Unstable distal tibia fractures are challenging injuries requiring surgical treatment. Intramedullary nails are frequently used; however, distal fragment fixation problems may arise, leading to delayed healing, malunion or nonunion. Recently, a novel angle-stable locking nail design has been developed that maintains the principle of relative construct
The clinical success of osteochondral autografts is heavily reliant on their mechanical
Arthritis is a common and debilitating disease and is associated with an increased fall risk. The purpose of this study was to examine the effect of impacted joint and limb on fall risk as measured by the margin of
While high-performance ceramics like alumina and zirconia exhibit excellent wear resistance, they provide poor osseointegration capacity. As osseointegration is crucial for non-cemented joint prostheses, new techniques have been successfully developed for biofunctionalizing high-performance ceramic surfaces. Stable cell adhesion can be achieved by covalently bound specific peptides. In this study we investigate the effect of sterilization processes on organo-chemically functionalized surfaces. To enhance the performance of alumina-toughened zirconia ceramics (ATZ), a 3-aminopropyldiisopropylethoxysilane (APDS) monolayer was applied and coupled with cyclo-RGD peptides (cRGD) by using bifunctional crosslinker bis(sulfosuccinimidyl)suberat (BS³). The samples were sterilized using e-beam or gamma-sterilization at 25 kGy, either before or after biofunctionalization with cRGD. Functionalization
Abstract. Objectives. Osteochondral grafting (OCG) is one treatment strategy for osteoarthritis with good clinical results. Decellularised tissues provide a promising alternative to standard autografts or allografts. This study aimed to compare the
Abstract. Objectives. The aim of this study was to develop an open-source finite element model of the ankle for identification of the best clinical treatment to restore
Abstract. Approximately 20% of primary and revision Total Knee Arthroplasty (TKA) patients require multiple revisions, which are associated with poor survivorship, with worsening outcomes for subsequent revisions. For revision surgery, either endoprosthetic replacements or metaphyseal sleeves can be used for the repair, however, in cases of severe defects that are deemed “too severe” for reconstruction, endoprosthetic replacement of the affected area is recommended. However, endoprosthetic replacements have been associated with high complication rates (high incidence rates of prosthetic joint infection), while metaphyseal sleeves have a more acceptable complication profile and are therefore preferred. Despite this, no guidance exists as to the maximal limit of bone loss, which is acceptable for the use of metaphyseal sleeves to ensure sufficient axial and rotational
The quest for optimal treatment of acute distal tibiofibular syndesmotic disruptions is still in progress. Using suture-button repair devices is one of the dynamic stabilization options, however, they may not be always appropriate for stabilization of length-unstable syndesmotic injuries. Recently, a novel screw-suture repair system was developed to address such issues. The aim of this study was to investigate the performance of the novel screw-suture repair system in comparison to a suture-button stabilization of unstable syndesmotic injuries. Eight pairs of human cadaveric lower legs were CT scanned under 700 N single-leg axial loading in five foot positions – neutral, 15° external/internal rotation and 20° dorsi-/plantarflexion – in 3 different states: (1) pre-injured (intact); (2) injured, characterized by complete syndesmosis and deltoid ligaments cuts simulating pronation-eversion injury types III and IV as well as supination-eversion injury type IV according to Lauge-Hansen; (3) reconstructed, using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implants for syndesmotic stabilization, placed 20 mm proximal to the tibia plafond. Following, all specimens were: (1) biomechanically tested over 5000 cycles under combined 1400 N axial and ±15° torsional loading; (2) rescanned. Clear space (diastasis), anterior tibiofibular distance, talar dome angle and fibular shortening were measured radiologically from CT scans. Anteroposterior (AP), axial, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via motion tracking. In each group clear space increased significantly after injury (p ≤ 0.004) and became significantly smaller in reconstructed compared with both pre-injured and injured states (p ≤ 0.041). In addition, after reconstruction it was significantly smaller in Group 1 compared to Group 2 (p < 0.001). AP and axial movements were significantly smaller in Group 1 compared with Group 2 (p < 0.001). No further significant differences were identified/detected between the groups (p ≥ 0.113). Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw-suture reconstruction provides better anteroposterior translation and axial
The quest for optimal treatment of acute distal tibiofibular syndesmotic disruptions is still in full progress. Using suture-button repair devices is one of the dynamic stabilization options, however, they may not be always appropriate for stabilization of length-unstable syndesmotic injuries. Recently, a novel screw-suture repair system was developed to address such issues. The aim of this study was to investigate the performance of the novel screw-suture repair system in comparison to a suture-button stabilization of unstable syndesmotic injuries. Eight pairs of human cadaveric lower legs were CT scanned under 700 N single-leg axial loading in five foot positions – neutral, 15° external/internal rotation and 20° dorsi-/plantarflexion – in 3 different states: (1) pre-injured (intact); (2) injured, characterized by complete syndesmosis and deltoid ligaments cuts simulating pronation-eversion injury types III and IV, and supination-eversion injury type IV according to Lauge-Hansen; (3) reconstructed, using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implants for syndesmotic stabilization, placed 20 mm proximal to the tibia plafond/joint surface. Following, all specimens were: (1) biomechanically tested over 5000 cycles under combined 1400 N axial and ±15° torsional loading; (2) rescanned. Clear space (diastasis), anterior tibiofibular distance, talar dome angle and fibular shortening were measured radiologically from CT scans. Anteroposterior, axial, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via motion tracking. In each group clear space increased significantly after injury (p ≤ 0.004) and became significantly smaller in reconstructed compared with both pre-injured and injured states (p ≤ 0.041). In addition, after reconstruction it was significantly smaller in Group 1 compared to Group 2 (p < 0.001). Anteroposterior and axial movements were significantly smaller in Group 1 compared with Group 2 (p < 0.001). No further significant differences were detected between the groups (p ≥ 0.113). Conclusions. Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw-suture reconstruction provides better anteroposterior translation and axial
Surgical treatment of fragility sacrum fractures with percutaneous sacroiliac (SI) screw fixation is associated with high failure rates in terms of screw loosening, cut-through and turn-out. The latter is a common cause for complications, being detected in up to 20% of the patients. The aim of this study was to develop a new screw-in-screw concept and prototype implant for fragility sacrum fracture fixation and test it biomechanically versus transsacral and SI screw fixations. Twenty-seven artificial pelves with discontinued symphysis and a vertical osteotomy in zone 1 after Denis were assigned to three groups (n = 9) for implantation of their right sites with either an SI screw, the new screw-in-screw implant, or a transsacral screw. All specimens were biomechanically tested to failure in upright position with the right ilium constrained. Validated setup and test protocol were used for complex axial and torsional loading, applied through the S1 vertebral body. Interfragmentary movements were captured via optical motion tracking. Screw motions in the bone were evaluated by means of triggered anteroposterior X-rays. Interfragmentary movements and implant motions in terms of pull-out, cut-through, tilt, and turn-out were significantly higher for SI screw fixation compared to both transsacral screw and screw-in-screw fixations. In addition, transsacral screw and screw-in-screw fixations revealed similar construct
MicroRNA´s are regulatory sequences which influence the posttranscriptional synthesis of about 70% of protein encoding genes. In different studies, MicroRNA-146a (miR-146a) was associated with inflammatory and autoimmunological processes. In vitro it was shown, that miR-146a influences the bone metabolism by regulating differentiation of mesenchymal stem cells. The miR-146a deficient mouse starts to develop lymphoproliferative and myeloproliferative disease by 6–8 months of age. In this study, we investigate the influence of miR-146a deficiency on bone structure and
Introduction and Objective. Intramedullary nails are frequently used for treatment of unstable distal tibia fractures. However, insufficient fixation of the distal fragment could result in delayed healing, malunion or nonunion. The quality of fixation may be adversely affected by the design of both the nail and locking screws, as well as by the fracture pattern and bone density. Recently, a novel concept for angular stable nailing has been developed that maintains the principle of relative
Osteosynthesis of high-energy metaphyseal proximal tibia fractures is still challenging, especially in patients with severe soft tissue injuries and/or short stature. Although the use of external fixators is the traditional treatment of choice for open comminuted fractures, patients' acceptance is low due to the high profile and therefore the physical burden of the devices. Recently, clinical case reports have shown that supercutaneous locked plating used as definite external fixation could be an efficient alternative. Therefore, the aim of this study was to evaluate the effect of implant configuration on
Abstract. Objectives. Oil-based fluids can be used to enhance the properties of polyethylene materials. For example, vitamin E infused polyethylene has a superior oxidation resistance and Lipiodol infused polyethylene has an enhanced X-ray attenuation. The aim of this study was to evaluate the long-term influence of oily fluid on the chemical, physical and tensile properties of polyethylene. Methods. An accelerated ageing procedure (an elevated temperature (80. °. C) for four weeks in air. 1. ) was used to investigate the oxidative
Normal function of the patellofemoral joint is maintained by a complex interaction between soft tissues and articular surfaces. No quantitative data have been found on the relative contributions of these structures to patellar
Thermostability is a key property in determining the suitability of local delivery of antibiotics in the treatment of orthopaedic infections. Herein, we aimed to assess the thermal
Introduction. Despite decades of clinical research in artificial joints and underlying failure mechanisms, systematical and reproducible identification of reasons for complications in total knee replacements (TKR) remains difficult. Due to the complex dynamic interaction of implant system and biological situs, malfunction eventually leading to failure is multifactorial and remains not fully understood. The aim of present study was to evaluate different TKR designs and positions with regard to joint kinematics and
Objectives. Thermal
Insufficiency of the lateral collateral ligamentous complex causes posterolateral rotatory instability (PLRI). During reconstruction surgery the joint capsule is repaired, but its biomechanical influence on elbow
Summary Statement. Proximal femoral bony deficits present a surgical and biomechanical challenge to implant longevity in revision hip arthroplasty. This work finds comparable primary