Treatment of High-Grade Chronic Osteomyelitis and Nonunions with PerOssal®: A Retrospective Analysis of Clinical Efficacy and Patient Perspectives

Abstract

Background/Objectives: Traditional autologous bone grafts as a treatment for bone defects have drawbacks like donor-site morbidity and limited supply. PerOssal^®, a ceramic bone substitute, may overcome those drawbacks and could offer additional benefits like prolonged, local antibiotic release. This study investigates the clinical and radiological outcomes, including patient-reported outcomes, of using PerOssal^® in nonunions (NU) and high-grade chronic osteomyelitis (COM). Methods: A single-center, retrospective study, investigating patients treated with PerOssal^® between January 2020 and December 2023. Collected data include patient characteristics as well as various surgical and outcome parameters including the Lower Extremity Functional Scale (LEFS). Results: A total of 82 patients were analyzed. Reinfection occurred in 19.5% of cases. Osseous integration of PerOssal^® was achieved in 89% of cases, higher in cavitary defects (91.5%) than segmental defects (72.7%). The revision rate was 32.9%, mainly due to wound healing disorders and reinfections. Mean LEFS score was 53.4 which was heavily influenced by sex (male: 50.7 vs. female: 63.4), revision surgery (no: 55.7 vs. yes: 49.1), reinfection (no: 56.6 vs. yes: 39.4), and osseous integration of PerOssal^® (yes: 55.8 vs. no: 38.4). Conclusions: PerOssal^® demonstrates promising outcomes in treating NUs and high-grade COM, especially in cavitary defects, with high osseous integration rates and acceptable functional results. However, reinfection remains a concern, particularly with difficult-to-treat pathogens and extensive surgical histories. Early, comprehensive surgical intervention and tailored antibiotic strategies are essential. Patient selection, defect characteristics, and comorbidities significantly influence success. Further research is needed to optimize treatment protocols.

Keywords: PerOssal®; bone defects; bone graft substitute; chronic osteomyelitis; lower extremity functional scale; nonunion.

Figure 1

LEFS Outcome measurement: (a) mean LEFS score for all localizations (53.4 ± 2.5) and specific localizations of the lower extremity or pelvis. No statistically significant difference was observed; (b) analysis for main drivers for worse LEFS via linear regression showed highest differences in dependence on sex, infection, revision, and failed integration. Accordingly, direct comparison of LEFS showed significantly worse LEFS scores for male patients, patients who had reinfection, or in whom integration of the bone substitute failed. Revision in general lowered the LEFS score but statistical analysis remained non-significant. Medians are the black horizontal lines; interquartile range is the height of the rectangle; minimum and maximum value are the whiskers. LEFS: Lower Extremity Functional Scale; ns = not significant, * = p < 0.05.

Figure 2

Analysis of reinfection: (a) percentage of reinfection in general and split up in between different initial diagnoses; (b) influence of chronic kidney disease on reinfection rate; (c) infection rate in different localizations; (d) mean previous surgeries in patients without and with reinfection. CKD is chronic kidney disease, COM is chronic osteomyelitis, SNU is septic nonunion, ANU is aseptic nonunion; ns = not significant, * = p < 0.05.

Figure 3

Analysis of revision: (a) percentage breakdown of reasons for revision surgeries in general and categorized by the presence or absence of reinfection; (b) impact of bacterial testing on revision rate; (c) Kaplan–Meier survival analysis of PerOssal^®; (d) average time between index surgery and first revision for different complications; (e) correlation between the number of revision surgeries and the time between the index surgery and the first revision. Black lines indicate linear regression with 95% confidence intervals. WHD is wound healing disorder; ns = not significant; * = p < 0.05.

Figure 4

Analysis of integration of PerOssal^® in cavitary defects or consolidation of nonunions after usage of PerOssal^® in segmental defects: (a) overall percentage across all analyzed patients; (b) percentage in cavitary compared to segmental defects; (c) percentage in patients with and without reinfection. *** = p < 0.001.