Vanessa Jane Chow, Rejith Mannambeth
A standardized custom Abx-IMN is a pragmatic, immediately available consolidating strategy for complex infected nonunion, coupling locked intramedullary stability with organism-matched local antibiotics. In a high-risk real-world cohort, it achieved clinically meaningful rates of infection control, union, and limb preservation, with an expected revision surgery burden driven by biology rather than the device. Findings support broader evaluation in multicenter, protocol-driven comparative studies against commercial coatings and frame-based reconstruction.
AIM: To evaluate the safety and effectiveness of a standardized, custom PMMA-coated antibiotic-eluting interlocking nail (Abx-IMN) for chronically infected femoral and tibial nonunion, quantifying infection eradication, radiographic union, and limb preservation.
METHODS: This was a retrospective cohort (single center) with consecutive adults with infected tibial or femur nonunions undergoing limb salvage with a custom PMMA-coated, antibiotic-eluting interlocking nail (Abx-IMN) between 1 January, 2021, and 31 August, 2024. The technique used an ECMO tube mold to cast a uniform ∼1.5 to 2 mm mantle around a standard interlocking nail with 1.5 mm to 2 mm canal over-reaming and protected interlocking windows. The primary end points were radiographic union and limb preservation (analyzed per limb) and infection eradication (analyzed per patient). Proportions were reported with exact 95% confidence intervals.
RESULTS: Fourteen limbs in 13 patients were included. Radiographic union occurred in 11/14 limbs (0.78; 95% CI, 0.49 to 0.95). Infection eradication was achieved in 12/13 patients (0.92; 95% CI, 0.64 to 0.99). Limb preservation was maintained in 13/14 limbs (0.93; 95% CI, 0.66 to 0.99). Unplanned revision surgery occurred in 3/14 limbs (0.21; 95% CI, 0.05 to 0.51). The cohort represented a high-risk population with severe soft-tissue injury and a substantial burden of multidrug-resistant organisms.
CONCLUSION: A standardized custom Abx-IMN is a pragmatic, immediately available consolidating strategy for complex infected nonunion, coupling locked intramedullary stability with organism-matched local antibiotics. In a high-risk real-world cohort, it achieved clinically meaningful rates of infection control, union, and limb preservation, with an expected revision surgery burden driven by biology rather than the device. Findings support broader evaluation in multicenter, protocol-driven comparative studies against commercial coatings and frame-based reconstruction.