Intrinsic capacity patterns and their association with early postoperative functional outcomes in older adults undergoing total knee arthroplasty

Ruixin Zhang, J Chen, Xueer Chen, Huang Wx, Shulin Zhang

Abstract This study aimed to identify latent classes of intrinsic capacity (IC) among older adults undergoing total knee arthroplasty (TKA) and to examine the association between IC patterns and short-term postoperative functional outcomes assessed by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Following the Integrated Care for Older People framework, IC was assessed across five domains—cognition, psychology, vitality, locomotion, and sensory function—using validated instruments. WOMAC scores were evaluated preoperatively and at 3 months postoperatively. Latent class analysis was performed to identify IC patterns, and multinomial logistic regression was used to examine factors associated with IC pattern classification. Three IC patterns were identified in older adults undergoing TKA: C1 “Low impairment” (59.34%), C2 “Vit + Psy” (10.75%), and C3 “Loc + Sen” (29.91%). Age, manual labour occupations, and use of walking assistive devices were significantly associated with IC pattern classification (all P < 0.05). After adjustment for baseline WOMAC and other covariates, no statistically significant differences were observed among IC pattern groups in WOMAC scores at 3 months postoperatively or ΔWOMAC ( P > 0.05). Identification of IC patterns may enhance the understanding of multidimensional functional heterogeneity among older adults undergoing TKA and provide a potential framework for personalised perioperative assessment and future longitudinal research.