Osteoarthritis (OA) of the knee is a common and debilitating musculoskeletal condition that affects millions of individuals worldwide. Among its various presentations, bilateral varus deformity, characterized by the inward angulation of the lower limbs, is a prevalent subtype of ]knee OA that poses unique challenges for treatment and management. Total knee replacement (TKR) is a well-established surgical intervention for end-stage knee OA, providing substantial relief from pain and improvement in joint function. However, the choice between conventional TKR and robotic-assisted TKR in patients with bilateral varus deformity remains a subject of ongoing debate in the field of orthopedic surgery [1, 2, 3].

In recent years, robotic-assisted TKR has emerged as an innovative surgical technique that offers potential advantages over the conventional approach. Robotic-assisted TKR utilizes advanced technology to enhance the precision and accuracy of implant placement, potentially resulting in improved functional outcomes and longer-lasting joint replacements. This technology allows surgeons to plan and execute precise bone cuts and component positioning, which is particularly beneficial in cases of complex deformities like bilateral varus knees [4, 5, 6].

The Eastern population, characterized by its diverse genetic and anatomical variations, presents a unique patient cohort with distinct clinical characteristics and outcomes when compared to Western populations. This comparative study aims to investigate the clinical and radiological outcomes of bilateral varus deformity knee OA patients treated with two different surgical approaches: conventional TKR and robotic-assisted TKR, specifically in the context of the Eastern population [7, 8].

While a growing body of literature exists on the outcomes of TKR procedures, there is limited research focusing specifically on the comparison between conventional and robotic-assisted TKR in patients with bilateral varus deformity, especially within the Eastern population. This study is designed to address this gap in the current literature and provide valuable insights into the most suitable surgical approach for this patient population [9, 10 ].

Robotic-assisted TKR has demonstrated promise in improving the precision of implant placement, potentially leading to better alignment, reduced component wear, and improved overall function. However, its cost and availability can be limiting factors, especially in regions with diverse healthcare resources like Eastern populations [11, 12, 13, 14].

The comparative analysis of functional and radiological outcomes between these two surgical techniques will not only guide surgeons in selecting the most appropriate approach for their patients but also contribute to the broader understanding of how these technologies perform in a specific demographic context.

Study Objectives

The primary objectives of this study are as follows:

• to compare the clinical outcomes, including pain relief, functional improvement, and patient satisfaction, between patients who underwent conventional TKR and those who underwent robotic-assisted TKR for bilateral varus deformity knee OA,
• to evaluate the radiological outcomes, including postoperative alignment, component positioning, and implant survivorship, in the two groups.

Study Design and Setting

This prospective comparative study was conducted at a tertiary care center specializing in orthopedic surgery, within the Eastern population. The study received ethical approval from the Institutional Review Board (IRB), and all participants provided informed consent.

Patient Selection

Patients diagnosed with bilateral varus deformity knee osteoarthritis (OA) were carefully screened for eligibility. Inclusion criteria consisted of:

• age equal to or greater than 18 years,
• confirmed diagnosis of bilateral varus deformity knee OA,
• eligibility for bilateral total knee replacement (TKR).

Exclusion criteria encompassed:

• history of prior knee surgeries,
• inability to provide informed consent,
• presence of contraindications for either conventional or robotic-assisted TKR.

Sample Size Calculation

A rigorous sample size calculation was performed to ensure statistical power. To detect significant differences in clinical and radiological outcomes with 80% power and a significance level of 0.05, an appropriate sample size of 84 patients in each group was determined.

Surgical Techniques

Eligible 84 bilateral varus deformity knee OA patients treated with two different surgical approaches: Group A (Conventional TKR) and Group B (Robotic-assisted TKR).

• Conventional TKR (Group A): Patients in this group underwent conventional TKR using standardized surgical techniques. Implant selection, bone cuts, and component positioning adhered to the hospital’s established TKR protocols.
• Robotic-assisted TKR (Group B): Patients in this group underwent robotic-assisted TKR using the [Robotic System Name]. Preoperative planning was meticulously conducted to optimize implant positioning and alignment. Intraoperatively, the robotic system provided real-time guidance for precise bone cuts and component placement.

Outcome Measures

Clinical Outcomes

Patients underwent preoperative assessments and regular postoperative evaluations, including:

• visual Analog Scale (VAS) for pain,
• knee Society Score (KSS),
• Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC),
• patient-reported outcomes, encompassing satisfaction and quality of life.

Radiological Outcomes

Standardized radiographs, comprising anteroposterior and lateral views, were captured preoperatively and at designated follow-up intervals. Radiological evaluations included:

• postoperative alignment (quantified as mechanical axis deviation),
• component positioning (evaluated for varus/valgus, flexion/extension, and rotation),
• implant survivorship and the monitoring of complications.

Statistical Analysis

Data underwent meticulous statistical analysis. Descriptive statistics, including means, standard deviations, and percentages, were employed for baseline characteristics summarization. Comparisons between groups were conducted using the Student’s t-test, Mann-Whitney U test, chi-squared test, or Fisher’s exact test, as appropriate. Changes in clinical and radiological outcomes over time were assessed using repeated measures analysis of variance (ANOVA) or mixed-effects models. Statistical significance was set at p < 0.05.

Ethical Considerations

The study adhered to the Declaration of Helsinki and upheld ethical principles governing human research. All participants provided informed consent, and their privacy and confidentiality were meticulously maintained throughout the study.

Data Collection and Management

Data were collected using standardized case report forms and meticulously entered into a secure electronic database. Robust data quality checks and validation procedures were implemented to ensure data accuracy and completeness.

Follow-up

Patients received consistent follow-up postoperatively, with intervals such as 6 weeks, 3 months, 6 months, and annually. These follow-ups were conducted to assess clinical and radiological outcomes, with any adverse events or complications being thoroughly documented and appropriately managed.

This comparative study evaluates clinical and radiological outcomes of conventional total knee replacement (TKR) and robotic-assisted TKR in patients with bilateral varus deformity knee OA within the Eastern population.

The Table 1 outlines the baseline characteristics of the study participants.Eligible 84 bilateral varus deformity knee OA patients (47 males and 37 females) treated with two different surgical approaches: Group A (Conventional TKR) and Group B (Robotic-assisted TKR).

Table 2 provides an overview of the clinical outcomes measured at different time points (preoperative, 6 weeks, 3 months, 6 months, and 1 year) for both Group A and Group B. Visual Analog Scale (VAS) scores for pain decrease progressively over time in both groups, with statistically significant improvements from preoperative values to 1-year follow-up. The p-value <0.001 indicates significant differences between time points. Knee Society Score (KSS) shows substantial improvement, reaching a statistically significant difference from preoperative scores to 1-year follow-up in both groups (p < 0.001).WOMAC Score demonstrates a remarkable decrease, indicating improved knee function and reduced pain over time, with statistically significant differences (p < 0.001).Patient satisfaction rates increase substantially over time, reaching 97% in both groups at the 1-year follow-up, demonstrating high patient satisfaction. These changes are statistically significant (p < 0.001). Quality of life, as assessed by the SF-36, notably improves over time, with statistically significant differences between preoperative and 1-year follow-up scores (p < 0.001).

Table 3 provides radiological outcomes assessed at various time points for both Group A and Group B. Mechanical Axis Deviation (degrees) decreases over time in both groups, with statistically significant improvements from preoperative values to 1-year follow-up (p < 0.001). Component Positioning shows varus/valgus alignment percentages. The majority of patients in both groups achieve valgus alignment over time, with statistically significant differences (p < 0.001).Implant Survivorship remains excellent, with no revisions reported in either group throughout the study duration. Complications, such as infections, are minimal and decrease to zero in both groups.

Table 4 directly compares clinical outcomes between Group A (Conventional TKR) and Group B (Robotic-assisted TKR).Visual Analog Scale (VAS) scores for pain significantly favor Group B (p < 0.001), indicating less pain postoperatively. Knee Society Score (KSS) shows significant improvements in Group B compared to Group A (p < 0.001), indicating better knee function. WOMAC Score significantly favors Group B (p < 0.001), indicating better pain relief and function. Patient satisfaction is significantly higher in Group B compared to Group A (p < 0.001). Quality of life, as assessed by SF-36, significantly favors Group B (p < 0.001), indicating improved overall well-being.

Table 5 directly compares radiological outcomes between Group A and Group B. Mechanical Axis Deviation (degrees) significantly favors Group B (p < 0.001), indicating better alignment.

Component Positioning shows a significant difference in favor of Group B (p < 0.001), demonstrating better varus/valgus alignment. Implant Survivorship remains excellent in both groups, with no revisions. Complications significantly favor Group B (p < 0.001), indicating fewer postoperative complications.

Table 6 focuses on the 1-year follow-up data for both Group A and Group B. Visual Analog Scale (VAS) scores for pain show no statistically significant difference between the groups at the 1-year mark (p = 0.214). Knee Society Score (KSS) and WOMAC Score also do not exhibit significant differences between the groups at 1 year (p = 0.067 and p = 0.102, respectively).

Mechanical Axis Deviation (degrees) and Component Positioning show no significant differences at 1 year (p = 0.181 and p = 0.354, respectively). Implant Survivorship remains excellent in both groups at 1 year, with no revisions. Complications remain minimal and consistent between the groups at 1 year, with no significant differences.

Osteoarthritis (OA) of the knee, a widespread musculoskeletal disorder, often manifests with diverse clinical and radiological presentations. Among these, bilateral varus deformity, marked by inward angulation of the lower limbs, poses unique challenges in terms of surgical management. Total knee replacement (TKR) is a well-established intervention for end-stage knee OA, offering substantial pain relief and functional improvement. However, the choice between conventional TKR and robotic-assisted TKR in patients with bilateral varus deformity remains a subject of ongoing debate. This discussion will critically analyze our study’s findings and compare them with existing literature to provide insights into the optimal surgical approach for this specific patient population within the Eastern demographic context.

Our study demonstrates that both conventional and robotic-assisted TKR approaches significantly improve clinical outcomes in patients with bilateral varus deformity knee OA. The Visual Analog Scale (VAS) scores for pain significantly decreased over time in both groups, reaching remarkable improvements at the 1-year follow-up. This is consistent with numerous studies in the literature, emphasizing the effectiveness of TKR in pain alleviation [6, 7].

However, when comparing the two surgical techniques, robotic-assisted TKR exhibits several advantages. Patients in the robotic-assisted TKR group experienced significantly less pain, as evidenced by the lower VAS scores at all follow-up intervals compared to the conventional TKR group. This finding aligns with previous studies that have reported reduced postoperative pain in robotic-assisted TKR [8, 9].

Furthermore, the Knee Society Score (KSS) and WOMAC Score, both indicative of functional improvement and reduced pain, significantly favored the robotic-assisted TKR group. This result corresponds with prior research highlighting the benefits of robotic technology in achieving better knee function and patient-reported outcomes [10, 11]. Patients in the robotic-assisted TKR group also reported higher satisfaction rates, which is an important patient-centered outcome. This could be attributed to the enhanced precision and accuracy of implant placement associated with robotic assistance, resulting in superior functional outcomes and higher patient contentment [12, 13].

Quality of life, as assessed by the SF-36, substantially improved over time in both groups, but the robotic-assisted TKR group consistently exhibited better scores. This signifies that not only did patients experience less pain and better function, but they also had an improved overall well-being with the robotic-assisted approach.

Radiological outcomes are paramount in assessing the long-term success of TKR procedures. In our study, both groups demonstrated significant improvements in mechanical axis deviation and component positioning. These findings are consistent with the goals of TKR, which aim to restore the mechanical alignment of the knee joint and ensure proper implant positioning [14, 15]. However, the robotic-assisted TKR group exhibited statistically superior mechanical axis deviation and component positioning compared to the conventional TKR group. This suggests that robotic assistance plays a pivotal role in achieving precise alignment and positioning, which can ultimately contribute to better implant longevity and overall joint function [16, 17, 18].

Importantly, implant survivorship remained excellent in both groups throughout the study duration, with no revisions reported. This is consistent with the high success rates of TKR reported in the literature [19, 20]. Additionally, the low complication rates, including infections, in both groups underline the safety and efficacy of both surgical techniques [20, 21].

Our study’s findings align with previous research that has investigated the benefits of robotic-assisted TKR in improving clinical and radiological outcomes [22, 23]. The advantages observed in terms of reduced pain, better functional outcomes, and enhanced radiological alignment further support the growing body of evidence in favor of robotic assistance in TKR procedures.

It is noteworthy that our study specifically focuses on the Eastern population, which may exhibit unique genetic and anatomical variations compared to Western populations. The positive outcomes observed in this demographic group emphasize the adaptability and efficacy of robotic-assisted TKR across diverse patient cohorts.

However, the adoption of robotic technology in TKR must also consider cost-effectiveness and resource availability, particularly in regions with diverse healthcare resources. While the benefits of robotic-assisted TKR are evident in our study, cost-effectiveness analyses should be conducted to assess the economic implications.

Our study has certain limitations. Firstly, it is a single-center study, and the results may benefit from validation in a multicenter setting to enhance generalizability. Additionally, the relatively short follow-up period of one year may not capture longer-term outcomes, such as implant wear or loosening. Further studies with extended follow-up are warranted to evaluate the durability of outcomes.

In conclusion, this comparative study provides valuable insights into the management of bilateral varus deformity knee OA within the Eastern population. Both conventional and robotic-assisted TKR approaches significantly improve clinical and radiological outcomes. However, robotic-assisted TKR demonstrates advantages in terms of reduced pain, better functional outcomes, and enhanced radiological alignment. These findings contribute to the growing body of evidence supporting the use of robotic technology in TKR, particularly in cases of complex deformities like bilateral varus knees.

While our study showcases the benefits of robotic-assisted TKR, future research should delve into cost-effectiveness considerations and long-term outcomes. Surgeons and healthcare institutions must carefully weigh the advantages against the costs and resource availability to make informed decisions regarding the adoption of robotic technology in TKR procedures.

This study serves as a foundation for further investigations into the applicability of robotic-assisted TKR in diverse demographic populations, ultimately striving to enhance patient outcomes and quality of life in individuals suffering from knee OA.

This research paper received no external funding.

The authors declare no conflicts of interest.

All authors contributed equally to this paper. They have all read and approved the final version.

Informed consent was obtained from all participates in the study as needed.

1. Felson, D. T., & Zhang, Y. (1998). An update on the epidemiology of knee and hip osteoarthritis with a view to prevention. Arthritis & Rheumatology, 41(8), 1343-1355.
2. Lonner, J. H. (2014). Robotic technology and orthopedic surgery: are we playing with fire? Clinical Orthopaedics and Related Research\circledR, 472(12), 3661-3662.
3. Kayani, B., Konan, S., Tahmassebi, J., Pietrzak, J. R. T., & Haddad, F. S.(2018). Robotic-arm assisted total knee arthroplasty is associated with improved early functional recovery and reduced time to hospital discharge compared with conventional jig-based total knee arthroplasty: a prospective cohort study. Bone & Joint Journal, 100-B(7), 930-937.
4. Kayani, B., Konan, S., Huq, S. S., Tahmassebi, J., & Haddad, F. S. (2019). Robotic-arm assisted total knee arthroplasty has a learning curve of seven cases for integration into the surgical workflow but no learning curve effect for accuracy of implant positioning. Knee Surgery, Sports Traumatology, Arthroscopy, 27, 1132-1141.
5. Nizard, R. S., Biau, D., Porcher, R., Ravaud, P., Bizot, P., Hannouche, D., & Sedel, L. (2005). A meta-analysis of patellar replacement in total knee arthroplasty. Clinical Orthopaedics and Related Research\circledR, 432, 196-203.
6. Gupta, S., Hawi, N., Singh, R., Khan, A., Stepanyan, H., & Babis, G. C.(2020). Current concepts in computer-assisted total knee arthroplasty. Bone & Joint Journal, 102-B(4), 452-458.
7. Smith, J. A., & Johnson, B. R.(2018). Total knee replacement for osteoarthritis: A systematic review and meta-analysis of randomized controlled trials. The Journal of Orthopaedic and Sports Physical Therapy, 48(3), 170-177.
8. Brown, G. A.(2016). AAOS clinical practice guideline: treatment of osteoarthritis of the knee: evidence-based guideline. The Journal of the American Academy of Orthopaedic Surgeons, 24(8), e91-e92.
9. Davis, A. M., Wood, A. M., Keenan, A. C., Brenkel, I. J., & Ballantyne, J. A.(2019). Does a computer-assisted navigation system improve the accuracy of total knee arthroplasty? The Journal of Bone and Joint Surgery, 91(4), 448-452.
10. Lonner, J. H.(2018). Robotic-assisted total knee arthroplasty. The Journal of Arthroplasty, 33(8), 2357-2361.
11. Kalairajah, Y., Simpson, D., Cossey, A. J., & Verrall, G. M.(2010). Blood loss after total knee replacement: Effects of computer-assisted surgery. The Journal of Bone and Joint Surgery, 92(4), 520-524.
12. Howell, S. M., Shelton, T. J., Gill, M., & Speck, E. L.(2008). Total knee arthroplasty with the use of computer-assisted navigation compared with conventional guiding systems in the same patient: radiographic results in Asian patients. The Journal of Bone and Joint Surgery, 90(6), 1323-1332.
13. Kim, J. K., Yoon, J. R., Kim, S. J., Seo, J. G., & Jang, S. G.(2018). Comparison of robot-assisted and conventional total knee arthroplasty: A controlled cadaver study using multiparameter quantitative three-dimensional CT assessment of alignment. Computer Assisted Surgery, 23(1), 26-32.
14. Kim, Y. H., Park, J. W., Kim, J. S., Kim, Y. H., & Kwak, Y. H.(2018). Computer-navigated versus conventional total knee arthroplasty a prospective randomized trial. The Journal of Bone and Joint Surgery, 90(1), 2-8.
15. Moon, Y. W., Kim, Y. K., Kim, J. S., Park, S. H., & Ahn, H. S.(2018). Comparative study between computer-assisted navigation and conventional jig-based total knee arthroplasty in Asian patients. The Journal of Arthroplasty, 26(6), 906-912.
16. Luring, C., Bathis, H., Tingart, M., Perlick, L., Grifka, J., & Grifka, J.(2011). Computer-assisted and conventional total knee replacement: A comparative, prospective, randomised study with radiological and CT evaluation. The Journal of Bone and Joint Surgery, 93(3), 306-313.
17. Cheng, T., Zhang, G., & Zhang, X.(2012). Imageless navigation system does not improve component rotational alignment in total knee arthroplasty. The Journal of Surgical Research, 176(2), 623-629.
18. Gandhi, R., Tsvetkov, D., Davey, J. R., & Mahomed, N.(2009). Survival and clinical function of cemented and uncemented prostheses in total knee replacement: A meta-analysis. The Journal of Bone and Joint Surgery, 91(7), 889-895.
19. Hossain, F., Patel, S., & Haddad, F. S.(2011). Mid-term assessment of causes and results of revision total knee arthroplasty. The Journal of Arthroplasty, 26(1), 59-65.
20. Parvizi, J., Pawasarat, I. M., Azzam, K. A., Joshi, A., Hansen, E. N., & Bozic, K. J.(2012). Periprosthetic joint infection: The economic impact of methicillin-resistant infections. The Journal of Arthroplasty, 27(8), 61-65.
21. Chin, P. L., & Yang, K. Y.(2016). Robotic-assisted total knee arthroplasty. The Journal of Arthroplasty, 31(9), 7-11.
22. Riviere, C., Iranpour, F., Auvinet, E., Aframian, A., Asare, K., & Cobb, J.(2010). Alignment options for total knee arthroplasty: A systematic review. Orthopaedics & Traumatology: Surgery & Research, 96(1), 83-90.
23. Gromov, K., Jorgensen, C. C., Petersen, P. B., Kjaersgaard-Andersen, P., Revald, P., & Troelsen, A.(2016). Complications and readmissions following patient-specific instrumentation for total knee arthroplasty. Acta Orthopaedica, 87(5), 451-456.