AO Technical Commission Meet the Experts sessions
Meet the Experts 2018
Advances in femoral nailing
Paulo Barbosa and Christopher Finkemeier, voting members of the AO Technical Commission Intramedullary Nailing Expert Group, presented the newly developed Femoral Recon Nail System. This offers surgeons the opportunity to select, based on their preference, either a nail for a piriformis fossa entry point or a nail for a trochanter tip entry point. These nails are specifically designed to enhance anatomical fit by reducing the nail radius of curvature to 1.0 m.
The presenters explained the various proximal and distal locking options provided by the nail which increase implant stability and which address a variety of femoral fracture types. The audience heard about the innovative instruments that facilitate this surgical technique and support the surgeon in achieving precise implant placement. A large part of the practical demonstration addressed the tips and tricks for proper fracture reduction, which remains the key to successful fracture treatment.
Femoral neck system (FNS): a new technique for the minimally invasive fixation of femoral neck fractures
Karl Stoffel and Christoph Sommer from the AO Technical Commission Lower Extremity Expert Group presented a new implant system designed for the minimally invasive fixation of femoral neck fractures—the Femoral Neck System: the Femoral Neck System. This innovative implant is a fixed-angle gliding fixation device that allows for the controlled collapse of the femoral neck, while simultaneously restricting rotation around the head-neck axis.
The head element of this new implant (consisting of a bolt and an anti-rotation screw) features a telescoping mechanism that avoids any lateral implant protrusion, which could lead to soft-tissue irritation.
After explaining the main advantages of the FNS, the presenters led the audience through the surgical technique in a practical demonstration that highlighted procedural efficiency. Both experts shared clinical cases and illustrated important surgical steps based on intraoperative imaging.
Augmentation of the Philos Plate
Franz Kralinger (chief of the Trauma Department, Wilhelminenspital, Vienna, Austria) and Stefaan Nijs (voting member with the AO Technical Commission Upper Extremity Expert Group) presented the rationale for cement augmentation of the Philos Plate. Screw penetration and secondary loss of reduction are potential complications of proximal humeral plate fixation, especially in osteoporotic bone. Cement augmentation through fenestrated screws, leading to cement clouds around the screw tips, has been shown to strengthen implant anchorage in the bone. Surgeons may decide intraoperatively if augmentation should be performed.
The presenters gave a detailed explanation of the surgical technique of screw augmentation. It is important to perform a leakage test with contrast dye to assure that no cement is injected into the joint. Implant removal of augmented screws is not an issue of concern. The presentation concluded that augmentation is a safe technique that enhances fixation stability.
Evolution of craniofacial distraction
AO CMF surgeons Richard Hopper (chair of the AO Technical Commission Craniofacial Expert Group) and Adi Rachmiel (director, Department of Oral and Maxillofacial Surgery, Rambam Health Care Campus, Haifa, Israel) presented a comprehensive overview about the evolution of craniofacial (alveolar, mandible, midface and cranial) distraction. They explained both external and internal distraction devices, which developed over time as new technology emerged. Internal devices are preferred, especially as they are associated with high patient satisfaction levels, but external devices are used in complex cases as they offer high versatility and functionality.
The audience heard about different treatment concepts ranging from single vector to multi-vector distraction, as exemplified by the curvilinear distraction system for the correction of mandibular deformities. From an intervention perspective, surgeons should note the timeline of the distraction procedure.
Session attendees learned about state-of-the-art treatment concepts for vector control and molding of the alveolars, differential movements of the midface to improve patient appearance and function, and control of sleep apnea by mandible movement, as well as orchestrated interventions for cranial pressure. Clinical cases were used to illustrate the effectiveness of the treatment methods applied.
Guidance in the planning, design and use of patient specific implants
Alexander Schramm (director, Department of Oral and Maxillofacial Surgery, Ulm University Medical Center, Germany) and Pit Voss (CMF surgeon, Department of Oral and Maxillofacial Surgery, Medical University Freiburg, Germany) gave a presentation on the planning, design and use of patient specific implants (PSI) in orbital and periorbital reconstructions, mandibular reconstructions, and orthognathic surgery. Recent advances in digital planning and innovative approaches to design and manufacture patient specific surgical guides and implants mean that complex surgical procedures can be performed in a highly reproducible manner.
Clinical results of waferless maxillary positioning underline the potential of this new digital approach the advantages of high predictability and accuracy, independent of the surgical experience, as well as reduced operating room (OR) time may outweigh the disadvantage of the high costs which are currently associated with the use of PSI.
The technique of using patient specific surgical drill guides, osteotomy guides and 3D implants is especially powerful in orbital and mandibular reconstructions after large bone resections in tumor surgery, as illustrated by several case examples shared by the presenters.
Introducing the LCP Pancarpal Arthrodesis Plate family
This veterinary topic was presented by Michael Kowaleski (Chair of the AO Technical Commission Veterinary Expert Group; and professor at Cummings School of Veterinary Medicine, Tufts University, North Grafton, United States) and Eva Schnabl-Feichter (Veterinärmedizinische Universität Wien, Austria). The session was streamed live, giving online participants the chance to put their questions to the expert presenters via moderator Bruno Peirone (Department of Veterinary Sciences, University of Turin, Italy).
The LCP Pancarpal Arthrodesis Plate family comprises three plate sizes for the treatment of hyperextension injuries of the carpal joint in skeletally mature dogs between about 7kg and 40kg. The presenters explained the plate-specific design features. One of these is that the plate thickness tapers proximally and distally to improve soft tissue coverage and to gradually decrease plate stiffness towards the plate ends. This helps reduce the risk of metacarpal bone fractures. The surgical technique to position and to apply the plate with the appropriate order of screw insertion was presented to achieve the desired compression at each joint level.
A practical demonstration on an artificial bone model illustrated the most important surgical steps of this procedure to the session participants. The session closed with the presentation of clinical cases.