[Fractures of the ankle joint in elderly patients].

The number of ankle fractures in elderly patients is increasing. The aim of treatment of ankle fractures in the elderly is to guarantee a possible unlimited autonomy and quality of life for patients. This is achieved by minimization of the complications and impairments after ankle joint fractures.

Biomechanical comparison of a lateral polyaxial locking plate with a posterolateral polyaxial locking plate applied to the distal fibula.

Background: Polyaxial locking plates are becoming popular for the fixation of distal fibula fractures. This study establishes how construct stiffness and plate loosening, measured as range of motion, differs between lateral and posterolateral plate location.

Methods: Seven matched pairs of cadaver fibulae were osteotomized in standardized fashion to produce a Weber type B distal fibula fracture.

Utility of the cortical thickness of the distal radius as a predictor of distal-radius bone density.

Background: Bone density is an important factor in the management of fractures of the distal radius.

Objectives: The aim of this study was to establish whether standard anteroposterior (AP) radiographs would provide the attending physician with a prediction of bone density.

Patients And Methods: Six pairs of human cadaveric radii were harvested.

Modified Lapidus arthrodesis with plantar plate and compression screw for treatment of hallux valgus with hypermobility of the first ray: a preliminary report.

Background: TMT-1 arthrodesis is an established method in hallux valgus surgery, but it is technically demanding and typically calls for a period of postoperative immobilization.

Methods: In this cohort study, initial experience with a plantar plate is described. 58 patients (59 arthrodesis) were included.

Adjustment of traumatic femur shortening assisted by an intramedullar skeletal kinetic distractor: a case report.

Introduction: Distal comminuted femoral fractures with joint involvement are highly challenging for the surgeon. We present a potential therapeutic concept that aims especially at the treatment of posttraumatic leg length discrepancy.

Case Presentation: This case report describes a polytraumatized 19-year-old German woman.

Long-term stability of angle-stable versus conventional locked intramedullary nails in distal tibia fractures.

Background: In the last years intramedullary nailing has become the treatment of choice for most displaced diaphyseal tibia fractures. In contrast intramedullary nailing of distal tibia fractures is accompanied by problems like decreased biomechanical stability. Nevertheless the indications for intramedullary nailing have been extended to include even more distal fractures.

Biomechanical performance of different cable and wire cerclage configurations.

Purpose: Cerclage technology is regaining interest due to the increasing number of periprosthetic fractures. Different wiring techniques have been formerly proposed and have hibernated over years. Hereby, they are compared to current cerclage technology.

Volar versus dorsal latest-generation variable-angle locking plates for the fixation of AO type 23C 2.1 distal radius fractures: a biomechanical study in cadavers.

Introduction: Anatomicaly preformed variable-angle locking plates are technologically mature and appear to be optimal for the fixation of distal radius fractures. However, there is still much argument about whether volar plating is equivalent to dorsal (buttressing) plating, especially in the management of intra-articular extension fractures. This biomechanical study was performed to determine, in a simple intra-articular fracture model, whether dorsal or volar plate constructs would be more stable.

The effect of polyelectrolyte multilayer coated titanium alloy surfaces on implant anchorage in rats.

Advances have been achieved in the design and biomechanical performance of orthopedic implants in the last decades. These include anatomically shaped and angle-stable implants for fracture fixation or improved biomaterials (e.g.

Fatigue performance of angle-stable tibial nail interlocking screws.

Purpose: Tibial nail interlocking screw failure often occurs during delayed fracture consolidation or at early weight bearing of nailed unstable fractures, in general when high implant stress could not be reduced by other means. Is there a biomechanical improvement in long-term performance of angle stable locking screws compared to conventional locking screws for distal locking of intramedullary tibial nails?

Methods: Surrogate bones of human tibiae were cut in the distal third and distal locking of the 10 mm intramedullary tibial nail was performed with either two angle stable locking screws or two conventional locking screws in the mediolateral plane. Six specimens per group were mechanically tested under quasi-static and cyclic axial loading with constantly increasing force.

The locking attachment plate for proximal fixation of periprosthetic femur fractures--a biomechanical comparison of two techniques.

Purpose: Mechanical properties of a locking attachment plate construct (LAP-LCP), allowing bicortical screw placement laterally to the prosthesis stem, are compared to a cerclage-LCP construct.

Methods: Eight right synthetic femora with implanted uncemented hip endoprosthesis were cut distally and fixed with LCP, monocortical locking screws and either LAP (n = 4) or cerclage (n = 4). Cyclic testing was performed with monotonically increasing sinusoidal load until failure.

Screw placement for acetabular fractures: which navigation modality (2-dimensional vs. 3-dimensional) should be used? An experimental study.

Objectives: Screw navigation techniques with different image guidance [2-dimensional (2D) vs. 3-dimensional (3D) fluoroscopy] were evaluated for acetabular fracture surgery.

Methods: Two-dimensional and 3D navigation images were analyzed for visualization of different osseous corridors: supra-acetabular, anterior column, posterior column, and infra-acetabular.

Plantar versus dorsomedial locked plating for Lapidus arthrodesis: a biomechanical comparison.

Background: Lapidus arthrodesis with a plate and a compression screw is an established procedure in hallux valgus surgery. The present study was performed to investigate the potential benefit of a compression screw combined with a plantarly applied angle-stable, anatomically precontoured plate or a dorsomedially applied angle-stable plate.

Methods: In six pairs of human cadaver specimens, one specimen each was randomized to receive a dorsomedial H-shaped plate, while the other received a plantar plate.

The primary stability of angle-stable versus conventional locked intramedullary nails.

Purpose: The aim of this study was to compare the initial biomechanical characteristics of the angle-stable locking system for intramedullary nails using the new biodegradable sleeve with conventional locking in the treatment of unstable distal tibial fractures.

Methods: Eight pairs of fresh, frozen porcine tibiae were used for this study. The expert tibial nail (Synthes) was equipped with either conventional locking screws (CL) or the angle-stable locking system (AS).

The effect of plasma chemical oxidation of titanium alloy on bone-implant contact in rats.

Many different technologies have been used to enhance osseointegration in orthopaedic and dental implant surgery. Hydroxyapatite coatings, pure or in combination with growth factors or bisphosphonates, showed improved osseointegration of titanium alloy implants. We choose a different approach to enhance osseointegration: plasma chemical oxidation was used to modify the surface of titanium alloy implants.

Freezing of rat tibiae at -20°c does not affect the mechanical properties of intramedullary bone/implant-interface: brief report.

Background: The effects of freezing-thawing cycles on intramedullary bone-implant interfaces have been studied in a rat model in mechanical pull-out tests. IMPLANTS: Twenty TiAl6V4 rods (Ø 0.8 mm, length 10 mm) implanted in rat tibiae

Methods: 10 rats underwent bilateral tibial implantation of titanium rods.

Internal fixation of type-C distal femoral fractures in osteoporotic bone: surgical technique.

Background: Fixation of distal femoral fractures remains a challenge, especially in osteoporotic bone. This study was performed to investigate the biomechanical stability of four different fixation devices for the treatment of comminuted distal femoral fractures in osteoporotic bone.

Methods: Four fixation devices were investigated biomechanically under torsional and axial loading.

Evaluation of a polyaxial angle-stable volar plate in a distal radius C-fracture model--a biomechanical study.

Introduction: Polyaxial angle-stable plating is thought to be particularly beneficial in the management of complex intra-articular fractures of the distal radius. The purpose of the present study was to investigate whether the technique provides stability to match that of conventional (fixed-angle) angle-stable constructs.

Material And Methods: In seven pairs of human cadaver radii, an Arbeitsgemeinschaft für Osteosynthese (AO) 23 C2.

Short-term outcome of retrograde tibiotalocalcaneal arthrodesis with a curved intramedullary nail.

Background: The aim of this study was to investigate the potential clinical benefit of tibiotalocalcaneal arthrodesis (TTCA) with an intramedullary nail with a valgus curve, two compression options, and angle-stable locking.

Material And Methods: Patients who had undergone TTCA at two tertiary hospitals were eligible. Patients who had undergone TTCA before the beginning of the study were evaluated retrospectively, then all following patients were examined prospectively.

Choosing a proper working length can improve the lifespan of locked plates. A biomechanical study.

Background: It is hypothesized that the working length influences the implants fatigue behavior. However, few studies addressing this issue came to contrary results. Therefore, we tested systematically the influence of working length and implant material on the plate's endurance.

Arthroscopic treatment of osteochondral lesions of the ankle with matrix-associated chondrocyte implantation: early clinical and magnetic resonance imaging results.

Background: Conventional autologous chondrocyte transplantation in the ankle often requires tibial or fibular osteotomies with potential morbidity for the patient. Advances in biotechnology and surgical techniques have resulted in the development of matrix-associated chondrocyte implantation (MACI). As the chondrocyte-loaded scaffold can be applied arthroscopically, this procedure is especially useful for the treatment of osteochondral defects in the ankle.

Arthroscopic-controlled navigation for retrograde drilling of osteochondral lesions of the talus.

Background: Retrograde drilling of symptomatic osteochondral lesions (OCL) is usually controlled by fluoroscopy. Due to the limited visualization of the OCLs in the acquired images and the narrow access to the talar dome, this approach can be demanding. Several navigation procedures have been reported (2D- or 3D- fluoroscopy or intraoperative CT-based) to increase the accuracy and reduce the radiation exposure.

Distal femur fractures of the elderly--different treatment options in a biomechanical comparison.

Background: Fractures of the distal femur, especially in the elderly patient, are an unsolved problem in orthopaedic and trauma surgery. Poor bone stock quality caused by osteoporosis often results in bad implant anchorage in the distal part with a high risk of secondary failures such as cutout. This study investigates the biomechanical characteristics of four implants with different distal locking options under quasi-static torsional and cyclic axial loading.