Christopher C. Tzioupis

Percutaneous fixation of the pelvic ring: AN UPDATE

With the development of systems of trauma care the management of pelvic disruption has evolved and has become increasingly refined. The goal is to achieve an anatomical reduction and stable fixation of the fracture. This requires adequate visualisation for reduction of the fracture and the placement of fixation. Despite the advances in surgical approach and technique, the functional outcomes do not always produce the desired result. New methods of percutaneous treatment in conjunction with innovative computer-based imaging have evolved in an attempt to overcome the existing difficulties. This paper presents an overview of the technical aspects of percutaneous surgery of the pelvis and acetabulum.

The Safety and Efficacy of Parathyroid Hormone (PTH) as a Biological Response Modifier for the Enhancement of Bone Regeneration.

Osteoporosis is characterized by low bone mineral density and deterioration in the microarchitecture of bone that increases its fracture vulnerability. The mainstay of therapy for osteoporosis is anti-resorptive in mechanism. Parathyroid hormone (PTH) is the most recently approved anabolic agent for osteoporosis. The mechanism of PTHs skeleton anabolic action is composite involving pathways linked to common signalling peptides that affect gene osteoblast transcription. A number of animal studies and clinical trials have demonstrated that intermittent PTH administration induces anabolic effects on both cancellous and cortical bone, enhances bone mass and increases mechanical bone strength, increasing spine and hip bone mineral density and reducing fragility fractures. Preclinical studies investigating the effect of PTH on fracture healing show an increase in bone density and strength indicating an enhancement of this biological cascade. Preclinical and clinical safety assessments have revealed little evidence of toxic effects and there have been few reports of adverse events related to their use. An increase in osteosarcoma in rats probably is not prognostic of an equivalent possibility in humans. In summary, parathyroid hormone is a major advance in the treatment of osteoporosis. Additional studies addressing long-term clinical safety are needed. However the current evidence is very promising.

The immuno-inflammatory response to trauma

The systemic inflammatory response syndrome is a well recognized physiological entity being part of our homeostatic mechanisms. It represents the cascade of inflammatory reactions initiated in the immediate aftermath following trauma reflecting the state of alertness that our body undergoes in order to fight for survival. A variety of inflammatory mediators and cellular elements are involved during this process interacting amongst each other. This allows communication between the different organ systems and thus regulating local and systemic responses. We have just begun to characterize and quantify the immuno-inflammatory response to trauma and this has opened new horizons in the way we understand the pathophysiological response to injury. As our knowledge evolves new therapeutic agents and innovative treatment plans will be developed contributing to increased survival rates in patients with multiple injuries.

Patient Selection: Orthopedic Approach in Polytrauma

The development of the “two hit” theory has been helpful in understanding why certain patients may deteriorate unexpectedly after a major trauma and subsequent major surgery [1, 2]. Both the type and the severity of injury, the rescue conditions, and the individual patient’s response are given facts at the time of patient’s admission, representing the “first hit” in a trauma patient [1]. The subsequent treatment and unexpected complications can modify the clinical course substantially [3–7]. Thus, during the hospital stay, volume replacement, ventilatory support, and the surgical strategy are important variables [8] that may be modified by the hospital physician and thus regulate the degree of the impact of the second hit [9]. An individualized selection process determines which patients undergo a primarydefinitive procedure and which patients benefit from temporary stabilization of their major extremity fractures to minimize the impact of surgery, also known as condition-tailored damage control orthopedic surgery. For decades, assessment of the patient’s clinical status relied on systolic blood pressure alone or in combination with other cardiovascular parameters [10]. The first criteria for appraising blunt trauma patients for orthopedic surgery were published in 1978 and suggested the use of systolic blood pressure, heart rate, central venous pressure, and hematocrit for essential evaluation. In addition, cardiac index, pulmonary arterial pressure, coagulation status, and acid-base parameters were also found to be of value for the early period after trauma [11]. Threshold levels for decision making, however, had not yet been developed at this stage. Later, Asensio and colleagues [12] described the use of intraoperative parameters for predicting outcome and providing guidelines as to when to institute the damage control approach. These parameters include body temperature of £34°C, pH £ 7.2, serum bicarbonate £15 mEq/L, transfusion volume of

Pelvic Fractures in Polytrauma Patients

In recent years, the surgical insult has been described, measured, and quantified with inflammatory mediators such as interleukins and other chemokines [1–3]. The “two-hit” theory for trauma patients indicates that the likelihood of developing post-traumatic complications is increased if several adverse impacts such as hemorrhage, infection, or surgery occur sequentially. Despite the introduction of organized trauma systems, pelvic ring disruptions continue to be a significant source of morbidity and mortality [4–7]. Indeed, in closed pelvic fractures with hemodynamic instability, a mortality rate of up to 42% has been reported [8]. Other factors that have been found to correlate with increased mortality rates include age injury severity score, bony pelvic instability, size and status of the wound in open injuries, presence of rectal injury, number of blood units transfused, and presence of associated injuries [9–11]. Furthermore, mortality following pelvic fractures has been shown to have a trimodal distribution: early at the scene (within minutes), delayed (within 48 h), and late (days to weeks later) [12]. Late mortality is due to multiple organ dysfunction syndrome and sepsis, whereas early mortality is due to uncontrollable hemorrhage (shock), clotting disturbances, and an exaggerated systemic inflammatory response syndrome. Patients with pelvic fractures can be divided into two subgroups: