Total Knee Arthroplasty After Intramedullary Tibial Nail: A Matched Cohort Study

Background: As the use of intramedullary nails (IMNs) has become more common, there are an increasing number of patients requiring total knee arthroplasty (TKA) who have an indwelling tibial IMN. The purpose of this study is to compare implant survivorship, clinical outcomes, and complications in patients undergoing primary TKA with a history of tibial IMN to those without. Methods: We retrospectively identified 24 TKAs performed between 2000 and 2017 after ipsilateral tibial IMN. Patients were matched 1:2 to patients undergoing primary TKA without history of tibial IMN based upon age, gender, body mass index, and year of surgery. Mean follow-up was 7 years. Results: The 10-year survivorship free of any revision was 100% for the tibial IMN cohort, and 96% for the control cohort, while the 10-year survivorship free of any reoperation was 91% and 89%, respectively (P =.72). Patients with a history of tibial IMN had similar Knee Society Scores to matched controls at 2 years (P =.77) and 5 years (P =.09). Acquired idiopathic stiffness trended toward being more common (17% vs 6%, P =.21) and operative time trended toward being longer (135 vs 118 min, P =.07) when the tibial IMN was removed, but there was no overall difference in complication rate between cohorts. Conclusions: To our knowledge, this is the first report of primary TKA in patients with a history of ipsilateral tibial IMN. Compared to a matched cohort of patients without tibial IMN, these patients have similar outcomes in regards to implant survivorship, clinical outcomes, and risk of complications. Level of Evidence: Therapeutic Level III.