OA KneeNCT06835621
Comparison of Functional Recovery Between Restricted Inverse Kinematic Alignment and Adjusted Mechanical Alignment With Robotic-assisted Unilateral Total Knee Arthroplasty.
A study testing Restricted inverse kinematic alignment Total Knee Arthroplasty and Adjusted Mechanical alignment Total Knee Arthroplasty in people with OA Knee and TKA, run by Thammasat University at 2 sites in Thailand.
Trial summary
The goal of this clinical trial is to learn if restricted inverse kinematic alignment total knee arthroplasty (restricted iKA TKA) improves functional recovery compared to adjusted mechanical alignment total knee arthroplasty (aMA TKA) in patients undergoing unilateral robotic-assisted total knee arthroplasty by… Read more about this study
- Who is it for?
- Ages 50 to 80 years
- What is being tested?
- Restricted inverse kinematic alignment Total Knee Arthroplasty and Adjusted Mechanical alignment Total Knee Arthroplasty
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 2 sitesThailand
- Study dates
- Mar 2025to Aug 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 50 - 80 years old
- Diagnosed with primary OA knee and indicated for unilateral total knee arthroplasty with MAKO robotic-assisted knee replacement system
- ASA classification I-II
Who cannot join
- Valgus deformity
- KL grading > 3 on contralateral knee
- Unable or difficulty for walking due to comorbidities
- BMI > 40 kg/m2
- Previous knee surgery
- Infection around the knee
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Thailand2 sites
Faculty of Medicine, Thammasat University
Klongluang, Changwat Pathum Thani, 12120
Faculty of Medicine, Thammasat University
Klongluang, Changwat Pathum Thani, 12120
Chananyu Susrivaraput, M.D., +66989169544, chananyu.atom@gmail.com
Krit Boontanapibul, M.D.
About this study
Official title: Comparison of Functional Recovery Between Restricted Inverse Kinematic Alignment and Adjusted Mechanical Alignment With Robotic-assisted Unilateral Total Knee Arthroplasty. A Randomized Controlled Trial.
The goal of this clinical trial is to learn if restricted inverse kinematic alignment total knee arthroplasty (restricted iKA TKA) improves functional recovery compared to adjusted mechanical alignment total knee arthroplasty (aMA TKA) in patients undergoing unilateral robotic-assisted total knee arthroplasty by comparing performance-based outcome, 2-minute walk test (2MWT) as a primary outcome. This trial will also assess other outcomes including satisfaction, patient-reported functional outcomes, range of motion, visual analog scale for pain and complication of both techniques. The main question aims to answer is:
In unilateral robotic-assisted total knee arthroplasty, dose Restricted iKA technique provide better postoperative performance-based outcome compared to aMA technique?
Read more
Researchers will compare restricted iKA and aMA technique to determine which technique offers better acceleration in functional recovery and patient satisfaction.
Participants will:
After randomization, participants will allocate to either restricted iKA or aMA technique for unilateral robotic-assisted total knee arthroplasty.
Attend follow-up visits for assessments of 2-minute walk test (Primary outcome), Time up and go test (TUG), VAS for pain, ROM and complete patient-reported functional outcome questionnaires regarding knee function and satisfaction at regular intervals.
Read the detailed description
Nowadays, total knee arthroplasty (TKA) for the treatment of osteoarthritis patients generally aims to achieve a neutral alignment of the leg. This involves cutting the bones perpendicular to the mechanical axis in both the femur and tibia. This method is called mechanical alignment TKA (MA TKA), which is widely popular and is often considered the standard technique for TKA. It has shown satisfactory long-term outcomes. However, despite advancements in materials and surgical techniques, MA TKA still requires bone and soft tissue adjustments to correct alignment, which may involve releasing soft tissues. This can result in post-surgical pain or dissatisfaction, with up to 20% of patients reporting dissatisfaction despite improved knee pain compared to pre-surgery. Furthermore, 1 in 4 of these dissatisfied patients do not wish to undergo a revision surgery, as the MA TKA method is a "one-size-fits-all" approach that aims to achieve equal and parallel gaps between the femur and tibia components without respecting individual soft tissue balance and the original alignment of each patient's leg. However, adjusted mechanical alignment technique, an adaptation of conventional MA technique with under-correction of constitutional coronal deformity, within a limit of ± 3° (HKA -3° to 3) has been introduced according to the constitutional deformity and coronal plan alignment of the knee concept.
In 2006, Howell introduced kinematic alignment TKA (KA TKA) as an alternative, with the goal of restoring the patient's natural kinematic axis and reducing the incidence of pain related to TKA rather than focusing on equal medial and lateral joint line gap and neutral mechanical axis like in mechanical alignment technique. KA TKA is considered a more personalized approach because it aims to replicate the knee's pre-arthritic alignment and movement, believing that each patient's knee has a unique alignment. This approach has gained increasing interest in recent years, with studies reporting good short- to mid-term clinical outcomes. However, the KA technique is more complex because we cannot always know the pre-arthritic alignment of individual patients and measuring soft tissue tension remains imprecise.
Later, Dr. Pascal-André Vendittoli proposed the restricted kinematic alignment TKA (rKA TKA) technique to restore natural knee movement while avoiding excessive correction of coronal alignment by maintain the HKA axis within ± 3 degrees (safe zone). By maintaining some of the constitutional deformity, this technique reduces the need for excessive soft tissue or ligament releases. In 2020 Winnock et al, introduced the Inversed kinematic technique (iKA) or tibia-referenced technique by resurfacing the tibia with equal medial and lateral resections maintaining the native tibial joint line obliquity before distal femoral bone. When combines these KA principles with robotic-assisted TKA, enhancing the accuracy of soft tissue balancing and the overall effectiveness of the procedure.
In 2020, McEwen et al. compared the use of robotic-assisted KA with MA in the same patients who underwent bilateral knee surgery using different techniques. They found that clinical outcomes, including range of motion and knee scores, were not significantly different at any time point. However, Elbuluk conducted a similar comparison, specifically robotic-assisted (MAKO) KA versus MA, and found that the KA group had less pain and better knee scores, including a higher Forgotten Joint Score. Later, Abhari conducted a study comparing robotic-assisted (MAKO) restricted KA with non-robotic MA TKA and found that the robotic-assisted (MAKO) restricted KA group had superior clinical outcomes and knee scores, including the Forgotten Joint Score, KOOS, WOMAC, Knee Society Score, as well as greater patient satisfaction. However, there are still limited prospective RCTs that study differences in outcomes, especially performance-based outcomes between restricted inverse kinematic alignment (restricted iKA) versus adjusted mechanical alignment (aMA). Therefore, the researchers aim to conduct a study comparing the efficiency of performance-based outcomes as a primary focus, including patient-reported outcome questionnaires, ROM, VAS for postoperative pain, postoperative morphine consumption within 24 hours, postoperative lower limb alignment (HKA axis), operative time, blood loss, and complications. The goal is to further advance the development of knee replacement surgery.
- Being tested
- Restricted inverse kinematic alignment Total Knee Arthroplasty, Adjusted Mechanical alignment Total Knee Arthroplasty
- Keywords
- Osteoarthritis (OA) of the Knee, OA knee, MAKO, Kinematic alignment, Mechanical alignment, Restricted Kinematic alignment, Inversed Kinematic alignment, Inversed Restricted Kinematic alignment, Robotic assist Total Knee Arthroplasty, Adjusted mechanical alignment
- Medical subject headings
- Osteoarthritis, Knee, Osteoarthritis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Restricted inverse kinematic alignment Total Knee ArthroplastyProcedure or surgery
Also called Restricted kinematic alignment, rKA, Inverse kinematic alignment, iKA
Restricted inverse kinematic alignment (restricted iKA) total knee arthroplasty is an alignment technique of total knee replacement surgery, aim to maintain the native coronal alignment within a HKA angle safe zone of 177° to 183°. This technique aims to 'resurface' the femur maintaining the native femoral joint line obliquity, with the flexion and extension gaps balanced by adjusting the tibial resection first. It is considered a more personalized approach because it aims to replicate the knee's pre-arthritic alignment and movement, believing that each patient's knee has a unique alignment.
Adjusted Mechanical alignment Total Knee ArthroplastyProcedure or surgery
Also called aMA
The adjusted Mechanical Alignment (aMA) technique is an adaptation of the conventional MA technique but with undercorrection of constitutional coronal deformity, within a limit of ± 3°. The femoral resection is adjusted to preserve mild constitutional deformity and/or reduce more severe deformity while leaving the tibial component mechanically aligned. The tibial component was positioned with the aim to be perpendicular (90°) to the mechanical tibial axis.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 | Active comparator | Restricted inverse kinematic alignment Receives: Procedure: Restricted inverse kinematic alignment Total Knee Arthroplasty |
| Group 2 | Active comparator | Adjusted mechanical alignment Receives: Procedure: Adjusted Mechanical alignment Total Knee Arthroplasty |
What is being measured
The primary outcome is the main question the study is designed to answer.
2-minute walk test
The 2-minute walk test (2mwt) is a performance-based test that evaluates functional recovery after total knee arthroplasty (TKA) by measures the distance a person can walk in two minutes (meters) and has been validated as performance-based test with responsiveness properties. Being simple and easy to perform, it can be used routinely in clinical practice to evaluate functional recovery after TKA.
Measured: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Secondary outcomes (12)
Time up and go test
The Timed Up and Go test (TUG) are simple, quick, and can be applied in a short time as part of the routine medical examination. They were shown to be reliable and valid tests in many patient groups including postoperative performance-based outcome for patients undergone TKA.
Measured: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
modified WOMAC scale for knee pain (Thai version)
The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a widely used questionnaire for assessing pain, stiffness, and functional limitation in patients with osteoarthritis, particularly in the knee and hip joints. The modified WOMAC scale adapts the original WOMAC to better suit specific populations or clinical settings. In this study, we use the modified WOMAC scale for knee pain Thai version to assess the pre and post operative functional outcome.
Measured: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Thai version of the Forgotten Joint Score
This score aims for evaluation of joint awareness in everyday life, which is one of the aspects to evaluate the outcome and the ability to forget the artificial joint, is claimed as the ultimate goal resulting in maximum patient satisfaction. The Thai language version of the FJS had high level of internal consistency and was proved to be a reliable tool for evaluating knee arthroplasty patients in Thailand. The low ceiling effect characteristic of the score can help the surgeon to detect small difference in the good and excellent outcomes after knee arthroplasty.
Measured: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Oxford knee score
The Oxford Knee Score (OKS) is a widely used patient-reported outcome measure designed to assess the function and quality of life of individuals with knee problems, particularly those undergoing knee surgery, such as total knee arthroplasty. It focuses specifically on how knee-related issues affect daily activities and overall well-being. (Thai version is available on the official website of the Oxford knee score website)
Measured: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Range of Motion
Preoperative and Postoperative active range of motion (ROM) will be recorded for evaluation of the knee ROM for both groups including flexion contracture (FC) or extension gap which may be presented as complication.
Measured: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Hip knee ankle angle
The hip knee ankle angle is radiographic measurement for determine the coronal alignment of the lower limbs. On a weight-bearing, full-length AP lower limb radiograph measuring 2 lines from center of the femoral head to the femoral intercondylar notch, while the latter from the tibial interspinous point to the tibial mid-plafond. The HKA is defined as the angle between these two lines.
Measured: From enrollment (preoperative measurement) and at 1-year postoperative follow-up.
Visual analog scale for Pain
Each patient will be asked for Visual analog scale (VAS) for pain for the knee, which is the subjective patient reported pain rating from 0-10 either from numerical order or facial expression picture indicating 0 is the minimum or no pain and 10 is the maximum or the worst pain.
Measured: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Morphine consumption
Postoperative morphine consumption (mg) in the first 72 hours during hospital admission could reflect the need of strong opioid as the rescue analgesia after operation.
Measured: Postoperative interval of 24-72 hours
Complication
Total knee arthroplasty-related complication e.g. surgical site infection, bleeding, wound complication, deep vein thrombosis, acute pulmonary embolism and implant failure.
Measured: After surgery and up to 2 years
Medial proximal tibial angle (MPTA)
In whole leg AP weight baring film, measure the proximal medial angle formed between the tibial mechanical axis and the knee joint line of the tibia in the frontal plane.
Measured: From enrollment (preoperative measurement) and at 1-year postoperative follow-up.
Lateral distal femoral angle (LDFA)
In whole leg AP weight baring film, it's defined as the lateral angle formed between the mechanical axis line of the femur and the knee joint line of the femur.
Measured: From enrollment (preoperative measurement) and at 1-year postoperative follow-up.
Joint line obliquity (JLO)
Joint line obliquity (degrees) = MPTA + LDFA
Measured: From enrollment (preoperative measurement) and at 1-year postoperative follow-up.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Feb 2025
- Study startMar 2025 (estimated)
- Primary completionAug 2026 (estimated)
- Study completionAug 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (15)Papers the sponsor has linked to this study.
- Other trials for OA KneeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Thammasat University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Krit Boontanapibul, Thammasat University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06835621
- Sponsor's protocol ID
- MTU-EC-OT-0-240/67
- Status last verified
- Feb 2025
- First submitted
- 14 Feb 2025
- Last updated
- 19 Feb 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Elbuluk AM, Jerabek SA, Suhardi VJ, Sculco PK, Ast MP, Vigdorchik JM. Head-to-Head Comparison of Kinematic Alignment Versus Mechanical Alignment for Total Knee Arthroplasty. J Arthroplasty. 2022 Aug;37(8S):S849-S851. doi: 10.1016/j.arth.2022.01.052. Epub 2022 Jan 31.
PubMed 35093548McEwen PJ, Dlaska CE, Jovanovic IA, Doma K, Brandon BJ. Computer-Assisted Kinematic and Mechanical Axis Total Knee Arthroplasty: A Prospective Randomized Controlled Trial of Bilateral Simultaneous Surgery. J Arthroplasty. 2020 Feb;35(2):443-450. doi: 10.1016/j.arth.2019.08.064. Epub 2019 Sep 5.
PubMed 31591010Van Essen J, Stevens J, Dowsey MM, Choong PF, Babazadeh S. Kinematic alignment results in clinically similar outcomes to mechanical alignment: Systematic review and meta-analysis. Knee. 2023 Jan;40:24-41. doi: 10.1016/j.knee.2022.11.001. Epub 2022 Nov 17.
PubMed 36403396Blakeney WG, Vendittoli PA. Restricted Kinematic Alignment: The Ideal Compromise? 2020 Jul 1. In: Riviere C, Vendittoli PA, editors. Personalized Hip and Knee Joint Replacement [Internet]. Cham (CH): Springer; 2020. Chapter 17. Available from http://www.ncbi.nlm.nih.gov/books/NBK565760/
PubMed 33347126Howell SM, Shelton TJ, Hull ML. Implant Survival and Function Ten Years After Kinematically Aligned Total Knee Arthroplasty. J Arthroplasty. 2018 Dec;33(12):3678-3684. doi: 10.1016/j.arth.2018.07.020. Epub 2018 Jul 31.
PubMed 30122435Vanlommel L, Vanlommel J, Claes S, Bellemans J. Slight undercorrection following total knee arthroplasty results in superior clinical outcomes in varus knees. Knee Surg Sports Traumatol Arthrosc. 2013 Oct;21(10):2325-30. doi: 10.1007/s00167-013-2481-4. Epub 2013 Apr 4.
PubMed 23552665Winnock de Grave P, Luyckx T, Claeys K, Tampere T, Kellens J, Muller J, Gunst P. Higher satisfaction after total knee arthroplasty using restricted inverse kinematic alignment compared to adjusted mechanical alignment. Knee Surg Sports Traumatol Arthrosc. 2022 Feb;30(2):488-499. doi: 10.1007/s00167-020-06165-4. Epub 2020 Jul 31.
PubMed 32737528Yang Y, Wang Y, Chen Y, Wang J, Lu B, Zhu W, Zhu J, Zhu C, Zhang X. Tracing the evolution of robotic-assisted total knee arthroplasty: a bibliometric analysis of the top 100 highly cited articles. J Robot Surg. 2023 Dec;17(6):2973-2985. doi: 10.1007/s11701-023-01742-4. Epub 2023 Oct 26.
PubMed 37882976Vendittoli PA, Martinov S, Blakeney WG. Restricted Kinematic Alignment, the Fundamentals, and Clinical Applications. Front Surg. 2021 Jul 20;8:697020. doi: 10.3389/fsurg.2021.697020. eCollection 2021.
PubMed 34355018Hirschmann MT, Becker R, Tandogan R, Vendittoli PA, Howell S. Alignment in TKA: what has been clear is not anymore! Knee Surg Sports Traumatol Arthrosc. 2019 Jul;27(7):2037-2039. doi: 10.1007/s00167-019-05558-4. Epub 2019 Jun 12. No abstract available.
PubMed 31190246Dossett HG, Estrada NA, Swartz GJ, LeFevre GW, Kwasman BG. A randomised controlled trial of kinematically and mechanically aligned total knee replacements: two-year clinical results. Bone Joint J. 2014 Jul;96-B(7):907-13. doi: 10.1302/0301-620X.96B7.32812.
PubMed 24986944Roth JD, Howell SM, Hull ML. Native Knee Laxities at 0 degrees , 45 degrees , and 90 degrees of Flexion and Their Relationship to the Goal of the Gap-Balancing Alignment Method of Total Knee Arthroplasty. J Bone Joint Surg Am. 2015 Oct 21;97(20):1678-84. doi: 10.2106/JBJS.N.01256.
PubMed 26491132Brar AS, Howell SM, Hull ML, Mahfouz MR. Does Kinematic Alignment and Flexion of a Femoral Component Designed for Mechanical Alignment Reduce the Proximal and Lateral Reach of the Trochlea? J Arthroplasty. 2016 Aug;31(8):1808-13. doi: 10.1016/j.arth.2016.01.040. Epub 2016 Feb 4.
PubMed 26923495Hiranaka T, Suda Y, Saitoh A, Tanaka A, Arimoto A, Koide M, Fujishiro T, Okamoto K. Current concept of kinematic alignment total knee arthroplasty and its derivatives. Bone Jt Open. 2022 May;3(5):390-397. doi: 10.1302/2633-1462.35.BJO-2022-0021.R2.
PubMed 35532356Nisar S, Palan J, Riviere C, Emerton M, Pandit H. Kinematic alignment in total knee arthroplasty. EFORT Open Rev. 2020 Aug 1;5(7):380-390. doi: 10.1302/2058-5241.5.200010. eCollection 2020 Jul.
PubMed 32818065
Study at a glance
From the registry record, last updated by the sponsor on 19 Feb 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Functional Recovery Between Restricted Inverse Kinematic Alignment and Adjusted Mechanical Alignment With Robotic-assisted Unilateral Total Knee Arthroplasty. A Randomized Controlled Trial.
- ClinicalTrials.gov ID
- NCT06835621
- Acronym / sponsor ID
- MTU-EC-OT-0-240/67
- Keywords
- Osteoarthritis (OA) of the Knee, OA knee, MAKO, Kinematic alignment, Mechanical alignment, Restricted Kinematic alignment, Inversed Kinematic alignment, Inversed Restricted Kinematic alignment
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- Thammasat UniversityUniversity, hospital or other
- Study start
- Mar 2025 (estimated)
- Primary completion
- Aug 2026 (estimated)
- Study completion
- Aug 2028 (estimated)
- First posted
- 19 Feb 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to learn if restricted inverse kinematic alignment total knee arthroplasty (restricted iKA TKA) improves functional recovery compared to adjusted mechanical alignment total knee arthroplasty (aMA TKA) in patients undergoing unilateral robotic-assisted total knee arthroplasty by comparing performance-based outcome, 2-minute walk test (2MWT) as a primary outcome. This trial will also assess other outcomes including satisfaction, patient-reported functional outcomes, range of motion, visual analog scale for pain and complication of both techniques. The main question aims to answer is:
In unilateral robotic-assisted total knee arthroplasty, dose Restricted iKA technique provide better postoperative performance-based outcome compared to aMA technique?
Researchers will compare restricted iKA and aMA technique to determine which technique offers better acceleration in functional recovery and patient satisfaction.
Participants will:
After randomization, participants will allocate to either restricted iKA or aMA technique for unilateral robotic-assisted total knee arthroplasty.
Attend follow-up visits for assessments of 2-minute walk test (Primary outcome), Time up and go test (TUG), VAS for pain, ROM and complete patient-reported functional outcome questionnaires regarding knee function and satisfaction at regular intervals.
Detailed description
Nowadays, total knee arthroplasty (TKA) for the treatment of osteoarthritis patients generally aims to achieve a neutral alignment of the leg. This involves cutting the bones perpendicular to the mechanical axis in both the femur and tibia. This method is called mechanical alignment TKA (MA TKA), which is widely popular and is often considered the standard technique for TKA. It has shown satisfactory long-term outcomes. However, despite advancements in materials and surgical techniques, MA TKA still requires bone and soft tissue adjustments to correct alignment, which may involve releasing soft tissues. This can result in post-surgical pain or dissatisfaction, with up to 20% of patients reporting dissatisfaction despite improved knee pain compared to pre-surgery. Furthermore, 1 in 4 of these dissatisfied patients do not wish to undergo a revision surgery, as the MA TKA method is a "one-size-fits-all" approach that aims to achieve equal and parallel gaps between the femur and tibia components without respecting individual soft tissue balance and the original alignment of each patient's leg. However, adjusted mechanical alignment technique, an adaptation of conventional MA technique with under-correction of constitutional coronal deformity, within a limit of ± 3° (HKA -3° to 3) has been introduced according to the constitutional deformity and coronal plan alignment of the knee concept.
In 2006, Howell introduced kinematic alignment TKA (KA TKA) as an alternative, with the goal of restoring the patient's natural kinematic axis and reducing the incidence of pain related to TKA rather than focusing on equal medial and lateral joint line gap and neutral mechanical axis like in mechanical alignment technique. KA TKA is considered a more personalized approach because it aims to replicate the knee's pre-arthritic alignment and movement, believing that each patient's knee has a unique alignment. This approach has gained increasing interest in recent years, with studies reporting good short- to mid-term clinical outcomes. However, the KA technique is more complex because we cannot always know the pre-arthritic alignment of individual patients and measuring soft tissue tension remains imprecise.
Later, Dr. Pascal-André Vendittoli proposed the restricted kinematic alignment TKA (rKA TKA) technique to restore natural knee movement while avoiding excessive correction of coronal alignment by maintain the HKA axis within ± 3 degrees (safe zone). By maintaining some of the constitutional deformity, this technique reduces the need for excessive soft tissue or ligament releases. In 2020 Winnock et al, introduced the Inversed kinematic technique (iKA) or tibia-referenced technique by resurfacing the tibia with equal medial and lateral resections maintaining the native tibial joint line obliquity before distal femoral bone. When combines these KA principles with robotic-assisted TKA, enhancing the accuracy of soft tissue balancing and the overall effectiveness of the procedure.
In 2020, McEwen et al. compared the use of robotic-assisted KA with MA in the same patients who underwent bilateral knee surgery using different techniques. They found that clinical outcomes, including range of motion and knee scores, were not significantly different at any time point. However, Elbuluk conducted a similar comparison, specifically robotic-assisted (MAKO) KA versus MA, and found that the KA group had less pain and better knee scores, including a higher Forgotten Joint Score. Later, Abhari conducted a study comparing robotic-assisted (MAKO) restricted KA with non-robotic MA TKA and found that the robotic-assisted (MAKO) restricted KA group had superior clinical outcomes and knee scores, including the Forgotten Joint Score, KOOS, WOMAC, Knee Society Score, as well as greater patient satisfaction. However, there are still limited prospective RCTs that study differences in outcomes, especially performance-based outcomes between restricted inverse kinematic alignment (restricted iKA) versus adjusted mechanical alignment (aMA). Therefore, the researchers aim to conduct a study comparing the efficiency of performance-based outcomes as a primary focus, including patient-reported outcome questionnaires, ROM, VAS for postoperative pain, postoperative morphine consumption within 24 hours, postoperative lower limb alignment (HKA axis), operative time, blood loss, and complications. The goal is to further advance the development of knee replacement surgery.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group 1 | Active comparator | Procedure: Restricted inverse kinematic alignment Total Knee ArthroplastyRestricted inverse kinematic alignment |
| Group 2 | Active comparator | Procedure: Adjusted Mechanical alignment Total Knee ArthroplastyAdjusted mechanical alignment |
Who may qualify
- Ages
- 50 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Age 50 - 80 years old
- Diagnosed with primary OA knee and indicated for unilateral total knee arthroplasty with MAKO robotic-assisted knee replacement system
- ASA classification I-II
Key exclusion criteria (6 listed)
- Valgus deformity
- KL grading > 3 on contralateral knee
- Unable or difficulty for walking due to comorbidities
- BMI > 40 kg/m2
- Previous knee surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Restricted inverse kinematic alignment Total Knee ArthroplastyAlso: Restricted kinematic alignment, rKA, Inverse kinematic alignment, iKARestricted inverse kinematic alignment (restricted iKA) total knee arthroplasty is an alignment technique of total knee replacement surgery, aim to maintain the native coronal alignment within a HKA angle safe zone of 177° to 183°. This technique aims to 'resurface' the femur maintaining the native femoral joint line obliquity, with the flexion and extension gaps balanced by adjusting the tibial resection first. It is considered a more personalized approach because it aims to replicate the knee's pre-arthritic alignment and movement, believing that each patient's knee has a unique alignment. | Procedure or surgery | Group 1 |
| Adjusted Mechanical alignment Total Knee ArthroplastyAlso: aMAThe adjusted Mechanical Alignment (aMA) technique is an adaptation of the conventional MA technique but with undercorrection of constitutional coronal deformity, within a limit of ± 3°. The femoral resection is adjusted to preserve mild constitutional deformity and/or reduce more severe deformity while leaving the tibial component mechanically aligned. The tibial component was positioned with the aim to be perpendicular (90°) to the mechanical tibial axis. | Procedure or surgery | Group 2 |
Primary outcome
2-minute walk test
Time frame: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
The 2-minute walk test (2mwt) is a performance-based test that evaluates functional recovery after total knee arthroplasty (TKA) by measures the distance a person can walk in two minutes (meters) and has been validated as performance-based test with responsiveness properties. Being simple and easy to perform, it can be used routinely in clinical practice to evaluate functional recovery after TKA.
12 secondary outcomes
Time up and go test
Time frame: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
modified WOMAC scale for knee pain (Thai version)
Time frame: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Thai version of the Forgotten Joint Score
Time frame: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Oxford knee score
Time frame: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Range of Motion
Time frame: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Hip knee ankle angle
Time frame: From enrollment (preoperative measurement) and at 1-year postoperative follow-up.
Visual analog scale for Pain
Time frame: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)
Morphine consumption
Time frame: Postoperative interval of 24-72 hours
Complication
Time frame: After surgery and up to 2 years
Medial proximal tibial angle (MPTA)
Time frame: From enrollment (preoperative measurement) and at 1-year postoperative follow-up.
Lateral distal femoral angle (LDFA)
Time frame: From enrollment (preoperative measurement) and at 1-year postoperative follow-up.
Joint line obliquity (JLO)
Time frame: From enrollment (preoperative measurement) and at 1-year postoperative follow-up.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Feb 2025.
- Background: PubMed 35093548Elbuluk AM, Jerabek SA, Suhardi VJ, Sculco PK, Ast MP, Vigdorchik JM. Head-to-Head Comparison of Kinematic Alignment Versus Mechanical Alignment for Total Knee Arthroplasty. J Arthroplasty. 2022 Aug;37(8S):S849-S851. doi: 10.1016/j.arth.2022.01.052. Epub 2022 Jan 31.
- Background: PubMed 31591010McEwen PJ, Dlaska CE, Jovanovic IA, Doma K, Brandon BJ. Computer-Assisted Kinematic and Mechanical Axis Total Knee Arthroplasty: A Prospective Randomized Controlled Trial of Bilateral Simultaneous Surgery. J Arthroplasty. 2020 Feb;35(2):443-450. doi: 10.1016/j.arth.2019.08.064. Epub 2019 Sep 5.
- Background: PubMed 36403396Van Essen J, Stevens J, Dowsey MM, Choong PF, Babazadeh S. Kinematic alignment results in clinically similar outcomes to mechanical alignment: Systematic review and meta-analysis. Knee. 2023 Jan;40:24-41. doi: 10.1016/j.knee.2022.11.001. Epub 2022 Nov 17.
- Background: PubMed 33347126Blakeney WG, Vendittoli PA. Restricted Kinematic Alignment: The Ideal Compromise? 2020 Jul 1. In: Riviere C, Vendittoli PA, editors. Personalized Hip and Knee Joint Replacement [Internet]. Cham (CH): Springer; 2020. Chapter 17. Available from http://www.ncbi.nlm.nih.gov/books/NBK565760/
- Background: PubMed 30122435Howell SM, Shelton TJ, Hull ML. Implant Survival and Function Ten Years After Kinematically Aligned Total Knee Arthroplasty. J Arthroplasty. 2018 Dec;33(12):3678-3684. doi: 10.1016/j.arth.2018.07.020. Epub 2018 Jul 31.
- Background: PubMed 23552665Vanlommel L, Vanlommel J, Claes S, Bellemans J. Slight undercorrection following total knee arthroplasty results in superior clinical outcomes in varus knees. Knee Surg Sports Traumatol Arthrosc. 2013 Oct;21(10):2325-30. doi: 10.1007/s00167-013-2481-4. Epub 2013 Apr 4.
- Background: PubMed 32737528Winnock de Grave P, Luyckx T, Claeys K, Tampere T, Kellens J, Muller J, Gunst P. Higher satisfaction after total knee arthroplasty using restricted inverse kinematic alignment compared to adjusted mechanical alignment. Knee Surg Sports Traumatol Arthrosc. 2022 Feb;30(2):488-499. doi: 10.1007/s00167-020-06165-4. Epub 2020 Jul 31.
- Background: PubMed 37882976Yang Y, Wang Y, Chen Y, Wang J, Lu B, Zhu W, Zhu J, Zhu C, Zhang X. Tracing the evolution of robotic-assisted total knee arthroplasty: a bibliometric analysis of the top 100 highly cited articles. J Robot Surg. 2023 Dec;17(6):2973-2985. doi: 10.1007/s11701-023-01742-4. Epub 2023 Oct 26.
- Background: PubMed 34355018Vendittoli PA, Martinov S, Blakeney WG. Restricted Kinematic Alignment, the Fundamentals, and Clinical Applications. Front Surg. 2021 Jul 20;8:697020. doi: 10.3389/fsurg.2021.697020. eCollection 2021.
- Background: PubMed 31190246Hirschmann MT, Becker R, Tandogan R, Vendittoli PA, Howell S. Alignment in TKA: what has been clear is not anymore! Knee Surg Sports Traumatol Arthrosc. 2019 Jul;27(7):2037-2039. doi: 10.1007/s00167-019-05558-4. Epub 2019 Jun 12. No abstract available.
- Background: PubMed 24986944Dossett HG, Estrada NA, Swartz GJ, LeFevre GW, Kwasman BG. A randomised controlled trial of kinematically and mechanically aligned total knee replacements: two-year clinical results. Bone Joint J. 2014 Jul;96-B(7):907-13. doi: 10.1302/0301-620X.96B7.32812.
- Background: PubMed 26491132Roth JD, Howell SM, Hull ML. Native Knee Laxities at 0 degrees , 45 degrees , and 90 degrees of Flexion and Their Relationship to the Goal of the Gap-Balancing Alignment Method of Total Knee Arthroplasty. J Bone Joint Surg Am. 2015 Oct 21;97(20):1678-84. doi: 10.2106/JBJS.N.01256.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Restricted inverse kinematic alignment Total Knee Arthroplasty and Adjusted Mechanical alignment Total Knee Arthroplasty in people with OA Knee and TKA, run by Thammasat University at 2 sites in Thailand.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 19 Feb 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Thailand. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Chananyu Susrivaraput, M.D. (+66989169544, chananyu.atom@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
2-minute walk test (time frame: From enrollment (preoperative measurement) to the end of postoperative follow-up (2 years)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06835621, which also lists 15 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Feb 2025; AzTrials last refreshed its copy on 26 Oct 2026.