Cemented vs. Uncemented Total Knee Arthroplasty in Obese Patients: A Systematic Review of Implant Survival, Complications, and Clinical Outcomes

Obesity is a primary global health concern that negatively affects the outcomes of total knee arthroplasty (TKA). To mitigate complications, both cemented and uncemented fixation techniques have been considered. However, there remains no consensus in the literature regarding the optimal fixation method for obese patients despite the renewed interest in uncemented fixation. This systematic review aims to compare the survival rates, causes of failure, and patient-reported outcome measures (PROMs) between cemented TKA (cTKA) and uncemented TKA (uTKA) in the obese population. A comprehensive literature search was conducted according to PRISMA guidelines across five databases-PubMed, Scopus, Embase, Medline, and Cochrane-focusing on studies directly comparing cTKA and uTKA in obese patients. The ROBINS-I tool was used to assess the risk of bias, while the PRISMA flow diagram guided the study selection process based on predefined inclusion and exclusion criteria. This systematic review was registered on PROSPERO. Four retrospective studies encompassing 1622 patients met the inclusion criteria and were included in the final qualitative analysis. Among these, 50 % of patients underwent uTKA, with three studies exclusively analyzing individuals with at least class II obesity (BMI ≥35 kg/m2). All four studies reported higher rates of aseptic loosening in the cemented fixation group. However, only two studies demonstrated a statistically significant improvement in implant survival, reduced aseptic loosening, and lower revision rates with cementless fixation in the short-to mid-term follow-up. Regarding clinical outcomes, only one study reported a significant improvement in Knee Society Score (KSS) function, range of motion (ROM), and pain scores in the cementless group compared to the cemented group, particularly in the subgroup analysis of posterior-stabilized constrained TKA. This systematic review suggests that in obese patients, particularly those with BMI ≥35 kg/m2, cementless fixation offers comparable or superior implant survival rates and lower rates of aseptic loosening compared to cemented fixation in the short-to mid-term follow-up. Furthermore, cementless fixation may provide similar or enhanced clinical outcomes in this high-risk and growing patient population.