Acute Osteomyelitis – Beyond Neonatal To 18 Months

  • Etiology: hematogenous spread from asymptomatic or symptomatic bacteremia or by direct extension from skin wound, infection starts in marrow space with significant edema with proliferation of excess WBC and bacterial growth and through bony canals the infected fluid permeates outward and elevates the periosteum, most commonly Staphylococcus aureus
  • Imaging: most commonly occurs at metaphysis and metaphyseal equivalents (apophyses, areas at the junction of bone and cartilage in flat bones) both of which are highly vascular with slow blood flow, before epiphyseal ossification centers appear (18 months) infection can cross growth plate into epiphysis as there is free communication between vessels of epiphysis and metaphysis and these transphyseal vessels can serve as a path of spread of infection from metaphysis to epiphysis, infection can spread into joint space / subperiosteal space / soft tissues / diaphysis of bone, most common regions involved are extremities and pelvis, continuous periosteal reaction, deep soft tissue edema
  • Complications: subperiosteal abscess, intramedullary abscess
  • Clinical: multicentric in 10%

Radiology Cases of Acute Osteomyelitis – Beyond Neonatal To 18 Months

Radiograph of osteomyelitis beyond neonatal to 18 months
AP (left) and lateral radiographs (right) of the elbow show extensive periosteal reaction of the distal humerus and proximal ulna and an effusion of the elbow joint.
Radiograph of osteomyelitis beyond neonatal to 18 months
AP radiograph of the elbow shows a lucent destructive lesion in the distal ulna without periosteal reaction.
Radiograph of osteomyelitis beyond neonatal to 18 months
CXR at presentation (above) is unremarkable. AP radiograph of the left shoulder obtained 5 days later (below) shows displacement and destruction of the epiphysis of the proximal humerus.
Radiograph of osteomyelitis with Brodie's abscess
AP radiograph of the knee at presentation (upper left) shows lucent lesions of the metaphysis and epiphysis which show some interval healing on a followup AP radiograph of the knee taken 2 months later (upper right). The patient was lost to followup and did not complete antibiotic therapy and returned to clinic 2 years later and the AP radiograph at that time (lower left) shows a lucent sinus tract extending from the epiphysis to the metaphysis that persists on the next AP radiograph of the knee obtained 1 year later (lower right).