Home Up Materials Radiography Arthrography CT and MRI References


Prosthesis Types
 Total Hip 
Baseline Exam
 -Acetab. Position
 -Center of Rotation
 -Femoral Stem 
 -Leg Length Discr.
 Intra-op- Fractures 
 Cement Herniation
Follow-up Study
 Bony Abnormalities
 Heterotopic Bone
 Non Union
 Hardware Failure
 -Polyethylene Wear
CT and MRI


  • Incidence
    • 1 to 2 per cent of primary arthroplasties and 3 to 4 per cent of revisions.[1,2,3,4,5,6,7]
  • Radiographic findings
    • Similar to findings in loosening with progressive interface widening
    • There are no definitive radiographic signs to differentiate loosening from infection except for soft tissue gas
    • Soft tissue gas (ulcer or sinus tract)
    • Laminated periosteal reaction (rare)
  • Diagnostic evaluation
    • Blood tests
    • Aspiration – arthrography
    • Nuclear medicine
  • Treatment
    • Acute e.g. after dental surgery
      • Open surgical lavage
    • Sub acute or chronic
      • Resection of hardware with flail hip (Girdlestone)
      • Resection of hardware and placement of cement spacer

INFECTION—Markedly widened interfaces about acetabular and femoral components

INFECTION Progressive interface widening about acetabular component

INFECTION—Soft tissue gas. 

Gas in neo capsule of right total hip replacement secondary to sinus tract from joint to skin

INFECTION—Soft tissue gas adjacent to dislocated cement spacer

INFECTION—Gas bubbles in synovial cyst anterior to right total hip replacement. Patient had infected left hip joint 1 year previously treated by Girdlestone procedure. Right total hip replacement was grossly loose and with migrated hardware.

Resection of hardware, flail hip

Resection of hardware, cement spacer placement

Cement spacers are antibiotic impregnated, allowing for local dispersal of antibiotics.

  • Maintain leg length
  • Minimize dead space
  • Preserve soft tissue planes
  • Facilitate ease of revision arthroplasty

Cement spacers are fabricated in the surgical suite using methylmethacralate cement impregnated with antibiotics sensitive to cultured organisms. A Rush rod is cut and bent to 120 degrees to mimic the femoral neck-shaft angle. Antibiotic impregnated cement is placed into a blue bulb syringe which simulates the femoral head contour and allowed to dry. The plastic is then removed. A second batch of cement is prepared and formed around the femoral shaft portion of the Rush rod.