Low compartment pressure and myoglobin levels in tibial fractures with suspected acute compartment syndrome.

BACKGROUND: The intense ischemic pain of acute compartment syndrome can be difficult to discriminate from the pain related to an associated fracture. Lacking objective measures, the decision to perform fasciotomy is often only based on clinical findings and performed at a low threshold. Biomarkers of muscle cell damage might help to identify and monitor patients at risk. In patients with fractures, however, markers of muscle cell damage could be elevated because of other reasons associated with the trauma, which would make interpretation difficult. In a review of all patients who underwent emergency fasciotomy in our health care district we aimed to investigate the decision-making process and specifically the use of biomarkers in patients with and without fractures. METHODS: In the southeast health care region of Sweden 79 patients (60 men) with fractures (median age 26 years) and 42 patients (34 men) without associated fractures (median age 44 years) were treated with emergency fasciotomy of the lower leg between 2007 and 2016. Differences in clinical findings, p-myoglobin and p-creatine phosphokinase as well as pressure measurements were investigated. RESULTS: P-myoglobin was analyzed preoperatively in 20% of all cases and p-creatine phosphokinase in 8%. Preoperative levels of p-myoglobin were lower in patients with fractures (median 1065 µg/L, range 200-3700 µg/L) compared with those without fractures (median 7450 µg/L, range 29-31,000 µg/L), p < 0.05. Preoperative intracompartmental pressure was lower in the fracture group (median 45 mmHg, range 25-90 mmHg) compared with those without fractures (median 83 mmHg, range 18-130 mmHg), p < 0.05. CONCLUSIONS: Biomarkers are seldom used in the context of acute fasciotomy of the lower leg. Contrary to our expectations, preoperative levels of p-myoglobin and intracompartmental pressures were lower in fracture patients. These findings support differences in the underlying pathomechanism between the groups and indicate that biomarkers of muscle cell necrosis might play a more important role in the diagnosis of acute compartment syndrome than previously thought.

Haematology panel biomarkers for humeral, femoral, and tibial diaphyseal fractures.

PURPOSE: The neutrophil to lymphocyte ratio (NLR) is a simple predictor used in oncology and cardiology. We aimed to analyze the NLR profile of patients with diaphyseal fractures of the humerus, femur, and tibia. METHODS: We performed a cross-sectional, consecutive-case population-based study including 148 patients (41.9% men respectively 58.1% women) with humeral (23.0%), femoral (30.4%), and tibial (46.6%) diaphyseal fractures, admitted for surgical treatment in our level 1 trauma centre over two years. RESULTS: The differences in NLR between the studied subgroups were not significant (p = 0.067), the highest value being observed in patients with femoral fracture (5.6) in contrast to patients with humeral fracture (4). In the global cohort, there was a significantly positive correlation between NLR and PLR (platelet to lymphocyte ratio; Spearman's r = 0.595; p < 0.001). The stratified subgroup analysis found significant association between NLR and duration of admission only for patients with femoral fracture (Spearman's r = - 0.308; p < 0.001). When compared with controls, all three fracture types had significantly higher neutrophil numbers and NLR and lower thrombocyte numbers. CONCLUSIONS: NLR are elevated in femur diaphyseal fractures compared with tibia and humerus, up to cut-off values with negative prediction of outcome in malignancy and cardiovascular patients. Increased NLR are predictive of longer hospital admissions for femur fractures.

Local transplantation of bone marrow concentrated granulocytes precursors can cure without antibiotics infected nonunion of polytraumatic patients in absence of bone defect.

PURPOSE: Infected, long bone non-unions present a significant clinical challenge. New and alternative therapies are needed to address this problem. The purposes of this study were to compare the number of circulating granulocyte-macrophage colony-forming units (CFU-GM) in the peripheral blood of polytraumatic patients with infected tibial non-unions and in the peripheral blood of control patients with the hypothesis that their number was decreased in polytraumatic patients; and to treat their infection without antibiotics and with local transplantation of bone marrow concentrated granulocytes precursors. METHODS: Thirty (18 atrophic and 12 hyperthrophic ) infected tibial non-unions (without bone defect) that occurred after open fractures in polytraumatic patients were treated without antibiotics and with percutaneous injection of autologous bone marrow concentrate (BMC) containing granulocytes precursors (CFU-GM). CFU-GM progenitors were assessed in the bone marrow aspirate, peripheral blood, and fracture site of these patients. The number of these progenitors was compared with the CFU-GM progenitors of control patient samples (healthy donors matched for age and gender). Outcome measures were: timing of union, callus formation (radiographs and CT scan), and recurrence of clinical infection. RESULTS: As compared to control patients, the number of CFU GM derived colonies was lower at peripheral blood in patients with infected nonunions. The bone marrow graft injected in nonunions contained after concentration 42 621 ± 20 350 CFU-GM-derived colonies/cc. Healing and cure of infection was observed at six months for 25 patients and at one year follow up for 30 patients. At the median ten year follow-up (range: 5 to 15), only one patient had clinical recurrent infection after healing (between 6 months and last follow-up). CONCLUSION: The peripheral blood of these polytraumatic patients with infected nonunions had a remarkable decrease in CFU-GM-derived colonies as compared with normal controls. Local transplantation of concentrated CFU-GM-derived colonies aspirated from bone marrow allowed cure of infection and healing without antibiotics.

Circulating bone morphogenetic protein levels and delayed fracture healing.

OBJECTIVE: Despite adequate treatment 5-30% of bone fracture patients experience delayed union. During normal fracture union, bone morphogenetic proteins (BMPs) induce healing through a sequential cascade of events. Improved fracture healing after BMP-2 or -7 supplementation in patients with impaired fracture union suggests a deficiency of one or more of these factors. We postulated that low levels of circulating BMPs may result in delayed bone healing. The aim of this study was to quantify differences in levels of circulating BMP-2, -4, -6, -7, and -9 in patients that have demonstrated normal or delayed fracture healing. PATIENTS AND METHODS: Blood samples were collected from an unselected cohort of 65 patients that had been treated for a diaphyseal tibia or femur fracture. Patients were divided into a group with fracture healing within nine months after injury and a group with delayed fracture union. BMP plasma concentrations were quantified using ELISAs and compared between these two groups. RESULTS: Circulating plasma levels of BMP-2, -4, -6, and -7 did not differ between 34 patients with normal fracture healing and 31 patients with delayed fracture healing. Also the median BMP-9 plasma levels were not statistically different between the two groups of patients. However, the distribution in the patients with normal union showed a wider range (72-2496 pg/ml) compared with the delayed union group (120-816 pg/ml). CONCLUSION: In general, circulating BMP concentrations are not statistically different between patients who demonstrated normal or delayed fracture healing. High circulating BMP-9 levels seem to be associated with faster fracture healing, but are apparently not decisive.

Release of growth factors and the effect of age, sex, and severity of injury after long bone fracture. A preliminary report.

BACKGROUND AND PURPOSE: The systemic response after fracture is regulated by a complex mechanism involving numerous growth factors. In this study, we analyzed the kinetics of key growth factors following lower-limb long bone fracture. MATERIALS AND METHODS: Human serum was isolated from 15 patients suffering from lower-limb long bone fracture (tibia/femur) requiring surgical fixation. The levels of platelet-derived growth factor (PDGF-BB), vascular edothelial growth factor (VEGF), insulin growth factor-I (IGF-I), and transforming growth factor ß1 (TGF-ß1) were assayed by colorimetric ELISA at different time points during the first week after fracture. 10 healthy volunteers made up the control group of the study. Serum levels of the growth factors measured were compared to age, sex, and injury severity score. RESULTS: We found that there was a decline in the levels of PDGF-BB, IGF-I and TGF-ß1 during the first 3 days after fracture. However, VEGF levels remained unchanged. The levels of all the growth factors studied then increased, with the highest concentrations noted at day 7 after surgery. No correlation was found between circulating levels of growth factors and age, injury severity score (ISS), blood loss, or fluid administration. INTERPRETATION: There are systemic mitogenic and osteogenic signals after fracture. Important growth factors are released into the peripheral circulation, but early after surgery it appears that serum levels of key growth factors fall. By 7 days postoperatively, the levels had increased considerably. Our findings should be considered in cases where autologous serum is used for ex vivo expansion of mesenchymal stem cells. There should be further evaluation of the use of these molecules as biomarkers of bone union.

Changes in serum levels of TNF-alpha, IL-6, OPG, RANKL and their correlation with radiographic and clinical assessment in fragility fractures and high energy fractures.

Stages of bone turnover during fracture repair can be assessed employing serum markers of osteoblastic and osteoclastic activity, inflammatory cytokines, clinical evaluation and imaging instruments. Our study compare the fracture healing process in fragility fractures and high energy fractures by evaluating serum changes of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), osteoprotegerin (OPG) and receptor activator of the nuclear factor-kB ligand (RANKL) in combination with radiographic (Radiographic Union Scale for Tibial fractures, RUST) and clinical (Lower extremity measure, LEM) assessments. We enrolled 56 patients divided into four corresponding groups: group A with high energy trauma fracture (tibial/femoral shaft); group B with low energy trauma fracture (femoral fractures); healthy (control A) and osteoporotic subjects (control B). Blood samples were collected before surgery (T0) and after 10 weeks (T10). Serum concentrations of IL-6, TNF-alpha, RANKL and OPG were quantified using commercial enzyme-linked immunosorbent assay (ELISA) kits. Our results show that RANKL values are significantly higher at T10 than at T0 in low energy trauma fractures (group B). OPG is significantly lower in each control group than that of the respective fractured group and its concentration at T0 and at T10 is significantly lower in high than in low energy fractures. RANKL/OPG ratio is significantly higher in both controls than in fractured groups, and significantly increases after 10 weeks. IL-6 and TNF-alpha concentrations significantly decrease during fracture healing and are higher in high (group A) than in low energy fractures (group B). Significant differences were also found in both RUST score and LEM between groups A and B. Changes in TNF-alpha and IL-6 levels correlate with RUST and LEM in fragility and high energy fractures, while RANKL/OPG ratio is associated with these clinical parameters only in fragility fractures. These findings suggest that serum levels of IL-6, TNF-alpha, RANKL and OPG might be used to monitor the stages of fracture repair. Further studies will be needed to confirm the role of these cytokines in fracture repair.

[The characteristics of metabolism in patients with fractures of shin and thigh bones depending on immobilization period].

The comprehensive biochemical examination of 20 patients with fractures of shin and thigh bones aged from 18 to 50 years was organized. The treatment consisted of skeletal traction meaning a lingering limitation of locomotive activity The blood sampled at 7th, 14th, 21th, 28th and 35th days after trauma. The blood plasma was analyzed to establish the indicators of protein and purine metabolism, lipoperoxidation processes and antiradical activity. The study established the catabolic direction of metabolism and the intensification of lipoperoxidation processes of the background of decreasing of antiradical activity. The research data can be recommended to apply in controlling the impact of forced limitation of locomotive activity on the course of post-trauma process.

A quantitative serum biomarker of circulating collagen X effectively correlates with endochondral fracture healing.

Currently, there are no standardized methods for quantitatively measuring fracture repair. Physicians rely on subjective physical examinations and qualitative evaluation of radiographs to detect mineralized tissue. Since most fractures heal indirectly through a cartilage intermediate, these tools are limited in their diagnostic utility of early repair. Prior to converting to the bone, cartilage undergoes hypertrophic maturation, characterized by the deposition of a provisional collagen X matrix. The objective of this study was to characterize the kinetics of a novel collagen X biomarker relative to other biological measurements of fracture healing using a murine model of endochondral fracture repair in which a closed, mid-shaft tibia fracture was created using the classic drop-weight technique. Serum was collected 5 to 42 days post-fracture in male and female mice and compared to uninjured controls (n = 8-12). Collagen X in the serum was quantified using a recently validated ELISA-based bioassay ("Cxm")1 and compared to genetic and histological markers of fracture healing and inflammation. We found the Cxm biomarker reliably increased from baseline to a statistically unique peak 14 days post-fracture that then resolved to pre-fracture levels by 3 weeks following injury. The shape and timing of the Cxm curve followed the genetic and histological expression of collagen X but did not show a strong correlation with local inflammatory states. Assessment of fracture healing progress is crucial to making correct and timely clinical decisions for patients. This Cxm bioassay represents a minimally invasive, inexpensive technique that could provide reliable information on the biology of the fracture to significantly improve clinical care.

[Biochemical parameters in the prediction of the course of osteoreparative processes in skeletal injury].

A mathematical analysis was made to examine changes in the biochemical parameters of blood and daily urine in patients with closed shin fractures in the early posttraumatic period in order to determine the most important markers for the evaluation of the course and the prediction of the duration of osteoreparative processes.

The influence of brain injury or peripheral nerve injury on calcitonin gene-related peptide concentration variation and fractures healing process.

To investigate the changes of calcitonin gene-related peptide (CGRP) in rat's blood plasma, spinal anterior motorneuron, and dorsal root ganglion (DRG) after fractures combined with central or peripheral nerve injuries and its influence on fracture healing, 72 healthy adult SD rats (male or female) were divided into 4 groups (18 rats in each group): group A, simple(left) tibial fracture; group B, left tibial fracture combined with left sciatic nerve injury; group C, left tibial fracture combined with T9-11 spinal cord transection injury; group D, left tibial fracture combined with right cerebral cortex injury. Group A was the control group. The concentration of serum CGRP was measured immediately, 1w, 2w, and 4w after injury using radio immunoassay. X-ray photograph was taken at 1w, 2w, and 4w after injury to assess fracture healing. The concentration of serum CGRP in spinal anterior motorneuron and dorsal root ganglion was measured 1w, 2w, and 4w after injury. Bony callus at 2w after injury using H.E.staining was observed. 1w and 2w after injury, the fracture line was still clear on the X-ray of all groups, but 4w after injury the fracture line disappeared with complete healing except the peripheral nerve injury group. By H.E. staining, we found lesser bony callus contents in the peripheral nerve injury group than the simple fracture group at 2w after injury; irregular bone trabecula and healing defect were found in the former group. While the spinal injury group and cerebral cortex injury group represented more bony callus than the simple fracture group, increased bone trabecula and regularity, medullary cavity occluded and finally solid bony connections were found. CGRP concentration in blood plasma and spinal anterior motorneuron represented no apparent differences among all groups during each observation period. For the dorsal root ganglion group, 1w after fracture, there was no apparent difference of CGRP concentration in the peripheral nerve injury group and cerebral cortex group compared with the control group (P > 0.05), but the spinal injury group showed more CGRP than the control group (P < 0.01). 2w after injury, the peripheral nerve injury group and cerebral cortex group also showed no difference compared with the control group, but the cerebral cortex group had more CGRP contents than the peripheral nerve injury group (P < 0.05), and the spinal injury group showed more CGRP than the control group (P < 0.01). 4w after injury, the peripheral nerve group, spinal injury group, and cerebral cortex injury group all showed higher concentration of CGRP than the control group. Among the 3 groups, the spinal injury group is the highest (P < 0.01). When fracture combined with peripheral nerve injury, the healing process can be slowed down. In contrast, fracture combined with spinal injury and cerebral cortex injury will accelerate the healing process. The CGRP in dorsal root ganglion in spinal injury group and cerebral cortex injury group increased, which may have positive effects on fracture healing.

Changes in serum levels of receptor activator of nuclear factor-kappaB ligand, osteoprotegerin, IL-6 and TNF-alpha in patients with a concomitant head injury and fracture.

INTRODUCTION: Several reports indicated that interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF- alpha) play important regulatory roles in bone remodeling and homeostasis. In addition, receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) have been shown to be important regulators of osteoclastogenesis during bone remodeling, and their expressions were examined during fracture healing in a mouse model of tibial fracture. However, studies linking RANKL, OPG, IL-6 and TNF-alpha in patients with head injury and fracture are lacking. PATIENTS AND METHODS: Within the first few hours of admission to hospital and at 4, 8, and 12 weeks after the injury, we evaluated changes in serum levels of RANKL, OPG, IL-6 and TNF-alpha in 24 male patients with a concomitant head injury and fracture and in 26 male patients with fracture only. These levels were compared with those found in 36 healthy controls. RESULTS: The RANKL/OPG ratios were found to significantly lower in patients with a concomitant head injury and fracture than in the controls immediately after admission and at 4, 8, and 12 weeks after the injury. In addition, RANKL/OPG ratios were significantly lower in patients with a concomitant head injury and fracture than in those with fracture at 8 and 12 weeks after the injury. The serum IL-6 levels were significantly higher in patients with a concomitant head injury and fracture than in the controls upon admission, and at 4, 8, and 12 weeks after the injury. Moreover, the serum IL-6 levels were significantly higher in patients with a head injury and fracture than in those with just a fracture at 4, 8, and 12 weeks after the injury. CONCLUSIONS: Based on these changes in the profiles of RANKL, OPG, and IL-6 and the RANKL/OPG ratio, altered repair of a fracture can occur in patients with a concomitant head injury and fracture.

Increased perioperative C-reactive protein and decreased postoperative albumin is associated with acute posttraumatic osteomyelitis in patients with high-energy tibial fractures.

BACKGROUND: Early diagnosis of acute posttraumatic osteomyelitis (POM) is of vital importance for avoiding devastating complications. Diagnosing POM is difficult due to the lack of a highly specific and sensitive test, such as in myocardial infarct, stroke and intracranial bleeding. Serum inflammatory markers, C-reactive protein (CRP), procalcitonin (PCT), white blood cells (WBC) can support clinical findings but they are not able to differentiate between inflammatory response to infection and the host response to non-infection insult with high specificity and sensitivity. AIM: The objectives of the study were to investigate whether the biochemical and immunoinflammatory patient profile could facilitate postoperative monitoring, guide the antibiotic treatment and timing of revision surgery. PATIENTS AND METHODS: This prospective nonrandomised cohort study included 86 patients after high-energy injury to the shin requiring primary surgical treatment (open or closed reduction and internal fixation of tibial fracture). Values of the biochemical and immunoinflammatory profile were measured on admission (ADD), first postoperative day (POD1) and fourth-postoperative day (POD4). RESULTS: We discovered on our sample that the development of POM is associated with increased CRP on ADD, POD1 and decreased albumins on POD4. Further studies are needed to prove that these differences can be useful in diagnosing the risk of infection. The assessment of other important risk factors such as: the extent of soft tissue damage, multiple fractures, transfusion rate, need for conversion primary external fixation to intramedullary (IM) nailing or locking plate fixation can empower our clinical judgment of POM. CONCLUSIONS: We can improve prediction of posttraumatic osteomyelitis by using the perioperative inflammatory biomarker CRP in combination with postoperative albumins levels and other associated independent risk factors.

Hyperglycemia as a risk factor for postoperative early wound infection after bicondylar tibial plateau fractures: Determining a predictive model based on four methods.

OBJECTIVES: Identify a glucose threshold that would put patients with isolated bicondylar tibial plateau fractures at risk of early wound infection (i.e. < 90 days). DESIGN: Retrospective review of medical records. SETTING: Academic American College of Surgeons (ACS) Level 1 trauma center. PATIENTS: Adult patients between 2010 and 2015 with an operatively treated isolated bicondylar tibial plateau fracture and at least three glucose measurements during their hospitalization. MAIN OUTCOME MEASUREMENT: To predict infection using four different methods: maximum preoperative blood glucose (PBG), maximum blood glucose (MGB), Hyperglycemic Index (HGI), and Time-Weighted Average Glucose (TWAG). RESULTS: 126/381 patients met our inclusion criteria. Fifteen (12%) patients had an open fracture and 30/126 (23%) developed an infection. Median glucose for each predictive method studied was 114 (IQR 101.2-137.8) mg/dL for PBG, 144 (IQR 119-169.8) mg/dL for MBG, 0.8 (IQR 0.20-1.60) mmol/L for HGI, and 120.4 (IQR 106.0-135.6) mg/dL for TWAG. As expected, infected patients had higher PBG, MGB, and TWAG. HGI was similar in both groups. None of these differences prove to be statistically significant (p > .05). Logistic regression models for all the methods showed that having an open fracture was the strongest predictor of infection. CONCLUSION: It is well known that stress-induced hyperglycemia increases the risk of infection, we present and compare four models that have been used in other medical fields. In our study, none of the methods presented identified a glucose threshold that would increase the risk of infection in patients with bicondylar tibial plateau fractures. LEVEL OF EVIDENCE: Retrospective review, Level III. See Instructions for Authors for a complete description of levels of evidence.

Multifocal (tarsus and knee) activation of neuroarthropathy following rapid glycaemic correction.

OBJECTIVE: To report a case of neuroarthropathy in the tarsus and knee following rapid glycaemic normalisation in a female patient with type I diabetes. METHODS: A retrospective review of case notes. RESULTS: We describe the case of a female patient with type I diabetes who had developed a multifocal neuroarthropathy in only six months, probably due to a rapid glycaemic normalisation. The onset of this neuroarthropathy was not only fast but mostly multifocal affecting two levels of joints. CONCLUSION: The link between the onset of multifocal neuroarthropathy and the rapid correction of chronic hyperglycaemia is probably proven in our case. Patients with chronic hyperglycaemia with sensitive neuropathy should benefit from a gradual correction of their glycaemic imbalance in order to avoid the apparition of neuroarthropathy.

C-reactive protein levels for early detection of postoperative infection after fracture surgery in 787 patients.

BACKGROUND AND PURPOSE: For early detection of postoperative infections, the level of C-reactive protein (CRP) may be useful. We analyzed baseline and time-dependent reference values for the postoperative use of CRP as an indicator of infection. METHODS: We studied the kinetics of CRP levels after fracture surgery in 1,418 patients. In 787 cases the operative fracture treatment was uneventful; in 17 of the other cases a deep wound infection occurred. RESULTS: In the uneventful cases, a similar evolution in CRP concentrations was found: the peak level, which occurred on the second postoperative day, depended on the region (136 mg/L in femoral fractures and 45 mg/L in ankle fractures) and reflected the extent of surgical trauma. For deep wound infection, a cutoff level of 96 mg/L (sensitivity 92%, specificity 93%) after the fourth day of surgery was recorded. INTERPRETATION: CRP kinetics permit establishment of a time-dependent set of reference values of CRP after operative fracture treatment. Deviations of this course--especially CRP concentrations above 96 mg/L after the fourth day--may aid in early detection of surgical complications.

The effects of phytoestrogens on fracture healing: experimental research in New Zealand white rabbits.

BACKGROUND: Phytoestrogens are plant-derived natural molecules having some bone forming and bone substituting effects. In the present study, the role of phytoestrogens on bone healing was investigated in a rabbit fracture model. METHODS: Twenty-two New Zealand white rabbits with right tibia fracture were divided into two groups randomly. The plant derived extract of Vitex agnus-castus L. (Verbenaceae) prepared before the study was administered intramuscularly in group 1 and group 2 was chosen as control. Fracture healing was monitored in weekly basis with blood alkaline phosphatase level, radiographs of extremities and 99m-Tc MDP bone scintigraphy. The study was finished at the end of the 3rd week. The extremities including tibial fractures were collected for histological examination. RESULTS: Radiographic evidence of fracture healing obtained on postoperative day seven was superior in group 1 than control group (p<0.01). The 99m-Tc MDP bone scintigraphy uptake ratios on postoperative seventh day showed higher uptake in group 1 than in group 2 (p<0.05). The differences of scintigraphic uptakes in fractured tibias calculated on postoperative seventh day and postoperative 14th in group 1 were higher than group 2 (p=0.04). The histopathologic evaluation performed after sacrification of all rabbits on postoperative 25th day showed no significant difference between both groups. No statistical difference was determined related to the other variables. CONCLUSION: Flavonoids affected positively the early periods of fracture healing mechanism in New Zealand white rabbits. We suggest further studies with phytoestrogens to determine the effects of various dosages and administration ways.

Evaluation of matrix metalloproteases as early biomarkers for bone regeneration during the applied Masquelet therapy for non-unions.

INTRODUCTION: In the current study, we sought to determine if serum concentrations of MMPs correlate with bone regeneration occurring during the course of the Masquelet-therapy and to identify if MMPs may serve as early biomarkers reflecting successful bone regeneration and tissue remodeling. MATERIAL AND METHODS: This study was designed as a prospective clinical observer study. We compared serum samples over the time of treatment, as a matched-pair analysis, from 10 patients who were treated successfully with the Masquelet-therapy (Responder) with 10 patients who did not respond to the Masquelet-therapy (Non-Responder). The quantitative measurement was performed with Luminex Performance Human High Sensitivity Assays according to manufacturer's instructions. The lab technician performing the Luminex assays was blinded to both patient data and clinical outcome. RESULTS: Analysis of the expression pattern of MMP-2, -8 and -9 showed significant differences between groups. Two days after the first step of the Masquelet therapy Responder showed peak values of MMP-8 and MMP-9 that where significantly higher (p = 0.003 and p = 0.042, respectively) than in Non-Responder. In contrast serum levels of MMP-2 were lower after the first step of the Masquelet therapy in the Non-Responder group. The ratio of MMP-9 and MMP-2 was significantly higher in the Responder group two days after step I (p = 0.031) as well as 4 weeks after step II (p = 0.030). CONCLUSION: The findings of the current study emphasize the potential role of MMPs as biomarkers in bone remodeling. In particular, a distinct expression of MMP-2 correlates with successful bone regeneration, whereas initial overexpression of MMP-2 serum levels might identify patients that have a higher risk for a poor outcome of the Masquelet-therapy. Furthermore, we were able to introduce the serum analysis of the ratio of MMP-9 and MMP-2 as promising novel modality for early prediction of the outcome of the Masquelet therapy. Further analysis of this ratio over time subsequent to the second step might serve as an early indicator of a favorable response to the induced membrane technique.

Clinical and pathological features of fat embolism with acute respiratory distress syndrome.

FES (fat embolism syndrome) is a clinical problem, and, although ARDS (acute respiratory distress syndrome) has been considered as a serious complication of FES, the pathogenesis of ARDS associated with FES remains unclear. In the present study, we investigated the clinical manifestations, and biochemical and pathophysiological changes, in subjects associated with FES and ARDS, to elucidate the possible mechanisms involved in this disorder. A total of eight patients with FES were studied, and arterial blood pH, PaO(2) (arterial partial pressure of O(2)), PaCO(2) (arterial partial pressure of CO(2)), biochemical and pathophysiological data were obtained. These subjects suffered from crash injuries and developed FES associated with ARDS, and each died within 2 h after admission. In the subjects, chest radiography revealed that the lungs were clear on admission, and pulmonary infiltration was observed within 2 h of admission. Arterial blood pH and PaO(2) declined, whereas PaCO(2) increased. Plasma PLA(2) (phospholipase A(2)), nitrate/nitrite, methylguanidine, TNF-alpha (tumour necrosis factor-alpha), IL-1beta (interleukin-1beta) and IL-10 (interleukin-10) were significantly elevated. Pathological examinations revealed alveolar oedema and haemorrhage with multiple fat droplet depositions and fibrin thrombi. Fat droplets were also found in the arterioles and/or capillaries in the lung, kidney and brain. Immunohistochemical staining identified iNOS (inducible nitric oxide synthase) in alveolar macrophages. In conclusion, our clinical analysis suggests that PLA(2), NO, free radicals and pro-inflammatory cytokines are involved in the pathogenesis of ARDS associated with FES. The major source of NO is the alveolar macrophages.

[Hemodynamic steal syndrome in the distal limb segments in patients treated by Ilizarov method].

Complex physiological examination of 149 patients with lower limb bone defects was performed using Doppler ultrasonography, rheovasography, percutaneous measurement of oxygen and carbon dioxide during treatment with Ilizarov apparatus. Within the process of treatment with Ilizarov apparatus, with marked collateral circulation, steal syndrome is noted in the distal parts of limb due to the effect of "functional shunting" in the zone of distraction regenerate bone. Steal syndrome during treatment by Ilizarov technique is registered, according to rheovasography and Doppler data, in 57% of patients with a defect in the femoral bone, in 24% of patients with post-traumatic defects in shin bones, and in 85% of patients with congenital defects in shin bones. In the compensated form of steal syndrome in the distal segment, according to polarography data, normoxia combined with hypocapnia is registered; oxygen requirements at rest are met by its more complete utilization, and activation of anaerobic processes.

Identification of KRT16 as a target of an autoantibody response in complex regional pain syndrome.

OBJECTIVE: Using a mouse model of complex regional pain syndrome (CRPS), our goal was to identify autoantigens in the skin of the affected limb. METHODS: A CRPS-like state was induced using the tibia fracture/cast immobilization model. Three weeks after fracture, hindpaw skin was homogenized, run on 2-d gels, and probed by sera from fracture and control mice. Spots of interest were analyzed by liquid chromatography-mass spectroscopy (LC-MS) and the list of targets validated by examining their abundance and subcellular localization. In order to measure the autoantigenicity of selected protein targets, we quantified the binding of IgM in control and fracture mice sera, as well as in control and CRPS human sera, to the recombinant protein. RESULTS: We show unique binding between fracture skin extracts and fracture sera, suggesting the presence of auto-antigens. LC-MS analysis provided us a list of potential targets, some of which were upregulated after fracture (KRT16, eEF1a1, and PRPH), while others showed subcellular-redistribution and increased membrane localization (ANXA2 and ENO3). No changes in protein citrullination or carbamylation were observed. In addition to increased abundance, KRT16 demonstrated autoantigenicity, since sera from both fracture mice and CRPS patients showed increased autoantibody binding to recombinant kRT16 protein. CONCLUSIONS: Pursuing autoimmune contributions to CRPS provides a novel approach to understanding the condition and may allow the development of mechanism-based therapies. The identification of autoantibodies against KRT16 as a biomarker in mice and in humans is a critical step towards these goals, and towards redefining CRPS as having an autoimmune etiology.