By: 17 December 2018
Infection management in orthopaedics and trauma surgery


Local antibiotics for better results for at-risk patients, trauma and revision

Hip and knee joint surgeries are some of the most common procedures carried out in orthopaedics and trauma surgery. As for any surgical procedure, complications can occur. A rare but serious complication is periprosthetic infection (PJI). It is associated with high costs for the healthcare system and is stressful for patients. PJI is caused by microorganisms that form a biofilm on the surface of the implant and in this sessile state they are difficult to diagnose and treat.Successful management of a PJI is therefore based on prevention and prophylaxisso that infections are not able to develop in the first place.

Antibiotic prophylaxis using antibiotic-loaded bone cement

Antibiotic concentrations for systemic and local antibiotics

Polymethylmethacrylate (PMMA) bone cement, which is primarily used to fix prosthetic implants, can support effective infection management in primary arthroplasty, revision and the treatment of periprosthetic infections. The local release of the antibiotic from the bone cement supplements standard systemic antibiotic prophylaxis. The advantage lies in the considerably higher local concentration of the antibiotics with a low systemic load.

Bone cement with combinations of antibiotics for successful infection management

Choosing the right treatment algorithm is a critical factor for successful prevention and reduction of PJI. Combinations of antibiotics – systemic and local – are advantageous for effective infection management for revisions, in cases of trauma after femoral neck fracture and occasionally in primary arthroplasty. When choosing the antibiotic, the current resistance situation and the prevalence of the microorganisms responsible for PJI should be taken into account.

The COPAL bone cements COPAL G+C and COPAL G+V, for instance, contain combinations of antibiotics (gentamicin and clindamycin and gentamicin and vancomycin respectively) that tackle most of the microorganisms responsible for PJI. Synergistic effects of the combinations of antibiotics enable a high local antibiotic concentration in situ.

In revision, the range of treatments includes one-stage replacement with good soft tissue conditions and known susceptible pathogens, as well as two-stage replacement with precarious soft tissue conditions and unknown resistant pathogens. In both cases the effectiveness of the treatment can be increased by using bone cement with combinations of antibiotics. The combination of antibiotics used should be determined after completing diagnostics and an antibiogram.

For revisions that are due to verified resistant microorganisms (MRSA/MRSE), the use of COPAL G+V is recommended. It contains the antibiotic gentamicin combined with vancomycin, which as a reserve antibiotic is an option for use with known bacterial resistance to MRSA/MRSE, for example.

For septic loosening or chronic infections, a spacer made of antibiotic-loaded bone cement is often inserted as a temporary joint replacement for the purposes of infection elimination. Articulating spacers with an implant-like design, e.g. from COPAL knee moulds, should be given preference here to preserve the joint function and to prevent the formation of contractures and scar tissue.

In primary arthroplasty patients who are at a high risk of infection in particular are recommended for combinations of antibiotics for antibiotic prophylaxis, and therefore the use of COPAL G+C bone cement. The risk factors that can increase the likelihood of infections include diabetes, osteoporosis, limited mobility, excess weight and dementia.

When treating femoral neck fractures with a cemented hemiarthroplasty using COPAL G+C, it can be verifiably demonstrated that the risk of deep infections (surgical site infections, SSI) can be considerably reduced by using dual antibiotic-loaded bone cement.

69 per cent reduction in the rate of deep infections following femoral neck fracture when using high-dose antibiotic-loaded bone cement. Source: Sprowson et al