The SIGN nail for knee fusion: technique and clinical results

PURPOSE Evaluate the efficacy of using the SIGN nail for instrumented knee fusion. METHODS Six consecutive patients (seven knees, three males) with an average age of 30.5 years (range, 18-50 years) underwent a knee arthrodesis with SIGN nail (mean follow-up 10.7 months; range, 8-14 months). Diagnoses included tuberculosis (two knees), congenital knee dislocation in two knees (one patient), bacterial septic arthritis (one knee), malunited spontaneous fusion (one knee), and severe gout with 90° flexion contracture (one knee). The nail was inserted through an anteromedial entry point on the femur and full weightbearing was permitted immediately. RESULTS All knees had clinical and radiographic evidence of fusion at final follow-up and none required further surgery. Four of six patients ambulated without assistive device, and all patients reported improved overall physical function. There were no post-operative complications. CONCLUSION The technique described utilizing the SIGN nail is both safe and effective for knee arthrodesis and useful for austere environments with limited fluoroscopy and implant options.