bone, which returns to its normal position once the force is released. However, if the applied stress exceeds the mechanical strength of the bone, permanent bowing occurs due to microfractures along the concave border, which are not visible radiographically[35]. On plain films, bowing is evident only when viewed perpendicular to the curve, and the deformity often blends smoothly into normal bone at either end. These injuries frequently coexist with greenstick or complete fractures of the paired bone and, in some cases, with dislocations such as radial head dislocation[36].

On a plain radiograph, bone bowing can be seen when the image is taken in a plane different from the direction of the bowing. If the image is aligned with the plane of the bow, the bone may look entirely normal (Figure 9). The bowing usually appears gradual, blending smoothly into the normal bone at both ends. No fracture line or cortical damage is evident[37].

Figure 9 7-year-old girl who had a fall onto outstretched arm while playing in a play-park. A: Focal bowing of the radius in the mid-diaphysis is seen on the frontal radiograph. Associated bowing of the proximal ulna in a plane perpendicular to the radial bow. Radial head is in joint; B: Note how in the lateral projection on the right, the image is aligned with the plane of the bow, and thus the bone looks entirely normal[37]. Citation: Jones J. Radial bowing fracture. Case study, Radiopaedia.org 2016. Copyright ©The Authors 2016. Published by Radiopaedia. The authors have obtained the permission (Supplementary material).

Buckle, or torus, fractures are one of the most common fractures seen in children with the distal radius (wrist) being the most frequent location[38]. They occur as a result of compressive forces applied along the long axis of a bone. This mechanism leads to trabecular failure and outward cortical bulging, most frequently involving the distal radial metaphysis following a fall on an outstretched hand[39]. Unlike greenstick fractures, buckle fractures lack cortical disruption, are inherently stable, and rarely involve the physis[40-43]. Radiographically, they appear as subtle cortical buckling or bulging without a distinct fracture line, although mild angulation may occasionally be the only diagnostic clue (Figure 10). Because they are stable, buckle fractures are managed conservatively, traditionally with short-arm casts, although recent studies suggest that removable splints or elastic bandages provide equivalent clinical outcomes with fewer complications, reduced costs, and greater patient comfort. Prognosis is excellent, and complications are rare[42].

Figure 10  Radiograph demonstrate a distal radial torus fracture appearing as a subtle cortical bulging, particularly at the metaphysis[43]. Citation: Radswiki T. Torus fracture. Case study, Radiopaedia.org 2010. Copyright ©The Authors 2010. Published by Radiopaedia. The authors have obtained the permission (Supplementary material).

MUSCLE-TENDON-BONE UNIT INJURIES AND AVULSION FRACTURES

In children, the weakest component of the muscle-tendon-bone unit is often the bone itself, particularly at apophyseal sites. This predisposes them to avulsion injuries rather than tendon tears[44]. Avulsion fractures may occur at the anterior superior iliac spine (sartorius), lesser trochanter (iliopsoas), ischial tuberosity (hamstrings), and tibial spine (anterior cruciate ligament insertion)[45]. Patellar sleeve fractures are another variant seen in children due to a strong quadriceps pull, avulsing cartilage and bone at the inferior pole of the patella (Figure 11)[46].

Figure 11  Another example of an avulsion fracture. This is a patellar sleeve avulsion fracture. There’s a bone fragment that has been avulsed off of the inferior pole of the patella. An acute force has been applied at the patellar tendon and as a result has avulsed a piece of the patella off. Note: The bony fragments often underestimate the degree of injury, and so a magnetic resonance imaging could be obtain to understand how much chondral injury there is.

ACUTE PEDIATRIC-SPECIFIC INJURIES

Toddler’s fractures are subtle spiral or oblique fractures of the tibial shaft in children under 3 years, often initially occult and only visible on follow-up radiographs due to periosteal reaction[47]. A rare cuboid fracture variant may occur due to compression between the calcaneus and metatarsals[48].

Monteggia fractures involve a proximal ulnar shaft fracture with dislocation of the radial head[49]. Galeazzi fractures consist of a distal radial fracture with distal radioulnar joint dislocation. A Galeazzi-equivalent injury may involve a distal ulnar physeal fracture instead of a true dislocation[50].

CHRONIC OVERUSE INJURIES

Gymnast’s wrist is a chronic Salter-Harris type I injury to the distal radial physis due to repetitive axial loading. Radiographs may show physeal widening, metaphyseal fraying, and sclerosis, while MRI reveals cartilage overgrowth and bone marrow edema[51].

Little league shoulder affects the proximal humeral physis due to repetitive rotational stress in throwing athletes. Imaging shows widening and irregularity of the growth plate. Little league elbow, or medial epicondyle apophysitis, results from valgus overload, often with fragmentation and marrow edema visible on MRI. Sublime tubercle apophysitis represents a distal manifestation of valgus stress affecting the ulnar collateral ligament insertion[52,53].

Osgood-Schlatter disease is a traction apophysitis of the tibial tubercle in adolescents, particularly during growth spurts. Radiographs may show fragmentation, swelling, and ossicle formation[54]. Sinding-Larsen-Johansson syndrome affects the inferior pole of the patella and also results from repetitive quadriceps tension. MRI shows edema at the inferior patella and patellar tendon origin[55].

While understanding fracture patterns and overuse syndromes is essential, an equally important aspect of pediatric trauma imaging lies in the safe and judicious use of imaging modalities. Because children are especially vulnerable to the long-term risks of ionizing radiation, dose optimization and the use of non-ionizing alternatives must be central to any imaging strategy[55-58].

RADIATION DOSE CONSIDERATIONS

Radiation dose is an important concern in pediatric imaging. Children are more sensitive to its effects and have a longer lifetime for potential risks to develop. This is why the principle of “as low as reasonably achievable” (ALARA) is incredibly useful in pediatric scenarios and provides the foundation for safe imaging practice[60]. It emphasizes careful justification of every scan, limiting studies to situations where results will truly guide management. In pediatric trauma settings, guidance from professional bodies also stresses avoiding routine whole-body CT and instead using targeted imaging based on the clinical context.

When a CT scan is needed, there are several ways to lower the amount of radiation a child receives. Modern scanners can automatically adjust the dose based on the child’s size, and lowering the energy of the X-rays can often provide enough detail without extra exposure. Careful planning also matters keeping the scan focused only on the area of concern and avoiding repeat or multi-phase scans helps prevent unnecessary radiation. Advances in computer technology, such as newer image reconstruction methods, now allow high-quality pictures to be produced even when the scan is performed at a lower dose. In addition, some settings can be adjusted to reduce radiation to especially sensitive areas, like the thyroid[61].

THE EXPANDING ROLE OF ULTRASOUND

These strategies to reduce radiation underscore a parallel need for imaging methods that entirely avoid ionizing exposure. Ultrasound has therefore emerged as a critical first-line tool in pediatric musculoskeletal trauma, offering both diagnostic accuracy and safety. Its ability to provide dynamic, real-time evaluation is an additional advantage over static imaging modalities[62,63].

In practice, ultrasound has demonstrated high sensitivity for detecting fractures, including those that may be subtle or missed on radiographs. Studies show particular value in superficial sites such as the distal radius, clavicle, sternum, and ribs, as well as in children with incomplete or greenstick fractures. Ultrasound can also identify early callus formation, allowing monitoring of healing weeks before radiographic changes become apparent, and it can be used to guide closed reductions, significantly reducing or replacing fluoroscopic exposure during procedure[62-64].

Beyond bone injury, ultrasound is highly effective for evaluating soft tissue trauma. It can rapidly detect joint effusions, which may suggest an occult fracture or septic arthritis, and it guides aspiration or drainage when needed. For muscles, tendons, and ligaments, ultrasound provides dynamic assessment during movement, which is particularly useful in children with suspected tendon rupture, apophyseal avulsion, or intramuscular hematoma. It is also the modality of choice for superficial soft tissue infections, abscesses, or radiolucent foreign bodies, often altering management in the emergency setting[65].

In emergency and sideline care, point-of-care ultrasound supports rapid triage of fractures, dislocations, and soft tissue injuries, helping to avoid unnecessary transport or cross-sectional imaging. Its portability, bedside availability, and tolerance by children make it uniquely suited to pediatric trauma workflows[65,66].

Emerging applications are further expanding the role of ultrasound in pediatric musculoskeletal imaging. Contrast-enhanced ultrasound enables detailed assessment of tissue perfusion, such as evaluating femoral head vascularity in Legg-Calvé-Perthes disease or monitoring perfusion intraoperatively after hip reduction. Ultra-high-frequency ultrasound provides exceptional resolution for superficial structures, while elastography offers a noninvasive way to assess tissue stiffness in tendons and muscles. Together, these innovations broaden the diagnostic scope of ultrasound while preserving its radiation-free advantages[62-67].

Together, dose-reduction strategies and the expanding role of ultrasound illustrate how pediatric trauma imaging is evolving toward safer, more child-centered care. These principles are especially critical when evaluating cases of suspected non-accidental trauma (NAT), where imaging not only informs clinical management but also carries profound legal and social implications[62-67].

While X-ray is the primary modality, the specific indications and advantages of CT and MRI in complex pediatric musculoskeletal trauma are summarized in Table 3.

Table 3 Advanced imaging modalities.

Type1	Category	Subcategory and examples	Imaging modality indications
Acute trauma	Fractures	Physeal fractures: SH Type I-V; special adolescent variants: Tillaux (SH-III); Triplane (SH-IV). Incomplete fractures: Greenstick; torus/buckle; “Bowing”. Complete fractures: Transverse; comminuted; oblique. NAT fractures: Metaphyseal fractures; rib fractures; sternal fractures	Radiographs: Gold standard for initial evaluation. Advanced imaging: CT: For complex intra-articular or surgical planning MRI: Not for routine fracture detection; best for associated soft tissue, cartilage, or growth plate injury. Suspected NAT (based on RCH guidelines) < 2 years old: Primary: Full skeletal survey (mandatory). Follow-up: Limited skeletal survey after 14 days and no later than 28 days, to detect healing fractures. 2-5 years old: Assessment: Case-by-case depending on history, clinical signs and suspicion. Options: Skeletal survey; bone scan if expertise available. > 5 years old: Approach: Targeted imaging guided by clinical findings. Modalities: Radiographs o symptomatic areas; advanced imaging (CT/MRI) for specific injuries. Advanced imaging modalities: Bone scan: Only with appropriate expertise and when SS is limited/inconclusive. CT: Head CT for suspected abusive head trauma; CT chest/abdomen/pelvis only if unstable or visceral injury suspected. MRI: Brain/spine MRI for parenchymal, ischemic, ligamentous, or occult injury notes: US: May support abdominal or intracranial assessment but it’s not primary for skeletal injuries
	Soft tissue injuries. Note: These are less common than fractures as the bone is the weakest component in children	Ligaments: Sprains/partial tears; complete tears. Muscle-tendon unit: Apophyseal avulsions: Tendon ruptures (rarer). Cartilage. Osteochondral lesions	US: First-line for superficial injuries, effusions, apophyseal avulsions. MRI: Preferred for deep, complex, or preoperative assessment. CT: Only for polytrauma or when MRI unavailable
Chronic/overuse trauma		Overuse injuries: Stress fractures; Gymnast’s wrist. Little league shoulder; Little league elbow (medial epicondyle apophysitis). Sever’s disease (calcaneal apophysitis). Osgood Schlatter: Sinding larsen johanson	Radiographs: First-line in most cases due to accessibility and ability to detect physeal changes, fragmentation, and obvious stress reactions. MRI: Most useful modality for many overuse injuries in children. It detects early stress reactions, marrow edema, cartilage/physeal injury, and osteochondral involvement, without radiation exposure. CT: Largely supplanted by MRI in pediatrics due to radiation concerns. Still occasionally useful for surgical planning or equivocal cases. US: Limited but sometimes useful for superficial apophyseal or tendon-related pathology (e.g. Osgood-Schlatter, sever disease), especially when radiation avoidance is a priority. Note: CT is rarely needed; MRI avoids radiation and provides superior tissue contrast

¹Acute: Single, identifiable event; chronic/overuse: Repetitive trauma.

SH: Salter Harris; NAT: Non-accidental trauma; CT: Computed tomography; MRI: Magnetic resonance imaging; US: Ultrasound; SS: Skeletal survey; RHC: Royal children’s hospital.

CHILD MALTREATMENT AND NAT

Definition and clinical context

Child maltreatment is broadly defined by the Centers for Disease Control and Prevention as any act or series of acts of commission or omission by a parent or caregiver that results in harm, potential for harm, or threat of harm to a child. Acts of commission are deliberate inflicted injuries, also referred to as child abuse. NAT fits within these acts of commission and specifically refers to intentionally inflicted physical injuries not caused by an accident. Clinically, NAT should be suspected when injuries are inconsistent with the reported mechanism or the child’s developmental abilities for example, fractures requiring ambulation in a non-ambulatory infant.

Clinical suspicion and red flags

Any concern for NAT should prompt a careful and systematic evaluation. Diagnosis depends on a thorough history and physical examination. Absent, vague, changing, or implausible stories, particularly when inconsistent with the child’s injury pattern, should heighten suspicion. Red flags include unwitnessed injuries or neurological events, delayed presentation for care, repeated emergency department visits, and current or prior involvement with child protection services.

On examination, bruising patterns can be highly informative. Any bruise in a pre-mobile infant is concerning. Bruises in atypical locations such as the torso, ears, and neck (TEN rule) or patterned injuries across the FACESp distribution (frenulum, angle of jaw, cheeks, eyelids, and subconjunctiva) should raise strong concern for inflicted injury and prompt further imaging[68].

IMAGING EVALUATION: PRIMARY AND ADJUNCT IMAGING

Skeletal survey

When child abuse is suspected, the primary imaging modality is a comprehensive skeletal survey (SS), consisting of a series of high-detail radiographs that evaluate the entire axial and appendicular skeleton. According to guidelines from the American College of Radiology and the American Academy of Pediatrics, all children younger than 24 months with suspected abuse should undergo a full SS, which includes standard anteroposterior and lateral views, supplemented by additional projections where appropriate. For example, oblique rib projections, which may increase the sensitivity for detecting rib fractures[69].

In children older than 24 months, imaging is typically directed to the area of clinical concern; however, a full survey should still be considered when unexplained injuries or a high index of suspicion exists. A repeat SS approximately two weeks after the initial evaluation is recommended when the first survey or clinical findings raise concern. While repeat surveys can omit areas initially free of injury to reduce radiation exposure, they are valuable in confirming subtle findings and in dating fractures, which can reveal injuries at different healing stages[69].

Adjunct imaging

Adjunct imaging modalities may be required in addition to the SS, depending on clinical suspicion, patient age, and initial findings. In cases of suspected abusive head trauma (AHT), an unenhanced CT scan of the head is the initial study of choice because it rapidly detects intracranial hemorrhage and skull fractures. MRI provides greater details as well as prognostic information in AHT, however it should be reserved for non-emergent settings.

Recent studies show that spinal injuries are common in children with AHT, so spinal MRI is valuable when investigating additional injuries such as vertebral fractures, ligamentous injury, or spinal subdural hemorrhage. CT can also play a role in the imaging workup of NAT. When performed with contrast, it is more sensitive for detecting occult injuries in the chest, abdomen, or pelvis that may not be apparent on plain radiographs.

SUSPICIOUS IMAGING FINDINGS/SPECIFIC FRACTURE PATTERNS

While the SS and adjunct imaging provide a framework for evaluating suspected NAT, certain injury patterns are particularly important because of their high specificity for abuse. These include classic metaphyseal lesions and characteristic rib or axial skeletal fractures, which are rarely explained by accidental mechanisms and therefore warrant careful attention in interpretation. Classic metaphyseal fractures of long bones, such as corner or bucket-handle fractures, are highly specific for child abuse, as nonambulatory children are incapable of causing such injuries themselves. These fractures result from tractional and torsional forces applied to a limb and are almost diagnostic of child abuse, especially in children under one year of age[56].

Violent shaking of an infant can damage the zone of provisional calcification in the physis, causing a fragment of bone to detach. This fragment produces a curvilinear density seen as a bucket-handle fracture (Figure 12). When viewed tangentially, it resembles a detached corner; when seen partially en face, it appears as a bucket handle (the bucket handle appearance can develop also as a result of progression of the corner fracture with time)[57,58].

Figure 12  Classic metaphyseal lesions showing bucket handle configuration at the distal tibia and fibula (arrows).

Classic metaphyseal lesions typically affect the metaphyses of long bones, most commonly the proximal or distal tibias, distal femurs, and proximal humeri, and are often bilateral. They usually involve the posteromedial portions of the distal femurs and proximal and distal tibias, while at the proximal humeri, they are generally lateral and best visualized with the arm in external rotation. The presence of fractures in various healing stages-such as rib fractures, sternal, scapular, or spinous process fractures-is also highly suspicious[56-59].

Posterior rib fractures are among the most specific injuries for abuse and are rarely explained by accidental mechanisms. They typically result from anterior–posterior chest compression, such as when an infant is forcibly squeezed, and are most often seen along the posteromedial arcs of ribs five through eight. In up to 30% of infants, posterior rib fractures may be the only skeletal finding of abuse, highlighting the importance of oblique rib projections on SS[56-59].

Injuries involving the scapula, sternum, or pelvis are also highly suspicious, as they require substantial force to occur and are typically seen only in high-energy trauma such as motor vehicle collisions or falls from height. When these injuries are identified, especially in non-ambulatory infants, they should prompt serious concern for inflicted trauma.

Finally, while these fracture patterns are highly specific for abuse, differential diagnoses must be considered. Conditions such as osteogenesis imperfecta, rickets, metabolic bone disease of prematurity, copper deficiency (e.g., Menkes disease), and scurvy can predispose children to fractures but typically do not mimic the fracture types most indicative of NAT, such as classic metaphyseal lesions or posterior rib fractures. Careful correlation with clinical history, physical examination, and laboratory findings is essential to distinguish these medical conditions from inflicted injury[56-59]. Table 4 summarizes key imaging features of NAT vs accidental trauma.

Table 4 Non-accidental trauma vs accidental trauma.

	Non-accidental trauma	Accidental trauma
Definition	Intentional physical harm inflicted by a caregiver (child abuse)	Unintentional injury (e.g. fall, sports, motor vehicle accident)
History/context	Inconsistent or changing history; delay in seeking care; injuries incompatible with child’s developmental stage (e.g., long bone fracture in a non-ambulatory infant)	Clear, consistent explanation of mechanism; injury matches developmental ability and timeline of presentation
Clinical clues	Bruises in atypical areas (torso, ears, neck-TEN rule; FACESp: Frenulum, angle of jaw, cheeks, eyelids, subconjunctiva); patterned bruises or burns; oral/sentinel injuries	Bruises over bony prominences (forehead, shins); abrasions/lacerations consistent with play or falls
Injury distribution	Multiple fractures at different healing stages; bilateral or symmetric injuries; high-specificity sites: Posterior ribs, classic metaphyseal lesions, scapula, sternum, pelvis	Usually single, isolated fracture; pattern matches mechanism (e.g., supracondylar humerus from FOOSH, toddler’s tibial spiral fracture, clavicle or buckle fracture)
First line imaging	Skeletal survey (< 2 years): Full series to detect acute, occult, and healing fractures; repeat limited survey at about 2 weeks increases sensitivity	Radiographs targeted to site of injury; sufficient in most cases
Other imaging	CT: Head CT for suspected abusive head trauma; chest/abdomen/pelvis CT only if unstable or high suspicion of internal injury. MRI: Brain MRI for parenchymal injury, ischemia, dating hemorrhage; spine MRI for occult fractures/Ligamentous injury in AHT; MSK MRI for complex/occult injuries	CT: Used when radiographs are insufficient or in severe head injury/neurological deficit. MRI: For selected complex fractures or suspected ligament/cartilage injury
Head trauma: Neuroimaging findings	Abusive head trauma: Subdural hemorrhage (often multiple or of varying ages), hypoxic-ischemic injury, spinal spinal subdural hemorrhage, retinal hemorrhages (clinical exam)	Isolated linear skull fractures, epidural hematoma with clear trauma history
Differential diagnoses	Bone fragility disorders (osteogenesis imperfecta, rickets, metabolic bone disease of prematurity, copper deficiency/Menkes, scurvy) can mimic fracture patterns; careful correlation with clinical and lab findings required	Consider NAT when the patterns/distributions are inconsistent (e.g. more than 3 bruises from a single event or bruises over opposite sides of the body). Note that accidental patterns rarely overlap with high-specificity injuries seen in NATs

TEN: Torso-ears–neck bruising rule; FACESp: Frenulum, angle of jaw, cheeks, eyelids, subconjunctiva; FOOSH: Fall on outstretched hand; CT: Computed tomography; MRI: Magnetic resonance imaging; MSK: Musculoskeletal; NAT: Non-accidental trauma; AHT: Abusive head trauma.

FUTURE DIRECTIONS

The future of pediatric musculoskeletal trauma imaging will likely be shaped by technologies that enhance diagnostic accuracy while reducing harm. Continued refinement of low-dose CT protocols and the introduction of dual-energy CT hold promise for decreasing radiation exposure without compromising detail, especially in complex fracture assessment. These advances build on existing efforts to align imaging practice with the ALARA principle, ensuring that children are exposed only to the minimum dose necessary.

At the same time, new modalities are expanding the scope of non-ionizing imaging. Quantitative MRI techniques, including T2 mapping and diffusion-based methods, offer the potential to monitor cartilage and growth plate integrity, detect early physeal injury, and characterize overuse syndromes before they progress to irreversible damage. Parallel developments in ultrasound, such as contrast-enhanced and ultra-high-frequency applications, extend its role beyond fracture detection into perfusion imaging and microstructural assessment, further strengthening its position as a frontline tool in pediatric trauma care.

Finally, artificial intelligence (AI) is emerging as a complementary force across modalities. When trained on pediatric-specific datasets, AI could aid in detecting subtle fractures, standardizing SS, and improving triage in emergency settings. While promising, these applications require careful validation to ensure safety, accuracy, and equity in child populations. Taken together, these innovations point toward a future in which multimodal imaging strategies, combining CT, MRI, and ultrasound, enhanced by AI, which will provide faster, safer, and more personalized care for injured children.

CONCLUSION

Imaging pediatric musculoskeletal trauma requires a nuanced grasp of growth-related anatomy, biomechanics, and injury patterns. Salter-Harris fractures, overuse syndromes, and apophyseal injuries exemplify how the developing skeleton responds differently to trauma. Key to optimal care are familiarity with age-appropriate radiographic anatomy, recognition of characteristic injury mechanisms, and vigilance for NAT. Together, these insights highlight that the pediatric skeleton is not simply a smaller version of the adult skeleton but a dynamic, evolving structure. Radiologists must therefore adopt an age-specific, tailored imaging and interpretation strategy to ensure accurate diagnosis and guide timely, appropriate management.