WHY IS THERE A NEED TO ENHANCE 3D PREOPERATIVE PLANNING?

Congenital or acquired complex three-dimensional (3D) deformities of the lower limbs often result in functional impairment or pain. Limb reconstruction with deformity correction through osteotomies can improve functional outcomes and reduce pain. Essentially, the distorted bone is cut at one or more sites and corrected until the alignment between the proximal and distal articular segments resembles the healthy, normal side or a reference bone. Gradual correction of the distorted bone can be achieved using an external hexapod fixator, which allows for precise 3D deformity correction and fine-tuning even after surgery. The major advantage of using a hexapod external fixator is its high precision in correcting complex 3D deformities. For instance, rotational deformities in the axial plane can be corrected first, leaving only 2D deformities in the frontal and sagittal planes to address. Using biplanar radiographs, these residual deformities can be accurately analyzed and corrected. However, external fixators have several disadvantages, such as patient discomfort, pin-site infections, and an increased risk of fractures after fixator removal. As a result, there is growing interest in using fully internal implants for 3D deformity correction. The drawback of internal implants, such as plates and intramedullary nails, is that all corrections must be completed during surgery. Therefore, successful acute 3D deformity correction depends on precise preoperative planning and careful execution. Preoperative CT scans can help create patient-specific cutting guides tailored to the bone, ensuring accurate correction of the deformity. However, using these guides often requires significant surgical exposure, which can negatively impact bone healing. To avoid extensive exposure, an alternative approach involves performing the deformity correction without cutting guides. Instead, minimally invasive percutaneous osteotomies are performed, followed by inserting an intramedullary nail. The nail is inserted at a site that is typically separate from the osteotomy, minimizing disruption to the bone's healing process. For such surgeries, preoperative planning must carefully consider corrections in all planes to address the complexity of multiplanar deformities effectively. This ensures that the deformity is resolved with the desired precision and minimizes the need for further interventions. This presentation aims to highlight the clinical challenges associated with using traditional methods for preoperative planning in acute complex 3D deformity correction. It underscores the critical need for improved 3D planning approaches that effectively integrate data from non-weight-bearing CT scans with weight-bearing full-length radiographs or EOS scans to enhance surgical outcomes.