Computer-assisted and patient-specific 3-D planning and evaluation of a single-cut rotational osteotomy for complex long-bone deformities

Abstract

Malunion after long bone fracture results in an incorrect position of the distal bone segment. This misalignment may lead to reduced function of the limb, early osteoarthritis and chronic pain. An established treatment option is a corrective osteotomy. For complex malunions, a single-cut rotational osteotomy is sometimes preferred in cases of angular deformity in three dimensions. However, planning and performing this type of osteotomy is relatively complex. This report describes a computer-assisted method for 3-D planning and realizing a single-cut rotational osteotomy with a patient-specific cutting guide for orienting the osteotomy and an angled jig for adjusting the rotation angle. The accuracy and reproducibility of the method is evaluated experimentally using plastic bones. In addition, complex rotational deformities are simulated by a computer to investigate the relation between deformity and correction parameters. The computed relation between deformity and correction parameters enables the surgeon to judge the feasibility of a single-cut rotational osteotomy. This appears possible for deformities combining axial misalignment with sufficient axial rotation. The proposed 3-D method of preoperative planning and transfer with a patient-specific cutting guide and angled jig renders the osteotomy procedure easily applicable, accurate, reproducible, and is a good alternative for complex and expensive navigation systems.

Computation of Femoral Canine Morphometric Parameters in Three‐Dimensional Geometrical Models

“…The increased emphasis on 3D computation is not only relevant for diagnostic purposes, but also for surgical planning . The 3D computations are more reliable for planning corrective osteotomies, including identifying the precise localization of the center of rotation of angulation (CORA) and the accurate orientation of the osteotomy cutting plane . The 3D models are regarded as essential for customizing templates and surgical devices for correction of bone deformities .…”

Computer-aided surgical planner for a new bone deformity correction device using axis-angle representation

“…The axis-angle concept was previously applied in single-cut rotational osteotomy, a surgical procedure that corrects angular deformity (without lengthening) by osteotomizing the bone and rotating the bone fragments on the osteotomy plane to restore their alignment [25,43]. However, this application is limited by the fact that the osteotomy plane can only deviate by a few angles from the bone axis.…”

“…However, this application is limited by the fact that the osteotomy plane can only deviate by a few angles from the bone axis. A steep angle is not feasible as it will cut through a large volume of bone or even the articular surfaces [25,43]. In contrast, in DO, the equivalent rotation axis is controlled by the external fixator and does not affect the choice of the osteotomy plane.…”

Study on the three‐dimensional orientation of the posterior facet of the subtalar joint using simulated weight‐bearing CT

“…The talus and calcaneus were segmented in the CT images with custom made software, which was developed at our academic hospital . This resulted in virtual 3D surface models of the talus and calcaneus.…”