Higher satisfaction and function scores in restricted kinematic alignment versus mechanical alignment with medial pivot design total knee arthroplasty: A prospective randomised controlled trial

Total knee arthroplasty (TKA) remains the gold standard surgical care for end-stage knee arthritis. Since its inception, TKA has seen many transformative factors with advances in material properties, implant design, and fixation. Improvements in implant longevity has culminated in TKA being recognized as one of modern medicine's most successful surgical procedures. Patient satisfaction, however, remains a significant challenge. Recent studies report that patient satisfaction with current implants and techniques remains at 80 to 90%, suggesting that up to one in five patients remain dissatisfied with their procedure. A balanced knee, defined as equal medial and lateral gaps in knee extension and flexion, is a desired outcome in TKA. This has been shown to be associated with improved clinical outcomes. Given the poor rate of surgeon-defined balance, intraoperative knee balance can be confirmed with objective load data using sensor-embedded smart inserts or by measuring gaps using computer-assisted or robotic platforms. Currently, there is no consensus on the correct alignment or laxity targets for individualized alignment strategies in TKA, and further research in this area is required to answer this. Tremendous advances in our understanding of knee anatomy and kinematics have come to light in the recent past, and these insights have spawned interest in alternative alignment techniques in TKA. More recently, an appreciation of individual knee phenotypes and associated classification systems have provided a platform and the scientific justification behind these contemporary alignment strategies. Paired with enabling technologies, it is becoming an accepted paradigm that surgeons have the ability to select a desired alignment target when undertaking an individualized alignment strategy in TKA and execute the surgery with a high degree of precision. It is hoped that this may reduce the rate of dissatisfaction following TKA and improve clinical outcomes. This review article provides an overview of the concepts of knee phenotypes, current alignment strategies in TKA, and the emerging benefits of enabling technologies.

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Comparison of patient satisfaction and function outcomes between restricted kinematic alignment and mechanical alignment: An early follow-up study

Liu,

Cao,

Lan

et al. 2024

Preprint

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Background Mechanical alignment (MA) is the gold standard for total knee arthroplasty (TKA). However, MA will inevitably modify the patient's native knee anatomy. Another alignment option is kinematic alignment (KA), which aims to restore the original anatomy of the knee. In recent years, restricted kinematic alignment (rKA), which aims to restore native knee kinematics without reproducing the extreme knee phenotype, has been developed as an alternative to unrestricted KA. This study was designed to evaluate the clinical outcomes and satisfaction scores between patients who underwent rKA and those who underwent MA during TKA. Methods We retrospectively analyzed the clinical data of 45 patients who were diagnosed with osteoarthritis and underwent MA-TKA and 45 patients who underwent rKA-TKA from January 2022 to January 2023. Demographic, perioperative, and radiological data were collected and compared. Unpaired two-sample t tests for continuous variables and χ2 tests for categorical variables were used to compare various measurements between two groups. The patient-reported outcome measures at baseline(T0) and at 3 (T3), 6 (T6), and 12 (T12) months after surgery were recorded and statistically analyzed. Result Forty-five robotic-assisted rKA-TKAs were performed, and 45 conventional MA-TKAs were performed. The changes in the hospital for special surgery score (HSS), visual analogue scale (VAS), forgotten joint score (FJS-12), knee society score (KSS), patient satisfaction, and complications from T0 to T12 for patients who underwent rKA were equal to those who underwent MA (86.58 vs. 86.22, P > 0.05 (KSS-Clinical, T12), 73.40 vs. 75.00, P > 0.05 (KSS-Function, T12), 86.11 vs. 85.28, P > 0.05 (HSS, T12), 0.87 vs. 0.82, P > 0.05 (VAS, T12), 83.29 vs. 83.38, P > 0.05 (FJS-12, T12), and 4.57 vs. 4.43, P > 0.05 (Satisfaction, T12)). The net change in the hip-knee-ankle (HKA) and medial proximal tibial angle (MPTA) for the constitutional varus was greater (P < 0.05) than that for the constitutional valgus knee in the rKA group. Both groups have a good range of motion (ROM). No revision was performed in the two groups at the one-year follow-up. Conclusion rKA is safe for short-term TKA and is a valid alternative to MA.

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Higher satisfaction and function scores in restricted kinematic alignment versus mechanical alignment with medial pivot design total knee arthroplasty: A prospective randomised controlled trial

Cited by 3 publications

References 50 publications

Patient‐reported outcome measures, the holy grail of outcome assessment: Are they powerful enough to show a difference in knee arthroplasty alignment? A call for more comprehensive and objective data collection

Patient‐reported outcome measures, the holy grail of outcome assessment: Are they powerful enough to show a difference in knee arthroplasty alignment? A call for more comprehensive and objective data collection

Alignment Strategies in Total Knee Arthroplasty: The Rise and Role of Enabling Technology

Comparison of patient satisfaction and function outcomes between restricted kinematic alignment and mechanical alignment: An early follow-up study

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