TKAs in younger patients associated with acceptable survivorship but with elevated risk of complications

Total knee arthroplasty (TKA) provides good survivorship free of revision. With these successful results, TKA has been performed increasingly in younger patients. Many of the larger studies used to evaluate the impact of age on primary TKAs are from registries and thus, lack some of the specific clinical details that can be elucidated from an institutional study.

N.M. Hernandez et al conducted a study to evaluate a larger group of young patients (aged 45 years or younger) undergoing a primary TKA from a single institution and evaluate the survivorship free of revision and aseptic revision, the type and frequency of complications, and risk factors for periprosthetic joint infection (PJI) and arthrofibrosis.

The study has been published in "Arthroplasty Today" journal.

This was a retrospective, single-institution study, from 2003 to 2018, evaluating primary TKA in patients aged 45 years or younger. The authors 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. They evaluated survivorship free of revision for any reason and aseptic revision. In addition, we characterized complication rates and risk factors for failure.

Key findings of the study:

•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 (P = .031), and marital status at the time of TKA was associated with arthrofibrosis requiring an intervention (P = .045).

The authors concluded that – "At a mean follow-up duration of 7 years, we found a satisfactory rate of survivorship free of revision in patients aged 45 years or younger. Although we believe this rate was acceptable, it was lower than that in some studies and may be related to the challenging cohort. As surgeons and young patients face the dilemma of whether to pursue such a major procedure, these survivorship data can be shared and potentially aide in this process. Furthermore, specific complications such as arthrofibrosis and PJI were more common than reported in other non-age-restricted series on primary TKAs; this too can be discussed during shared decision making with young patients considering TKA. Given the limited number of young TKA series, often including patients in their fifties, we believe this study adds valuable information that can help educate young patients as they consider primary TKA."

Further reading:

Primary Total Knee Arthroplasty in Patients Aged 45 Years or Younger: 162 Total Knee Arthroplasties With a Mean Follow-up Duration of 7 Years N.M. Hernandez et al Arthroplasty Today 18 (2022) 163-16 https://doi.org/10.1016/j.artd.2022.09.018