Are personalized alignment strategies achievable in revision total knee arthroplasty? A scoping review of the current literature

Personalized alignment strategies, including kinematic alignment (KA), restricted kinematic alignment (rKA), and functional alignment (FA), are emerging as alternatives to mechanical alignment in total knee arthroplasty (TKA). These approaches aim to restore patient-specific limb alignment and joint-line orientation, potentially improving functional outcomes. Although their use is well established in primary TKA, evidence supporting their application in revision total knee arthroplasty (rTKA) remains limited. The complexity of revision surgery, together (combined) with implant constraints and altered anatomy, has historically hindered the adoption of personalized alignment. This scoping review aims to evaluate the current evidence regarding the feasibility, accuracy, and clinical outcomes of personalized alignment strategies in rTKA and unicompartmental knee arthroplasty (UKA) toTKA conversion. A scoping review was conducted using PubMed, Scopus and Web of Science to identify English-language clinical studies published between January 2010 and December 2024. Eligible studies reported the use of KA, rKA, or FA in revision TKA or UKA conversion. Case reports, case series, cohort studies, and technical notes were included, whereas computational studies, cadaveric reports, and investigations limited to primary TKA were excluded. Two reviewers independently assessed study eligibility and extracted data regarding the alignment strategy, radiographic restoration, surgical workflow, range of motion (ROM), patient-reported outcome measures (PROMs), and complications. Ten clinical studies met the inclusion criteria. Across the included literature, personalized alignment demonstrated technical feasibility in revision settings and was associated with improved joint-line restoration, limb alignment closer to constitutional values, and good postoperative ROM. Patient-reported outcome measures (PROMs), when reported, showed a trend toward improvement. No major complications directly attributable to personalized alignment techniques were described. Robotic-assisted FA, described in four studies, suggested the precision of bone resections and soft-tissue balancing. However, the evidence base remains limited by small sample sizes, heterogeneous methodologies, and short-term follow-up. Personalized alignment strategies appear feasible and clinically beneficial in selected revision TKA cases. Early data suggest that KA, rKA, and FA may improve alignment accuracy and functional outcomes without increasing complications. Nevertheless, heterogeneity in study design and limited long-term evidence constrain broader adoption. Future research should prioritize standardized protocols, comparative trials, and long-term survivorship to define the role of personalized alignment in rTKA.