3D LEDECO is the acronym for 3D Leg Deformity Correction and stands for a project aiming at the development of algorithms for simulation-based preoperative planning of leg deformity correction under consideration of weight-bearing.
The Swiss National Science Foundation (SNSF) awarded the required funding for the four-year project in September 2018, whereupon the project could be launched in January 2019.
Deformities of the lower extremity (e.g., genu varum & valgus) are a frequent cause of degeneration in the knee joint known as osteoarthritis. These processes are initiated by a change in the mechanical axis of the leg due to the deformity, which leads to punctual overloading of the knee joint cartilage. While a replacement of the joint is unavoidable in advanced stages of osteoarthritis, patients in an earlier stage can be treated by an intervention called corrective osteotomy. Thereby, the deformed bone anatomy is surgically cut and repositioned such that the mechanical leg axis is realigned and physiological cartilage load is restored.
Up until today, it is still common practice to base the assessment and preoperative planning of leg deformities on (biplanar) radiographs. However, studies have shown that the mechanical leg axis is considerably shifted under the influence of weight bearing. A CT-based three-dimensional computer simulation of the individual postoperative anatomy under weight-bearing would be a helpful tool to evaluate different surgical strategies and to optimize the surgical outcome.
3D-LEDECO aims at the development of computer-based methods for three-dimensional planning and optimization of corrective osteotomies under consideration of weight-bearing. The project comprises three parts: Extensive cadaver experiments will be performed to systematically quantify the influence of femoral and tibial deformities on the mechanical axis and the load distribution within the knee joint. A robot-controlled setup will be built to simulate various deformities, while the results will be recorded using pressure sensors and visual tracking. The obtained findings will serve as a basis for the computer simulation in which algorithms will be developed, capable of simulating the patient-specific leg pose under weight bearing. The last part includes the development of a mathematical optimization algorithm which optimizes the parameters of the planned osteotomy towards the optimal postoperative result.
The methods resulting from this project will finally be combined into a prototype planning software (3D-LEDECO). The increased precision and predictability of the result is expected to result in a significantly improved quality of patient treatment.
1. Jud L*, Roth T*, Fürnstahl P, Vlachopoulos L, Sutter R, Fucentese S. The Impact of Limb Loading and the Measurement Modality (2D versus 3D) on the Measurement of the Limb Loading Dependent Lower Extremity Parameters. BMC Musculoskeletal Disorders, June 2020.
2. Hoch A*, Roth T*, Marcon M, Fürnstahl P, Fucentese S, Sutter R. Tibial torsion analysis in computed tomography: Development and validation of a real 3D measurement technique. Insights into Imaging, 2020. Accepted/in press.
3. Hoch A, Jud L, Roth T, Vlachopoulos L, Fürnstahl P, Fucentese S. A real 3D measurement technique for the tibial slope: differentiation between different articular surfaces and comparison to radiographic slope measurement . BMC
Musculoskeletal Disorders, 2020. 21: 635
4. Roth T, Carrillo F, Wieczorek W, Ceschi G, Esfandiari H, Sutter R, Vlachopoulos L, Wein W, Fucentese SF, Fürnstahl P. Three-dimensional preoperative planning in the weight-bearing state: validation and clinical evaluation. Insights into Imaging, 2021.
5. Roth T, Fürnstahl P, Jud L, Sutter R, Fucentese S. Lower limb deformity measurements: comparison of 2D vs. 3D and weight-bearing vs. non-weightbearing measures in biplanar radiographs and CT. ESSKA Virtual Congress 2021 (accepted).
6. Roth, T., Wieczorek, M., Ceschi, G., Wein, W., Sutter, R., Fucentese, S., Fürnstahl, P. A novel method for 2D/3D registration between non-weight-bearing 3D CT-reconstructed models and weight-bearing plain radiographs for preoperative planning in lower limb realignment surgery, Swiss Orthopaedics Jahreskongress (SGOT) 2020.
* Equally contributing authors