Age and body mass index associate with total knee arthroplasty after anterior cruciate ligament reconstruction: A retrospective study.

Abstract

To investigate the association of age, body mass index (BMI), and systemic indices of the immune system and inflammation with the odds of undergoing total knee arthroplasty (TKA) following anterior cruciate ligament reconstruction (ACLR). This retrospective, case-control study consisted of three groups of patients that underwent ACLR: (1) those with a documented knee osteoarthritis (OA) diagnosis and TKA procedure (Cases, n = 15), (2) those without a documented knee OA diagnosis or TKA procedure (control-1 [CON1], n = 15), and (3) those with a documented knee OA diagnosis but without a TKA procedure after ACLR (control-2 [CON2], n = 15). Control groups were matched to the Cases (1:1:1) based on sex and date of ACLR. Logistic regression analyses consisted of two models. Model 1 examined risk factors of TKA (Cases vs CON1 and CON2) and Model 2 examined risk factors of a documented knee OA diagnosis (Cases and CON2 vs CON1) following ACLR. Risk factors included age at ACLR, BMI, and systemic indices of the immune system and inflammation (systemic inflammation response index, systemic immune-inflammatory index [SII], and neutrophil-to-lymphocyte, platelet-to-lymphocyte [PLR], and monocyte-to-lymphocyte ratios). Increased age (p = 0.01) and BMI (p < 0.01) were associated with significantly high odds of undergoing TKA. Increased BMI (p = 0.02) and PLR (p = 0.05) and decreased SII (p = 0.03) were risk factors for a documented knee OA diagnosis. Increased BMI and systemic inflammatory-immune indices associated with increased odds of subsequent knee OA diagnosis following ACLR. Increased age and BMI associated with increased odds of subsequent knee OA diagnosis and TKA following ACLR. III. What are the new findings?