Osteomyelitis in association with orthopaedic implants

Orthopaedic procedures should always be performed in sterile conditions, preferably in an operating theatre with laminar flow. At least three doses of prophylactic antibiotics should be used, the first given 1 hour before the procedure starts, the second 8 hours later and the third 8 hours after that. There is no evidence that continuing antibiotics beyond this reduces the risk of infection. There is, however, good evidence that prolonged use of antibiotics increases the risk of producing multiple antibiotic-resistant staphy­lococci (MARS). Any organism introduced into the operative field effectively turns the exposed bone into an open fracture. The most likely organism will be S. aureus and therefore an antibiotic with good activity against this organism should be used. Flucloxacillin has excellent activity against Staphylococcus. If Streptococcus is a possibility, then penicillin should be added.

Preventing infection of orthopaedic implants

Strict operative discipline with laminar flow

Three doses of antibiotics starting 1 hour before surgery

Reopen and wash out suspicious wounds and persisting haematomas

Features which suggest that an orthopaedic operation has become infected

Postoperatively, many patients have a pyrexia in the first 24 hours but it rarely goes above 380C. If this pyrexia persists or the temperature goes above 380C then a careful check should be made for a source of infection. This may be the lungs, urine or the wound itself. If a wound is infected it may appear red and swollen, and may start discharging old blood (Fig. 24.2). A persistently discharging haematoma is infection until otherwise proven. The patient should be taken back to theatre, the wound opened and deep samples taken for histology and bacteriology before any antibiotics are given. The wound should be carefully washed out and all dead tissue excised. Infection is more likely to occur in patients who are immunocompromised. The most common cause for this is diabetes or steroids.