SUBACUTE EPIPHYSEAL OSTEOMYELITIS

TIMOTHY P. DOMER, D.O., Orthopaedic Surgery Resident

KIRK DABNEY M.D., Attending Pediatric Orthopaedic Surgeon

January, 29, 1996

CLINICAL CASE PRESENTATION

ORTHOPAEDIC DEPARTMENT

THE ALFRED I. DUPONT INSTITUTE

WILMINGTON, DELAWARE

CASE HISTORY:

PATIENT 1.

  1. Bone scan: Revealed increased uptake in the region of the distal femur with a predominant epiphyseal location and slight uptake in the metaphysis on the flow and pool images. Delayed images showed focally increased uptake in the epiphysis of the distal right femur.
  2. CT scan: No subperiosteal fluid collections were noted. There was an area in the region of the distal femoral epiphysis that contained a difference in density from the surrounding bone.
  3. Ultrasound: Soft tissue swelling in the region of the distal femur

The patient was taken to the operating room for fluoroscopic guided needle aspiration of the distal femoral metaphysis and epiphysis and the proximal tibial metaphysis. Aspiration of the knee joint was also performed.

Final cultures: Blood cultures obtained at initial presentation were positive for Staphylococcus aureus. Aspirates of the distal femoral epiphysis were positive for Staphylococcus aureus

SUBACUTE EPIPHYSEAL OSTEOMYELITIS

Pathogenesis:

Predisposing factors that may influence the septic process in bone:

  1. Host resistance
  2. Virulence of infecting organism
  3. Adequacy of antibiotic therapy
  4. Trauma resulting in vascular injury and hypoxemia in bone

Staphylococcus aureus is the most common bacterial isolate, and it has been found that S. aureus has a certain affinity for epiphyseal cartilage.

Pathoanatomy:
Radiographic features:
Radiographic differential diagnosis (of all locations of subacute osteomyelitis)
Radiographic classification:

Ia-- metaphyseal; punched out lucency suggestive of eosinophilic granuloma

IIb-- metaphyseal ; sclerotic margin with classic appearance for Brodies abscess

III-- diaphyseal ; localized cortical and periosteal reaction simulating osteoid osteoma

IV-- diaphyseal ; onion-skin periosteal reaction simulating Ewing's sarcoma

V-- epiphyseal ; concentric radiolucency

VI-- vertebral body ; erosive or destructive process

Treatment:

Ross and Cole used the radiographic appearance of lesions associated with subacute osteomyelitis to classify their patients into two groups as follows:

All patients were initially treated with two days of intravenous antibiotics and then were switched to oral antibiotics to complete a six week course.

Results:
Treatment of group 1 lesions
Treatment of group 2 lesions
References:
  1. Green,N.E., Beauchamp,R.D., Griffin, P.P. Primary subacute epiphyseal osteomyelitis. J Bone Joint Surg 63-A:107, 1981.
  2. Green, N.E. Osteomyelitis of the epiphysis. In Behavior of the growth plate. Raven press, 1988.
  3. Letts, R.M. Subacute osteomyelitis of the growth plate. In Behavior of the growth plate. Raven press, 1988.
  4. Lindenbaum,S. Alexander, H. Infections stimulating bone tumors: a review of subacute osteomyelitis. Clin. Orthop. 184:193, 1984.
  5. Roberts, J.M., Drummond, D.S., Breed, A.L., Chesney, J. Subacute hematogenous osteomyelitis in children: a retrospective study. J Pediatr Orthop 2:249, 1982.
  6. Ross, E.R.S., Cole, W.G. Treatment of subacute osteomyelitis in childhood. J Bone Joint Surg 67-B:443, 1985.