Computer assisted SCFE osteotomy planning

Abstract

Slipped capital femoral epiphysis (SCFE) is a common pediatric orthopedic disorder that requires surgical correction. Preoperative planning of a proximal femoral osteotomy is essential in cases of SCFE. This planning is usually done using 2D radiographs, but 3D data can be acquired with CT and analyzed with 3D visualization software. SCFEanalyzer is a computer program developed for preoperative planning of proximal femoral osteotomy to correct SCFE. Computed tomography scans were performed on human bone specimens: one pelvis and two femoral bones (right and left) and volume data of a patient. The CT data were used to test the abilities of the SCFEanalyzer software, which utilizes 3D virtual models of anatomic structures constructed from CT image data. Separation of anatomical bone structures is done by means of “cutting” 3D surface model of the pelvis. The software enables qualitative and quantitative spatial analysis of chosen parameters analogous to those done on the basis of plain radiographs. SCFEanalyzer makes it possible to evaluate the function of the hip joint by calculating the range of motion depending on the shape of bone structures based on oriented bounding box object representation. Pelvic and hip CT scans from a patient with SCFE were subjected to femoral geometry analysis and hip joint function assessment. These were done to plan and simulate osteotomy of the proximal femur. Analogous qualitative and quantitative evaluation after performing the virtual surgery were evaluated to determine the potential treatment effects. The use of computer assistance in preoperative planning enable us to increase objectivity and repeatability, and to compare the results of different types of osteotomy on the proximal femur, and thus to choose the optimal operation in each individual case.