Systematic Review of Tibial Stems in Primary Total Knee Arthroplasty.

Tibial stems are increasingly used in primary total knee arthroplasty (TKA) to enhance stability and reduce component load, particularly in complex cases involving obesity, severe deformity, bone loss, and inflammatory arthritis. However, limited literature exists on their indications, outcomes, and complications. This study systematically reviews the indications for tibial stems in primary TKA, the types of stems used, and their associated outcomes, including revision rates and complications. A systematic review, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, was conducted using PubMed, Embase, and Cochrane databases up to January 2024. Studies comparing stemmed and non-stemmed tibial baseplates, as well as those not comparing with non-stemmed tibial baseplates, were included. Abstracts, commentaries, and case reports were excluded. Twenty-three studies, comprising 2,073 tibial stems (30-145 mm), met the inclusion criteria. The primary indication for tibial stems was in obese patients, with variable body mass index (BMI) thresholds. The use of tibial stems, particularly short cemented stems, demonstrated favorable outcomes in complex primary TKA, including reduced rates of aseptic loosening and improved functional scores. In cases of severe varus deformity and osteoarthritis with associated tibial stress or plateau fractures, tibial stems were effective in reducing complications and improving implant stability. Short cemented tibial stems benefit complex primary TKA, especially in obese patients and those with severe deformities, preserving bone stock, optimizing load transmission, and minimizing complications. Further research is needed to establish standardized guidelines for optimal tibial stem use in primary TKA.