a sheean, k spinder, d jin, l withrow, l harris, m bradley
Abstract accepted for poster presentation at the 2026 Military Health System Research Symposium (MHSRS)
INTRODUCTION: Increased knee pain prior to ACL reconstruction (ACLR) may portend worse post-op pain, difficult rehabilitation, prolonged recovery, and/or increased knee pain at 2 years. We aimed to identify demographic and injury factors influencing baseline (BL) pain and knee function in military Service Members (SMs) undergoing ACLR. We hypothesized that female sex, enlisted status, smoking history, presence of meniscal and/or chondral injuries, and prior history of mental health diagnosis (MH dx) predict increased pain and decreased physical and knee-related function.
METHODS: The Military Orthopaedic Tracking Injuries and Outcomes Network (MOTION) was queried for CPT code 29888 to compile a list of all primary & revision ACLR and primary ACL repairs performed by MOTION surgeons from 2016-2023. A fellowship trained surgeon reviewed all operative reports noting graft type, procedure type, meniscal and chondral pathology, and treatments. Inclusion required primary ACLR with available operative reports and BL PROMs (SANE, PROMIS-PF, PROMIS-PI, IKDC). Multivariable linear regressions were used to model BL PROMIS PI and BL IKDC. The predictors in the model included age, sex, previous meniscus surgery, officer or enlisted SM status, smoking, MH dx, presence of grade 3/4 chondral injuries, meniscal tears, race, and BL PROMIS PI, and IKDC models. All tests were two-sided, with an α = 0.05.
RESULTS: 606 SM that underwent primary ACLR were included in the final analysis. There were 443 males (73.1%) and163 females (26.9%) with a mean age of 26.0 years (22.0; 33.0 years.) Overall, enlisted SM status was significantly associated with BL PROMIS PI. After controlling for other predictors in the model, those who are officers have lower BL PROMIS PI compared to those who are enlisted (Estimates = -2.93 (-4.17, -1.69), P < 0.001). The top two predictors of increased BL pain were enlisted SM status and previous history of MH dx. After controlling for other predictors in the model, BL PROMIS PI was significantly associated with BL IKDC. Those with a higher BL PROMIS PI had lower BL IKDC ((-7.66 (-9.18, -6.14), P-value < 0.001).
CONCLUSION: Enlisted SM status and previous history of MH dx significantly predicted more pain and worse knee-specific function prior to ACLR. These results help to forecast those SM at risk for greater pain and worse function and should inform strategic efforts to appropriately allocate resources to address perioperative SM outcomes and force readiness.