The main postoperative complications in fixation of ulna shaft fractures are non-union and implant irritation using currently recommended 3.5-mm locking compression plates. An alternative approach using a combination of two smaller plates in orthogonal configuration has been proposed. The aim of this study was to compare the biomechanical properties of a single 3.5-mm locking compression plate versus double plating using one 2.5-mm and one 2.0-mm mandible plate in a human ulna shaft fracture model. Eight pairs human ulnar specimens with a standardized 10-mm fracture gap were pairwise assigned for instrumentation with either a single 3.5-mm plate placed posteriorly, or for double plating using a 2.5-mm and a 2.0-mm mandible plate placed posteriorly under the flexor muscles and laterally under the extensor muscles. All constructs were initially non-destructively biomechanically tested in axial compression, torsion, and bending, which was followed by cyclic torsional loading to failure. Interfragmentary movements were monitored by means of optical motion tracking.Introduction
Method
Tendon ruptures are a common injury and often require surgical intervention to heal. A refixation is commonly performed with high-strength suture material. However, slipping of the thread is unavoidable even at 7 knots potentially leading to reduced compression of the sutured tendon at its footprint. This study aimed to evaluate the biomechanical properties and effectiveness of a novel dynamic high-strength suture, featuring self-tightening properties. Distal biceps tendon rupture tenotomies and subsequent repairs were performed in sixteen paired human forearms using either conventional or the novel dynamic high-strength sutures in a paired design. Each tendon repair utilized an intramedullary biceps button for radial fixation. Biomechanical testing aimed to simulate an aggressive postoperative rehabilitation protocol stressing the repaired constructs. For that purpose, each specimen underwent in nine sequential days a daily mobilization over 300 cycles under 0-50 N loading, followed by a final destructive test.Introduction
Method
Distal triceps tendon rupture is related to high complication rates with up to 25% failures. Elbow stiffness is another severe complication, as the traditional approach considers prolonged immobilization to ensure tendon healing. Recently a dynamic high-strength suture tape was designed, implementing a silicone-infused core for braid shortening and preventing repair elongation during mobilization, thus maintaining constant tissue approximation. The aim of this study was to biomechanically compare the novel dynamic tape versus a conventional high-strength suture tape in a human cadaveric distal triceps tendon rupture repair model. Sixteen paired arms from eight donors were used. Distal triceps tendon rupture tenotomies and repairs were performed via the crossed transosseous locking Krackow stitch technique for anatomic footprint repair using either conventional suture tape (ST) or novel dynamic tape (DT). A postoperative protocol mimicking intense early rehabilitation was simulated, by a 9-day, 300-cycle daily mobilization under 120N pulling force followed by a final destructive test.Introduction
Method
Unstable intertrochanteric hip fractures (AO 31A2) continue to be a challenge, as non-locking implants have shown a considerable rate of loss of reduction. Intramedullary fixation has been recommended, although screw cut-out has been identified as problematic. This study was performed to ascertain whether treatments with the established proximal femoral nail (PFN) and the newer PFNA with blade design (proximal femoral nail antirotation) have advantages over the use of the Percutaneous Compression Plate (PCCP, developed by Gotfried). Cohort study. Between March 2003 and March 2008, 134 patients with unstable fractures were treated with a PCCP, (n=44, 78.3 yrs, ASA 2.8), a PFN (n=50, 77.2 yrs, ASA 2.8), or a PFNA (n=40, 75.8 yrs, ASA 2.6). The patients (31 PCCP, 33 PFN, 30 PFNA) were then reexamined clinically and radiologically after approximately 21 months.Introduction
Methods
Patients with bilateral femur fractures are known to be at a high risk for the Systemic Inflammatory Response Syndrome; however the impact of fracture-associated soft tissue injury in the induction of systemic inflammation following bilateral femur fracture is poorly understood. To address this, the systemic inflammatory response and remote organ dysfunction following bilateral femur fracture with various degrees of soft tissue injuries were investigated in this study. 6–8 weeks old male C57/BL6 mice (n = 4–8 animals per group) were grouped as follows: Control-group (no anaesthesia, no femoral catheterisation); Sham-group (6 hour anaesthesia, femoral catheterisation); Fx-group (6 hour anaesthesia, femoral catheterisation, bilateral femur fracture with minor soft tissue injury); Fx+STI-group (6 hour anaesthesia, femoral catheterisation, bilateral femur fracture with severe soft tissue injury). Six hours after bilateral femur fracture serum levels of IL-2, IL-4, IL-6, IL-10, IL-12, TNF-α, KC and MCP-1 were measured. Furthermore, IL-6 levels of homogenized liver tissue were assessed. Neutrophil accumulation in liver and lung was determined with a myeloperoxidase (MPO) assay. Changes in liver permeability were assessed by measuring the wet-dry-ratio. The Fx+STI-group showed significantly increased serum cytokine levels as compared to the Fx- or Sham-group. The homogenized liver tissue of the Fx+STI-group showed significantly increased IL-6 levels as compared to the Sham-group. The MPO activity in lung and liver in the Fx+STI-group was significantly increased in comparison to the Fx- or Sham-group and in the Fx-group in comparison to the Sham-group. The wet-dry-ratio of the liver was significantly increased in the Fx+STI-group as compared to the Sham-group. The degree of fracture-associated soft tissue injury appears to modify systemic inflammation following bilateral femur fracture and is able to induce remote organ dysfunction. These results may have implications that have been underestimated, thus warranting clinical follow-up studies.
