Patient-Specific Femoral Guide with 3-Dimensional Support Software in Anterolateral Supine Approach of Total Hip Arthroplasty: A Single-Arm Trial.

Currently, there is no surgical assistance system that can perform a three-dimensional (3D) planned total hip arthroplasty (THA) by methods other than surgical assistance navigation or robots. However, they are expensive, cumbersome, and subject to additional invasiveness, so there is a need for a simpler and less expensive 3D surgical support system. In this study, THA was performed using the anterolateral approach (Watson-Jones) in the supine position in 23 subjects to examine the efficacy and safety of a patient-specific femoral guide linked to 3D surgery support software. In 48% of the subjects, the difference in anterior torsion angle from the preoperative plan was within ±5 degrees, while in 83% of the subjects, the difference was within ±10 degrees. The 95% confidence interval (4.61-8.70) of the absolute difference did not fall below the pre-defined threshold of 7.2 degrees (p = 0.293). No adverse events were observed other than 2 cases (8.7%) of hemorrhage that required a blood transfusion. We confirmed the efficacy and safety of the patient-specific femoral guide in anterolateral supine approach THA.

The Efficacy and Safety of a Novel Extramedullary Guide Coordinated with 3D Surgical Assistive Software for Total Knee Arthroplasty: an Open-Label Single-Arm Trial.

To improve component-placement accuracy in total knee arthroplasty, we developed two devices: an original extramedullary patient-specific guide for the femur and an original extramedullary universal guide for the tibia (EM-TIBIA). We also developed a new function in ZedView, a three-dimensional surgical assistive software, that provides the parameters necessary to install the EM-TIBIA. Compared with conventional manual methods based on X-ray two-dimensional images or ZedView, these newly developed devices function as an extramedullary intraoperative support guide in conjunction with ZedView, simplifying surgical procedures. We conducted a study to evaluate the efficacy and safety of the surgery using the new guides and software function. Nineteen patients underwent surgery. On the femoral side, the mean absolute difference of the installation alignment was within 3° for all parameters. On the other hand, on the tibial side, the mean absolute difference from the preoperative plan for the rotation was 5.26±5.30°. The proportion of patients whose difference fell within ±3° was 52.6% (95% confi dence interval: 28.9 to 75.6%), and did not meet the pre-specified criteria for efficacy (P=0.261). No serious adverse events were reported, and no excessive bleeding, thrombosis, infections, or intraoperative or postoperative fractures were noted. The two new guides can easily reproduce the preoperative plan as 3D intraoperative support jigs, but errors can occur on the tibia side due to soft tissue that is not recognized by CT, creating problems in installation accuracy.

An Open-Label, Single-Arm Study of a Patient-Specific Femoral Guide for Total Hip Arthroplasty via the Anterolateral Supine Approach, Linked with Three-Dimensional Surgical Support Software: Study Protocol.

In total hip arthroplasty (THA), it is generally accepted that the bones of the acetabular cup and femur of hip joint must be accurately cut and components (artificial joint parts) be implanted in exact positions at exact angles to achieve improvement of daily living (ADL) and quality of life (QOL). However, with the conventional surgical method, it is difficult to grasp and measure the acetabular cup and femoral stem precisely during surgery, making some kind of reliable guide necessary. Although it was reported that an accurate angle was achieved in acetabular cup implantation by support instruments for surgical planning, an effective support instrument is now being developed for stem implantation on the out-of-reach femur side. This is the first clinical study to assess the efficacy and safety of anterolateral approach THA using an extracorporeal patient-specific femoral guide (PSG) for stem implantation with three-dimensional (3D) surgical support software in patients with hip joint disease.

An Open-label Single-arm Trial of a Novel Extramedullary Guide Coordinated with 3D Surgical Assistive Software for Total Knee Arthroplasty.

There is no assistive device for extramedullary surgery coordinated with 3D surgical assistive software for the total knee arthroplasty (TKA). We developed a novel extramedullary universal guide coordinated with 3D surgical assistive software and a novel extramedullary patient-specific assistive guide for the placement of femoral components by referring to an area not affected by cartilage or bone spurs, and filed a patent application. In this study, we visualize and reconstruct the total alignment of the lower extremity in TKA using these surgical devices, and validate their precision. A report releasing study results will be submitted in an appropriate journal.