Immediate management of a stable patient with unstable pelvis.

The diagnosis of a traumatic unstable pelvis in a stable patient is a temporary concept depending on when we see the patient, as all patients presenting with hemorrhagic shock have hemodynamic stability until they become unstable. As a rule, the more unstable the pelvic fracture is, the higher the risk of bleeding and hemodynamic instability it has. Therefore, in unstable pelvic fractures, hemodynamic stability should be a diagnosis by exclusion. For bleeding detection in stable patients, an immediate one-stage contrast-enhanced CT scan is the appropriate diagnosis test; however, since CT scan radiation is always an issue, X-rays should be considered in those cases of hemodynamically stable patients in whom there is a reasonable suspicion that no unsafe bleeding is going on. Pelvic fracture classification is essential as usually there is an association between the injury mechanism, the fracture displacement, and the hemodynamic stability. Anteroposterior and, particularly, vertical traumatisms have much more proclivity to provoke major pelvic displacement and bleeding. The use of a pelvic binder, as early as possible including pre-hospital management, should be standard in high-impact blunt trauma patients independently of the trauma mechanisms. External fixation is the preferred method of stabilization in case of open fractures, and, in closed ones, when the schedule for definite osteosynthesis prolongs because of the patient's general condition. If possible, immediate percutaneous sacroiliac screw insertion for unstable pelvic fractures produce excellent results even in open fractures.

L4 fixation is not necessary in L5-Iliac spinopelvic fixation after trauma, but coadjutant transilio-transsacral fixation is.

INTRODUCTION: Spinopelvic dissociation (SPD) is a severe injury characterized by a discontinuity between the spine and the bony pelvis consisting of a bilateral longitudinal sacral fracture, most of the times through sacral neuroforamen, and a horizontal fracture, usually through the S1 or S2 body. The introduction of the concept of triangular osteosynthesis has shown to be an advance in the stability of spinopelvic fixation (SPF). However, a controversy exists as to whether the spinal fixation should reach up to L4 and, if so, it should be combined with transiliac-transsacral screws (TTS). OBJECTIVE: The purpose of this study is to compare the biomechanical behavior in the laboratory of four different osteosynthesis constructs for SPD, including spinopelvic fixation of L5 versus L4 and L5; along with or without TTS in both cases. MATERIAL AND METHODS: By means of a formerly described method by the authors, an unstable standardized H-type sacral fracture in twenty synthetic replicas of a male pelvis articulated to the lumbar spine, L1 to sacrum, (Model: 1300, SawbonesTM; Pacific Research Laboratories, Vashon, WA, USA), instrumented with four different techniques, were mechanically tested. We made 4 different constructs in 5 specimen samples for each construct. Groups: Group 1. Instrumentation of the L5-Iliac bones with TTS. Group 2. Instrumentation of the L4-L5-Iliac bones with TTS. Group 3. Instrumentation of L5-Iliac bones without TTS. Group 4: Instrumentation of L4-L5-Iliac bones without TTS. RESULTS AND CONCLUSIONS: According to our results, it can be concluded that in SPD, better stability is obtained when proximal fixation is only up to L5, without including L4 (alternative hypothesis), the addition of transiliac-transsacral fixations is essential.

The treatment of bacterial biofilms cultivated on knee arthroplasty implants using the bioelectric effect.

Introduction: The formation of bacterial biofilms on knee arthroplasty implants can have catastrophic consequences. The aim of this study was to analyze the effectiveness of the bioelectric effect in the elimination of bacterial biofilms on cultivated knee arthroplasty implants. Methods: A novel device was designed to deliver a bioelectric effect on the surface of knee arthroplasty implants. 4-femoral prosthetic implants were cultivated with a staphylococcus aureus inoculum for 15 days. The components were divided into four different groups: A (not treated), B (normal saline 20-minutes), C (bioelectric effect 10-minutes), D (bioelectric effect 20-minutes). The implants were sonicated, and the detached colonies were quantified as the number of colony-forming unit (CFUs). The implants were sterilised and the process was repeated in a standardized manner four more times, to obtain a total of five samples per group. Results: The number of the CFUs after a 10-minute exposure to the bioelectric effect was of 208.2 ± 240.4, compared with 6,041.6 ± 2010.7 CFUs in group A, representing a decrease of 96.5% ± 4.3 (p = 0.004). And a diminution of 91.8% ± 7.9 compared with 2,051.0 ± 1,364.0 CFUs in group B (p = 0.109). The number of bacterial colonies after a 20-minute exposure to the bioelectric effect was 70 ± 126.7 CFUs, representing a decrease of 98.9% ± 1.9 (p = 0.000) compared with group A. And a decrease of 97.8% ± 3.0 (p = 0.019) compared with group B. Conclusions: The bioelectric effect was effective in the elimination of bacterial biofilm from knee arthroplasty implants. This method could be used in the future as part of conventional surgical procedures.