Time-dependent effects of chlorhexidine soaks on grossly contaminated bone

Successful sterilization and immediate reimplantation of extruded femoral diaphyseal segment: A case report and review of literature

Extrusion of bone is a rare situation in open fractures due to high energy trauma. There are few studies, reporting successful reimplantation of the extruded bone segment using various sterilization and fixation protocols. However, there are no definitive treatment strategies for this challenging situation. We report a case of 30-year-old male patient with grade IIIB compound right distal femur fracture with an extruded long bone segment, who was treated with successful sterilization and immediate reimplantation of an extruded long diaphyseal segment of distal femur following extensive cleaning with sterile normal saline, removal of debris with scrubbing by sterile brush, soakage in the broad-spectrum antimicrobial solution for 30 min, sterilization by autoclaving at 121°C for 45 min, and reimplantation during stable internal fixation with lateral distal femur locking plate using Arbeitsgemeinschaft für Osteosynthesefragen techniques. At 3 months, iliac crest bone grafting, osteoperiosteal flaps, and augmented fixation with a medial locking plate were performed through a subvastus approach for a void in the medial supracondylar femur region. Intraoperatively, punctate bleeding was observed from the reimplanted fragment. Infection was ruled out with normal leukocyte count, C-reactive protein marker, no evidence of unhealthy granulation tissue, and a sterile culture report from the fracture site. The fracture healed in 12 months and the patient had good functional outcome with a lower extremity functional score of 80% and knee range of motion of 110° at short-term follow up of 2 years without any complication. Decision of reimplantation is individualized depending on the time of presentation, contamination, and comminution of extruded fragment with scarce literature on standard treatment strategies. In our case, early presentation, meticulous debridement, unique sterilization technique, immediate reimplantation, and augmented dual distal femur plating with bone grafting aided in achieving successful union with good functional outcome and knee range of motion, avoiding any complications.

Salvage of contaminated osteochondral allografts: the effects of chlorhexidine on human articular chondrocyte viability

BACKGROUND

Because chondrocyte viability is imperative for successful osteochondral allograft transplantation, sterilization techniques must provide antimicrobial effects with minimal cartilage toxicity. Chlorhexidine gluconate (CHG) is an effective disinfectant; however, its use with human articular cartilage requires further investigation.

PURPOSE

To determine the maximal chlorhexidine concentration that does not affect chondrocyte viability in allografts and to determine whether this concentration effectively sterilizes contaminated osteoarticular grafts.

STUDY DESIGN

Controlled laboratory study.

METHODS

Osteochondral plugs were subjected to pulse lavage with 1-L solutions of 0.002%, 0.01%, 0.05%, and 0.25% CHG and cultured for 0, 1, 2, and 7 days in media of 10% fetal bovine serum and antibiotics. Chondrocyte viability was determined via LIVE/DEAD Viability Assay. Plugs were contaminated with Staphylococcus aureus and randomized to 4 treatment groups. One group was not contaminated; the 3 others were contaminated and received no treatment, saline pulse lavage, or saline pulse lavage with 0.002% CHG. Serial dilutions were plated and colony-forming units assessed.

RESULTS

The control group and the 0.002% CHG group showed similar cell viability, ranging from 67% ± 4% to 81% ± 22% (mean ± SD) at all time points. In the 0.01% CHG group, cell viability was reduced in comparison with control by 2-fold at day 2 and remained until day 7 (P < .01). The 0.05% and 0.25% CHG groups showed a 2-fold reduction in cell viability at day 1 (P < .01). At day 7, cell viability was reduced to 15% ± 18% (4-fold decrease) for the 0.05% CHG group and 10% ± 19% (6-fold decrease) for the 0.25% CHG group (P < .01). Contaminated grafts treated with 0.002% CHG demonstrated no colony-forming units.

CONCLUSION

Pulse lavage with 0.002% CHG does not cause significant cell death within 7 days after exposure, while CHG at concentrations >0.002% significantly decreases chondrocyte viability within 1 to 2 days after exposure and should therefore not be used for disinfection of osteochondral allograft. Pulse lavage does not affect chondrocyte viability but cannot be used in isolation to sterilize contaminated fragments. Overall, 0.002% CHG was shown to effectively decontaminate osteoarticular fragments.

CLINICAL RELEVANCE

This study offers a scientific protocol for sterilizing osteochondral fragments that does not adversely affect cartilage viability.