Evaluation of functional outcomes and patient satisfaction after unicompartmental knee arthroplasty: a retrospective analysis from 2011 to 2022

Background. Despite the proven advantages of unicompartmental knee arthroplasty (UKA) over total knee arthroplasty for isolated single-compartment pathology, the proportion of UKA in Russia remains extremely low (less than 6%), which is due to a lack of objective information about long-term functional outcomes and factors influencing patient satisfaction. The aim of the study — to evaluate functional outcomes and patient satisfaction following unicompartmental knee arthroplasty, as well as to determine the impact of demographic factors and obesity on clinical outcomes and subjective pain perception during various activities of daily living. Methods. A retrospective analysis was conducted on data from 302 patients who underwent UKA between 2011 and 2022. Patient satisfaction was assessed using a 5-point Rasch scale, and pain syndrome was measured using the Likert scale across 12 types of activities. Two integral indicators were calculated: the pain index (PI) and the pain-free percentage (PFP). Results. Overall satisfaction was high across the sample (median score — 5). Women exhibited a higher PI (1.30±0.12) than men (0.74±0.17), although the differences were not significant. The most painful activities for women were rising from a low object, walking on uneven surfaces, and climbing stairs, while for men they were prolonged standing, household chores, and rising from a low object. No significant differences were found between age groups or BMI categories. The percentage of patients with high satisfaction (scores of 4-5) gradually increased with age, although these differences did not reach statistical significance. Conclusion. Unicompartmental knee arthroplasty has demonstrated high effectiveness in achieving patient satisfaction (92.1%) and restoring functional mobility, regardless of sex, age, or BMI, over a 12-year observation period.