Antibiotic-Impregnated Bone Grafts in the Masquelet Technique Reduce the Risk of Persistent Infection at Early Follow-up

OBJECTIVES: To compare antibiotic-impregnated composite bone grafts (AIBG) with the standard autologous cancellous bone graft for reconstruction of infected segmental bone defects (ISBD) using the induced membrane technique (IMT). DESIGN: Retrospective study of prospectively collected data. SETTING: Four tertiary care hospitals in Cameroon. PATIENT SELECTION CRITERIA: All adult patients with ISBD treated with the IMT between January 1, 2020, and June 30, 2024, were included. At the second stage, bone reconstruction was performed using an autologous cancellous bone graft (standard group, 2020-2022) or a handmade antibiotic-impregnated composite bone graft (AIBG group, 2023-2024), corresponding to two consecutive time periods. OUTCOME MEASURES AND COMPARISONS: The primary outcomes were bone union and infection recurrence. Outcomes were compared between the AIBG group and the standard group. Subgroup analyses compared outcomes according to culture status at stage 2 and treatment group. RESULTS: Forty patients were included, with 13 in the AIBG group (84.6% male; mean age 38.7 ± 19.9 years) and 27 in the standard group (70.4% male; mean age 39.9 ± 16.6 years). Mean follow-up was 20.7 ± 12.1 months. Bone union was achieved in 92.3% (12/13) of the AIBG group and 85.2% (23/27) of the standard group (p = 0.52). Recurrent infection occurred in 7.7% (1/13) of the AIBG group and 29.6% (8/27) of the standard group (p = 0.22). Twelve patients (30.0%) had positive cultures at stage 2. Positive cultures at stage 2 were associated with a higher risk of treatment failure (nonunion or infection recurrence) compared with culture-negative patients (66.7% vs 14.3%, p = 0.002; OR = 12.9, 95% CI [2.4-59.4]). Among culture-positive patients, infection recurrence occurred in 75.0% (6/8) of the standard group and 0.0% (0/4) of the AIBG group (p = 0.01). Bone union without infection recurrence occurred in 75.0% (3/4) of the AIBG group and 12.5% (1/8) of the standard group (p = 0.03). CONCLUSION: In patients with persistent positive cultures at the second stage (bone grafting) of the induced membrane technique, antibiotic-impregnated composite bone grafts were associated with lower infection recurrence and higher rates of bone union without infection recurrence. LEVEL OF EVIDENCE: Therapeutic Level II.