Association of Posterior Tibial Slope and Functional Outcome After Total Knee Arthroplasty: An Observational Study

Introduction Precise implant positioning, particularly a well-balanced posterior tibial slope (PTS), is crucial for the success of total knee arthroplasty (TKA) because it enhances sagittal plane stability and significantly influences knee motion patterns. The long-term impact of tibial slope on active and passive range of motion (ROM) still needs to be studied, despite ROM's crucial role in patient contentment. This study examined the relationship between tibial slope and active and passive ROM following TKA, with a follow-up period of at least three months. Materials and methods The study included 40 knees of 30 participants who had undergone initial TKA for knee osteoarthritis (KOA). These subjects were recruited between September 2023 and May 2024, with a minimum postoperative follow-up period of three months. Results Significant improvements in the average Kujala score and knee ROM were observed at postop day 7 and at the three-month follow-up as compared to preoperative measurements (p<0.001). Concurrently, there was a notable decrease in the mean posterior tibial slope (PTS) angle (p<0.001). While patients with a larger PTS angle exhibited higher average Kujala scores and knee ROM, the correlations between these variables and the PTS angle were not statistically significant. Conclusion Considering its limitations, this research indicates that the posterior tibial slope does not significantly affect the functional outcomes of patients after primary total knee replacement in the initial treatment phase.