Total Hip Arthroplasty Is Increasing in Patients Under Age 21

    The number of young patients – those under age 21 – who undergo total hip arthroplasty (THA) in the US annually is miniscule compared with older age groups.

    However, like other age groups, the number has been growing over the past 2 decades: Between 2000 and 2016, the number of THAs in patients under age 21 increased from 347 to 551, according to a study from researchers at Hospital for Special Surgery. Interestingly, the total pediatric population in the US remained stable during that period.

    The study findings, recently published in The Journal of Arthroplasty, were presented at ACR Convergence 2021, the annual meeting of the American College of Rheumatology.

    Understanding the Young THA Patient

    Total hip arthroplasty in patients under age 21 is so rare that little was known before this study about how many procedures were being performed in the US, where and why they were being performed, and whether the frequency was rising or dropping.

    To find answers, the researchers queried the Kids’ Inpatient Database (KID) for elective and non-elective primary THAs performed between 2000 and 2016. The KID is a repository of information on patients under 21 years of age from approximately 4200 hospitals in 46 states.

    The mean age of patients undergoing THA was 17.1 years. Most patients were white (55.3%) and had private insurance (56.5%). The majority of THAs (80%) were performed in urban teaching hospitals.

    The latter point is important, noted Mark P. Figgie, MD, chief emeritus of the Surgical Arthritis Service at Hospital for Special Surgery and a study co-author. As has been demonstrated in other studies, patients typically experience better outcomes when THAs are performed by surgeons with significant experience. For younger patients, the nuances of the developing anatomy “require expertise and knowledge to avoid complications and optimize outcomes,” Dr. Figgie said.

    Decrease in THA for Arthritis

    The most common diagnoses for young patients undergoing THA were osteonecrosis, osteoarthritis, and juvenile idiopathic arthritis/inflammatory arthritis, the researchers found. Over the course of the study, the frequency of THA for osteonecrosis rose from 24% to 38%, while the frequency of THA for arthritis fell from 27% to 4% – likely a reflection of recent improvements in medical management for the condition.

    “Our study shows that although THA procedures are increasingly being performed in young people, we aren’t seeing more of these patients seeking surgery for inflammatory arthritis,” said Bella Mehta, MBBS, MS, MD, a rheumatologist at Hospital for Special Surgery and the senior author of the study.

    “We’re doing a better job at treating these individuals so [that] they don’t develop end-stage joint damage. Twenty years ago, we didn’t have access to effective pharmacologic treatments for these conditions, and now we’re using them well and helping these patients live a better life.”

    Final Thoughts

    Dr. Mehta said the findings of this study have value for clinicians and their young patients, for whom, in many cases, THA is their first major operation.

    “I would use these results to say to a young person: ‘There are a lot of people who get these procedures; you’re not alone.’ I find that, especially for young patients, knowing they’re not the only ones to experience something really helps. And it’s a life-changing procedure for them,” Dr. Mehta said.


    Gibbons J, Kahlenberg C, Jannat-Khah D, Goodman S, Mandl L, Sculco P, Goodman S, Figgie M, Mehta B. Use of total hip arthroplasty in patients under 21 years old: a U.S. population analysis [abstract]. Arthritis Rheumatol. 2021; 73 (suppl 10). https://acrabstracts.org/abstract/use-of-total-hip-arthroplasty-in-patients-under-21-years-old-a-u-s-population-analysis/. Accessed November 8, 2021. Presented at ACR Convergence 2021, the annual meeting of the American College of Rheumatology, November 5-9 (virtual meeting).

    Kahlenberg CA, Gibbons JAB, Jannat-Khah DP, et al. Use of total hip arthroplasty in patients under 21 years old: a US population analysis. J Arthroplasty. 2021 Aug 9;S0883-5403(21)00644-6. doi: 10.1016/j.arth.2021.08.004. Online ahead of print.