Assessing Taper Geometry, Head Size, Head Material, and Their Interactions in Taper Fretting Corrosion of Retrieved Total Hip Arthroplasty Implants.

Background: Decreased fretting and corrosion damage at the taper interface of retrieved ceramic-on-polyethylene total hip arthroplasty (THA) implants has been consistently reported; however, resultant fretting corrosion as a function of femoral head size and taper geometry has not been definitively explained.

Methods: Eight cohorts were defined from 157 retrieved THA implants based on femoral head composition (n = 95, zirconia-toughened alumina, ZTA vs n = 62, cobalt-chromium alloy, CoCr), head size (n = 56, 32mm vs n = 101, 36mm), and taper geometry (n = 84, 12/14 vs n = 73, V40). THA implants were evaluated and graded for taper fretting and corrosion.

Evaluation of the Painful Total Knee Arthroplasty.

Total knee arthroplasty (TKA) has been associated with notable improvements in health-related quality of life of patients with end-stage knee arthritis. Although most patients experience substantial symptomatic relief after TKA, up to 19% of patients are unsatisfied with their outcome. With the dramatic, projected increase in the number of TKAs performed annually, it is crucial to appreciate the various modes of failure associated with this procedure.

Does Taper Design Affect Taper Fretting Corrosion in Ceramic-on-Polyethylene Total Hip Arthroplasty? A Retrieval Analysis.

Background: Ceramic-on-polyethylene (CoP) implants have exhibited lower fretting and corrosion scores than metal-on-polyethylene implants. This study aims at investigating the effect of taper design on taper corrosion and fretting in modular CoP total hip arthroplasty (THA) systems.

Methods: Under an institutional review board--approved protocol, a query of an implant retrieval library from 2002 to 2017 identified 120 retrieved CoP THA systems with zirconia toughened alumina femoral heads.

Poor Outcomes of Irrigation and Debridement in Acute Periprosthetic Joint Infection With Antibiotic-Impregnated Calcium Sulfate Beads.

Background: One proposed strategy to increase the success of irrigation and debridement with implant retention for the treatment of acute periprosthetic joint infection (PJI) is the use of dissolvable antibiotic-impregnated calcium sulfate beads to provide a local depot of antibiotics. The purpose of this study was to evaluate the outcome of such an approach.

Methods: Thirty-two patients with acute hematogenous (18 patients; 1 bilateral) or acute postoperative (14 patients) PJIs who underwent irrigation and debridement with implant retention and addition of antibiotic-impregnated calcium sulfate beads were retrospectively reviewed.

The molecular fingerprint of lung inflammation after blunt chest trauma.

Background: After severe blunt chest trauma, the development of an acute lung injury (ALI) is often associated with severe or even lethal complications. Especially in multiple injured patients after blunt chest trauma ALI/ARDS [acute respiratory distress syndrome (ARDS)] is frequent. However, in the initial posttraumatic phase, inflammatory clinical signs are often not apparent and underlying changes in gene-expression profile are unknown.

Rotation and Displacement Predict Adverse Events in Pediatric Supracondylar Fractures.

The goal of this study was to identify supracondylar fracture patterns that were predictive of adverse events and poor outcomes. The study consisted of a retrospective review of patients admitted for surgical treatment of a supracondylar humerus fracture between June 2008 and August 2010. Preoperative radiographs were assessed based on appearance (simple vs oblique vs comminuted), coronal plane displacement (angulated, posterior, posteromedial vs posterolateral), and rotation (rotation vs no rotation).

Deficiency of complement receptors CR2/CR1 in Cr2⁻/⁻ mice reduces the extent of secondary brain damage after closed head injury.

Complement activation at the C3 convertase level has been associated with acute neuroinflammation and secondary brain injury after severe head trauma. The present study was designed to test the hypothesis that Cr2-/- mice, which lack the receptors CR2/CD21 and CR1/CD35 for complement C3-derived activation fragments, are protected from adverse sequelae of experimental closed head injury. Adult wild-type mice and Cr2-/- mice on a C57BL/6 genetic background were subjected to focal closed head injury using a standardized weight-drop device.

Outcomes and complication rates of different bone grafting modalities in long bone fracture nonunions: a retrospective cohort study in 182 patients.

Background: Novel bone substitutes have challenged the notion of autologous bone grafting as the 'gold standard' for the surgical treatment of fracture nonunions. The present study was designed to test the hypothesis that autologous bone grafting is equivalent to other bone grafting modalities in the management of fracture nonunions of the long bones.

Methods: A retrospective review of patients with fracture nonunions included in two prospective databases was performed at two US level 1 trauma centers from January 1, 1998 (center 1) or January 1, 2004 (center 2), respectively, until December 31, 2010 (n = 574).

Successful LCL reconstruction and PCL repair for LCL tear and PCL avulsion following total knee arthroplasty.

Total knee arthroplasty represents a well-established and successful procedure; however, ligament incompetence is known to negatively affect surgical outcomes. Here we present an unusual case of early total knee arthroplasty failure secondary to femoral posterior cruciate ligament (PCL) avulsion and associated lateral collateral ligament (LCL) tear, treated successfully with primary PCL repair and LCL reconstruction. For LCL reconstruction, a peroneus longus allograft was passed through an anterior to posterior bony tunnel in the fibular head and docked into a horizontal femoral tunnel.

Zonulin as prehaptoglobin2 regulates lung permeability and activates the complement system.

Zonulin is a protein involved in the regulation of tight junctions (TJ) in epithelial or endothelial cells. Zonulin is known to affect TJ in gut epithelial cells, but little is known about its influences in other organs. Prehaptoglobin2 has been identified as zonulin and is related to serine proteases (MASPs, C1qrs) that activate the complement system.

Changes and regulation of the C5a receptor on neutrophils during septic shock in humans.

During experimental sepsis, excessive generation of the anaphylatoxin C5a results in reduction of the C5a receptor (C5aR) on neutrophils. These events have been shown to result in impaired innate immunity. However, the regulation and fate of C5aR on neutrophils during sepsis are largely unknown.

The impact of a standardized "spine damage-control" protocol for unstable thoracic and lumbar spine fractures in severely injured patients: a prospective cohort study.

Background: In contrast to the established principles of "damage-control orthopedics" for temporary external fixation of long bone or pelvic fractures, the "ideal" timing and modality of fixation of unstable spine fractures in severely injured patients remains controversial.

Methods: A prospective cohort study was designed to evaluate the safety and efficacy of a standardized "spine damage-control" (SDC) protocol for the acute management of unstable thoracic and lumbar spine fractures in severely injured patients. A total of 112 consecutive patients with unstable thoracic or lumbar spine fractures and Injury Severity Score (ISS) of greater than 15 were prospectively enrolled in this study from October 1, 2008, to December 31, 2011.

A new experimental polytrauma model in rats: molecular characterization of the early inflammatory response.

Background: The molecular mechanisms of the immune response after polytrauma are highly complex and far from fully understood. In this paper, we characterize a new standardized polytrauma model in rats based on the early molecular inflammatory and apoptotic response.

Methods: Male Wistar rats (250 g, 6-10/group) were anesthetized and exposed to chest trauma (ChT), closed head injury (CHI), or Tib/Fib fracture including a soft tissue trauma (Fx + STT) or to the following combination of injuries: (1) ChT; (2) ChT + Fx + STT; (3) ChT + CHI; (4) CHI; (5) polytrauma (PT = ChT + CHI + Fx + STT).

Challenging the role of adaptive immunity in neurotrauma: Rag1(-/-) mice lacking mature B and T cells do not show neuroprotection after closed head injury.

The role of adaptive immunity in contributing to post-traumatic neuroinflammation and neuropathology after head injury remains largely unexplored. The present study was designed to investigate the pathophysiological sequelae of closed head injury in Rag1(-/-) mice devoid of mature B and T lymphocytes. C57BL/6 wild-type and Rag1(-/-) mice were subjected to experimental closed head injury, using a standardized weight-drop device.

Early complementopathy after multiple injuries in humans.

After severe tissue injury, innate immunity mounts a robust systemic inflammatory response. However, little is known about the immediate impact of multiple trauma on early complement function in humans. In the present study, we hypothesized that multiple trauma results in immediate activation, consumption, and dysfunction of the complement cascade and that the resulting severe "complementopathy" may be associated with morbidity and mortality.

Disturbances of the hypothalamic-pituitary-adrenal axis and plasma electrolytes during experimental sepsis.

Background: Sepsis continues to be a poorly understood syndrome with a high mortality rate. While we are beginning to decipher the intricate interplay of the inflammatory response during sepsis, the precise regulation of the hypothalamic-pituitary-adrenal (HPA) axis and its impact on electrolyte homeostasis during sepsis remains incompletely understood.

Methods: Sepsis was induced in adult male Sprague-Dawley rats by cecal ligation and puncture (CLP).

Molecular mechanisms of inflammation and tissue injury after major trauma--is complement the "bad guy"?

Trauma represents the leading cause of death among young people in industrialized countries. Recent clinical and experimental studies have brought increasing evidence for activation of the innate immune system in contributing to the pathogenesis of trauma-induced sequelae and adverse outcome. As the "first line of defense", the complement system represents a potent effector arm of innate immunity, and has been implicated in mediating the early posttraumatic inflammatory response.

Survival following a vertical free fall from 300 feet: the crucial role of body position to impact surface.

We report the case of a 28-year old rock climber who survived an "unsurvivable" injury consisting of a vertical free fall from 300 feet onto a solid rock surface. The trauma mechanism and injury kinetics are analyzed, with a particular focus on the relevance of body positioning to ground surface at the time of impact. The role of early patient transfer to a level 1 trauma center, and "damage control" management protocols for avoiding delayed morbidity and mortality in this critically injured patient are discussed.

Influence of preoperative 7.5% hypertonic saline on neutrophil activation after reamed intramedullary nailing of femur shaft fractures: a prospective randomized pilot study.

Objectives: Femoral reaming and intramedullary nailing (IMN) primes polymorphonuclear leukocytes (PMNL) and thereby increases the posttraumatic systemic inflammatory response. Resuscitation with hypertonic saline (HTS) attenuates PMNL activation after trauma-hemorrhage. We hypothesized that preoperative administration of 7.

Complement C3 serum levels in anorexia nervosa: a potential biomarker for the severity of disease?

Background: Anorexia nervosa carries the highest mortality rate of any psychiatric disorder. Even the most critically ill anorexic patients may present with normal 'standard' laboratory values, underscoring the need for a new sensitive biomarker. The complement cascade, a major component of innate immunity, represents a driving force in the pathophysiology of multiple inflammatory disorders.

Traction table-related complications in orthopaedic surgery.

Traction tables are used in numerous procedures about the hip and femur, including fracture fixation, hip arthroscopy, and less invasive arthroplasty. The use of a traction table is not without risks, however, and significant complications have been described, including injury to the perineal integument and soft tissues, neurologic impairment, and iatrogenic compartment syndrome of the well leg. The orthopaedic surgeon who uses a traction table for the surgical management of femur fracture must be familiar with the associated potential dangers and risks and must develop a plan to avoid traction table-associated complications, such as use of a radiolucent flat-top operating table for obese patients, adequate patient positioning, and the minimum possible surgical time.

Targeted modulation of the neuroinflammatory response after spinal cord injury: the ongoing quest for the "holy grail".

This Commentary discusses the role of inflammation after spinal cord injury.

Stress radiograph to detect true extent of symphyseal disruption in presumed anteroposterior compression type I pelvic injuries.

Background: The differentiation between anteroposterior compression (APC)-I and APC-II pelvic fracture patterns is critical in determining operative versus nonoperative treatment. We instituted a protocol in which a stress examination was performed for patients presenting with an APC-I injury diagnosed with static radiographs to reveal the true extent of the injury.

Methods: During a 4-year study period, we performed 22 stress radiographs in patients with a presumed APC-I injury, which showed symphyseal diastasis ≥ 1.