Abstract:

This paper presents the application of 3D computer simulation models and 3D printed models to study 1) the distribution and volume of bone cement used in a kyphoplasty repair of a compression fracture at the L1 vertebra and 2) the height restoration resulting from the kyphoplasty. The results of this study are being integrated in the Simulation Based Learning Experiences (SBLEs) in the College of Nursing (CoN) at the University of Alabama in Huntsville. SBLEs are structured activities that represent actual or potential situations in nursing practice that allow students to develop knowledge and skills to analyze and respond to realistic situations in a simulated environment. The College of Nursing has developed over one-hundred SBLE training scenarios. All the 3D printed models of the lumbar spine segment with the compression fracture at L1, of the kyphoplasty repair at L1 and of the L1 vertebrae with the inserted bone cement are being added into the selected SBLEs. Also, the following training topics are being integrated into the SBLEs: 1) vertebral compression fractures, especially in the elderly, 2) repairs of compression fractures with kyphoplasty, 3) the flow of the bone cement in kyphoplasty, 4) restoration of patient height and 4) use of statistics and data analysis. In addition, nursing students are being introduced to 3D printing. A 3D printer has been placed in the CoN for student use. The Systems Management and Production Center at UAH is providing 3D printing and data analysis assistance to the nursing student SBLEs. The patient in this study was a 78 year old female who had suffered a compression fracture at the L1 vertebra. The radiologist report stated “compression of the vertebral body with approximately 75% vertebral height loss.” A surgeon performed a kyphoplasty to repair the fracture. Shortly thereafter the patient had a compression fracture at T12 which was also repaired using kyphoplasty. 3D models were printed of the lumbar spine segment from the two MRIs (magnetic resonance imaging). With the 3Dbuilder software it was possible to analyze the height restoration and the flow of the cement in L1. A 3D printed model of the bone cement was created and slid out of the L1 vertebral. The volume of bone cement measured 4.9ml. The surgeon performing the kyphoplasty estimated between 8-9ml of cement for L1. A number of measurements were also made of the compression fracture and after the kyphoplasty to determine height restoration. With the kyphoplasty the height of L1 was restored from 8.70mm to 16.85mm which was still approximately 4.85mm less than the original height before the compression fracture. The restoration rate of the vertebral height for L1 was 62.7% above the height of the compression fracture. Segmenting the bone cement object from the MRI was difficult and prone to errors with the primary source of error being the MRI spatial resolution. A second, more precise 3D model was then printed of the kyphoplasty repair. The bone cement volume of the second model was 8.9ml which corresponded to the surgeon’s estimate. Included in this paper are: 1) a description of the 3D simulation models and the 3D printed models, 2) a discussion of the volume of the bone cement inserted in L1 and the restoration rate of L1, 3) SBLEs, 4) the integration of the results into selected SBLEs to teach nursing students and 5) conclusions.

Keywords:

3D Models, Compression Fracture, Analysis of Bone Cement, Kyphplasty.