Background:The aim of the present study was to compare the accuracy of prosthetic alignment with three-dimensional computed tomography (3DCT) measurements following total knee arthroplasty (TKA) performed using a robotic-assisted surgical technique versus a conventional TKA. Methods: 41 TKAs were performed with a handheld robotic-assisted surgical procedure (Robot group) between 2019 and 2020. Another 41 patients underwent TKA with a conventional manual surgical procedure (Manual group) using the same prosthesis. The operation durations between both groups were investigated. 3DCT scans of the entire lower extremities were taken before and after the surgery and femoral and tibial alignments in the coronal, sagittal, and axial planes were measured using computer software. The differences in prosthetic alignment and translation between the preoperative 3DCT plan and postoperative 3DCT image were also measured. Results: There were no statistically significant differences in the post-operative outliers of the femorotibial angle between the groups. In the tibial-axial plane, the mean of prosthetic alignment in the anteroposterior plane was 4.0°in the Robot group and 6.7°in the Manual group (p < 0.01). The rate of outliers for tibial-axial alignment in the Robot group was significantly less than in the Manual group (p < 0.01). There were no statistically significant differences in prosthetic translation in the proximal-distal, anterior-posterior and medial-lateral orientations between the groups. Conclusions: In a radiologic study using 3DCT, robotic-assisted TKA reduced the outliers for rotational alignment of the tibial prosthesis in comparison to conventional TKA, which can lead to improved tracking of the femoral-tibial bearing surfaces.

Background Total knee arthroplasty (TKA) is a common and cost-effective surgical treatment for osteoarthritis of the knee. However, only 82-89% of patients who performed TKA are satisfied with the postoperative outcomes. Therefore, bi-cruciate retaining (BCR) TKA is re-attracting attention. By retaining the anterior cruciate ligament (ACL), the knee may obtain the kinematic pathway that are closer to the native knee. The aim of the present study is to compare the ability to walk before and after surgery in patients who underwent bi-cruciate retaining total knee arthroplasty (BCR TKA) versus bi-cruciate stabilized (BCS) TKA during the early postoperative period. Methods Subjects included patients who underwent BCR TKA (10 knees) and BCS TKA (15 knees). We administered 10-meter gait tests before surgery and at 6 weeks and 3 months after surgery. We collected the following triaxial accelerometery data with a portable gait analyzer: walking time, number of steps, velocity, stride length, and coefficient of variability (CV) of double-leg support time while walking. Results Patients who underwent BCR TKA improved their gait ability [walking time ( p < 0.01), number of steps ( p < 0.05), velocity ( p < 0.01), and stride length ( p < 0.01) more than those who received BCS TKA at 6 weeks after surgery. BCR TKA improved gait ability (walking time, number of steps, velocity, and stride length) more than BCS TKA at 6 weeks after surgery. At 6 weeks after surgery, CV of double-leg support time while walking improved more in the BCR TKA group than in the BCS TKA group ( p < 0.05). Conclusions BCR TKA is associated with improved gait ability in the early postoperative period.

Introduction. Open reduction and internal fixation (ORIF) of compound fractures around the knee in elderly patient raise concerns about long-term postoperative external fixation and complications. Total knee arthroplasty (TKA) has been proposed as an alternative solution. We report a case where robotic-assisted (RA) TKA was used to treat lateral knee osteoarthritis (OA) with distal femur fracture. Case Presentation. A 90-year-old female visited our hospital with complications of sustained knee pain after a fall at home. Fracture line from the trochlea to the intercondylar notch was diagnosed on plain radiographs, and prior to this injury, the patient was receiving conservative treatment for lateral OA. We selected a conventional TKA over ORIF because the latter is associated with residual pain and the need for long-term immobilization, which can lead to other complications. However, the fracture site was the entry point for intramedullary rod, and there was concern that the fracture site would be displaced by conventional TKA. Therefore, the unique aspect of the case is that the technique utilized involved robotic milling using the Navio system while temporarily stabilizing the fracture using two tracker pins. RA TKA could determine osteotomy and implant placement by predicting the postoperative patient’s soft tissue balance for no medial loosening and lateral contracture. The arthritic cartilage and bone were then methodically removed using the handheld sculptor. After immobilizing the fracture site with a bone grasper before removing the pin tracker, reaming of the femur and insertion of a stem prosthesis with semiconstrained were performed. Primary RA TKA is a viable option for intra-articular fractures in elderly patients with advanced knee osteoarthritis.

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Autologous chondrocyte implantation (ACI) is an important operative option when repairing cartilage defects of the knee. This report introduces a new product development with one-stage ACI using a Reveille Cartilage Processor (Reveille CP) as well as the assessment of MRI and clinical results at a 1-year follow-up. The report compared cases between a 42-year-old female who underwent ACI surgery using Reveille CP and a 51-year old female who received treatment with two-stage ACI of tissue-engineered cartilage-like tissue (J-TEC Autologous Chondrocyte Cultured Cartilage [JACC]). One year after JACC, magnetic resonance imaging (MRI) showed signal intensity area in the grafted area, while patients with Reveille CP showed greater thickness than the surrounding healthy cartilage. The Lysholm, pain and QOL scores of Knee Injury and Osteoarthritis Outcome (KOOS) at one 1 year after surgery with Reveille CP were higher than JACC.