A Positioning Navigation Template for Assisting the Placement of Modular Hemipelvic Endoprostheses for Patients Undergoing Pelvic Bone Tumor Resection.

A Positioning Navigation Template for Assisting the Placement of Modular Hemipelvic Endoprostheses for Patients Undergoing Pelvic Bone Tumor Resection.

A Novel Positioning Navigation Template for Accurately and Precisely Assisting the Placement of Modular Hemipelvic Endoprostheses for Patients Undergoing Pelvic Bone Tumor Resection: A Retrospective Cohort Study

Background: Acetabular reconstruction in situ after extensive pelvic resection is technically challenging because the significant loss of bone stock and bony landmarks. The aim of the present study was to investigate the feasibility of an individualized navigation template for acetabular reconstruction following pelvic malignancy resection. Methods: This retrospective cohort study included patients who underwent type II or II+III pelvic tumor resection and reconstruction using a modular hemipelvic prosthesis. In the template-guided group (n = 10), a navigation template was designed and applied to assist acetabular reconstruction. In the traditional operation group (n = 14), the patients underwent the same surgery but without the navigation template. To compare the displacement of the hip rotation center before and after surgery between the two groups, an innovative method based on pelvic CT was developed and a validation group of cases was used to assess the effectiveness of this measurement approach. In the validation group (n = 12), patients undergoing periacetabular puncture or curettage without hip joint reconstruction were included. The displacements for the validation group were calculated and compared with 0 cm, the theoretical value. Subsequently, the displacements between the template-guided group and the traditional operation group were compared.

This study is a "Retrospective Cohort Study" through retrospectively collecting patients undergoing acetabulum reconstruction after pelvic tumor resection. The patients were interfered with or without the acetabular navigation template during the hip reconstruction process.

In the template-guided group (n = 10), a navigation template was designed and applied to assist acetabular reconstruction using a modular hemipelvic prosthesis.

In the traditional operation group (n = 14), acetabulum was manually reconstructed using a modular hemipelvic prosthesis by the surgeon's experience.

In the validation group (n = 12), patients undergoing periacetabular puncture or curettage without acetabulum reconstruction.

In the template-guided group (n = 10), a navigation template was designed and applied to assist acetabular reconstruction. In the traditional operation group (n = 14), the patients underwent the same surgery but without the navigation template. To compare the displacement of the hip rotation center before and after surgery between the two groups, an innovative method based on pelvic CT was developed and a validation group of cases was used to assess the effectiveness of this measurement approach. In the validation group (n = 12), patients undergoing periacetabular puncture or curettage without hip joint reconstruction were included. The displacements for the validation group were calculated and compared with 0 cm, the theoretical value. Subsequently, the displacements between the template-guided group and the traditional operation group were compared.

Compare the change of acetabular rotation center before and after surgery between the template-guided group and the traditional operation group.

Compare the change of acetabular rotation center (the displacement displayed in centimeters) before and after surgery between the template-guided group and the traditional operation group based on preoperative and postoperative CT images.

Inclusion Criteria: All the patients diagnosed with a pelvic tumor； Underwent limb salvage surgery following type II or II+III pelvic resection； Acetabulum reconstruction using a modular, titanium hemipelvic prosthesis. Exclusion Criteria: A lack of postoperative CT images; Having undergone revision surgery or noninitial/primary resection; unable to calculate the hip displacement by the specific measurement method we proposed.