Helical plating - a novel technique to increase stiffness in defect fractures.

Single-plate fixation bridging bone defects provokes nonunion and risks plate-fatigue failure due to under- dimensioned implants. Adding a helical plate to bridge the fracture increases stiffness and balances load sharing. This study compares the stiffness and plate surface strain of different constructs in a transverse contact and gap femoral shaft fracture model. Eight groups of six synthetic femora each were formed: intact femora; intact femora with lateral locking plate; contact and gap transverse shaft osteotomies each with lateral locking plate, lateral locking plate and helical locking plate, and long proximal femoral nail. Constructs underwent non-destructive quasi-static axial and torsional loading. Plate surface strain evaluation was performed under 200 N axial loading. Constructs with both lateral and helical plates demonstrated similar axial and torsional stiffness- independent of the contact or gap situations - being significantly higher compared to lateral plating (p < 0.01). Torsional stiffness of the constructs, with both lateral and helical plates in the gap situation, was significantly higher compared to this situation stabilised by a nail (p < 0.01). Plate surface strain dropped from 0.3 % in the gap situation with a lateral plate to < 0.1 % in this situation with both a lateral and a helical plate. Additional helical plating increases axial and torsional construct stiffness in synthetic bone and seems to provide well-balanced load sharing. Its use should be considered in very demanding situations for gap or defect fractures, where single-plate osteosynthesis provides inadequate stiffness for fracture healing and induces nonunion.

Evolution of AO Fracture Treatment Part 1: the Internal Fixator.

Surgical fracture treatment has undergone an extensive evolution in the past decades. In the early days achieving solid healing in anatomically reduced position was the primary and nearly exclusive goal of fracture treatment. Since mainly Lambotte, Danis and Müller in Europe the focus of surgical fracture treatment shifted to achieving early recovery of the function of the injured limb with safe healing. Considering the shortcomings of the early fracture treatment helps understanding the evolution of surgical fracture treatment. The evolution of the biomechanical and biological principles of AO plate fixation are discussed as a model.

Cerclage, evolution and potential of a Cinderella technology. An overview with reference to periprosthetic fractures.

Periprosthetic fractures are increasingly frequent. The fracture may be located over the shaft of the prosthesis, at its tip or below. The treatment of explosion fractures is difficult because the shaft blocks the application of implants, like screws, which need to penetrate the medullary cavity. The cerclage, as a simple periosteal loop, made of wire or more recently cable, does not only avoid the medullary cavity. Its centripetal mode of action is well suited for reducing and maintaining radially displaced fractures. Furthermore, the cerclage lends itself well for minimally invasive internal fixation. New insight challenges the disrepute of which the cerclage technology suffered for decades. The outcome of cerclage fixation benefits from an improved understanding of its technology, mechano-biology and periosteal blood supply. Preconceived and generally accepted opinions like "strangulation of blood supply" need to be re-examined. Recent mechanical evaluations demonstrate that the wire application may be improved but cable is superior in hand- ling, maintenance of tension and strength. Beside the classical concepts of absolute and relative stability a defined stability condition needs consideration. It is typical for cerclage. Called "loose-lock stability" it specifies the situation where a loosened implant allows first unimpeded displacement changing abruptly into a locked fixation preventing further dislocation.

The principle of helical implants. Unusual ideas worth considering.

The clinical use of helical implants (implants extruded over helical paths either periosteal (plates / internal fixators) or intramedullary implants for bone fixation is presented. A helical nail permits more degrees of freedom when choosing an entry point. With a helical periosteal device it is possible to position an implant on different aspects of bone (for instance, laterally in the proximal part of the bone or anteriorly in the distal part of the bone). These options have proven particularly useful when attempting to avoid damage to the vascular system of the femoral head and when performing MIPO bridge plating of humeral shaft fractures. Helical implants open up a new and still unexplored field in bone fixation. Early results have been very encouraging. It is hoped that indications for its use will broaden once the international community of orthopaedic surgeons realizes its existence and its major innovative features.

Osteosynthesis of diaphyseal fractures of the radius and ulna using an internal fixator (PC-Fix). A prospective study.

Over a five year period, 121 forearm shaft fractures in 82 patients including nine non unions were fixed using the PC-Fix. Two patients died early; of the remaining 80 patients (119 bones) 96% were followed until bone healing. No non unions or late infections were observed in spite of the fact that no primary bone grafts were used except when treating non unions. In this clinical study with a high follow up rate using a newly developed internal fixator, encouraging overall results were achieved and the technology of monocortical locked screws was proven to be valid.

Treating forearm fractures using an internal fixator: a prospective study.

Some major complications of internal fixation with plates, such as infections and disturbance of healing, have been shown to be related to necrosis of bone and to the soft tissues immediately deep to the plate. This is attributable to plate contact. To deal with this phenomenon, an internal fixator, the Point Contact Fixator, was developed according to a new concept. The Point Contact Fixator resembles a plate but functions like a fixator, that is, the fracture is stabilized using a splint fixed to the bone by monocortical, angularly locked screws that are designed not to exert pressure between the splint and the bone, thereby minimizing implant-to-bone contact. Vascular damage to the osseous blood supply consequently is avoided. The new internal fixator is the first of a new family of implants in addition to nails, plates, and external fixators. To study the potential of the Point Contact Fixator in a prospective study, 79 forearm fractures in 55 patients were treated in a consecutive series by one surgeon using the same technique throughout. Followup to union is reported for 100% of the patients. Handling the fixator was simple; healing was uneventful; and the rate of complication was low.

External fixation of fractures with a new frame in managing patients with multiple trauma.

The use of a new modular frame with the AO tubular fixator in managing the cases of severely injured patients is reported. The simplicity in design, the versatility, and the ease of insertion make this frame very useful in managing a patient with multiple injuries in the emergency department when stable fixation of a variety of fractures is needed. Our clinical experience with 23 patients, all with an ISS of 16 or greater, is reported and four representative cases are described.