SIGN Interlocking Nail for the Treatment of Infected Nonunion

Summary: Chronic infection of bone with nonunion and/or bone defects is traditionally treated by a 2-stage procedure involving initial debridement and antibiotic delivery for control of infection and then definitive internal fixation for fracture stabilization. The external fixators have been used to provide stability in the presence of active infection. A technique of Surgical Implant Generation Network (SIGN) solid interlocking nail is used in the femur and tibia bones after thorough irrigation and debridement at the same stage. Although not most suitable for all infected nonunions and/or segmental bone defects, this technique is particularly useful for patients who are poor and hence cannot afford multiple surgeries and are not ideal candidates for external fixation and for those who do not want to have an external fixator applied. This technique was used in a series of 250 patients from multiple centers. The goal of control of infection and bony union was achieved in 213 (85%) cases, 165 cases after a single operation, and 48 cases after additional interventions. In the remaining 37 (15%) patients, the goal of control of infection was achieved with stable nonunion, which were taken care of by standard procedure of bone grafting after control of active infection. Four patients needed exchange nailing to another thicker SIGN nail for continued infection and implant loosening. Subsequently complete control of infection could be achieved in these cases. From the total, 14 fractures went on bone healing despite persistent infection, with or without sinuses. Early removal of nail after union and thorough debridement made them free from infection. But 7 cases are still coming at follow-up with infection but pain-free functional limb, that is, persistent infection even after fracture union. In summary, control of infection and stability to promote union has traditionally been provided by 2 separate procedures, which have proved to be efficacious in the past. However, both these goals can be achieved with 1 surgical procedure in a variety of scenarios in our limited circumstances, using the technique of SIGN solid intramedullary nail. This 1-step surgical procedure eliminates the complications that can occur secondary to the use of external fixation and bone transport. It may also reduce the morbidity of 2 surgical procedures and inpatient admissions required for the two-stage procedures or for the application and removal of external fixators to that of a single procedure and inpatient admission. Additional procedures may be required with both treatment methods for achieving control of infection, bony union, or soft tissue coverage.