2. Materials and Methods
thrombosis, Knee Injury, Osteoarthritis, dislocations, arthritis, KOA, knee arthroplasty, pain, Osteoarthrtis, primary KOA, infection, fractures, TKA, flexion deformity
THROMBOSIS, INFLAMMATORY ARTHRITIS, OSTEOARTHRITIS, BEND, POSTOPERATIVE COMPLICATIONS, OSTEOARTHRITIS, DEEP VEIN THROMBOSIS, POLAND, RECRUITMENT, ARTHRITIS, MAY, INFECTION
This randomized, triple-blinded (Care Provider, Investigator, Outcomes Assessor) clinical trial included 215 patients who were randomly assigned to one of a three groups to undergo TKA. All of the procedures were performed by a single senior surgeon (KM). The groups were divided according the operation technique. These were: NAVIO or CORI robotic-assisted systems or conventional technique TKA performed on patients fulfilling the inclusion criteria. The recruitment took place between 1 December 2021 and 31 July 2022 at Hospital in Ostrow Mazowiecka, Poland. The randomization process was done by the parallel allocation between the three groups using a computer program. While the learning curve with the NAVIO/CORI was not essential in this study, the surgeon (KM) performed 15 robotic-assisted TKAs using the NAVIO system prior to the start of this study. KM is an experienced surgeon with approximately 1500 mTKA surgeries performed. He underwent traineeship with the professional trainers for NAVIO in May 2020 first and afterwards for CORI in November 2021. Taking into account the aforementioned implications, CORI did not require such a learning curve, because it was launched as an updated version of NAVIO by the same company. This study was approved by the Institutional Committee on Human Rights Related to Research Involving Human of the Medical University of Warsaw under the study protocol: KB/109/2020. All patients had been referred to the hospital for TKA to treat primary KOA and were recruited by a research associate and surgeons (JS, JŚ, KM). All patients were informed of the benefits and risks of robot-assisted TKA and were aware of the potential increased operating time. Eligible patients were those deemed suitable for TKA by a senior surgical author (KM) and were aware and agreed to sign the informed consent. The 215 patients were allocated for either robotic-assisted or conventional method procedures on alternate days of their surgery, with 76 assigned to the NAVIO robotic-assisted TKA cohort, 71 to the CORI robotic-assisted TKA cohort and 68 assigned to the conventional manual TKA cohort. Five TKA procedures were performed regularly in 1day. There were no significant demographic and comorbidities differences between the groups (Participants-inclusion and exclusion criteriaThe inclusion criteria for treatment with TKA were: (1). Listed for a primary total knee arthroplasty; (2). suffering from KOA involving one or more compartments; (3). aged 18 or over; and (4). patient willing to provide full informed consent to the trial in polish language. Exclusion Criteria: (1). Primary stage of one-sided KOA; (2). severe symptoms in the contralateral knee so as to require staged bilateral knee replacements within 6 months of the primary procedure; (3). fixed flexion deformity of 15 degrees or greater who will require excessive resection of the distal femur; (4). clinically assessed as varus/valgus deformity of 15 degrees or greater; (5). any co-morbidity which, in the opinion of the investigator, is severe enough to present an unacceptable risk to the patient’s safety; (6). inflammatory arthritis; and (7). unable to understand written and spoken Polish.Study procedures and data collectionUpon recruiting completion, the medical charts of patients were prospectively completed, consisting of epidemiologic characteristics and details of the surgical procedure and postoperative condition. All patients underwent TKA procedures with standard perioperative antibiotics prophylaxis with use of 3 doses of 750 mg cefuroxime– preoperatively, 6 and 12 h postoperatively, and standard thrombosis prophylaxis of one dose of 40 mg low-molecular-weight heparin. The day following the surgery, all the patients had to have a control X-ray. During control visits (6 weeks follow up), patients underwent 3D computed tomography scan imaging (CT) to detect the radiographic accuracy of implanted components positioning. Surgical techniqueAll surgical procedures were performed by a single experienced surgeon (KM) for ra-TKA and mTKA, respectively. They took place in one hospital with all the patients under epidural anesthesia. A tourniquet was applied and inflated before software registration in the case of ra-TKA and before the skin incision in the case of mTKA. The tourniquet was deflated after wound closure. A standard medial parapatellar quadriceps-sparing incision and approach were used with patellar eversion and patelloplasty. The TKA procedure was standardized and performed using the instrumentation in accordance with the operative technique. For the ra-TKA groups, additional stabilization pins, trackers and camera setup were installed to allow for navigation markers and bone movement monitors detection of the workspace within the joint. The patient was rigidly connected to NAVIO/CORI software via two transverse stabilization pins in the distal femur and proximal tibia. A detailed registration process was completed by the identification of 4 landmarks on the femur and the tibia (Actual surgical technique for the mTKA group consisted of measured resection using an anterior referencing system. Femur cut orientation was prepared using a combination of methods. For a varus knee, the surgeon started with 3 degrees of external rotation based on the posterior condyles. Afterwards, this was checked manually to ensure that this is parallel to the transepicondylar axis. A final confirmation was undertaken by ensuring the Whiteside’s line is perpendicular to the transepicondylar axis. The operation technique was according to the company manual for the implant type. For both ra-TKA cohorts, NAVIO and CORI, the surgical technique consisted of measured resection, respecting gap balancing. Therefore, the method is more of a hybrid technique. The software allows for intraoperative assessment of compartment gaps with fine adjustments using the robotic navigation, all upon surgeon control and incorporating modifications. The robotic system allows for the assessment of the joint intraoperatively through mapping of the articular surface, measurement of the mechanical axis, and measurement of soft tissue tension throughout the full range of motion of the knee. Tibia cut was performed in the coronal plane in the perpendicular axis to the long axis of the tibia. Soft tissue tension, specifically laxity, is measured by applying varus and valgus stress to the knee as it is ranged and allows for the assessment of gap balancing in real time. A surgical plan for component selection and placement, as well as the required bony resection, is created and can be adjusted by the surgeon. Feedback on gap balancing is provided based on the surgical plan and the real-time modifications. In addition to being performed during planning, measurement of soft tissue tension can be repeated during the trialing phase and after soft tissue releases. All patients received a cemented, fixed-bearing prosthesis with metal-bearing polyethylene (Journey II; Smith&Nephew) in the imageless NAVIO and CORI systems and mTKA.Postoperative carePatients were discharged after adequate pain control, knee flexion to a minimum of 90 degrees, independent mobilization with the use of crutches, and independent ascent and descent of stairs. All study patients were discharged to home. No patient was discharged to a rehabilitation center or other skilled nursing facility. All patients in both groups were prescribed the same standardized postoperative rehabilitation program, with full weight-bearing and active ROM exercises commenced from the day following the surgery. The exercises consisted of bilateral stance (static stance, mediolateral weight shift, multidirectional weight shift), unilateral stance (yoga position with the knee bend on tree position with and without a foam), sit to stand, lunging (static- yoga warrior pose and dynamic- strengthening lunge) and climbing the stairs.Clinical assessmentPatients were examined during admission for a TKA procedure and followed up postoperatively at 6 weeks and 12 months. Full hospital and clinic medical charts review of demographic preoperative and postoperative knee score measurements were recorded. The primary outcomes of interest were the Knee Injury and Osteoarthritis Outcome Score (KOOS), which assesses patient pain (9 items), other symptoms (7 items), function in daily living (17 items), function in sport and recreation (5 items), and knee related quality of life (4 items). Scores range from 0 to 100 with a score of 0 indicating the worst possible knee symptoms and 100 indicating no knee symptoms. The (KOOS) is an extension of the Western Ontario and McMaster Universities Osteoarthrtis Index (WOMAC), the most commonly used outcome instrument for the assessment of patient-relevant treatment effects in osteoarthritis. The VAS as a pain-measuring scale was utilized in order to obtain the numerical representation of the intensity of the pain bothering the patient throughout the day globally. Additionally, ROM and any postoperative complications were monitored, such as deep vein thrombosis, infection, loosening of implants, fractures, lateral compartment arthritis, and dislocations of the polyethylene component. Radiographic assessmentAll patients underwent a CT scan at 6 weeks follow up appointments with use of a multislice scanner (General Electric Light Speed Plus; GE Medical System, Milwaukee, WI, USA) to determine the rotational alignment of the components. The CT scan sequence was between 10 cm proximal to the superior pole of the patella and 10 cm distal to the tibial tuberosity and was made in contiguous 2.5-mm slices. Specifically, we measured the anatomic rotational axis on postoperative CT scans in knees of patients undergoing conventional primary TKA (mTKA). We then measured the femoral component rotational alignment optimized by a robotic system (raTKA), which took into account constitutional anatomy of the patient and best functional performance to the posterior condylar axis (PCA) and measured the difference between the femoral component rotation and the actual transepicondylar axis (TEA) (Femoral rotation in the following study was defined based on the postoperative CT scans as the angle subtended by a line between the most prominent parts on lateral and medial sites (A TEA) and the line between most posterior parts of the condylar components on the medial and lateral sides of the femur, the so called PCA (Statistical analysisThe sample size was calculated to detect a mean difference in KOOS (0–100) between NAVIO and CORI (ra-TKA) and manual method TKA (mTKA). A power analysis was conducted with type-I error set at 0.05 (α b 0.05) and the type-II error at 0.15 (85% power). The estimated sample size was 65 for each group in order to detect the minimal clinically significant mean difference of KOOS of 6.1 units. Loss to follow-up was estimated to be 20%, which yields a required sample size per group. Data were described using means and standard deviations or median (range) as appropriate for continuous data. The values were checked for normality using Shapiro-Wilk test. Because the distributions were not normal, non-parametric tests were used in statistical evaluation (