Diagnostic imaging of skeletal pathologies

Specific types of fractures

The diagnosis of bone tissue trauma requires an understanding of the patient's biomechanics and anatomical features.

• Stress fractures (fatigue injuries). Most commonly seen in athletes and military personnel involving the tibia, metatarsal bones, and pelvic ring. The method of choice for early detection is MRI, as radiography may only show periosteal reaction after some time.
• Avulsion fractures. Occur due to excessive traction of tendons or ligaments at their attachment sites. Key feature: the injury must strictly correspond to anatomy (e.g., ischial tuberosity apophysis avulsion). Old avulsion fractures with signs of ossification are sometimes mistaken for neoplasms.
• Pediatric fractures. Due to the high elasticity of the immature skeleton, specific morphological types are distinguished: plastic deformation (permanent bending without a fracture line), buckle fracture (impaction of the cortical layer on the concave side), and greenstick fracture (buckling with cortical disruption on the convex side).
• Growth plate injuries. Evaluated using the Salter-Harris classification (types 1–5). The higher the type, the greater the risk of premature closure of the epiphyseal plate.

Capabilities of diagnostic imaging methods

The choice of method depends on the nature of the pathology and the patient's age.

1. Magnetic resonance imaging (MRI). The method of choice for inflammatory bone lesions. In acute osteomyelitis, it visualizes bone marrow edema, while in chronic osteomyelitis, it shows the specific "rim" sign (a zone of fibrosis surrounding active infection). MRI is also informative for septic arthritis and growth plate injuries.
2. Ultrasonography (US). Effective for detecting fluid collections. In septic arthritis, joint effusion appears echogenic due to the presence of cellular debris. Ultrasound guidance is critical during fluid aspiration for bacteriological culture.
3. Radioisotope diagnostics. Three-phase bone scintigraphy is used to search for foci of increased uptake; however, the method lacks high specificity.
4. Computed tomography (CT). Rarely used in pediatric practice due to a lack of clear advantages over MRI and high radiation exposure.

Osteoporosis: imaging findings and complications

Decreased bone mineral density can be generalized, regional, or localized.

Regional osteoporosis develops against the background of disuse (immobilization), transient joint involvement (often the hip), or reflex sympathetic dystrophy.

Special attention should be paid to complications of bisphosphonate therapy. Prolonged use of these drugs is associated with the risk of atypical femoral fractures. During imaging, it is important to pay attention to the thickening of the lateral cortical layer—a red flag preceding a complete fracture. "Drug holidays" may be used to prevent such conditions.

Surgical treatment of osteoporotic vertebral compression fractures includes:

• Kyphoplasty: introduction of a special balloon into the vertebral body to create a cavity, which is then filled with bone cement.
• Vertebroplasty: direct injection of cement into the cancellous bone of the vertebra without prior balloon expansion.

Skeletal developmental anomalies

Pathologies of the osteoarticular system in children may be caused by primary (congenital) defects, systemic diseases, or exogenous factors. Diagnostic imaging reveals a multitude of dysplasia variants:

• Spine: clefting of the posterior vertebral arches (spina bifida), segmentation disorders such as sacralization (fusion of a lumbar vertebra with the sacrum) or lumbarization (separation of the upper sacral vertebra).
• Skull and jaws: formation of the craniopharyngeal canal, cleft palate, abnormal number of tooth sockets.
• Rib cage: rib agenesis or presence of supernumerary ribs (cervical, lumbar), sternal clefting.
• Limbs: congenital hip dislocation (hypoplasia of ossification centers and flattening of the acetabulum), absence of clavicles in cleidocranial dysostosis, complete absence of limbs (amelia), or presence of extra digits (polydactyly).

Class and exam questions

What else to study on this topic

• Transient osteoporosis of the hip: clinical and radiological manifestations.
• Disuse osteoporosis and reflex sympathetic dystrophy (complex regional pain syndrome).
• Chronic recurrent multifocal osteomyelitis in children.
• Biochemical markers of bone metabolic disorders (calcium, phosphorus, alkaline phosphatase).

Other topics in the "Musculoskeletal System" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.