The National Institutes of Health (NIH) remains one of the predominant sources of biomedical research funding in the United States, yet its impact on total hip and knee arthroplasty research is poorly understood. This study defines the portfolio of NIH funding for total joint arthroplasty (TJA) and the impact of orthopaedic surgeons on this portfolio.

The Research Portfolio Online Reporting Tools Expenditures and Results (RePORTER) database was queried for NIH grants that had been awarded for total hip and knee arthroplasty and total NIH funding from 2010 to 2020. Compound annual growth rates (CAGRs) were calculated. Funding totals were compared with those from 20 other clinical areas. The principal investigators (PIs) and grants were characterized, and comparisons were made with use of the Student t test.

A total of 489 grants were awarded, totaling $181 million (CAGR of 10.3%). This was >3 times the growth rate for the total NIH budget (CAGR of 2.9%), which increased from $31.2 to $41.7 billion over the 11-year period. When compared with 20 other clinical areas, TJA received the least amount of NIH funding over that period. Alzheimer disease received the most funding ($12.1 billion, CAGR of 19.5%), and cerebral palsy received the penultimate amount of funding ($284 million, CAGR of 6.3%). The R01 grant mechanism was the predominant source (63.1%), and the Mayo Clinic (Rochester, Minnesota) received the most funding (9.7%). Departments of orthopaedic surgery were awarded the most funding (23.5%), yet only 20 orthopaedic surgeons were identified as PIs (16.0%). There were no significant differences in NIH funding totals by PI demographic and academic characteristics (p > 0.05), yet orthopaedic surgeons had among the highest Hirsch indices (h-indices) (p < 0.001). Funding supported clinical (63.5%), translational (19.3%), basic science (7.1%), and other types (10.1%) of research. The top areas with funding were postoperative complications (44.4%), postoperative pain management (17.6%), rehabilitation (15.1%), and implant design (12.4%).

There is a paucity of orthopaedic surgeon representation among NIH grants awarded for TJA. Opportunities may exist for orthopaedic surgeons to collaborate in identified areas of clinical interest. Additional research is needed to understand the obstacles to obtaining NIH grant funding for orthopaedic surgeon PIs.

Increasing the levels of funding from the NIH is a strategic priority for departments of orthopaedic surgery. Understanding levels of funding for clinical areas in total joint arthroplasty is critical to foster research and discovery support from the NIH.