The use of tibial stems in total knee arthroplasty (TKA) has emerged as an alternative for patients with morbid obesity (MO) in order to reduce bone collapse and aseptic tibial loosening. The aim of this study was to compare pain, functional capacity, and postoperative complications in morbidly obese patients undergoing TKA without a tibial stem vs. with a tibial stem.
Clinical, non-blind, randomized, retrospective, longitudinal study of patients with MO (BMI>40kg/m2) who underwent TKA (n=112) between July 2015 and July 2017. Group A (n=63) with a conventional prosthesis and group B (n=49) a prosthesis with a tibial stem, with a 5-year follow-up. For statistical analysis, the Kruskal-Wallis test (continuous variables) and chi-square (categorical variables) were used.
Statistically significant differences (p=.000) were found in pain with the VAS scale (Group A 0.57±0.89 vs. Group B 0.55±0.56), WOMAC questionnaire (Group A 6.02±3.97 vs. Group B 4.12±3.12) and form IKDC 2000 (Group A 71.19±13.51 vs Group B 82.74±7.89) at 36 months. With regard to postoperative complications, they were found in 21.4% of the sample, with aseptic tibial loosening and surgical wound closure being the most common. All mechanical complications occurred in the group without a tibial stem.
In conclusion, the results of this study suggest that the use of tibial stems in TKA reduces the risk of aseptic tibial loosening in morbidly obese patients at early follow-up.