Active Robotic Total Knee Arthroplasty (TKA): Initial Experience with the TSolution One ® TKA System.

Several recent advances, including the use of robotic devices, have been explored to improve outcomes in total knee arthroplasty (TKA). The TSolution One ® Total Knee Application (THINK Surgical, Inc., Fremont, CA, USA) introduces an active robotic device that supports an open implant platform and CT-based preoperative planning workflow, and requires minimal surgeon intervention for making bone cuts. Our experience was part of a multi-center, prospective, non-randomized trial assessing the safety and effectiveness of this active robotic system for TKA. Each patient underwent a preoperative CT-scan, which was uploaded to proprietary planning software. The surgeon reviewed the software-generated 3D digital model, selected the appropriate implants and generated a final preoperative plan. Intra-operatively, a standard medial parapatellar approach was used. The leg was then rigidly attached to the robot via fixation pins, and registration markers were placed in the tibia and femur. Landmark registration was performed to inform the robot of the knee's position in space and to confirm the robot's ability to execute the preoperative plan. Next, the robot performed femoral and tibial cuts using a cutter in a sequential fashion along a defined cut-path. The robot was then removed from the operative field and the surgeon completed the procedure by removing marginal bone and performing final balancing and implantation in the usual fashion. The TSolution One® Total Knee Application is a computer-assisted device that potentially allows a surgeon to make more accurate cuts and to determine optimal implant position based on the patient's specific anatomy. It is the only active robotic system currently available. In this manuscript, we describe the operative technique and workflow involved in performing this surgery and offer insight on optimizing safety and efficiency as we introduce new technologies to the operating theater. We also present two cases performed by the senior author to further demonstrate technical aspects of the procedure.

Safe and effective use of active robotics for TKA: Early results of a multicenter study.

BACKGROUND: A novel active robotic system for total knee arthroplasty (TKA) performs automated milling of bone surfaces. Study objectives were to assess system safety and effectiveness in a US population. METHODS: A multicenter clinical trial was conducted, following 115 patients for at least 6-months. A pre-defined list of robot-related adverse events was used to evaluate safety. Efficacy was assessed radiographically comparing planned versus achieved coronal limb alignment. RESULTS: No pre-defined adverse events occurred and postoperative limb alignment more than ±3° from plan occurred in 11.2 % of cases. CONCLUSION: Active robotics for TKA is safe and effective as demonstrated in this trial.

Evaluation of the Accuracy and Precision of a Next Generation Computer-Assisted Surgical System.

BACKGROUND: Computer-assisted orthopaedic surgery (CAOS) improves accuracy and reduces outliers in total knee arthroplasty (TKA). However, during the evaluation of CAOS systems, the error generated by the guidance system (hardware and software) has been generally overlooked. Limited information is available on the accuracy and precision of specific CAOS systems with regard to intraoperative final resection measurements. The purpose of this study was to assess the accuracy and precision of a next generation CAOS system and investigate the impact of extra-articular deformity on the system-level errors generated during intraoperative resection measurement. METHODS: TKA surgeries were performed on twenty-eight artificial knee inserts with various types of extra-articular deformity (12 neutral, 12 varus, and 4 valgus). Surgical resection parameters (resection depths and alignment angles) were compared between postoperative three-dimensional (3D) scan-based measurements and intraoperative CAOS measurements. Using the 3D scan-based measurements as control, the accuracy (mean error) and precision (associated standard deviation) of the CAOS system were assessed. The impact of extra-articular deformity on the CAOS system measurement errors was also investigated. RESULTS: The pooled mean unsigned errors generated by the CAOS system were equal or less than 0.61 mm and 0.64° for resection depths and alignment angles, respectively. No clinically meaningful biases were found in the measurements of resection depths (< 0.5 mm) and alignment angles (< 0.5°). Extra-articular deformity did not show significant effect on the measurement errors generated by the CAOS system investigated. CONCLUSIONS: This study presented a set of methodology and workflow to assess the system-level accuracy and precision of CAOS systems. The data demonstrated that the CAOS system investigated can offer accurate and precise intraoperative measurements of TKA resection parameters, regardless of the presence of extra-articular deformity in the knee.

Corrigendum to "Evaluation of the Accuracy and Precision of a Next Generation Computer-Assisted Surgical System".

[This corrects the article on p. 225 in vol. 7, PMID: 26217470.].