A RETROSPECTIVE CASE-SERIES ON THE USE OF S53P4 BIOACTIVE GLASS FOR THE ADJUNCTIVE TREATMENT OF SEPTIC DIAPHYSEAL NON-UNION

Clinical outcomes and complications of S53P4 bioactive glass in chronic osteomyelitis and septic non-unions: a retrospective single-center study

INTRODUCTION

Dead space management following debridement surgery in chronic osteomyelitis or septic non-unions is one of the most crucial and discussed steps for the success of the surgical treatment of these conditions. In this retrospective clinical study, we described the efficacy and safety profile of surgical debridement and local application of S53P4 bioactive glass (S53P4 BAG) in the treatment of bone infections.

METHODS

A consecutive single-center series of 38 patients with chronic osteomyelitis (24) and septic non-unions (14), treated with bioactive glass S53P4 as dead space management following surgical debridement between May 2015 and November 2020, were identified and evaluated retrospectively.

RESULTS

Infection eradication was reached in 22 out of 24 patients (91.7%) with chronic osteomyelitis. Eleven out of 14 patients (78.6%) with septic non-union achieved both fracture healing and infection healing in 9.1 ± 4.9 months. Three patients (7.9%) developed prolonged serous discharge with wound dehiscence but healed within 2 months with no further surgical intervention. Average patient follow-up time was 19.8 months ± 7.6 months.

CONCLUSION

S53P4 bioactive glass is an effective and safe therapeutic option in the treatment of chronic osteomyelitis and septic non-unions because of its unique antibacterial properties, but also for its ability to generate a growth response in the remaining healthy bone at the bone-glass interface.

Treatment of Infection-Related Non-Unions with Bioactive Glass-A Promising Approach or Just Another Method of Dead Space Management?

The treatment of infected and non-infected non-unions remains a major challenge in trauma surgery. Due to the limited availability of autologous bone grafts and the need for local anti-infective treatment, bone substitutes have been the focus of tissue engineering for years. In this context, bioactive glasses are promising, especially regarding their anti-infective potential, which could reduce the need for local and systemic treatment with conventional antibiotics. The aim of this study was to investigate the osteoinductive and osteoconductive effects, as well as the anti-infectious potential, of S53P4 using a standardized non-union model, which had not been investigated previously. Using an already established sequential animal model in infected and non-infected rat femora, we were able to investigate bioactive glass S53P4 under realistic non-union conditions regarding its osteoinductive, osteoconductive and anti-infective potential with the use of µCT scans, biomechanical testing and histological, as well as microbiological, analysis. Although S53P4 did not lead to a stable union in the non-infected or the infected setting, µCT analysis revealed an osteoinductive effect of S53P4 under non-infected conditions, which was diminished under infected conditions. The osteoconductive effect of S53P4 remained almost negligible in histological analysis, even 8 weeks after treatment. Additionally, the expected anti-infective effect could not be demonstrated. Our data suggested that S53P4 should not be used in infected non-unions, especially in those with large bone defects.

Treatment of infected tibial non-unions using a BMAC and S53P4 BAG combination for reconstruction of segmental bone defects: A clinical case series

INTRODUCTION

Treatment of infected non-unions of the tibia is a challenging problem. The cornerstones of optimal infected non-union treatment consist of extensive debridement, fracture fixation, antimicrobial therapy and creation of an optimal local biological bone healing environment. The combination of S53P4 bioactive glass (BAG), as osteostimulative antibacterial bone graft substitute, and bone marrow aspirate concentrate (BMAC) for the implantation of mesenchymal stem cells and growth factors might be a promising combination. In this paper, preliminary results of a new treatment algorithm for infected non-unions of the tibia is presented.

METHODS

In this retrospective case series patients with infected non-unions of the tibia are treated according to a new treatment algorithm. Patients are treated with extensive debridement surgery, replacement of the osteosynthesis and implantation of S53P4 BAG and BMAC in a one-stage or two-stage procedure based on non-union severity. Subsequently patients are treated with culture based antibiotic therapy and followed until union and infection eradication.

RESULTS

Five patients with an infected non-union were treated, mean age was 55, average NUSS-score was 44 and the average segmental bone defect was 4.6cm. One patient was treated in a one-stage procedure and four patients in a two-stage induced membrane-, or "Masquelet"-procedure. On average, 23 ml S53P4 BAG and 6.2 ml BMAC was implanted. The mean follow-up period was 13.6 months and at the end of follow-up all patients had clinical consolidation with an average RUST-score of 7.8 and complete eradication of infection.

DISCUSSION

These early data on the combined implantation of S53P4 BAG and BMAC in treatment of infected non-unions shows promising results. These fracture healing results and eradication rates resulted in promising functional recovery of the patients. To substantiate these results, larger and higher quality studies should be performed.