Osteopenia of Prematurity, Staphylococcal Rib Osteomyelitis
Osteopenia of Prematurity, Staphylococcal Rib Osteomyelitis
A 770 g infant boy was born to a Gravida 1, para 0 mother by caesarean section following premature rupture of membranes. The infant had initial Apgars of 4 at 1 min, 6 at 5 min and 8 at 10 min. He was intubated immediately after birth and initially treated in an outside hospital intensive care nursery until day 114 of life, when he was transferred to our neonatal intensive care unit because of persistent respiratory failure, bronchopulmonary dysplasia and retinopathy of prematurity (Figure 1). At the time of transfer the infant was found to have staphylococcal sepsis, which was treated with vancomycin. He subsequently developed and was treated for Candidal and Klebsiella urinary tract infections while in the hospital. At 2 months of life, diffuse and focal soft tissue swelling of the chest was appreciated and chest and rib radiographs were obtained. These were repeated 1 week later when swelling was more focal (Figure 2). Diffuse osteopenia, healing rib fractures and a focal expansile lytic lesion of the left ninth rib and right seventh were present. A chest wall sonogram was obtained (Figure 3) over the area of short tissue swelling. On the day of the sonogram the white cell count was 24 000, having been 15 000 3 weeks before, the erythrocyte sedimentation rate was 10 mm h (normal 0 to 20), and the C-reactive protein level was 42.7 mg l (normal 0 to 10). The alkaline phosphatase was 510 IU l (normal 100 to 310 IU l). Plasma calcium and phosphorus levels were normal.
(Enlarge Image)
Figure 1.
Frontal film of chest at admission. The ribs and scapula are well mineralized. Minimal right upper lobe infiltrate is present.
(Enlarge Image)
Figure 2.
(a) Frontal chest at 2 months of life, (b) Frontal chest 1 week later. The skeleton has become demineralized. On the chest radiograph at 2 months of life the posterior rib margins and scapula are difficult to visualize. The end of the right seventh rib (black arrow) is expanded and there is a destructive lesion seen in the left ninth rib (white arrow). On the radiograph 1 week later, the ends of the right seventh rib (R7) and left ninth rib (L9) are more expanded (white arrows). The cortex of both ribs is destroyed posteriorly. There is marked overlying soft tissue swelling (curved white arrow). Splenomegaly is also present.
(Enlarge Image)
Figure 3.
(a) Transverse and (b) longitudinal sonographic images of the chest wall over the area of soft tissue swelling. A well defined heterogeneous, hypoechoic mass (M) is present immediately anterior to the echogenic wall of the adjacent (ninth) rib (R), consistent with a subperiosteal abscess.
Case Presentation
A 770 g infant boy was born to a Gravida 1, para 0 mother by caesarean section following premature rupture of membranes. The infant had initial Apgars of 4 at 1 min, 6 at 5 min and 8 at 10 min. He was intubated immediately after birth and initially treated in an outside hospital intensive care nursery until day 114 of life, when he was transferred to our neonatal intensive care unit because of persistent respiratory failure, bronchopulmonary dysplasia and retinopathy of prematurity (Figure 1). At the time of transfer the infant was found to have staphylococcal sepsis, which was treated with vancomycin. He subsequently developed and was treated for Candidal and Klebsiella urinary tract infections while in the hospital. At 2 months of life, diffuse and focal soft tissue swelling of the chest was appreciated and chest and rib radiographs were obtained. These were repeated 1 week later when swelling was more focal (Figure 2). Diffuse osteopenia, healing rib fractures and a focal expansile lytic lesion of the left ninth rib and right seventh were present. A chest wall sonogram was obtained (Figure 3) over the area of short tissue swelling. On the day of the sonogram the white cell count was 24 000, having been 15 000 3 weeks before, the erythrocyte sedimentation rate was 10 mm h (normal 0 to 20), and the C-reactive protein level was 42.7 mg l (normal 0 to 10). The alkaline phosphatase was 510 IU l (normal 100 to 310 IU l). Plasma calcium and phosphorus levels were normal.
(Enlarge Image)
Figure 1.
Frontal film of chest at admission. The ribs and scapula are well mineralized. Minimal right upper lobe infiltrate is present.
(Enlarge Image)
Figure 2.
(a) Frontal chest at 2 months of life, (b) Frontal chest 1 week later. The skeleton has become demineralized. On the chest radiograph at 2 months of life the posterior rib margins and scapula are difficult to visualize. The end of the right seventh rib (black arrow) is expanded and there is a destructive lesion seen in the left ninth rib (white arrow). On the radiograph 1 week later, the ends of the right seventh rib (R7) and left ninth rib (L9) are more expanded (white arrows). The cortex of both ribs is destroyed posteriorly. There is marked overlying soft tissue swelling (curved white arrow). Splenomegaly is also present.
(Enlarge Image)
Figure 3.
(a) Transverse and (b) longitudinal sonographic images of the chest wall over the area of soft tissue swelling. A well defined heterogeneous, hypoechoic mass (M) is present immediately anterior to the echogenic wall of the adjacent (ninth) rib (R), consistent with a subperiosteal abscess.
Source...