Comprehensive Summary
This study investigates the efficacy of combining preoperative planning software with the arithmetic hip-knee-ankle angle (aHKA) in uni-compartmental knee arthroplasty (UKA) to enhance lower limb alignment, prosthesis positioning, and patient outcomes. A total of 292 patients who underwent mobile-bearing UKA between September 2020 and June 2023 were included, with 50 patients in the planning group (using preoperative planning software) and 242 patients in the conventional group (using standard surgical techniques). The primary objective of the study was to evaluate whether integrating aHKA with preoperative planning software improves recovery to constitutional alignment and yields better prosthesis positioning compared to conventional UKA techniques. The study further examined early patient-reported outcome measurements (PROMs), comparing clinical and functional scores across the groups. Results demonstrated that 86% of patients in the planning group achieved constitutional alignment (aHKA ± 2°), significantly higher than the 66% in the conventional group (p = 0.033). Additionally, the planning group exhibited lower rates of under-correction (10% vs. 23%) and overcorrection (4% vs. 11%) compared to the conventional group. There was no statistically significant difference between groups in terms of postoperative prosthesis position parameters or American Knee Society Scores (KSS) at six months post-surgery, indicating comparable functional outcomes. The postoperative HKA angle was also better in the planning group (177.51° ± 1.81 vs. 177.07° ± 2.62), showing a more consistent alignment. The study's findings highlight that preoperative planning with aHKA significantly enhances the precision of alignment recovery in UKA without compromising prosthesis positioning or short- term patient outcomes. These results suggest that the use of preoperative planning software in combination with aHKA may be a valuable tool for improving surgical precision and patient recovery.
Outcomes and Implications
The implications of this study are substantial for orthopedic practice, as it demonstrates that preoperative planning with aHKA significantly enhances the accuracy of alignment restoration following UKA. Patients in the planning group were 20% more likely to achieve constitutional alignment compared to those in the conventional group (86% vs. 66%, p = 0.033). The significant reduction in under-correction (10% vs. 23%) and overcorrection (4% vs. 11%) demonstrates the software’s effectiveness in achieving optimal lower limb alignment. Moreover, the use of preoperative planning software reduced alignment variability, contributing to more consistent outcomes. Despite the superior alignment, the study found no difference in KSS clinical scores between the planning and conventional groups (91.02 ± 4.20 vs. 90.61 ± 4.24), suggesting that while alignment precision improved, it did not immediately translate into significant clinical improvement within the six-month follow-up period. From a clinical perspective, utilizing aHKA-based planning may enhance long-term patient outcomes by reducing postoperative complications related to malalignment. Constitutional alignment recovery has been shown to correlate with improved long-term functional outcomes and reduced revision rates. Additionally, the software’s ability to facilitate precise surgical planning without the high costs or complexity associated with robotic-assisted UKA makes it an accessible and cost-effective alternative. Future studies should focus on long-term follow-up to assess the sustained impact on patient- reported outcomes and revision rates. Additionally, exploring the integration of personalized surgical protocols and incorporating more advanced AI-based planning tools may further optimize patient outcomes and reduce variability in surgical techniques.