The use of bone grafts in treating non- or delayed unions as the result of large bone loss is well established. However, despite good outcomes, the time to achieve complete union is still considerably long. To overcome this problem, the use of platelet-rich plasma (PRP) has been advocated albeit with varying success. To determine the true effectiveness of PRP in treating non-/delayed unions, a study was conducted using (n=12) rabbit models.
We studied the factors influencing the mid-term outcomes of tibial plateau fractures treated conservatively (n=21) and surgically (n=27) from December 1994 to December 1997. Joint stability was an important prognostic determinant. In the surgical group, the most important factor was good anatomical reduction. Functional outcomes were comparable between the conservative and surgical groups. We concluded that conservative treatment is a valid option for fractures with minimal displacement and surgical treatment is justified for severely displaced or depressed fractures. Attention must be paid to the recognition and restoration of joint stability and articular surface congruency for a satisfactory outcome.
Pilon fractures can be caused by high-energy vertical forces which may result in long-term patient immobilization. Many experts in orthopedic surgery recommend the use of a Delta external fixator for type III Pilon fracture treatment. This device can promote immediate healing of fractured bone, minimizing the rate of complications as well as allowing early mobilization. The characteristics of different types of the Delta frame have not been demonstrated yet. By using the finite element method, this study was conducted to determine the biomechanical characteristics of six different configurations (Model 1 until Model 6). CT images from the lower limb of a healthy human were used to reconstruct three-dimensional models of foot and ankle bones. All bones were assigned with isotropic material properties and the cartilages were assigned to exhibit hyperelasticity. A linear link was used to simulate 37 ligaments at the ankle joint. Axial loads of 70 and 350 N were applied at the proximal tibia to simulate the stance and swing phase. The metatarsals and calcaneus were fixed distally in order to prevent rigid body motion. A synthetic ankle bone was used to validate the finite element model. The simulated results showed that Delta3 produced the highest relative micromovement (0.09 mm, 7 μm) during the stance and swing phase, respectively. The highest equivalent von Mises stress was found at the calcaneus pin of the Delta4 (423.2 MPa) as compared to others. In conclusion, Delta1 external fixator was the most favorable option for type III Pilon fracture treatment. Graphical abstract ᅟ.
Bone allografts donated by other individuals offer a viable alternative to autograft. Risks of disease transmission are overcome by sterilizing the bone; unfortunately sterilization methods generally affect bone functional properties including osteogenic potential and biomechanical integrity. This study aimed to determine any enhancement effect when gamma sterilised allografts was impregnated with autologous bone marrow in improving the rate and quality of integration in metaphyseal-tibial defects of rabbits. Almost all subjects showed 50% of the defect being covered by new bones by the third week and smaller residual defect size in the treated group at the fifth week. Hounsfield units at the defect site showed increasing healing in all samples, with the treated group having an apparent advantage although insignificant (p > 0.05). In the histopathological score evaluating healing over cortical and cancellous bone at the fracture site showed only slight variations between the groups (p > 0.05). Therefore no enhanced healing by the autologous bone marrow was observed when added to the bone allografts in treating the unicortical defects.
Pilon fractures are commonly caused by high energy trauma and can result in long-term immobilization of patients. The use of an external fixator i.e. the (1) Delta, (2) Mitkovic or (3) Unilateral frame for treating type III pilon fractures is generally recommended by many experts owing to the stability provided by these constructs. This allows this type of fracture to heal quickly whilst permitting early mobilization. However, the stability of one fixator over the other has not been previously demonstrated. This study was conducted to determine the biomechanical stability of these external fixators in type III pilon fractures using finite element modelling. Three-dimensional models of the tibia, fibula, talus, calcaneus, navicular, cuboid, three cuneiforms and five metatarsal bones were reconstructed from previously obtained CT datasets. Bones were assigned with isotropic material properties, while the cartilage was assigned as hyperelastic springs with Mooney-Rivlin properties. Axial loads of 350 N and 70 N were applied at the tibia to simulate the stance and the swing phase of a gait cycle. To prevent rigid body motion, the calcaneus and metatarsals were fixed distally in all degrees of freedom. The results indicate that the model with the Delta frame produced the lowest relative micromovement (0.03 mm) compared to the Mitkovic (0.05 mm) and Unilateral (0.42 mm) fixators during the stance phase. The highest stress concentrations were found at the pin of the Unilateral external fixator (509.2 MPa) compared to the Mitkovic (286.0 MPa) and the Delta (266.7 MPa) frames. In conclusion, the Delta external fixator was found to be the most stable external fixator for treating type III pilon fractures.