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Pelvic pressure changes after a fracture: A pilot cadaveric study assessing the effect of pelvic binders and limb bandaging
Abstracts from the 2015 Meeting of the British Trauma Society, 4th–5th November 2015 / Injury, Int. J. Care Injured 47 (2016) 293–295
non-articular aspect of the fracture. Three different weights were applied to challenge both the techniques of tension band wiring. Results: Measurements from the non-articular surface of the fracture demonstrated greater compression with alternative tension band technique. However it was not statistically significant (ANOVA). Compression at the articular surface of the fracture exhibited statistically significant (p < 0.05) greater compression with the alternative technique. Neither technique produced greater compression during flexion of the simulated elbow. Conclusions: The alternative tension band wiring technique proved superior in providing greater compression over the fracture site and smaller displacement. Clinical studies required to investigate whether this translates into higher union rates and lower metal work loosening. http://dx.doi.org/10.1016/j.injury.2015.12.008
2nd Best Scientific Presentation Abstract 11 Pelvic pressure changes after a fracture: A pilot cadaveric study assessing the effect of pelvic binders and limb bandaging Rhys Morris1,2,*, Andrew Loftus1,2, Anna Lygas1,2, Rozina Mahmood1,2, Ian Pallister2,3 1
College of Medicine, Swansea University, SA2 8PP, UK Queen Elizabeth University Hospital Birmingham, B15 2TH, UK 3 Morriston Hospital, Swansea SA6 6NL, UK *Corresponding author. 2
Objectives: Pelvic binders are a life-saving intervention for hypovolaemic shock following displaced pelvic fractures, thought to act through increasing intra-pelvic pressure to reduce venous bleeding. This cadaveric study assesses changes in intra-pelvic pressure with different binders augmented by bandaging the thighs to recruit the femora as levers to close the pelvis. Access to femoral vessels via an in situ binder was also assessed. Methods: Two embalmed cadavers were used with unstable pelvic injuries (OA/OTA 61-C1) created through disrupting the pelvic ring anteriorly and posteriorly. To measure intravesical pressure, which reflects intra-pelvic pressure, a supra-pubic catheter was inserted and connected to a water manometer whilst a spigot was placed in a urethral catheter to reduce leakage of fluid. The common and superficial femoral arteries were dissected in the left groin for each specimen prior to any intervention to allow inspection following binder application. A SAM pelvic sling II, Trauma Pelvic Orthotic Device (T-POD), Prometheus pelvic splint and an improvised pelvic binder were used on each cadaver, with each applied following lower limb bandaging with the knees slightly flexed. The groins were then inspected to assess if the femoral vessels were visible. Statistical analysis was performed in SPSS using a paired samples t test to determine if any difference existed between initial pelvic pressure in specimens compared to pressures with bandaging on and binders applied. Results: Bandaging the lower limbs alone produced a significant increase in both peak and steady mean intra-pelvic pressure, 15.69 cmH2O and 12.38 cmH2O, respectively, compared to the baseline pressure, 8.73 cmH2O (p = 0.002 and p = 0.001, respectively). Applying the pelvic binder with the bandaging in place increased intra-pelvic pressure compared to the baseline (peak pressure of 25.38 cmH2O (p < 0.001) and steady pressure of 15.13 cmH2O
295
(p = 0.003)). Steady mean pressures between bandaging alone and bandaging with the binder applied were not significantly different (p = 0.09), whilst the peak pressures were significantly greater when the binder was applied (p = 0.005). The improvised binder and T-POD both required cutting to access the femoral vessels which resulted in decreasing efficacy. Conclusions: Intra-pelvic pressure was significantly increased through bandaging the lower limbs alone, and this represents a simple measure to increase intra-pelvic pressure and therefore efficacy of the binder. Access to the femoral vessels varied with binder type and represents an important consideration in polytrauma patients. http://dx.doi.org/10.1016/j.injury.2015.12.009 Poster 23 Are stainless steel elastic nails the solution to heavier children with femoral shaft fractures? Richard Hutchinson*, Sam Evans Cardiff University, United Kingdom *Corresponding author. Objectives: The use of titanium elastic intramedullary nails for the treatment of femoral shaft fractures, in children weighing 45 kg, has been questioned due to the increased rates of malunion. Our aim was to see if the mechanical properties of stainless steel elastic nails provided enough fracture stability to justify their use in heavier children. Methods: 20 synthetic paediatric-sized femoral Sawbones1, with mid-shaft fractures, fixed with either titanium or stainless steel elastic nails, were tested using a four-point bending set-up. The bending stiffness and bending moments of the constructs were calculated at increasing loads, along with the angle of fracture deformation. From this estimates of maximum permitted body weight for each nail type could be extrapolated. Results: Stainless steel nails created significantly stiffer constructs than titanium in both the coronal and sagittal planes (p < 0.0001). Steel nails required much bigger bending moments (19.1 Nm) before loosing acceptable alignment, than titanium (14.2 Nm), in the sagittal plane (p < 0.0001). However, despite steel just out performing titanium in the coronal plane, this difference was not statistically significant. The estimated body weights extrapolated in the sagittal plane were 45 kg and 61 kg, in titanium and steel, respectively (p < 0.0001). In the coronal plane they were 42 kg and 44 kg, in titanium and steel, respectively (p = 0.457). Conclusions: As stainless steel has nearly twice the Young’s modulus of titanium, it seems logical that fractures fixed with steel nails would be stiffer and fail at higher loads. However it is unclear why steel did not out perform titanium in the coronal plane. A theory was proposed that unequal nail slip from the insertion sites might be a contributing factor to these findings. Current evidence suggests neither stainless steel nor titanium elastic nails are suitable for stabilizing femoral shaft fractures in children 45 kg, due to risk of malunion. Further research into the use of end caps is needed to see if they provide the added stability needed in heavier children. http://dx.doi.org/10.1016/j.injury.2015.12.010
non-articular aspect of the fracture. Three different weights were applied to challenge both the techniques of tension band wiring. Results: Measurements from the non-articular surface of the fracture demonstrated greater compression with alternative tension band technique. However it was not statistically significant (ANOVA). Compression at the articular surface of the fracture exhibited statistically significant (p < 0.05) greater compression with the alternative technique. Neither technique produced greater compression during flexion of the simulated elbow. Conclusions: The alternative tension band wiring technique proved superior in providing greater compression over the fracture site and smaller displacement. Clinical studies required to investigate whether this translates into higher union rates and lower metal work loosening. http://dx.doi.org/10.1016/j.injury.2015.12.008
2nd Best Scientific Presentation Abstract 11 Pelvic pressure changes after a fracture: A pilot cadaveric study assessing the effect of pelvic binders and limb bandaging Rhys Morris1,2,*, Andrew Loftus1,2, Anna Lygas1,2, Rozina Mahmood1,2, Ian Pallister2,3 1
College of Medicine, Swansea University, SA2 8PP, UK Queen Elizabeth University Hospital Birmingham, B15 2TH, UK 3 Morriston Hospital, Swansea SA6 6NL, UK *Corresponding author. 2
Objectives: Pelvic binders are a life-saving intervention for hypovolaemic shock following displaced pelvic fractures, thought to act through increasing intra-pelvic pressure to reduce venous bleeding. This cadaveric study assesses changes in intra-pelvic pressure with different binders augmented by bandaging the thighs to recruit the femora as levers to close the pelvis. Access to femoral vessels via an in situ binder was also assessed. Methods: Two embalmed cadavers were used with unstable pelvic injuries (OA/OTA 61-C1) created through disrupting the pelvic ring anteriorly and posteriorly. To measure intravesical pressure, which reflects intra-pelvic pressure, a supra-pubic catheter was inserted and connected to a water manometer whilst a spigot was placed in a urethral catheter to reduce leakage of fluid. The common and superficial femoral arteries were dissected in the left groin for each specimen prior to any intervention to allow inspection following binder application. A SAM pelvic sling II, Trauma Pelvic Orthotic Device (T-POD), Prometheus pelvic splint and an improvised pelvic binder were used on each cadaver, with each applied following lower limb bandaging with the knees slightly flexed. The groins were then inspected to assess if the femoral vessels were visible. Statistical analysis was performed in SPSS using a paired samples t test to determine if any difference existed between initial pelvic pressure in specimens compared to pressures with bandaging on and binders applied. Results: Bandaging the lower limbs alone produced a significant increase in both peak and steady mean intra-pelvic pressure, 15.69 cmH2O and 12.38 cmH2O, respectively, compared to the baseline pressure, 8.73 cmH2O (p = 0.002 and p = 0.001, respectively). Applying the pelvic binder with the bandaging in place increased intra-pelvic pressure compared to the baseline (peak pressure of 25.38 cmH2O (p < 0.001) and steady pressure of 15.13 cmH2O
295
(p = 0.003)). Steady mean pressures between bandaging alone and bandaging with the binder applied were not significantly different (p = 0.09), whilst the peak pressures were significantly greater when the binder was applied (p = 0.005). The improvised binder and T-POD both required cutting to access the femoral vessels which resulted in decreasing efficacy. Conclusions: Intra-pelvic pressure was significantly increased through bandaging the lower limbs alone, and this represents a simple measure to increase intra-pelvic pressure and therefore efficacy of the binder. Access to the femoral vessels varied with binder type and represents an important consideration in polytrauma patients. http://dx.doi.org/10.1016/j.injury.2015.12.009 Poster 23 Are stainless steel elastic nails the solution to heavier children with femoral shaft fractures? Richard Hutchinson*, Sam Evans Cardiff University, United Kingdom *Corresponding author. Objectives: The use of titanium elastic intramedullary nails for the treatment of femoral shaft fractures, in children weighing 45 kg, has been questioned due to the increased rates of malunion. Our aim was to see if the mechanical properties of stainless steel elastic nails provided enough fracture stability to justify their use in heavier children. Methods: 20 synthetic paediatric-sized femoral Sawbones1, with mid-shaft fractures, fixed with either titanium or stainless steel elastic nails, were tested using a four-point bending set-up. The bending stiffness and bending moments of the constructs were calculated at increasing loads, along with the angle of fracture deformation. From this estimates of maximum permitted body weight for each nail type could be extrapolated. Results: Stainless steel nails created significantly stiffer constructs than titanium in both the coronal and sagittal planes (p < 0.0001). Steel nails required much bigger bending moments (19.1 Nm) before loosing acceptable alignment, than titanium (14.2 Nm), in the sagittal plane (p < 0.0001). However, despite steel just out performing titanium in the coronal plane, this difference was not statistically significant. The estimated body weights extrapolated in the sagittal plane were 45 kg and 61 kg, in titanium and steel, respectively (p < 0.0001). In the coronal plane they were 42 kg and 44 kg, in titanium and steel, respectively (p = 0.457). Conclusions: As stainless steel has nearly twice the Young’s modulus of titanium, it seems logical that fractures fixed with steel nails would be stiffer and fail at higher loads. However it is unclear why steel did not out perform titanium in the coronal plane. A theory was proposed that unequal nail slip from the insertion sites might be a contributing factor to these findings. Current evidence suggests neither stainless steel nor titanium elastic nails are suitable for stabilizing femoral shaft fractures in children 45 kg, due to risk of malunion. Further research into the use of end caps is needed to see if they provide the added stability needed in heavier children. http://dx.doi.org/10.1016/j.injury.2015.12.010