Precision in Three Dimensions: A Novel Approach to Tumor Resection and Reconstruction of the Femoral Trochanter

Advancing Surgical Techniques for Bone Tumors

The femoral trochanter, a common site for bone tumors, presents a complex surgical challenge. Tumor infiltration often complicates the accurate determination of resection margins, and the reconstruction of bone defects must maintain the structural integrity and function of the hip joint. While traditional surgical approaches have evolved over the years, the introduction of three-dimensional (3D) digital modeling and simulation technology marks a significant advancement in precision surgery for this area.

This study examines the application of 3D digital technology in the surgical resection and reconstruction of tumors in the femoral trochanter. By combining preoperative imaging, computer-assisted design (CAD), and personalized surgical guides, this approach achieves greater accuracy in tumor resection and improves postoperative outcomes for patients with diverse tumor types.

3D Digital Modeling: Mapping the Tumor Landscape

Accurate resection of bone tumors relies heavily on the precise determination of tumor boundaries. Traditional methods involving computed tomography (CT) and magnetic resonance imaging (MRI) provide valuable data but often fall short in translating two-dimensional (2D) images into actionable surgical plans. Here, 3D digital modeling addresses this gap, offering a comprehensive visualization of the tumor and surrounding structures.

Building the Digital Model

Preoperative imaging with CT and MRI scans serves as the foundation for constructing a 3D digital model of the femoral trochanter and tumor. Software such as Mimics and Imageware enables the alignment of anatomical structures and tumor margins, allowing surgeons to evaluate the extent of infiltration in three dimensions. This step provides a clear visualization of the tumor’s shape, size, and depth, which is critical for planning the resection.

Simulating Tumor Resection

The digital model allows for a virtual simulation of the surgical procedure, including the resection of the tumor and the subsequent reconstruction of the bone defect. This simulation helps determine the most effective surgical trajectory and the type of fixation needed. By integrating these steps, surgeons can anticipate challenges and refine their approach before entering the operating room.

Designing Personalized Surgical Guides

Using the 3D model, CAD tools are employed to create patient-specific surgical guides. These guides are 3D printed to match the contours of the tumor and the bone defect, ensuring that tumor resection is both precise and consistent with the preoperative plan. Additionally, guides for trimming allograft bone to fit the defect are prepared, streamlining the reconstruction process.

Surgical Execution: Precision Tumor Resection and Reconstruction

The integration of digital modeling and personalized guides into the surgical workflow transforms the execution of tumor resection and reconstruction. This approach minimizes intraoperative uncertainty and ensures that the surgical plan is faithfully implemented.

Tumor Resection

During the operation, the surgical guide is used to define the resection margins with high precision. This eliminates reliance on visual estimation or palpation, both of which are prone to error. The guide ensures that the tumor is completely removed without excessive loss of healthy bone, preserving as much structural integrity as possible.

Allograft Preparation and Implantation

Following tumor resection, the allograft bone is trimmed using the corresponding guide to fit the 3D shape of the defect. This precise matching between the defect and the graft minimizes gaps and promotes effective integration. The graft is then fixed in place using proximal femoral anatomical plates or femoral reconstruction nails, depending on the extent and location of the defect.

Soft Tissue and Functional Reconstruction

In addition to reconstructing the bone, the surgical technique incorporates reattachment of critical soft tissues. For instance, the hip abductor muscles are sutured to the allograft to restore hip stability and function. This holistic approach addresses both the structural and functional aspects of the reconstruction, enabling better postoperative recovery.

Postoperative Outcomes: Recovery and Functional Assessment

The success of any surgical intervention is ultimately measured by its outcomes. In this study, postoperative assessments included X-ray imaging, functional recovery evaluations, and monitoring for complications such as recurrence or graft failure.

Bone Healing and Integration

Postoperative X-rays revealed satisfactory reconstruction of the bone defect, with stable fixation and accurate alignment. Bridging callus formation between the allograft and autologous bone was observed within six months of surgery, indicating successful bone healing. By the end of the follow-up period, complete fusion between the graft and the native bone was consistently achieved.

Functional Recovery

Patients demonstrated significant functional improvement following surgery. The Musculoskeletal Tumor Society (MSTS) scoring system was used to evaluate pain, mobility, and overall limb function. Most patients achieved excellent or good scores, reflecting effective preservation of hip joint function. Walking and weight-bearing activities were typically resumed within six months, and long-term outcomes showed sustained functional restoration.

Recurrence and Complications

Of the 11 patients included in the study, one experienced local recurrence, which was subsequently managed with additional surgery. The recurrence was associated with a transformation from enchondroma to chondrosarcoma, highlighting the importance of ongoing surveillance. No other significant complications, such as infections or fixation failures, were reported.

Technical Advancements: The Role of Digital Technology

The success of this approach underscores the transformative potential of 3D digital technology in orthopedic oncology. By enhancing surgical planning and execution, this method addresses many of the limitations associated with conventional techniques.

Enhanced Surgical Accuracy

The use of 3D digital modeling and simulation enables precise evaluation of tumor boundaries and infiltration. This minimizes the risk of incomplete resection, which is a major factor in recurrence. At the same time, it avoids unnecessary removal of healthy bone, preserving function and reducing the complexity of reconstruction.

Customization and Flexibility

The personalized nature of the surgical guides and allograft templates allows for tailored solutions to each patient’s unique anatomy and tumor characteristics. This level of customization improves the fit and stability of the reconstruction, leading to better long-term outcomes.

Reduced Operating Time

Preoperative planning and simulation streamline the intraoperative process, reducing operating time and associated risks. The ability to simulate all steps of the procedure ensures a smoother and more predictable surgical experience.

A Paradigm Shift in Tumor Resection and Reconstruction

The application of 3D digital modeling and simulation in the resection and reconstruction of femoral trochanteric tumors represents a significant advancement in orthopedic surgery. This approach combines precision, customization, and efficiency to achieve superior outcomes, including high rates of functional recovery and low recurrence.

By leveraging the power of digital technology, this method addresses longstanding challenges in the surgical management of bone tumors. As this technique continues to evolve, it has the potential to set a new standard for precision surgery, offering hope for improved prognoses and quality of life for patients with complex orthopedic conditions.

Study DOI: https://doi.org/10.1016/j.imed.2023.07.001

Engr. Dex Marco Tiu Guibelondo, B.Sc. Pharm, R.Ph., B.Sc. CpE

Editor-in-Chief, PharmaFEATURES