Objectives

Deep bone and joint infections (DBJI) are directly intertwined with health, demographic change towards an elderly population, and wellbeing.

The elderly human population is more prone to acquire infections, and the consequences such as pain, reduced quality of life, morbidity, absence from work and premature retirement due to disability place significant burdens on already strained healthcare systems and societal budgets.

DBJIs are less responsive to systemic antibiotics because of poor vascular perfusion in necrotic bone, large bone defects and persistent biofilm-based infection. Emerging bacterial resistance poses a major threat and new innovative treatment modalities are urgently needed to curb its current trajectory.

A resorbable, antibiotic-eluting bone void filler (AEBVF) was developed to address device-related infections. The AEBVF provides two functions: osteoconductive matrix for bone restoration, and local antibiotic delivery to treat device-related infections. In vitro evaluations of this AEBVF demonstrated antimicrobial activity to 7 weeks against Staphylococcus aureus (S. aureus).1 Subsequent rabbit studies demonstrated bactericidal capacity2 of the AEBVF against 105 CFU S. aureus and osteoconductivity.1 We hypothesized that the AEBVF would restore bone volume while eliminating 105 CFU S. aureus in a pilot sheep femoral condyle defect model. Four groups (n=2/group) were utilized to assess osteoconductivity (Group A-commercial ProOsteon & B-AEBVF) and antimicrobial activity (Group C-ProOsteon with 105 CFU S. aureus & D-AEBVF with 105 CFU S. aureus). AEBVF devices comprised degradable polymers (PCL, PEG, PLGA), ProOsteon (Biomet, USA), CaCl2, and tobramycin.3 Devices (1.5cc ProOsteon or 6 AEBVF croutons) were implanted into rectangular defects in the medial face of each sheep femoral condyle. Defects were evaluated using backscatter electron microscopy, mineral apposition rate (MAR) analysis, and light microscopy with Sanderson's Rapid Bone Stain (SRBS). All animals in Groups A, B, and D survived to the 12-week endpoint. In contrast, Group C animals were euthanized 11 days post-op. MAR and SRBS demonstrated comparable bone remodeling and defect restoration after 12 weeks in Groups A, B, and D. Notably, implant volumes of Groups A and D were greatly diminished (0.16±0.1%; 0.35%) after 12 weeks, compared to Group A (13.23±3.2%) and Time “0” (16.8%). These data show the AEBVF device's ability to: eliminate 105 CFU S. aureus, promote bone remodeling comparable to known bone void filler, and degrade at rates that do not interfere with bone remodeling

Objective

A clinical investigation into a new bone void filler is giving first data on systemic and local exposure to the anti-infective substance after implantation.

We reviewed 59 bone graft substitutes marketed by 17 companies currently available for implantation in the United Kingdom, with the aim of assessing the peer-reviewed literature to facilitate informed decision-making regarding their use in clinical practice. After critical analysis of the literature, only 22 products (37%) had any clinical data. Norian SRS (Synthes), Vitoss (Orthovita), Cortoss (Orthovita) and Alpha-BSM (Etex) had Level I evidence. We question the need for so many different products, especially with limited published clinical evidence for their efficacy, and conclude that there is a considerable need for further prospective randomised trials to facilitate informed decision-making with regard to the use of current and future bone graft substitutes in clinical practice.

Cite this article: Bone Joint J 2013;95-B:583–97.