Prosthetic hip infections

Last revised by Craig Hacking on 18 Aug 2021

Prosthetic hip infections are one of the most severe complications of total hip arthroplasties. 

Prosthetic hip infections complicate around 0.57% of total hip arthroplasties 1.

Risk factors for prosthetic hip infections can be separated into pre-operative and post-operative risk factors. 

Pre-operative risk factors may include:

  • existing underlying infection
  • previous local surgery

Post-operative risk factors may include:

  • pain at the site of the arthroplasty
  • stiffness of the prosthetic joint
  • swelling around the site
  • overlying skin redness
  • tenderness

The main methods by which a prosthetic joint can become infected are:

  • directly during implantation
  • hematogenous spread
  • reactivation of a latent infection 2

The most common causative micro-organisms are Gram-positive bacteria, including Staphylococcus aureus, Staphylococcus epidermidis and coagulase-negative Staphylococcus. Infections may also be caused by fungi such as Candida 3.

Plain radiographs are the main imaging method utilized in diagnosis of prosthetic joint infections. Signs that may be seen include:

  • periosteal reaction
  • wide band of radiolucency at the cement-bone or metal-bone interface
  • patchy osteolysis
  • implant loosening
  • bone resorption around the implant
  • transcortical sinus tracts 3,5,6

CT is useful in helping to distinguish between septic and aseptic loosening of the joint 3

Bone scintigraphy is a highly sensitive method for diagnosing prosthetic joint infections, but it is not very specific, as increased periprosthetic bone activity can be due to a variety of causes 4

The use of PET in prosthetic joint infections is a relatively novel application. FDG-PET is thought to be highly sensitive and specific for diagnosis infection in hip prostheses, and may aid pre-operative planning 5,9.

Orthopedic surgery is indicated in most cases, unless the patient is not fit for surgery. Surgical options include:

  • polyethylene exchange with component retention and intravenous antibiotic therapy
  • one-stage replacement arthroplasty
  • two-stage replacement arthroplasty 8
  • resection arthroplasty 

In very severe cases, amputation may be necessary. 

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