Outcomes of Dual Mobility Versus Fixed-Bearing Components in Revision Total Hip Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: Dual mobility (DM) implants have received increasing interest in revision surgery due to their increased stability. The aim of this systematic review was to compare outcomes of DM versus conventional fixed-bearing (FB) implants in revision total hip arthroplasty (rTHA). METHODS: A comprehensive search was performed using the PubMed, Embase, and MEDLINE databases between January 2000 and 2023. Outcome measures included rerevision due to dislocation, rerevision for other causes, all-cause rerevision, total complication rate, and functional outcome measures. The Methodological Index for Nonrandomized Studies assessment tool was used to evaluate methodological quality and the risk of bias. A pooled meta-analysis was conducted, with an assessment of heterogeneity using the Chi-square and Higgins I2 tests. A further subgroup analysis was performed between DM implants and larger femoral head (> 36 mm) FB implants. RESULTS: A total of 13 studies met the final inclusion criteria, with an overall number of 5,004 rTHA hips included (2,108 DM and 2,896 FB). The DM implants had significantly lower odds of rerevision due to dislocation (odds ratio [OR] 0.38, P < 0.001), aseptic loosening (OR 0.54, P = 0.004), and all-cause rerevision (OR 0.55, P < 0.001) compared to FB implants. No statistically significant difference was seen in the odds of rerevision due to periprosthetic joint infection (OR 0.99, P = 0.94) or periprosthetic fracture (OR 0.59, P = 0.13) between the 2 groups. The total number of complications showed an odds benefit in favor of DM implants (OR 0.43, P < 0.001). In the subgroup analysis, there was no significant difference in the odds of rerevision due to dislocation (OR 0.69, P = 0.11) between DM and larger femoral head FB implants. CONCLUSIONS: Based on current literature, it appears DM implants are an effective modality for reducing dislocation following rTHA with lower complication rates compared to FB implants. However, further prospective randomized controlled trials with longer term follow-up are required.

Infrapatellar fat pad syndrome: a review of anatomy, function, treatment and dynamics.

The infrapatellar (Hoffa's) fatpad is an important structure within the knee, whose function and role are both poorly understood. This review explores the anatomy, neural innervation, vascularity, role in biomechanics, pathology, imaging (stressing the importance of dynamic ultrasound assessment) and treatment of disorders presenting within this structure.

Role of Adiponectin Receptor 1 in Promoting Nitric Oxide-Mediated Flow-Induced Dilation in the Human Microvasculature.

Chronic administration of exogenous adiponectin restores nitric oxide (NO) as the mediator of flow-induced dilation (FID) in arterioles collected from patients with coronary artery disease (CAD). Here we hypothesize that this effect as well as NO signaling during flow during health relies on activation of Adiponectin Receptor 1 (AdipoR1). We further posit that osmotin, a plant-derived protein and AdipoR1 activator, is capable of eliciting similar effects as adiponectin. Human arterioles (80-200 µm) collected from discarded surgical adipose specimens were cannulated, pressurized, and pre-constricted with endothelin-1 (ET-1). Changes in vessel internal diameters were measured during flow using videomicroscopy. Immunofluorescence was utilized to compare expression of AdipoR1 during both health and disease. Administration of exogenous adiponectin failed to restore NO-mediated FID in CAD arterioles treated with siRNA against AdipoR1 (siAdipoR1), compared to vessels treated with negative control siRNA. Osmotin treatment of arterioles from patients with CAD resulted in a partial restoration of NO as the mediator of FID, which was inhibited in arterioles with decreased expression of AdipoR1. Together these data highlight the critical role of AdipoR1 in adiponectin-induced NO signaling during shear. Further, osmotin may serve as a potential therapy to prevent microvascular endothelial dysfunction as well as restore endothelial homeostasis in patients with cardiovascular disease.

Impact of improved combat casualty care on combat wounded undergoing exploratory laparotomy and massive transfusion.

BACKGROUND: Studies have shown decreased mortality after improvements in combat casualty care, including increased fresh frozen plasma (FFP):red blood cell (RBC) ratios. The objective was to evaluate the evolution and impact of improved combat casualty care at different time periods of combat operations. METHODS: A retrospective review was performed at one combat support hospital in Iraq of patients requiring both massive transfusion (≥ 10 units RBC in 24 hours) and exploratory laparotomy. Patients were divided into two cohorts based on year wounded: C1 between December 2003 and June 2004, and C2 between September 2007 and May 2008. Admission data, amount of blood products and fluid transfused, and 48 hour mortality were compared. Statistical significance was set at p < 0.05. RESULTS: There was decreased mortality in C2 (47% vs. 20%). Patients arrived warmer with higher hemoglobin. They were transfused more RBC and FFP in the emergency department (5 units ± 3 units vs. 2 units ± 2 units; 3 units ± 2 units vs. 0 units ± 1 units, respectively) and received less crystalloid in operating room (3.3 L ± 2.2 L vs. 8.5 L ± 4.9 L). The FFP:RBC ratio was also closer to 1:1 in C2 (0.775 ± 0.32 vs. 0.511 ± 0.21). CONCLUSIONS: The combination of improved prehospital care, trauma systems approach, performance improvement projects, and improved transfusion or resuscitation practices have led to a 50% decrease in mortality for this critically injured population. We are now transfusing blood products in a ratio more consistent with 1 FFP to 1 RBC. Simultaneously, crystalloid use has decreased by 61%, all of which is consistent with hemostatic resuscitation principles.

Died of wounds on the battlefield: causation and implications for improving combat casualty care.

BACKGROUND: Understanding the epidemiology of death after battlefield injury is vital to combat casualty care performance improvement. The current analysis was undertaken to develop a comprehensive perspective of deaths that occurred after casualties reached a medical treatment facility. METHODS: Battle injury died of wounds (DOW) deaths that occurred after casualties reached a medical treatment facility from October 2001 to June 2009 were evaluated by reviewing autopsy and other postmortem records at the Office of the Armed Forces Medical Examiners (OAFME). A panel of military trauma experts classified the injuries as nonsurvivable (NS) or potentially survivable (PS), in consultation with an OAFME forensic pathologist. Data including demographics, mechanism of injury, physiologic and laboratory variables, and cause of death were obtained from the Joint Theater Trauma Registry and the OAFME Mortality Trauma Registry. RESULTS: DOW casualties (n = 558) accounted for 4.56% of the nonreturn to duty battle injuries over the study period. DOW casualties were classified as NS in 271 (48.6%) cases and PS in 287 (51.4%) cases. Traumatic brain injury was the predominant injury leading to death in 225 of 271 (83%) NS cases, whereas hemorrhage from major trauma was the predominant mechanism of death in 230 of 287 (80%) PS cases. In the hemorrhage mechanism PS cases, the major body region bleeding focus accounting for mortality were torso (48%), extremity (31%), and junctional (neck, axilla, and groin) (21%). Fifty-one percent of DOW casualties presented in extremis with cardiopulmonary resuscitation upon presentation. CONCLUSIONS: Hemorrhage is a major mechanism of death in PS combat injuries, underscoring the necessity for initiatives to mitigate bleeding, particularly in the prehospital environment.

Safety evaluation of new hemostatic agents, smectite granules, and kaolin-coated gauze in a vascular injury wound model in swine.

BACKGROUND: In 2007, a potent procoagulant mineral called WoundStat (WS), consisting of smectite granules, received clearance from the Food and Drug Administration for marketing in the United States for temporary treatment of external hemorrhage. Previously, we found that microscopic WS particles remained in the injured vessels that were treated, despite seemingly adequate wound debridement. Thus, we investigated the thromboembolic risk of using WS when compared with kaolin-coated gauze, Combat Gauze (CG); or regular gauze, Kerlix (KX) to treat an external wound with vascular injuries in pigs. METHODS: The right common carotid artery and external jugular vein of pigs were isolated and sharply transected (50%). After 30 seconds of free bleeding, the neck wounds were packed with WS, CG, or KX and compressed until hemostasis was achieved (n = 8 per group). Wounds were debrided after 2 hours, and vascular injuries were primarily repaired with suture. Blood flow was restored after infusing 1 L of crystalloid (no heparin or aspirin) and the wounds were closed. Two hours later, computed tomographic angiography was performed, and the wounds were reopened to harvest the vessels. The brains and lungs were recovered for gross and microscopic examination after euthanasia. RESULTS: No differences were found in baseline measurements. Thrombelastography showed similar hypercoagulability of the final blood samples when compared with baselines in all groups. All vessels treated with KX or CG were patent and had no thrombus or blood clot in their lumen. In contrast, seven of eight carotid arteries and six of eight jugular veins treated with WS developed large occlusive red thrombi and had no flow. Small clots and WS residues were also found in the lungs of two pigs. Histologically, significant endothelial and transmural damage was seen in WS-treated vessels with luminal thrombi and embedded WS residues. CONCLUSION: WS granules caused endothelial injury and significant transmural damage to the vessels that render them nonviable for primary surgical repair. The granules can enter systemic circulation and cause distal thrombosis in vital organs. More relevant in vitro and in vivo safety tests should be required for clearance of new hemostatic agents.

Impact of policy change on US Army combat transfusion practices.

BACKGROUND: Clinical practice guidelines (CPGs) are used to keep providers up-to-date with the most recent literature and to guide in decision making. Adherence is typically improved although many have a muted impact. In March 2006, the US Army issued a damage control resuscitation CPG, encouraging 1:1 plasma:red blood cell (RBC) transfusions and limiting crystalloid use. The objective of this study was to determine whether the CPG was associated with a change in the transfusion practices in combat-wounded patients. METHODS: All US service members injured in Operation Iraqi Freedom/Operation Enduring Freedom who received massive transfusions (MTs; > or = 10 RBC in 24 hours) were queried from the US Army Institute of Surgical Research transfusion database. Whole blood, when used, was counted as 1 unit of RBC, fresh frozen plasma (FFP), and platelet. Subjects were divided into pre- and post-CPG cohorts. Primary outcomes were ratios of FFP:RBC and crystalloid use. RESULTS: A total of 777 MT patients were identified. The cohorts were similar in age (25 years +/- 6 years vs. 25 years +/- 6 years; p = ns) and injury severity scale score (24 +/- 12 vs. 25 +/- 12; p = ns). The post-CPG cohort was warmer (96.5 degrees F +/- 7.8 degrees F vs. 98.2 degrees F +/- 1.9 degrees F; p < 0.05) and was transfused more RBC, platelets, and plasma but received less crystalloid (17 units +/- 12 units vs. 19 units +/- 11 units, 1 unit +/- 2 units vs. 2 units +/- 3 units, 8 units +/- 8 units vs. 14 units +/- 11 units, 14 L +/- 14 L vs. 9 L +/- 13 L, respectively; p < 0.05). The post-CPG cohort also received a higher ratio transfusion (0.5 +/- 0.31 vs. 0.8 +/- 0.31; p < 0.05) representing a change in practice. Overall mortality was not different between the two groups (24 vs. 19%; p = 0.115). CONCLUSIONS: MT patients are now receiving a higher FFP:RBC ratio and less crystalloid after implementation of the CPG. Additionally, patients are now presenting normothermic and have higher hemoglobin levels. All of these changes are consistent with the principles of damage control resuscitation. Changes in practice were associated with implementation of the CPG, maturity of the battlefield, and increased availability of products.

Clot-inducing minerals versus plasma protein dressing for topical treatment of external bleeding in the presence of coagulopathy.

BACKGROUND: Previous studies identified WoundStat (WS, smectite) and Combat Gauze (CG, kaolin-coated gauze) as the most effective available agents for controlling arterial bleeding with potential utility in casualty care. Tissue sealant properties of WS suggested its potential advantage over clot-promoting CG for treating coagulopathic bleeding. This study compared the efficacy of CG and WS with a fibrinogen-based (FAST) dressing to control bleeding in coagulopathic animals. METHODS: Coagulopathy was induced in pigs (n = 55, 35 kg) by ∼50% isovolemic hemodilution and hypothermia (core temperature, 33°C ± 0.5°C). A 6-mm arteriotomy was made in the femoral artery and free bleeding allowed for 30 seconds. A test agent (n = 13-15 per group) or control product (gauze, GZ, n = 12) was applied to the wounds and compressed with a Kerlix gauze for 2 minutes. Fluid resuscitation was given, titrated to a mean arterial pressure of 65 mm Hg. Animals were observed for 180 minutes or until death. Angiography using the computed tomography method was performed on survivors, and local tissues were collected for histology. RESULTS: No differences were seen in baseline measures. Coagulopathy, confirmed by a 31% increase in prothrombin time and a 28% reduction in clotting strength (maximum amplitude, thrombelastography assay), was similar in all groups before injury. The average pretreatment blood loss was 11.9 mL/kg ± 0.4 mL/kg with no difference among groups. Posttreatment blood loss, however, was significantly different (p = 0.015) ranging from 18.2 mL/kg ± 8.8 mL/kg (FAST) to 63.3 mL/kg ± 10.2 mL/kg (GZ controls). Stable hemostasis was achieved in 10 of 13 (FAST), 5 of 15 (CG), 2 of 15 (WS), and 1 of 12 (GZ) animals in each group, resulting in significantly different survival rates (8-77%; p = 0.001). The average survival times were 145 (FAST), 119 (CG), 75 (WS), and 74 (GZ) minutes for different groups (p < 0.002). The outcomes with the FAST dressing were significantly better than with WS or GZ in this coagulopathic bleeding model. Essentially, no difference was found between WS and GZ control. Computed tomography images showed limited blood flow only through the vessels treated with FAST dressings. Histologic observations of the vessels indicated minimal damage with FAST and CG and greater injury with WS with some residues present on the tissues. CONCLUSION: The tissue sealant property of WS is apparently mediated by clot formation in the wound; therefore, it was ineffective under coagulopathic conditions. CG was partially effective in maintaining blood pressure up to 1 hour after application. FAST dressing showed the highest efficacy because of the exogenous delivery of concentrated fibrinogen and thrombin to the wound, which bypasses coagulopathy and secures hemostasis.

Left Anterior Thoracotomy Minimally Invasive Aortic Valve Replacement Following Left Pneumonectomy.

We report the case of a 59-year-old man referred for aortic valve replacement for severe, symptomatic aortic insufficiency who underwent a minimally invasive left anterior thoracotomy aortic valve replacement. This approach was facilitated by his history of a left pneumonectomy for lung cancer 7 years prior to presentation, which resulted in a significant left mediastinal shift. The cannulation strategy and exposure were analogous to what would be expected from a standard right anterior thoracotomy minimally invasive aortic valve replacement. The minimally invasive approach allowed for early extubation and mobilization in a patient with moderate baseline pulmonary dysfunction.

Cardiac Surgery and Postoperative Renal Allograft Failure.

BACKGROUND: Although cardiac surgery among renal allograft recipients is relatively safe, less is known about the impact of cardiac surgery on the functioning renal allograft. This study assessed postoperative renal failure among renal transplant recipients undergoing cardiac surgery. METHODS: The study population was identified by matching medical record numbers from the United Network for Organ Sharing Kidney Transplant Database to a cardiovascular surgery database and The Society of Thoracic Surgeons Adult Cardiac Surgery Database for the authors' institution from January 1992 through August 2018. RESULTS: One hundred seventy-nine renal transplant recipients with a functioning allograft underwent cardiac surgery a mean of 6.4 ± 5.6 years after renal transplantation. Thirty (17.6%) of the 170 patients either died or had allograft failure during the first postoperative year. Receiver-operating characteristics curve analysis using Cox regression demonstrated an optimal cutoff point for preoperative serum creatinine predicting postoperative allograft loss is 1.9 mg/dL (hazard ratio 3; 95% confidence interval, 1.5 to 6.9) with a model C statistic of 0.642. CONCLUSIONS: The current study affirms findings in the literature that cardiac surgery in renal transplant recipients carries acceptable perioperative morbidity and mortality. Renal transplant recipients who underwent cardiac surgery had a constant hazard of renal allograft loss similar to that of the general transplant population. A preoperative serum creatinine value greater than 1.9 mg/dL increases the risk for long-term renal allograft loss after cardiac surgery.

Shedding light on a potential hazard: Dental light-curing units.

BACKGROUND: Dental light-curing units (LCUs) are powerful sources of blue light that can cause soft-tissue burns and ocular damage. Although most ophthalmic research on the hazards of blue light pertains to low levels from personal electronic devices, computer monitors, and light-emitting diode light sources, the amount of blue light emitted from dental LCUs is much greater and may pose a "blue light hazard." METHODS: The authors explain the potential risks of using dental LCUs, identify the agencies that provide guidelines designed to protect all workers from excessive exposure to blue light, discuss the selection of appropriate eye protection, and provide clinical tips to ensure eye safety when using LCUs. RESULTS: While current literature and regulatory standards regarding the safety of blue light is primarily based on animal studies, sufficient evidence exists to suggest that appropriate precautions should be taken when using dental curing lights. The authors found it difficult to find on the U.S. Food and Drug Administration database which curing lights had been cleared for use in the United States or Europe and could find no database that listed which brands of eyewear designed to protect against the blue light has been cleared for use. The authors conclude that more research is needed on the cumulative exposure to blue light in humans. Manufacturers of curing lights, government and regulatory agencies, employers, and dental personnel should collaborate to determine ocular risks from blue light exist in the dental setting, and recommend appropriate eye protection. Guidance on selection and proper use of eye protection should be readily accessible. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The Centers for Disease Control and Prevention Guidelines for Infection Control in the Dental Health-Care Setting-2003 and the Occupational Safety and Health Administration Bloodborne Pathogen Standard do not include safety recommendations or regulations that are directly related to blue light exposure. However, there are additional Occupational Safety and Health Administration regulations that require employers to protect their employees from potentially injurious light radiation. Unfortunately, it is not readily evident that these regulations apply to the excessive exposure to blue light. Consequently employers and dental personnel may be unaware that these Occupational Safety and Health Administration regulations exist.

Biomaterials and Fabrication to Optimise Scaffold Properties for Musculoskeletal Tissue Engineering.

Tissue engineering has emerged as a promising scientific field potentially yielding in vitro developed tissue to replace degenerative or injured tissues in vivo, thus avoiding the donor site morbidity associated with reconstructive surgery. Integral to the process is the role of scaffolds and the biomaterials used to form them. This review explores the concept of scaffold based tissue engineering and design considerations. The scaffold needs to have certain mechanical and architectural properties, it needs to be biocompatible and biodegradable, and allow combination with bioactive molecules. We also discuss scaffolding techniques, different biomaterial options and fabrication technologies, and future areas of development.

The Role of Bioreactors in Ligament and Tendon Tissue Engineering.

Bioreactors are pivotal to the emerging field of tissue engineering. The formation of neotissue from pluripotent cell lineages potentially offers a source of tissue for clinical use without the significant donor site morbidity associated with many contemporary surgical reconstructive procedures. Modern bioreactor design is becoming increasingly complex to provide a both an expandable source of readily available pluripotent cells and to facilitate their controlled differentiation into a clinically applicable ligament or tendon like neotissue. This review presents the need for such a method, challenges in the processes to engineer neotissue and the current designs and results of modern bioreactors in the pursuit of engineered tendon and ligament.

Atypical carpal tunnel syndrome in a holt oram patient: a case report and literature review.

We present a case report of a patient diagnosed with Holt-Oram syndrome (HOS) presenting with clinical and electrophysiologically confirmed carpal tunnel syndrome. Pre-operative Magnetic resonance imaging revealed an abnormal course of the median nerve; as such an atypical incision and approach were carried out to decompress the nerve to excellent post operative clinical effect. To our knowledge this is the first description of abnormal nervous course in a patient with HOS leading to peripheral entrapment. A literature surrounding the important aspects of HOS to the orthopaedic surgeon is presented concomitantly.

Compartment syndrome performance improvement project is associated with increased combat casualty survival.

BACKGROUND: In 2008, we showed that incomplete or delayed extremity fasciotomies were associated with mortality and muscle necrosis in war casualties with limb injury. Subsequently, we developed an education program focused on surgeon knowledge gaps regarding the diagnosis of compartment syndrome and prophylactic fasciotomy. The program included educational alerts, classroom training, video instruction, and a research publication. We compared casualty data before and after the program implementation to determine whether the education altered outcomes. METHODS: Similar to the previous study, a case series was made from combat casualty medical records. Casualties were US military servicemen with fasciotomies performed in Iraq, Afghanistan, or Germany between two periods (periods 1 and 2). RESULTS: In both periods, casualty demographics were similar. Most fasciotomies were performed to the lower leg and forearm. Period 1 had 336 casualties with 643 fasciotomies, whereas Period 2 had 268 casualties with 1,221 fasciotomies (1.9 vs. 4.6 fasciotomies per casualty, respectively; p < 0.0001). The mortality rate decreased in Period 2 (3%, 8 of 268 casualties) from Period 1 (8%, 26 of 336 casualties; p = 0.0125). Muscle excision and major amputation rates were similar in both periods (p > 0.05). Rates of casualties with revision fasciotomy decreased to 8% in Period 2, (22 of 268 casualties) versus 15% in Period 1 (51 of 336 casualties; p = 0.009). CONCLUSION: Combat casualty care following implementation of a fasciotomy education program was associated with improved survival, higher fasciotomy rates, and fewer revisions. Because delayed fasciotomy rates were unchanged, further effort to educate providers may be indicated. LEVEL OF EVIDENCE: Therapeutic study, level IV.

An experience in the management of the open abdomen in severely injured burn patients.

Few descriptions of temporary abdominal closure for planned relaparotomy have been reported in burned patients. The purpose of this study is to describe our experience and outcomes in the management of burned patients with an open abdomen. The authors performed a retrospective review of all admissions to our burn center from March 2003 to June 2008, identifying patients treated by laparotomy with temporary abdominal closure. The authors collected data on patient demographics, indication for laparotomy, methods of temporary and definitive abdominal closure, and outcomes. Of 2,104 patients admitted, 38 underwent a laparotomy with temporary abdominal closure. Their median TBSA was 55%, and the incidence of inhalation injury was 58%. Abdominal compartment syndrome was the most common indication for laparotomy (82%) followed by abdominal trauma (16%). The in-hospital mortality associated with an open abdomen was 68%. Temporary abdominal closure was performed most commonly using negative pressure wound therapy (90%). Fascial closure was performed in 21 patients but was associated with a 38% rate of failure requiring reexploration. Of 12 survivors, fascial closure was achieved in seven patients and five were managed with a planned ventral hernia. Burned patients who necessitate an open abdomen management strategy have a high morbidity and mortality. Fascial closure was associated with a high rate of failure but was successful in a select group of patients. Definitive abdominal closure with a planned ventral hernia was associated with no increased mortality and remains an option when "tension-free" fascial closure cannot be achieved.

Differential expression of the immunoinflammatory response in trauma patients: burn vs. non-burn.

RATIONALE: Cytokines are central mediators of the immune-inflammatory response to injury and subsequent multiple organ dysfunction syndrome (MODS). Although previous studies evaluated cytokine levels after trauma, differences between patients with burn and non-burn trauma have not been assessed systematically. METHODS: A prospective database of trauma patients admitted between May 2004 and September 2007 to the burn or surgical intensive care units within 24 h of injury with an anticipated stay of at least 72 h was analyzed. Sequential clinical and laboratory parameters were collected in the first week, including multiplex analysis data for plasma levels of inflammatory cytokines (IL-6, and IL-8). Patients with known pre-injury coagulopathy were excluded. A Marshall score of 10 or greater was defined as MODS. RESULTS: A total of 179 patients were enrolled (67 burn and 112 non-burn). Plasma IL-6 and IL-8 levels were markedly elevated in both burn and non-burn patients compared to healthy volunteers. Burn subjects had higher levels of IL-6 and IL-8 than the non-burn on days 1 through 7 after injury. Subjects with burns and at least 30% total body surface area were older and had a lower injury severity score, a higher prevalence of MODS, and correspondingly higher mortality. Multivariate analysis of injury type, MODS, and time did not demonstrate an influence of MODS. CONCLUSIONS: Burns were associated with a greater and more sustained immune-inflammatory response than non-burn trauma as evidenced by elevated plasma IL-6 and IL-8 levels during the first week. There was no association between MODS and plasma cytokine levels.