Background: Total knee arthroplasty is a golden standard procedure for end-stage knee osteoarthritis. However, up to 20% of the patients are not satisfied with the outcome. Recently, robotic-assisted TKAs have been developed to offer individual alignment and to achieve accuracy in positioning with more subtle soft-tissue handling, thus possibly leading into better outcome. Hypothesis: The investigators hypnotize that, robotic-assisted TKA is superior to manual TKA for end-stage osteoarthritis in respect to functional outcome, short-term rehabilitation and cost-efficiency. Trial desing: The investigators will conduct a single-center, randomized, controlled, double blinded superiority trial of 24-months to compare robotic-assisted and manual total knee arthroplasty in respect to functional outcome, implant positioning, short-term rehabilitation and cost-efficiency with up to 10 years follow-up for complications. The principle outcome measure will be patient reported outcome measure (PROM) Oxford knee score (OKS) points (0-48 points) at two years after surgery. Minimal clinically important difference will be considered as 5 points. Other PROMS, patient satisfaction, short-term rehabilitation, implant positioning, knee range of motion, length of sick leave and cost efficiency will also be reported. Patients will be followed up to 10 years for complications (infection, manipulation and revisions). This study will be conducted in Central Hospital of Satakunta (Satasairaala), Finland. The investigators will recruit 170 adult patients (aged 50-80), with end-stage (Kellgren-Lawrence grade IV) primary osteoarhritis. Patients will be randomly assingned to either robotic-assisted or manual TKA. Patients will be blinded by the intervention method used. Personnel and investigators assessing the patients and interpreting the data will also be blinded to the surgical method.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
170
In robotic-assisted total knee arthroplasty, the procedure is performed with the guidance of the robot according to CT-based plan.
In manual total knee arthroplasty, the procedure is performed with jig guides according to whole leg weight bearing x-ray planning.
Oxford Knee score OKS at 24 months
Patient reported outcome measure, knee function questionnaire Oxford Knee Score (OKS) at 24 month. Scale from 0 (=worst) to 48 (=excellent) points Minimal clinically important difference considered as 5 points.
Time frame: 24 month
Oxford Knee Score at 3 and 12 months
Patient reported outcome measure, knee function questionnaire Oxford Knee Score (OKS) at 3 and 12 months. Scale from 0 (=worst) to 48 (=excellent) points. Minimal clinically important difference considered as 5 points.
Time frame: 3 and 12 months visits
Knee injury and Osteoarthritis Outcome Score (KOOS) at 3, 12 and 24 months
Patient reported outcome measure, knee function questionnaire KOOS points at 3, 12 and 24 months after the operation. Scale from 0 (=worst) to 100 (=excellent).
Time frame: 3, 12 and 24 months
The Western Ontario and McMaster Universities Arthritis Index (WOMAC) at 3, 12 and 24 months.
Patient reported outcome measure, knee function questionnaire WOMAC score at 3, 12 and 24 months after the operation. Scale from 0 (= excellent) to 96 (= worst) points.
Time frame: 3, 12 and 24 months
Patient satisfaction inquiry at 3, 12 and 24 months
Patient satisfaction question asked at 3, 12 and 24 months after the operation: If you could choose again, would you still go for the sugery? 0= no 1 = probably not 2= I don't know 4 = probably yes 5 = yes.
Time frame: 3, 12 and 24 months
Working ability, lenght of the sick leave
Length of the sick leave after the surgery, measured as days. Asked from the patient and checked from the patient files.
Time frame: up to 24 months
Working ability, part-time vs full-time
Asked from the patient at the 3, 12 and 24 months follow-ups visits. Has the operation changed your ability to work full-time or part-time? Options: a) yes my work changed from full-time to part-time after surgery b) no my work is as much full-time or part-time as it was before the surgey c) yes my work changed from full-time to part-time after surgery d) my work as part-time or full-time has changed from other reasons not related to the knee.
Time frame: Asked at 3 month, 12 months and 24 months after the surgery
Working ability, physical demands of the job
Asked from the patient at the 3, 12 and 24 months follow-ups visits. Has the physical demands of your job changed after the operation because of the knee? Options: a) yes the physical demands of my job is now lower than it was before the surgery b) no my work is as physically demanding as it was before the surgery c) yes the physical demands of my job is now higher than it was before the surgery d) the physical demands of my job has changed from other reasons not related to the knee.
Time frame: Asked at 3 month, 12 months and 24 months after the surgery
Life quality questionnaire 15 dimensions (15D) at 3, 12 and 24 months
Life quality questionnaire 15 dimensions at 3 follow up visits. Scale from 15 (=exellent) to 75 (=worst) points.
Time frame: 3, 12 and 24 months
Pain at rest and during walking on visual analoque scale (VAS)
pain at rest and during walking on visual analoque scale (VAS) from 0 (=no pain) to 10 (=extreme pain)
Time frame: First day after the operation and at 3, 12 and 24 months
Opioid usage
Opioid usage mg/day
Time frame: Up to two weeks
Blood loss
Blood loss evaluated by the by measuring pre- and post-operative (first day after surgery) hemoglobin g/L. Difference between the pre-operative and post-operative Hemoglobin (g/L) values.
Time frame: First day after the operation
Lenght of the hospital stay
Length of hospital stay measured in days.
Time frame: Up to 1 week
Operation time
Time of the operation in hours and minutes checked form patient files.
Time frame: Day of the surgery
Post-operative CRP
post-op CRP as a indirect soft-tissue damage measure
Time frame: First day after the operation
Knee swelling
Knee swelling, knee diameter measured above the patella and compared to the unaffected size, the diameter difference in centimeters between the legs. Indirect soft-tissue damage measures
Time frame: First day after the operation
Range of knee motion (ROM)
Range of knee motion measured with goniometry as degrees at the ward on first post-operative day and ant the 3, 12 and 24 months visits.
Time frame: First day after the operation and at 3, 12 and 24 months visits
Radiological outcome measures, alingment
Knee alignment measured from post-operative weight bearing whole leg x-rays as degrees. Measured as the degrees between femoral mechanical axis line and tibial mechanical axis line.
Time frame: Weight bearing whole leg x-rays taken 3 months post-operatively.
Radiological outcome measures, posterior condylar offset
Post-op knee x-ray taken at the first post-operative day; posterior condylar offset, measured as maximal thickness of the posterior condyle projecting posteriorly to a straight line drawn as the extension of the posterior femoral shaft cortex, measured in millimeters
Time frame: post-operative knee x-rays taken within 1 week after the operation
Radiological outcome measures, Insall-salvati ratio
Measured from post-operative knee x-rays. Insall-salvati ratio: the length of the patellar tendon in millimeters divided by the length of the patella in millimeters.
Time frame: post-operative knee x-rays taken within 1 week after the operation
Radiological outcome measures, Overhanging
Measured from post-operative knee x-rays. Overhanging of the tibial or femoral component from medial lateral, posterior or anterior side measured as millimeters. The length between the bony edge to the edge of the component.
Time frame: post-operative knee x-rays taken within 1 week after the operation
Radiological outcome measures, Notching
Measured from post-operative knee x-rays. Notching of the anterior femoral cortex. The lenght in millimeters between the anterior femoral cortex and the anterior edge femoral component in sagittal x-ray.
Time frame: post-operative knee x-rays taken within 1 week after the operation
Complications, revisons
Revisions meaning re-operation of the knee due any reason. Checked from the patient files at 3, 12 and 24 months and five and ten years after surgery. Measured as number of revisions
Time frame: 3, 12 and 24 months and five and ten years
Complications, infections
Infections that recuire antibiotics or revision surgery. Checked from the patient files at 3, 12 and 24 months and five and ten years after surgery. Measured as number of infections
Time frame: 3, 12 and 24 months and five and ten years after surgery
Complications, knee manipulation under anestesia due stiff knee
Need for knee manipulations under anesthesia due stiff knee. Measured as number of manipulations. Checked form the patient files at 3, 12 and 24 months and five and ten years after surgery
Time frame: 3, 12 and 24 months and five and ten years after surgery.
Complications, re-admission
Unplanned post-operative re-admissions due to the knee operation. Measured as days at the ward.
Time frame: up to 24 months
Complications, unplannet emergency unit visits
Unplanned post-operative visits to the hospital emergency unit due to the knee operation, number of visits
Time frame: up to 24 months
Costs
Total cost of the treatment, measured as amount of money.
Time frame: up to 24 months
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