Menstrual Blood-Derived Stem Cell Paracrine Factors Possess Stimulatory Effects on Chondrogenesis In Vitro and Diminish the Degradation of Articular Cartilage during Osteoarthritis.

Articular cartilage is an avascular tissue with a limited capacity for self-regeneration, leading the tissue to osteoarthritis (OA). Mesenchymal stem cells (MSCs) are promising for cartilage tissue engineering, as they are capable of differentiating into chondrocyte-like cells and secreting a number of active molecules that are important for cartilage extracellular matrix (ECM) synthesis. The aim of this study was to evaluate the potential of easily accessible menstrual blood-derived MSC (MenSC) paracrine factors in stimulating bone marrow MSC (BMMSCs) chondrogenic differentiation and to investigate their role in protecting cartilage from degradation in vitro. MenSCs and BMMSCs chondrogenic differentiation was induced using four different growth factors: TGF-ß3, activin A, BMP-2, and IGF-1. The chondrogenic differentiation of BMMSCs was stimulated in co-cultures with MenSCs and cartilage explants co-cultured with MenSCs for 21 days. The chondrogenic capacity of BMMSCs was analyzed by the secretion of four growth factors and cartilage oligomeric matrix protein, as well as the release and synthesis of cartilage ECM proteins, and chondrogenic gene expression in cartilage explants. Our results suggest that MenSCs stimulate chondrogenic response in BMMSCs by secreting activin A and TGF-ß3 and may have protective effects on cartilage tissue ECM by decreasing the release of GAGs, most likely through the modulation of activin A related molecular pathway. In conclusion, paracrine factors secreted by MenSCs may turn out to be a promising therapeutical approach for cartilage tissue protection and repair.

Stimulation of Chondrocyte and Bone Marrow Mesenchymal Stem Cell Chondrogenic Response by Polypyrrole and Polypyrrole/Gold Nanoparticles.

Bone marrow mesenchymal stem cells (BMMSCs) possess a strong ability to differentiate into the chondrogenic lineage, which is important for cartilage regeneration. External stimuli, such as electrical stimulation (ES), are frequently studied for chondrogenic differentiation of BMMSCs; however, the application of conductive polymers such as polypyrrole (Ppy), has never been used for stimulating BMMSCs chondrogenesis in vitro before. Thus, the aim of this study was to evaluate the chondrogenic potential of human BMMSCs after stimulation with Ppy nanoparticles (Ppy NPs) and compare them to cartilage-derived chondrocytes. In this study, we tested Ppy NPs without and with 13 nm gold NPs (Ppy/Au) for BMMSCs and chondrocyte proliferation, viability, and chondrogenic differentiation for 21 days, without the use of ES. The results demonstrated significantly higher amounts of cartilage oligomeric matrix protein (COMP) in BMMSCs stimulated with Ppy and Ppy/Au NPs, as compared to the control. The expression of chondrogenic genes (SOX9, ACAN, COL2A1) in BMMSCs and chondrocytes were upregulated by Ppy and Ppy/Au NPs, as compared to controls. Histological staining with safranin-O indicated higher extracellular matrix production in Ppy and Ppy/Au NPs stimulated samples, as compared to controls. In conclusion, Ppy and Ppy/Au NPs stimulate BMMSC chondrogenic differentiation; however, BMMSCs were more responsive to Ppy, while chondrocytes possessed a stronger chondrogenic response to Ppy/Au NPs.

Modeling the Impact of Meniscal Tears on von Mises Stress of Knee Cartilage Tissue.

The present study aims to explore the stressed state of cartilage using various meniscal tear models. To perform this research, the anatomical model of the knee joint was developed and the nonlinear mechanical properties of the cartilage and meniscus were verified. The stress-strain curve of the meniscus was obtained by testing fresh tissue specimens of the human meniscus using a compression machine. The results showed that the more deteriorated meniscus had greater stiffness, but its integrity had the greatest impact on the growth of cartilage stresses. To confirm this, cases of radial, longitudinal, and complex tears were examined. The methodology and results of the study can assist in medical diagnostics for meniscus treatment and replacement.

The Effects of Mechanical Load on Chondrogenic Responses of Bone Marrow Mesenchymal Stem Cells and Chondrocytes Encapsulated in Chondroitin Sulfate-Based Hydrogel.

Articular cartilage is vulnerable to mechanical overload and has limited ability to restore lesions, which leads to the development of chronic diseases such as osteoarthritis (OA). In this study, the chondrogenic responses of human bone marrow mesenchymal stem cells (BMMSCs) and OA cartilage-derived chondrocytes in 3D chondroitin sulfate-tyramine/gelatin (CS-Tyr)/Gel) hydrogels with or without experimental mechanical load have been investigated. Chondrocytes were smaller in size, had slower proliferation rate and higher level of intracellular calcium (iCa2+) compared to BMMSCs. Under 3D chondrogenic conditions in CS-Tyr/Gel with or without TGF-ß3, chondrocytes more intensively secreted cartilage oligomeric matrix protein (COMP) and expressed collagen type II (COL2A1) and aggrecan (ACAN) genes but were more susceptible to mechanical load compared to BMMSCs. ICa2+ was more stably controlled in CS-Tyr/Gel/BMMSCs than in CS-Tyr/Gel/chondrocytes ones, through the expression of L-type channel subunit CaV1.2 (CACNA1C) and Serca2 pump (ATP2A2) genes, and their balance was kept more stable. Due to the lower susceptibility to mechanical load, BMMSCs in CS-Tyr/Gel hydrogel may have an advantage over chondrocytes in application for cartilage regeneration purposes. The mechanical overload related cartilage damage in vivo and the vague regenerative processes of OA chondrocytes might be associated to the inefficient control of iCa2+ regulating channels.

From Bad to Disaster: Iatrogenic Fracture Followed by Knee Perforation With Bone Fragments During Femoral Nailing.

Intramedullary nailing is the preferred treatment method in tibial, femoral shaft, and sub- or intertrochanteric fractures. Despite good results, a number of complications have been well-characterized. Joint perforation by bone fragment during nail insertion is one such complication. We report an eventful case of a 63-year-old female patient who presented with an intertrochanteric fracture. Osteosynthesis with a short proximal femoral nail was complicated by a well-known and recognized on-time complication - an iatrogenic fracture of the femoral shaft. However, it was further complicated by knee arthrodesis by a bone fragment when a long nail was inserted. The bone fragment not only "closed" the knee joint, but fractured the medial tibial condyle and protruded into the medial soft tissues of the joint. This misfortune was not recognized intraoperatively and led to revision surgery in the short term and joint post-traumatic arthrosis with resultant total knee replacement in the long term.

Management of Complex Pelvic Ring and Acetabular Fracture Associated With Open Tibia Fracture in Severe Polytrauma Patient: A Case Report.

With the increase of high energy injuries, acetabular and pelvic ring fractures tend to be a more common part of polytrauma patients. Despite growing incidence, management of these injuries remains one of the most difficult challenges in orthopedic surgery. As these patients are usually multiply injured, it is not only life-threatening trauma in acute settings but also crippling in long time. We present a case of a 40-year-old male who suffered from a dreadful traffic accident following the fractures of pelvic ring and both acetabulum, open fracture of tibia, urinary bladder rupture, and crush syndrome. We discuss the factors which dictated the timing of definitive management of pelvic and associated injuries and compare it with this study. Furthermore, we present patients' final outcomes and management of long-term complications.

Functional outcomes and quality of life after surgical treatment of spinopelvic dissociation: a case series with one-year follow-up.

BACKGROUND: Spinopelvic dissociation is a transverse sacral fracture in conjunction with a vertical fracture of the sacrum on both sides, which causes the dissociation of the upper sacrum and spine from the pelvis. The most common causes of these fractures are high energy injuries such as falls from height or motor vehicle accidents. Spinopelvic dissociation is rare and heterogenous with severe associated injuries. The aim of this study was to assess the injury characteristics, changes in the quality of life and functional outcomes in the 1-year period after spinopelvic dissociation. MATERIALS AND METHODS: During the period of 4 years (January 2016 and January 2020), 17 patients with spinopelvic dissociation were admitted to our centre and included in this single-centre prospective cohort study. One patient died during the admission; therefore 16 patients were enrolled in the analysis. Patients were followed-up for 12 months. The quality of life changes were evaluated via the SF-36 questionnaire, and the functional outcomes were evaluated using the Majeed pelvic score. Patients completed their questionnaires twice: firstly during hospitalization (regarding their pre-traumatic condition); and once again 1 year after their injury (regarding their current condition). RESULTS: The mean age of the patients was 40.2 ± 17.7 years. Mean Majeed, PCS and MCS scores of SF-36 before the injury were 95.81 ± 9.50, 55.87 ± 8.89, and 43.76 ± 12.45, respectively. Mean Majeed, PCS and MCS scores 1 year after the injury were 71.13 ± 20.98, 43.45 ± 9.64, and 43.41 ± 7.56. During the period of 1 year after the injury, Majeed and PCS results reduced statistically significantly (P = 0.001 and P = 0.003, respectively), while MCS results remained similar (P = 0.501). CONCLUSIONS: According to the data of our study, for patients with spinopelvic dissociation functional outcomes are significantly reduced and only one-third of the patients achieved pre-traumatic functional outcomes 1 year after the injury.

Short-Term Functional Outcomes and Quality of Life after B2.1 Type Pelvic Fractures for Surgically and Non-Surgically Treated Young Patients.

Background and Objectives: Lateral compression injuries of the pelvic ring are most common among young and elderly patients. Of all pelvic ring fracture injuries, the B2.1 type-involving lateral compression of the pelvic ring-is the most common. Despite this, we still have no high-level evidence to consult when choosing between the surgical and non-operative approaches. The purpose of this research was to compare the short-term functional and quality of life outcomes between operatively and non-operatively treated young patients after a B2.1 type pelvic fracture. Materials and Methods: Patients aged 18 to 65 years with pelvic B2.1 type fractures-according to AO/Tile classification-that were hospitalized in a single trauma center between 2016 November and 2019 September were included in the research. Patients were retrospectively divided into two groups regarding their treatment: non-operative and operative. Functional outcomes were evaluated using Majeed score, and SF-36 was used for the evaluation of quality of life. Patients completed these questionnaires twice: first during hospitalization, regarding their pre-traumatic condition (timepoint I); and again 10 weeks after the injury, regarding their current condition (timepoint II). Results: A total of 55 patients (70.6% of whom were female) with type B2.1 pelvic fractures were included in the analysis, with an average age of 37.24 ± 13.78 years. There were 21 (38.18%) patients with high injury severity, and 37 (67.3%) patients were treated operatively versus 18 (32.7%) non-operatively. Between the two timepoints, Majeed score reduced by 34.08 ± 18.95 for operatively and 31.44 ± 14.41 for non-operatively treated patients. For operatively and non-operatively treated patients, the physical component summary (PCS) of the SF-36 questionnaire reduced by 19.45 ± 9.95 and 19.36 ± 7.88, respectively, while the mental component summary (MCS) reduced by 6.38 ± 11.04 and 7.23 ± 10.86, respectively. Conclusions: We observed that operative treatment of B2.1 type pelvic fractures for young patients is not superior to non-operative in the short-term, because the functional outcomes and quality of life are similar in both groups.

Risk Factors for Revision After Early and Delayed Total Hip Arthroplasty Dislocation. An Analysis of Lithuanian Arthroplasty Register.

INTRODUCTION: Despite relatively low incidence, dislocation remains one of the main reasons for total hip arthroplasty (THA) revision. It is a devastating complication for a patient and a surgeon, and has high burden on the healthcare system. The aim of the present study was to assess and compare the risk factors for revision after early and delayed THA dislocations. METHODS: Some 3403 THA through posterior approach for primary osteoarthritis were retrospectively studied in the Lithuanian Arthroplasty Register from 2011 to 2018. Three months after THA was the splitting time between the first event of early and delayed dislocations. Revision was set as outcome measure. Gender, affected side, number of dislocations, femoral head and neck size, and prosthesis fixation type were tested as risk factors for revision after early and delayed THA dislocations. RESULTS: Dislocation occurred in 108 patients (3.2%), and 26 cases (0.8%) required revision. Men had statistically significant higher risk for revision due to early dislocation [hazard ratio (HR) 4.7; 1.3-17.7 confidence interval (CI)] and considerably lower risk for revision due to delayed dislocation (HR 0.5; 0.1-1.7 CI). The left side THA had twice the risk as compared to the right in the early settings (HR 2.1; 0.6-6.9 CI) which equalized after three months (HR 1.1; 0.4-3.1 CI). Some 32 mm femoral head had significantly lower risk in the early group as compared to 28 mm head (HR 0.3; 0.1-0.5 CI). Short head was associated with increased risk for revision after early dislocation, although, not statistically significant. Prosthesis fixation type was not a risk factor for revision surgery neither after early nor after delayed dislocation. CONCLUSION: The unique finding of gender separation was found -- men tend for revision after early dislocation and women after delayed dislocation. In early stage, additional precautions should be considered when 28 mm short metal heads are used.

Different phenotypes and chondrogenic responses of human menstrual blood and bone marrow mesenchymal stem cells to activin A and TGF-ß3.

BACKGROUND: Due to its low capacity for self-repair, articular cartilage is highly susceptible to damage and deterioration, which leads to the development of degenerative joint diseases such as osteoarthritis (OA). Menstrual blood-derived mesenchymal stem/stromal cells (MenSCs) are much less characterized, as compared to bone marrow mesenchymal stem/stromal cells (BMMSCs). However, MenSCs seem an attractive alternative to classical BMMSCs due to ease of access and broader differentiation capacity. The aim of this study was to evaluate chondrogenic differentiation potential of MenSCs and BMMSCs stimulated with transforming growth factor ß (TGF-ß3) and activin A. METHODS: MenSCs (n = 6) and BMMSCs (n = 5) were isolated from different healthy donors. Expression of cell surface markers CD90, CD73, CD105, CD44, CD45, CD14, CD36, CD55, CD54, CD63, CD106, CD34, CD10, and Notch1 was analyzed by flow cytometry. Cell proliferation capacity was determined using CCK-8 proliferation kit and cell migration ability was evaluated by scratch assay. Adipogenic differentiation capacity was evaluated according to Oil-Red staining and osteogenic differentiation according to Alizarin Red staining. Chondrogenic differentiation (activin A and TGF-ß3 stimulation) was investigated in vitro and in vivo (subcutaneous scaffolds in nude BALB/c mice) by expression of chondrogenic genes (collagen type II, aggrecan), GAG assay and histologically. Activin A protein production was evaluated by ELISA during chondrogenic differentiation in monolayer culture. RESULTS: MenSCs exhibited a higher proliferation rate, as compared to BMMSCs, and a different expression profile of several cell surface markers. Activin A stimulated collagen type II gene expression and glycosaminoglycan synthesis in TGF-ß3 treated MenSCs but not in BMMSCs, both in vitro and in vivo, although the effects of TGF-ß3 alone were more pronounced in BMMSCs in vitro. CONCLUSION: These data suggest that activin A exerts differential effects on the induction of chondrogenic differentiation in MenSCs vs. BMMSCs, which implies that different mechanisms of chondrogenic regulation are activated in these cells. Following further optimization of differentiation protocols and the choice of growth factors, potentially including activin A, MenSCs may turn out to be a promising population of stem cells for the development of cell-based therapies with the capacity to stimulate cartilage repair and regeneration in OA and related osteoarticular disorders.

Cross-Cultural Adaptation and Psychometric Properties of the Lithuanian Version of the Majeed Pelvic Score.

Background and Objectives: There are no valid patient-based pelvic ring function assessment tools in Lithuania. The most widely used instrument is the Majeed Pelvic Score (MPS), which is proven to be an effective tool for assessing pelvic function after pelvic injuries. The aims of our study were: (1) the translation and cross-cultural adaptation of the MPS for the Lithuanian-speaking population, (2) to test the psychometric properties of the Lithuanian version of the MPS (MPS-LT) at follow-up two-time points after pelvic fractures. Materials and Methods: The MPS was translated and culturally adapted. Psychometric properties of the MPS-LT were determined in one patient group (n = 40) at two time-points during follow-up examination from 1.5 to 3 months (mean 2 months) and from 11 to 20 months (mean 12 months). Results: At the mean time of 2 months after trauma, Cronbach's α of the MPS-LT was 0.65. Correlation of the MPS-LT with the Iowa Pelvic Score (IPS) was r = 0.84 (p < 0.001), and with the Lithuanian SF-36, PCS was r = 0.53 (p < 0.001). At the mean time follow-up of 12 months, Cronbach's α was 0.86, correlation with the IPS was r = 0.92 (p < 0.001), and with the Lithuanian SF-36, PCS - r = 0.82 (p < 0.001). At the 2-month follow-up, neither floor nor ceiling effects were reached, but at 12 months, 27.5% of patients reached the ceiling effect, while none reached the floor effect. The effect size of the MPS-LT was 1.66. Conclusions: The MPS-LT has limited ability to measure functional outcomes at 2 months after pelvic fracture. In contrast, at the 12-month follow-up examination, the MPS-LT had a good ability to assess pelvic function, and it was sensitive to health changes. The MPS-LT can be used as a pelvic function assessment tool after pelvic fractures for the Lithuanian-speaking population.

Comparison of One-Year Functional Outcomes and Quality of Life between Posterior Pelvic Ring Fixation and Combined Anterior-Posterior Pelvic Ring Fixation after Lateral Compression (B2 Type) Pelvic Fracture.

Background and Objectives: The treatment algorithm of lateral compression B2 type pelvic fractures are still under debate. Some authors advocate conservative treatment, while others recommend surgical approach. The clear indications for isolated anterior or posterior ring fixation or combined anterior-posterior pelvic ring fixation of B2 type fractures remain unclear. The aim of this study was to compare the functional outcomes and quality of life after isolated posterior pelvic ring fixation and combined anterior-posterior pelvic ring fixation for the treatment of B2 pelvic fractures. Materials and Methods: Patients aged 18 to 65 years with B2 type pelvic fracture hospitalized in a single trauma centre over a period of 3 years were included in the research. Based on the attending surgeon's preference, patients were treated with isolated posterior or combined anterior-posterior pelvic fixation. The quality of life and pelvic function were assessed using SF-36 and Majeed questionnaires, respectively. Patients filled in the questionnaires twice: during the first hospitalization (concerning their pre-trauma state-timepoint I) and one-year after the injury (timepoint II). Results: A cohort of 32 patients with B2 type pelvic fracture was enrolled in the analysis: 23 (72%) were female and 9 (28%) were male. The mean age was 35.3 ± 11.9 years. In this cohort 13 (41%) patients underwent isolated posterior pelvic ring fixation (group I) and 19 (59%) patients underwent combined anterior-posterior pelvic ring fixation (group II). No statistically significant differences were observed between the groups in both timepoints concerning Majeed, SF-36 PCS and MCS scores. However, in both groups Majeed and SF-36 PCS scores were statistically significantly lower one year after pelvic fracture compared with pre-trauma state, while SF-36 MCS scores did not differ. Conclusions: No differences were found in quality of life and functional outcomes between isolated posterior pelvic ring fixation and combined anterior-posterior fixation for the treatment of B2 type pelvic fractures.

The Expression of Inflammasomes NLRP1 and NLRP3, Toll-Like Receptors, and Vitamin D Receptor in Synovial Fibroblasts From Patients With Different Types of Knee Arthritis.

Activated rheumatoid arthritis (RA) synovial fibroblasts (SFs) are among the most important cells promoting RA pathogenesis. They are considered active contributors to the initiation, progression, and perpetuation of the disease; therefore, early detection of RASF activation could advance contemporary diagnosis and adequate treatment of undifferentiated early inflammatory arthritis (EA). In this study, we investigated the expression of nucleotide-binding, oligomerization domain (NOD)-like receptor family, pyrin domain containing (NLRP)1, NLRP3 inflammasomes, Toll-like receptor (TLR)1, TLR2, TLR4, vitamin D receptor (VDR), and secretion of matrix metalloproteinases (MMPs) in SFs isolated from patients with RA, osteoarthritis (OA), EA, and control individuals (CN) after knee surgical intervention. C-reactive protein, general blood test, anticyclic citrullinated peptide (anti-CCP), rheumatoid factor (RF), and vitamin D (vitD) in patients' sera were performed. Cells were stimulated or not with 100 ng/ml tumor necrosis factor alpha (TNF-α) or/and 1 nM or/and 0.01 nM vitamin D3 for 72 h. The expression levels of NLRP1, NLRP3, TLR1, TLR2, TLR4, and VDR in all examined SFs were analyzed by quantitative real-time PCR (RT-qPCR). Additionally, the secretion of IL-1ß by SFs and MMPs were determined by ELISA and Luminex technology. The expression of NLRP3 was correlated with the levels of CRP, RF, and anti-CCP, suggesting its implication in SF inflammatory activation. In the TNF-α-stimulated SFs, a significantly lower expression of NLRP3 and TLR4 was observed in the RA group, compared with the other tested forms of arthritis. Moreover, upregulation of NLRP3 expression by TNF-α alone or in combination with vitD3 was observed, further indicating involvement of NLRP3 in the inflammatory responses of SFs. Secretion of IL-1ß was not detected in any sample, while TNF-α upregulated the levels of secreted MMP-1, MMP-7, MMP-8, MMP-12, and MMP-13 in all patient groups. Attenuating effects of vitD on the expression of NLRP3, TLR1, and TLR4 suggest potential protective effects of vitD on the inflammatory responses in SFs. However, longer studies may be needed to confirm or fully rule out the potential implication of vitD in SF activation in inflammatory arthritis. Both VDR and NLRP3 in the TNF-α-stimulated SFs negatively correlated with the age of patients, suggesting potential age-related changes in the local inflammatory responses.

Diagnostic Challenge of Necrotizing Soft Tissue Infection in a Patient With B Lymphocytic Leukemia.

The necrotizing soft tissue infection is a rare surgical emergency. Early diagnosis and timely treatment can contribute to better survival and the preservation of the limb. Diagnosis of this pathology remains a challenge to the clinician at the initial stage of the disease, especially if the patient is immunocompromised. We present the case of a 75-year-old man with B lymphocytic leukemia who was diagnosed with necrotizing soft tissue infection but failed to exhibit typical clinical and laboratory measurements. This case highlights the difficulty of early diagnosis in hematology patient, altered sensitivity of disease-specific scoring systems, and importance of high clinician awareness.

The Antihypertensive Drug Nifedipine Modulates the Metabolism of Chondrocytes and Human Bone Marrow-Derived Mesenchymal Stem Cells.

Aging is associated with the development of various chronic diseases, in which both cardiovascular disorders and osteoarthritis are dominant. Currently, there is no effective treatment for osteoarthritis, whereas hypertension is often treated with L-type voltage-operated calcium channel blocking drugs, nifedipine being among the most classical ones. Although nifedipine together with other L-type voltage-operated calcium channel inhibitors plays an important role in controlling hypertension, there are unresolved questions concerning its possible effect on cartilage tissue homeostasis and the development of osteoarthritis. The aim of this study was to analyse the effects of nifedipine on metabolic processes in human chondrocytes and bone marrow mesenchymal stem cells. To better understand whether the metabolic effects are mediated specifically through L-type voltage-operated calcium channel, effects of the agonist BayK8644 were analyzed in parallel. Nifedipine downregulated and mitochondrial respiration and ATP production in both cell types. Analysis of cartilage explants by electron microscopy also suggested that a small number of chondrocyte mitochondria's lose their activity in response to nifedipine. Conversely, nifedipine enhanced glycolytic capacity in chondrocytes, suggesting that these cells have the capacity to switch from oxidative phosphorylation to glycolysis and alter their metabolic activity in response to L-type voltage-operated calcium channel inhibition. Such a metabolic switch was not observed in bone marrow mesenchymal stem cells. Nitric oxide activity was upregulated by nifedipine in bone marrow mesenchymal stem cells and particularly in chondrocytes, implying its involvement in the effects of nifedipine on metabolism in both tested cell types. Furthermore, stimulation with nifedipine resulted in elevated production of collagen type II and glycosaminoglycans in micromass cultures under chondrogenic conditions. Taken together, we conclude that the antihypertensive drug nifedipine inhibits mitochondrial respiration in both chondrocytes and bone marrow mesenchymal stem cells and that these effects may be associated with the increased nitric oxide accumulation and pro-inflammatory activity. Nifedipine had positive effects on the production of collagen type II and proteoglycans in both cell types, implying potentially beneficial anabolic responses in articular cartilage. These results highlight a potential link between antihypertensive drugs and cartilage health.

A mini volume loading test (mVLT) using 2.5-mLkg-1 boluses of crystalloid for indication of perioperative changes in hydration status.

BACKGROUND AND OBJECTIVE: A mini volume loading test (mVLT) evaluating hemodilution during step-wise crystalloid infusion has established that the arterio-capillary plasma dilution difference is inversely correlated to the body hydration level of subjects. This observational study aimed to test whether this can be replicated in a perioperative setting using a 2.5-mLkg-1 boluses. MATERIALS AND METHODS: The mVLT was performed before induction of regional anesthesia and 24h later. Step-wise infusion implied six mini fluid challenges. These consisted of 2.5-mLkg-1 boluses of Ringer's acetate infused during 2-3min and followed by 5-min periods with no fluids. Invasive (arterial) and noninvasive (capillary) measurements of hemoglobin were performed before and after each mini fluid challenge, as well as after a 20-min period without fluid following the last bolus. Hemoglobins were used to calculate the arterio-capillary plasma dilution difference which is used as an indication of changes in body hydration level. The 24-h fluid balance was calculated. RESULTS: Subjects were 69.5 (6.0) years old, their height was 1.62m (1.56-1.65), weight was 87.0kg (75.5-97.5) and body mass index (BMI) was 33.5kg/m2 (31.0-35.1). Preoperative arterio-capillary plasma dilution difference was significantly higher than postoperative (0.085 [0.012-0.141] vs. 0.006 [-0.059 to 0.101], P=0.000). The perioperative 24-h fluid balance was 1976mL (870-2545). CONCLUSIONS: The mVLT using 2.5-mLkg-1 boluses of crystalloid was able to detect the higher postoperative body hydration level in total knee arthroplasty patients.

A mini volume loading test for indication of preoperative dehydration in surgical patients.

BACKGROUND AND OBJECTIVE: Previously, a mini volume loading test (mVLT) detected signs of dehydration in healthy volunteers after an overnight fast. Our objective was to investigate whether mVLT could indicate preoperative dehydration in patients after an overnight fast. MATERIALS AND METHODS: The mVLT was performed in 36 elective primary total knee arthroplasty patients. Each subject received three fluid challenges before anesthesia induction. These consisted of 5 mL/kg boluses of Ringer's acetate infused over 3-5 min and followed by a 5-min period without fluids. Invasive (arterial, venous) and noninvasive (capillary) measurements of hemoglobin concentration were performed before and after each fluid challenge, as well as after a 20-min period without fluids which followed the last bolus. Arterial, venous and capillary plasma dilutions were calculated in every data point. Dilution values were used to calculate the plasma dilution efficacy of each fluid challenge. RESULTS: Venous dilution was higher than capillary after the first fluid challenge (P=0.030), but lower than capillary after 20 min period following the last bolus (P=0.009). Arterial dilution was lower than capillary (P=0.005) after 20 min following the last bolus. Veno-capillary and arterio-capillary plasma dilution efficacy differences decreased (P=0.004 and P=0.033, respectively) from positive to negative during mVLT. These are signs of re-hydration from pre-existing dehydration according to a transcapillary reflux model. CONCLUSIONS: Signs of dehydration were observed during mVLT in patients after pre-operative overnight fast. A revised transcapillary reflux model was proposed to explain the results.

Revision rates after surgical treatment for femoral neck fractures: results of 2-year follow-up.

BACKGROUND AND OBJECTIVE: Intracapsular fractures of the femoral neck account for a major share of fractures in the elderly. Open reduction and internal fixation has been shown to have a higher rate of revision surgery than arthroplasty. The aim of this study was to assess and compare the rates of revision surgery performed after internal fixation and primary total hip arthroplasty. MATERIAL AND METHODS: Between 2004 and 2006, 681 intracapsular femoral neck fractures in 679 consecutive patients were treated with internal fixation or total hip arthroplasty at our institution. Revision surgery rates were evaluated at 1-, 3-, 6-, 12-, and 24-month follow-up. RESULTS: There was no significant difference in the ratio of internal fixation to total hip arthroplasty during 2004-2006 (P=0.31). The mean rate of total hip arthroplasty was 19.1% with a lower rate being among patients younger than 60 years. Revision surgery rates at the 2-year follow-up were higher in the internal fixation group compared with total hip arthroplasty group (28.9% vs. 7.0%, P<0.001). Patients who underwent internal fixation were at a 4-fold greater risk of having revision surgery at the 2-year follow-up than those who underwent total hip arthroplasty (odds ratio, 4.11; 95% CI, 1.95-8.65; P<0.001). Age was a significant risk factor for revision surgery after total hip arthroplasty (hazard ratio, 0.93; 95% CI, 0.87-0.98; P=0.02), but not significant after the internal fixation (P=0.86). CONCLUSIONS: Higher revision surgery rates after internal fixation favors arthroplasty as a primary choice of treatment for the femoral neck fractures.

A randomized double-blind clinical trial of tourniquet application strategies for total knee arthroplasty.

PURPOSE: The optimal timing of pneumatic lower limb tourniquet application during primary elective total knee arthroplasty surgery (TKA) is a matter of debate. Most previous reports have failed to show significant differences between different tourniquet timings. The aim of the work was to determine how three strategies of lower limb pneumatic tourniquet application affect the outcome for TKA patients. METHODS: Forty-three patients who undergo TKA were randomized into one of the three groups, and 36 of these patients completed the study. The tourniquet was inflated just before incision and deflated after the hardening of the cement for twelve patients (Group 1), it was inflated just before cement application and deflated after its hardening for another twelve patients (Group 2), and it was inflated before incision and deflated after the last suture of the skin for a further twelve patients (Group 3). Fit-to-discharge criteria and six methods for calculating estimated blood loss were used. RESULTS: The estimated blood loss in Group 1 was lower than in Group 2, as determined by six methods of calculation (p < 0.05). Estimated blood loss in Group 3 was lower than in Group 2, as determined by one method (p = 0.050). The mobilization performance in Group 1 was better than in Group 2 (p = 0.023) and in Group 3 (p = 0.033). Group 1 was better fit to discharge than Group 3 (p = 0.030). CONCLUSIONS: Inflation of an automatic pneumatic lower limb tourniquet before skin incision and its deflation after hardening of cement tends to give better outcomes in TKA patients during six postoperative days. The estimated blood loss was highest when the tourniquet was inflated just before cement application and deflated after its hardening.

Mortality after femoral neck fractures: a two-year follow-up.

BACKGROUND AND OBJECTIVE: To identify the survival and standardized mortality ratio with respect to gender, age, and treatment method of patients treated for femoral neck fractures. MATERIAL AND METHODS: A retrospective review of medical records of 736 patients treated for femoral neck fractures at Vilnius University Emergency Hospital during 2004-2006 was carried out. RESULTS: The overall 1- and 2-year survival rates were 77.4% and 67.1%, respectively. Lower survival rates were observed in the internal fixation group than in the primary and secondary total hip arthroplasty groups (63.2% vs. 72.0% and 75.1%). Cox proportional hazards model analysis showed patient age to be a significant risk factor for survival (hazard ratio, 1.05; 95% CI, 1.04-1.07; P<0.001). The overall standardized mortality ratio was 2.50. The standardized mortality ratios for men and women were 3.07 and 2.27, respectively, but the difference between these groups was not significant. CONCLUSIONS: Standardized mortality and survival rates decreased with increasing patients' age. Significantly lower survival rates were documented in the internal fixation group as compared with primary and secondary total hip arthroplasty groups. There was a trend toward a higher standardized mortality ratio in men than women, but the difference was not significant.