The role of sex, age, and BMI in treatment decisions for knee osteoarthritis: conservative management versus total knee replacement

BackgroundKnee osteoarthritis (KOA) has a complex, multifactorial nature with well-established risk factors which may influence treatment decisions. Here we want to identify distinctive characteristics between patients receiving conservative treatment versus total knee replacement (TKR), analyzing both patient-specific and knee-specific features.MethodsThis case-control study compared patients assigned to TKR versus conservative management, examining subjects aged 60-75 years with radiographically confirmed KOA (Kellgren-Lawrence grades 2-3), with all participants evaluated by blinded clinicians using validated assessment tools including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Hospital Anxiety and Depression Scale (HADs), Pain Catastrophizing Scale (PCS) and Daily physical activity (DPA) questionnaires. The study employed multivariate analysis of variance for continuous variables at both patient and knee levels, followed by univariate analysis of variance for significant factors, while logistic and linear regression analyses were used to calculate odds ratios, with Bonferroni corrections applied to adjust p-values for multiple comparisons.ResultsBetween 2016 and 2020, the study included 87 patients (51 women and 36 men) with a mean age of 67.7 years in both treatment groups, with a slightly higher body mass index (BMI) of 31.9 kg/m2 in the TKR group vs 30.5 kg/m2 in the conservative management group. TKR patients demonstrated significantly worse scores in WOMAC, HADS, and PCS compared to the conservative management group, though DPA levels remained similar between both groups. At the knee level, women demonstrated significantly higher pain sensitivity and central sensitization compared to men, with no differences between conservative and TKR groups.ConclusionsPatients undergoing TKR exhibited significantly worse baseline clinical outcomes, particularly in WOMAC scores, despite having similar radiographic severity to those receiving conservative treatment, suggesting that functional and symptomatic measures may be more valuable than radiographic findings in determining surgical intervention.