Page 136 - Demo

Chapter 7134To individualize anatomical femoral tunnel placement and thus improve graft survival, we developed a novel surgical aiming device to create a femoral tunnel at the individualized anatomic ACL footprint during ACL reconstruction. The use of this patient specific instrumentation in ACL surgery aims for a constant and reliable method to assure a femoral tunnel emerging at the native ACL position. Moreover, patient specific instrumentation can be of aid in complex revision cases with multiple previous bone tunnels and in cases with posttraumatic or torsional deformities of the distal femur. In this cadaveric study the in vitro accuracy of a patient specific 3D printed surgical guide, to be used for femoral tunnel positioning in an outside-in ACL reconstruction, was determined. The aim of this study was to drill a femoral tunnel in the specimen, emerging within 2 mm of the femoral footprint of the ACL, as determined by planning on preoperative MRI. Materials and MethodsIn this experiment four knee joints of fresh frozen human cadavers were used. The study protocol has been reviewed by the Review Board of the University Medical Center Groningen (UMCG, Groningen, the Netherlands, study number 2015/057) and the committee has confirmed that no ethical approval was required. The cadavers were obtained from the Anatomy department of the UMCG. Knees with previous surgical procedures were excluded. Specimens were separated approximately 30 cm above and below the joint line. After 48 hours of defrosting, the knees were scanned using an MRI scanner. Image Acquisition.The specimens were placed supine in a patella forward position and fixed in a common knee coil. A 1.5 Tesla MAGNETOM® Aera MRI scanner (Siemens Healthcare GmbH, Erlangen, Germany) was used to acquire all scans. The used scanning protocol consisted of a routine clinical 2D knee sequence. The protocol consisted of Proton Density (PD) series in the sagittal, coronal, and axial planes. The use of PD series was chosen because of the more pronounced difference between the cartilage and the Mark Zee.indd 134 03-01-2024 08:56