Clinical Study on the Effects of Total Hip Arthroplasty Assisted by Virtual Planning Combined With Intraoperative Navigation Templates

Abstract

Objectives: Although total hip arthroplasty (THA) effectively alleviates pain and restores joint function in the end-stage hip disease, challenges remain in achieving precise osteotomy and minimizing subjective dependency on prosthesis positioning. This study aims to evaluate the efficacy and safety of preoperative virtual planning and navigation templates compared to conventional techniques, providing new methods to enhance the precision and personalization of THA.

Methods: During the period from 2022 to 2023, we conducted a retrospective case-control study on 74 patients who underwent THA surgery at our hospital, based on the inclusion and exclusion criteria. The study included 42 patients in the traditional method group, who underwent preoperative planning and surgical procedures according to traditional methods; and 32 patients in the digital assistance group, who used computer-assisted virtual preoperative planning and three-dimensional printed personalized navigation templates to assist in the surgery. The main parameters of the two groups were compared, including surgical time, blood loss, postoperative femoral anteversion, neck-shaft angle, anatomical-mechanical femoral axis angle (aMFA), leg length discrepancy (LLD), and the angle of hip prosthesis placement. The Harris hip score was recorded both preoperatively and at the final follow-up to assess the accuracy of the prosthesis placement and the prognosis of the patients.

Results: There were no significant differences in femoral anteversion, neck-shaft angle, aMFA, or LLD between the two groups. However, the digital group showed smaller deviations between the planned and actual acetabular prosthesis angles compared to the conventional group, with shorter operative times and reduced blood loss. Follow-up Harris hip scores were significantly higher in the digital group (p < 0.05).

Conclusions: Digital technology enhances the accuracy and reproducibility of prosthesis placement in THA, reduces operative time and blood loss, and shows a promising potential for broader application.

Keywords: 3D printing; digital technology; orthopedic; total hip arthroplasty.

FIGURE 1

Three‐dimensional pelvic model observation and anatomical parameter measurement. (A) Three‐dimensional model of the pelvis and femur. (B) Rotational observation of acetabular deformities. (C) Observation of the femur and three‐dimensional measurement of the femoral anteversion angle, which is the angle formed between the femoral neck–head axis and the posterior condylar line of the femur. (D) Measurement of the femoral neck‐shaft angle, which is the angle between the femoral neck–head axis and the femoral shaft axis. (E) Measurement of the aMFA.

FIGURE 2

Simulation of acetabular prosthesis matching and placement. A cross‐shaped acetabular reaming guide was constructed from the center of the acetabulum to ensure stability during use. Layers were added to refine the 3D model, and Kirschner wire holes were positioned to maintain 20° anteversion and 40° abduction. Based on these, an acetabular grinding navigator was designed to match the acetabular rasp, guiding grinding before prosthesis placement. A femoral head resection guide was developed for complete resection at 20° anteversion, with additional Kirschner wire holes for fixation. Extending into the femoral bone marrow cavity, guides for bone marrow cavity dilation and prosthesis placement were incorporated to ensure steps during THA—femoral head resection, femoral bone marrow cavity dilation, and prosthesis placement—aligned at 20° anteversion. The final navigation templates were 3D‐printed using photosensitive resin and sterilized with ethylene oxide for intraoperative use (Figure 3).

FIGURE 3

Design of surgical guides and predicted surgical outcomes. (A1) Software identifies the acetabular center and establishes a cross‐shaped framework. (A2, A3) Stacked design of the acetabular reaming guide. (B) Design of the acetabular grinding navigator. (C1, C2) Selection of the femoral head resection plane at 20° anteversion and design of the corresponding resection guide, with Kirschner wire holes marked by red arrows. (D1) Design of the femoral bone marrow cavity medulla dilatation guide perpendicular to the femoral resection plane, with Kirschner wire holes marked by red arrows. (D2) Three 3D model of the femoral bone marrow cavity medulla dilatation guide. (E1, E3) Femoral prosthesis placement guide based on the femoral resection guide, with a placement angle of 20° anteversion. (E2) The 3D model of the femoral prosthesis placement guide. (F, G) Postoperative outcome simulations.

FIGURE 4

Digital group intraoperative process. (A) 3D‐printed navigation templates: (1) acetabular grinding guide, (2) grinding navigator, (3) femoral osteotomy guide, (4 + 3) bone marrow cavity dilation guide, (5 + 3) femoral prosthesis placement guide, and (6, 7) Kirschner wire sleeves. (B) Incision site determined. (C) Acetabular grinding guide placed; Kirschner wires inserted at 20° anteversion, 40° abduction. (D) Acetabular grinding with navigator. (E) Acetabular cup placement via Kirschner wires. (F) Femoral neck osteotomy guided. (G) Femoral bone marrow cavity dilation. (I) Wound closure.