Treatment of chronic orthopaedic infection

Abstract

Chronic infections are one of the major challenges in orthopaedic surgery, both for surgeons and patients. They are characterised by obstinate persistency of the causing microorganisms and resulting long-term disablement of the patients, associated with remarkable costs for the health care system.Difficulties derive from the biofilm-mode of living of pathogens with resistances against immunological defence and antimicrobial substances, and osseous defects resulting from the disease itself and surgical interventions.Established techniques usually require multiple costly operations with extended periods of disablement and impairment of the patients, sometimes making the therapy worse than the disease.Better understanding of the backgrounds of the conditions has led to new surgical techniques and differentiated application of antibiotics, aiming in improved quality of life for our patients. Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160063. Originally published online at www.efortopenreviews.org.

Keywords: antibiotic delivery; biofilm; bone defect; chronic orthopaedic infection; chronic osteomyelitis; effective therapy; prosthetic joint infection.

Fig. 1

Loading of carriers with antibiotics. Purified bone may store 10x the amount of vancomycin compared with cement. Almost the whole amount is available, leading to markedly elevated local concentrations and a prolonged biofilm-active release.

Fig. 2

A 66-year-old male who sustained a femoral neck fracture treated with uncemented total hip arthroplasty. Post-operatively he complained of unspecific pain with only slightly elevated infection markers. a) Three years later loosening of the acetabular component was diagnosed with marked osseous defect periacetabular and signs of osteolysis around the proximal part of the stem. b) One stage exchange with uncemented components. The defects were filled with antibiotic impregnated bone Osteomycin V. Sonification of explanted material revealed growth of two strains of Staph. epidermidis (MSSE) and Propionibact. sp. Hospital stay was one week, with Cefuroxim intravenously, followed by six weeks of Amoxicillin/Clavulanic acid and Rifampicin orally. c) six months post-operatively the patient is painfree with no sign of infection and unlimited mobility. There is partial remodelling of the allograft.

Fig. 3

Radiographs from a 24-year-old male. He was involved in a car accident and had a fractured femur treated with intramedullary nailing. There was post-operative infection. He had three revisions, exchange of nail. fever, ongoing fistulation, cultures revealed Staph. aureus (methicillin sensitive) and Staph. epidermidis (methicillin resistant). a) Post-operative radiograph. An exchange of the intramedullary nail was performed with rigid fixation by locking screws proximally and distally, with defects filled with antibiotic-bone-compound ABC. b) Radiograph at six weeks after surgery. The patient was fully weight-bearing with no sign of infection. c) Radiograph at one year after surgery. Dynamisation was performed by removing the proximal interlocking screws; the patient is fully weight bearing with no signs of infection. d) Radiograph at seven years after surgery. Hardware has been removed. There is complete union and the defects are restored. The patient returned to sports with no signs of infection.