Validation of a novel osteoarticular fracture fragment decontamination-preservation system for delayed articular fracture reconstruction for limb preservation in a preclinical canine model pilot study.

Abstract

This study tests the hypothesis that a novel decontamination-preservation system (DPS) could effectively eradicate relevant pathogens in contaminated, devascularized, extruded osteoarticular fracture fragments while preserving essential viable chondrocyte density (VCD) for joint reconstruction resulting in functional limb preservation. With animal care and use committee approval, hounds were anesthetized for captive bolt-induced open bicondylar femoral fractures. One femoral condyle osteoarticular fragment was retrieved and randomly assigned to: Primary Bacterial Contamination (PBC) (n = 3 immediately processed using the DPS) or PBC+Secondary Methicillin-resistantStaphylococcus aureus(MRSA) Contamination (PBC+MRSA) (n = 3 directly inoculated with MRSA, incubated (24 h), then processed using the DPS). The injured limbs were stabilized with external skeletal fixators. One week following fracture, delayed joint reconstruction surgery was performed. Dogs were managed for pain and wound care, and assessed for safety (complete eradication of relevant pathogens) and efficacy (maintenance of VCD to allow for fracture healing and restoration of function, pain relief, and knee range-of-motion (ROM) to >80% of pre-operative levels). All retrieved osteoarticular fragments produced polymicrobial growth with all in the PBC+MRSA cohort including MRSA. The DPS eradicated all relevant pathogens in both cohorts. The induced-fracture was associated with significantly lower VCD (p ≤ .022) when compared to healthy-controls. Mean %Healthy-Control VCD for in situ fragments was 71.6% and for DPS fragments was 65.7% (p = .59). Radiographic fracture healing was documented in all knees by 3 months postoperatively. Function, pain, and ROM were restored to >80% of pre-operative levels. CONCLUSIONRESULTS: provide initial evidence for use of a novel system that combines saline irrigation with 0.002% chlorhexidine immersion followed by shelf-stable point-of-care storage in MOPS® for decontaminating devascularized, contaminated, extruded osteoarticular fracture fragments while maintaining chondrocyte viability. Using this system, contaminated, devascularized, extruded osteoarticular fragments from type 3 open articular fractures were retained, stored for at least 7 days, and used as osteochondral autografts for subsequent joint reconstruction for safe and effective limb preservation in a preclinical canine model.