Total Knee Arthroplasty in Patients Less Than 50 Years of Age: Results at a Mean of 13 Years.

ABSTRACT

BACKGROUND: Patients between 45 and 54 years old will be the fastest-growing cohort seeking total knee arthroplasty (TKA) over the next 15 years. The purpose of this investigation is to determine the clinical outcomes of TKA in patients less than 50 years old at a minimum of 10 years. We hypothesized that this patient population would have a high rate of survivorship that is similar to that of older patients. METHODS: We reviewed 298 consecutive TKAs on 242 patients at a minimum of 10 years postoperatively. Twenty patients died and 30 TKAs were lost to follow-up leaving 248 TKAs in 202 patients (91 male, 111 female) with a mean age of 45.7 years (range, 26-49) at the time of surgery. Patient-reported outcomes, survivorship, causes of reoperation, and initial postoperative radiographic parameters were collected. RESULTS: At a mean of 13.0 years, there were 9 revisions for tibial loosening (3.6%), 8 for deep infection (3.2%), 7 for polyethylene wear (2.8%), and 3 for failed ingrowth of a cementless femoral component (1.2%). Kaplan-Meier analysis demonstrated 92.0% survivorship with failures defined as aseptic component revision and 83.9% survivorship for all-cause reoperation at 13 years. Patients with tibial alignment of 4° or more of varus or 10° or more of posterior slope were found to have increased rate of failure. CONCLUSION: While overall durability was good in this young patient population, tibial fixation and deep infection were relatively common causes of failure. In addition, increased tibial varus and slope were found to increase the rate of failure. Furthermore, the nearly 3% risk of revision for wear suggests that the use of more wear-resistant bearing surfaces may reduce the risk of failure in this patient population.