Do Intramedullary Nails Affect Later Knee Surgery Outcomes?

Do patients with an existing tibial intramedullary nail fare better or worse (or no difference at all) when compared to total knee arthroplasty (TKA) patients without an intramedullary nail?

A team of researchers from the Mayo Clinic in Rochester, Minnesota, have recently completed a study which collected data from TKA patients with and without tibial intramedullary nails.

Their resulting paper, “Total Knee Arthroplasty After Intramedullary Tibial Nail: A Matched Cohort Study,” was published in the July 1, 2020 edition of The Journal of Arthroplasty.

The Mayo team retrospectively collected data from 24 TKAs performed between 2000 and 2017 after ipsilateral tibial intramedullary nails had been used on those same patients. The study group was matched based on age, gender, body mass index, and year of surgery. Average follow-up was 7 years.

According to the study authors, 100% of the tibial intramedullary nail cohort had a 10-year survivorship free of any revision while 96% for the control cohort had the same outcome. Ten-year survivorship free of any reoperation was 91% and 89%, respectively. Intramedullary nail TKA patients reported similar Knee Society Scores to matched controls at 2 years and 5 years. For those patients for whom the tibial tibial intramedullary nail was removed, acquired idiopathic stiffness trended toward being more common and operative time trended toward being longer. Bottom line, however, the research team reported that there was no overall difference in complication rate between cohorts.

According to Dr. Matthew P. Abdel and his research colleagues: “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 intramedullary nail, these patients have similar outcomes in regards to implant survivorship, clinical outcomes, and risk of complications.”

“Going into this study, I had hypothesized that those with a tibial intramedullary nail would have a lower implant survivorship, poorer clinical outcomes, and more complications. Surprisingly, survivorship and clinical outcomes were similar to a control group of patients without tibial intramedullary nails. While not significant, I did anticipate acquired idiopathic stiffness to be higher in those with a tibial intramedullary nail. In the future, we will continue to investigate the outcomes of patients with prior trauma undergoing conversion total knee arthroplasty.”