Primary Total Knee Arthroplasty in Patients Aged 45 Years or Younger: 162 Total Knee Arthroplasties With a Mean Follow-up Duration of 7 Years.

Background: There are few large studies evaluating total knee arthroplasty (TKA) in young patients. Therefore, we sought to evaluate patients aged 45 years or younger undergoing a primary TKA. Methods: This was a retrospective, single-institution study, from 2003 to 2018, evaluating primary TKA in patients aged 45 years or younger. We identified 162 TKAs with a minimum follow-up duration of 2 years. Common surgical indications were degenerative joint disease (50%), post-traumatic arthritis (21%), and inflammatory arthritis (20%). Forty-nine knees had a prior significant knee surgery. We evaluated survivorship free of revision for any reason and aseptic revision. In addition, we characterized complication rates and risk factors for failure. Results: The mean age was 39 years, 70% were female, and the mean clinical follow-up duration was 7 years. At 8 years, survivorship free of revision for any reason was 82%, and survivorship free of aseptic revision was 87%. Fifty-five knees experienced at least 1 complication, with an overall complication rate of 34%. There were 6 (4%) periprosthetic joint infections (PJIs), and 24 (15%) knees of patients underwent manipulation under anesthesia with or without arthroscopic lysis of adhesions. There were no specific risk factors for revisions identified. Age less than 40 years was associated with PJI ( Conclusions: TKAs in patients aged 45 years or younger are associated with acceptable survivorship at a mean follow-up duration of 7 years. Patients should be counseled about the elevated risk of complications, specifically PJI and arthrofibrosis.