[Effect of asymmetrical dimethylarginine for predicting pro-thrombotic risk in atrial fibrillation].

OBJECTIVE: Atrial fibrillation (AF) is responsible for some thromboembolic events. Asymmetrical dimethylarginine(ADMA) increases in atrial fibrillation(AF) animals with dysfunction of endothelium, but its role in pro-thrombotic state of AF was unknown. The aim of our study was to explore the role of ADMA in predicting the pro-thrombotic state in AF and to reveal its mechanism. METHODS: One hundred and thirty-eight patients in the First Affiliated Hospital, Sun Yat-sen University, from 2010 to 2012, were enrolled (persistent atrial fibrillation group, PAF, n=80; paroxysmal atrial fibrillation group, Paf, n=30; sinus rhythm, SR, n=28). Plasma ADMA levels were detected by ELISA-kits. CHADS2 and CHA2DS2-VASc scores were estimated for each patient.14 Beagles (pacing group, n=8; sham group, n=6) were subjected to rapid atrial pacing (RAP). ADMA level was detected after 4 weeks of RAP. RESULTS: ADMA level was elevated significantly in patients with atrial fibrillation especially in patients with persistent atrial fibrillation, and showed a significant linear correlation to CHADS2 and CHA2DS2-VASc score. With ADMA, ROC area under the curve was 0.865 in CHADS2 score ≥2 and was 0.959 in CHA2DS2-VASc score ≥2 (P<0.001 respectively). After 4 weeks of RAP, ADMA level was elevated compared to sham group and before operation. ADMA showed a linear correlation with atrial fibrillation susceptibility(r=0.686, P=0.007). CONCLUSIONS: ADMA levels are elevated both in AF patients and RAP beagles. ADMA correlates with stroke risk concerning with CHADS2/CHA2DS2-VASc score. ADMA may become a new biomarker for predicting pro-thrombotic risk in AF.

Limited open reduction is better for simple- distal tibial shaft fractures than minimally invasive plate osteosynthesis.

The aim of this study was to compare the effects and indications of minimally invasive plate osteosynthesis (MIPO) and limited open reduction (LOR) for managing distal tibial shaft fractures. A total of 79 cases of distal tibial shaft fractures were treated surgically in our trauma center. The 79 fracture cases were classified into type A, B, and C (C1) according to the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification, with 28, 32, and 19 cases, respectively. Among the 79 fracture cases, 52 were closed fractures and 27 were open fractures (GUSTILO, I-II). After adequate preparation, 48 cases were treated with LOR and 31 cases were treated with MIPO. All cases were followed up for 12 to 18 months, with an average of 16.4 months. During the follow-up period, 76 fracture cases were healed in the first stage, whereas the 3 cases that developed non-union were treated by changing the fixation device and autografting. For types A, B, and some of C simple fractures (C1), LOR accelerated the fracture healing and lowered the non-union rate. One case suffered from regional soft tissue infection, which was controlled by wound dressing and intravenous antibiotics. Another case that developed local skin necrosis underwent local flap transplant. LOR promoted bone healing and lowered the non-union rate of several simple-distal tibial shaft fractures. Thereafter, the incidence of soft tissue complication was not significantly increased. However, for complex and comminuted fractures, MIPO was the preferred method for correcting bone alignment and protecting soft tissue, leading to functional recovery.

Reliability and repeatability of tibial plateau fracture assessment with an injury mechanism-based concept.

OBJECTIVES: CT-based three-column classification (TCC) has been widely used in the treatment of tibial plateau fractures (TPFs). In its updated version (updated three-column concept, uTCC), a fracture morphology-based injury mechanism was proposed for effective treatment guidance. In this study, the injury mechanism of TPFs is further explained, and its inter- and intraobserver reliability is evaluated to perfect the uTCC. METHODS: The radiological images of 90 consecutive TPF patients were collected. A total of 47 men (52.2%) and 43 women (47.8%) with a mean age of 49.8 years (sd 12.4; 17 to 77) were enrolled in our study. Among them, 57 fractures were on the left side (63.3%) and 33 were on the right side (36.7%); no bilateral fracture existed. Four observers were chosen to classify or estimate independently these randomized cases according to the Schatzker classification, TCC, and injury mechanism. With two rounds of evaluation, the kappa values were calculated to estimate the inter- and intrareliability. RESULTS: The overall inter- and intraobserver agreements of the injury mechanism were substantial (κinter = 0.699, κintra = 0.749, respectively). The initial position and the force direction, which are two components of the injury mechanism, had substantial agreement for both inter-reliability or intrareliability. The inter- and intraobserver agreements were lower in high-energy fractures (Schatzker types IV to VI; κinter = 0.605, κintra = 0.721) compared with low-energy fractures (Schatzker types I to III; κinter = 0.81, κintra = 0.832). The inter- and intraobserver agreements were relatively higher in one-column fractures (κinter = 0.759, κintra = 0.801) compared with two-column and three-column fractures. CONCLUSION: The complete theory of injury mechanism of TPFs was first put forward to make the TCC consummate. It demonstrates substantial inter- and intraobserver agreement generally. Furthermore, the injury mechanism can be promoted clinically.Cite this article: B-B. Zhang, H. Sun, Y. Zhan, Q-F. He, Y. Zhu, Y-K. Wang, C-F. Luo. Reliability and repeatability of tibial plateau fracture assessment with an injury mechanism-based concept. Bone Joint Res 2019;8:357-366. DOI: 10.1302/2046-3758.88.BJR-2018-0331.R1.

A new method to locate the radial head "safe zone" on computed tomography axial views.

PURPOSE: Direct location of the "safe zone" on a CT axial view is impossible because the radial head is circular in shape. Previous "safe zone" location methods are not appropriate if the physician is unable to visualize the actual radial head. This study aims to introduce a new method to locate the "safe zone" on CT. METHODS: CT scans were performed on 20 intact cadaveric upper limbs from 20 different corpses in full pronation and supination. The DICOM-format raw data were then re-sliced and analyzed in Mimics 17.0 (Materialise, Belgium). The radial interosseous border (IB) is shaped like a droplet on the axial view; its axis was selected as our reference line (RL). A parallel line in the radial head axial slice was created, and its position relative to the "safe zone" was studied. Deviation in RL direction was evaluated. RESULTS: Safe-zone scope was 114.41°±11.99. The rotation angle from the RL to the safe-zone's anterior and posterior border was 215.03°±5.99 and 100.62°±8.12, respectively. Rotation direction (clockwise or anti-clockwise) depended on relative radius-ulna position. The safe zone was located by determining these two borders. The reference line's direction was stable in the upper half of the IB; its distance to the radial head fovea was 77.33° mm±6.24. CONCLUSIONS: The radial head "safe zone" can be located on CT axial view based on the upper half of the IB using this new method. The method is clinically applicable to determine whether postoperative elbow malrotation results from plate impingement.

Radiographic predictors for bone mineral loss: Cortical thickness and index of the distal femur.

OBJECTIVES: Researchers continue to seek easier ways to evaluate the quality of bone and screen for osteoporosis and osteopenia. Until recently, radiographic images of various parts of the body, except the distal femur, have been reappraised in the light of dual-energy X-ray absorptiometry (DXA) findings. The incidence of osteoporotic fractures around the knee joint in the elderly continues to increase. The aim of this study was to propose two new radiographic parameters of the distal femur for the assessment of bone quality. METHODS: Anteroposterior radiographs of the knee and bone mineral density (BMD) and T-scores from DXA scans of 361 healthy patients were prospectively analyzed. The mean cortical bone thickness (CBTavg) and the distal femoral cortex index (DFCI) were the two parameters that were proposed and measured. Intra- and interobserver reliabilities were assessed. Correlations between the BMD and T-score and these parameters were investigated and their value in the diagnosis of osteoporosis and osteopenia was evaluated. RESULTS: The DFCI, as a ratio, had higher reliability than the CBTavg. Both showed significant correlation with BMD and T-score. When compared with DFCI, CBTavg showed better correlation and was better for predicting osteoporosis and osteopenia. CONCLUSION: The CBTavg and DFCI are simple and reliable screening tools for the prediction of osteoporosis and osteopenia. The CBTavg is more accurate but the DFCI is easier to use in clinical practice.Cite this article: Q-F. He, H. Sun, L-Y. Shu, Y. Zhu, X-T. Xie, Y. Zhan, C-F. Luo. Radiographic predictors for bone mineral loss: Cortical thickness and index of the distal femur. Bone Joint Res 2018;7:468-475. DOI: 10.1302/2046-3758.77.BJR-2017-0332.R1.

Acute exercise-induced nitric oxide production contributes to upregulation of circulating endothelial progenitor cells in healthy subjects.

Exercise has been proved to promote the number and activity of circulating endothelial progenitor cells (EPCs) in humans, which contributes to improvement in endothelial function and maintenance of cardiovascular homoeostasis. However, the mechanism underlying the effect of exercise on circulating EPCs in healthy subjects is not completely understood. Here, we investigated whether the regulation of acute exercise on circulating EPCs is associated with nitric oxide (NO), vascular endothelial growth factors (VEGF) and granulocyte macrophage colony stimulating factor (GM-CSF) known to modulate circulating EPCs in healthy subjects. A total of 16 healthy male volunteers underwent a modified Bruce treadmill acute exercise protocol. The number and activity of circulating EPCs, as well as the levels of NO-VEGF and GM-CSF in plasma and culture medium before and after exercise in healthy subjects were measured. The number and activity of circulating EPCs after acute exercise were significantly higher than those before exercise in healthy subjects. In parallel, acute exercise significantly enhanced plasma NO level in healthy subjects. There is a significant linear regression relationship between the enhanced plasma NO level and increased number or activity of circulating EPCs. However, no change of plasma VEGF and GM-CSF level was observed after acute exercise. The secretion of NO-VEGF and GM-CSF by cultured EPCs remained unchanged in response to acute exercise. The present study demonstrates for the first time that acute exercise-induced NO production contributes to upregulation of circulating EPCs in healthy subjects, which suggests that NO plays an important role in the regulation of exercise on circulating EPCs.

Shear stress increases Cu/Zn SOD activity and mRNA expression in human endothelial progenitor cells.

Endothelial progenitor cells (EPCs) are involved in endothelial repair. However, the function of EPCs is impaired in the presence of cardiovascular risk factors. Therefore, upregulation of functional gene expression and bioactive substance production such as superoxide dismutase (SOD) activity and mRNA expression in EPCs may contribute to the maintenance of EPC-related endothelial repair. EPCs from human peripheral blood mononuclear cells were exposed to in vitro 5, 15 and 25 dyn/cm(2) shear stress for 5, 15 and 25 h, respectively. Shear stress in a dose- and time-dependent fashion increased Cu/Zn SOD activity of human EPCs. Shear stress also upregulated the Cu/Zn SOD mRNA expression of human EPCs, indicating that an increase in Cu/Zn SOD activity induced by shear stress was mediated by enhanced transcription. Our data are the first time to show that in vitro shear stress enhances mRNA expression and activity of Cu/Zn SOD in human EPCs, suggesting that shear stress can be used as a novel Means of manipulation to improve functional potential of EPCs. The augmentation in copper/zinc-containing enzyme (Cu/Zn SOD), with subsequent accelerated superoxide anion (O(2)(-)) inactivation, might increase locally nitric oxide (NO) biological availability, which contributes to EPC-related vascular protection.

A combined posterior reversed L-shaped and anterolateral approach for two column tibial plateau fractures in Caucasians: A technical note.

OBJECTIVE: Open reduction and internal fixation of two column posterior and lateral tibial plateau fractures through a combined posterior reversed L-shaped and anterolateral approach in floating position in Caucasians. INDICATIONS: Two column posterior and lateral tibial plateau fractures. CONTRAINDICATIONS: Tibial plateau fractures that do not involve the posterior and lateral column. SURGICAL TECHNIQUE: The patient is positioned in floating position, a reversed L-shaped skin incision is made, the posterior column after lateral retraction of the medial head of the gastrocnemius muscle is exposed, and the posterior fragments are reduced and fixed. Subsequently, flexion and varus stress on the knee is applied, an anterolateral skin incision is made, the lateral column is exposed, and the lateral fragments are reduced and fixed. CONCLUSION: Despite a different physique as Asians, a combined posterior reversed L-shaped and anterolateral approach in a floating position for the surgical treatment of two column posterior and lateral tibial plateau fractures is technically possible in Caucasians. In our experience, this combined approach is an excellent strategy in most patients for surgical treatment of two column posterior and lateral column fractures.

A comparison of proximal femoral locking compression plates with dynamic hip screws in extracapsular femoral fractures.

INTRODUCTION: The potential value of proximal femoral locking compression plate (PFLCP) for extracapsular femoral fractures has been discussed in several case reports; however, clinical control studies are lacking. Therefore, we performed a case control study to assess: (1) If PFLCP offers better functional results and fewer complications than dynamic hip screws (DHS)? (2) Which kind of extracapsular femoral fractures would benefit from PFLCP fixation? HYPOTHESIS: The PFLCP fixation offers better functional results and fewer complications than the DHS for the treatment of extracapsular fractures. PATIENTS AND METHODS: A total of 83 patients with extracapsular femoral fractures were recruited. Forty-one patients underwent PFLCP fixation, and 42 patients underwent DHS fixation. Patient information, operative time, blood loss, functional level (as assessed by Sanders' traumatic hip rating scale), bone union, and implant complications were compared for the two treatment groups. RESULTS: Patients with stable intertrochanteric fractures who underwent PFLCP fixation demonstrated shorter bone union time than the DHS fixation group (3.3 ± 0.2 vs. 4.3 ± 0.1 month; P<0.0001); however, both groups had 100% bone union and good to excellent scores on Sanders' traumatic hip rating scale (P=1.000). Patients with unstable intertrochanteric fractures who underwent PFLCP fixation experienced greater blood loss (619.0 ± 23.9 vs. 474.1 ± 19.8 ml; P<0.0001), which was mainly due to the need for open reduction (64.3% vs. 12.5%; P=0.003), compared to the DHS fixation group. No differences were identified with respect to bony union, functional level, or complications. Patients with subtrochanteric fractures who underwent PFLCP fixation demonstrated significantly shorter operative times (82.1 ± 4.3 vs. 102.2 ± 2.2 minutes; P<0.0001), less blood loss (751.8 ± 25.4 vs. 987.6 ± 32.0 ml; P<0.0001), shorter bone union times (5.2 ± 0.4 vs. 8.8 ± 1.0 month; P=0.006), more good to excellent Sanders' traumatic hip rating scale scores (92.9% vs. 55.5%; P=0.009), and fewer complications (14.2% vs. 66.6%; P=0.005) than the DHS fixation group. CONCLUSION: PFLCP fixation offers better functional outcomes and fewer complications for subtrochanteric femoral fractures but not for intertrochanteric femoral fractures. LEVELS OF EVIDENCE: Case control study, level III.

Utilization of bioreactance technique as indicator for preload responsiveness during living donor liver donation.

BACKGROUND: Fluid restriction has been used to decrease central venous pressure as a strategy of fluid management during living donor liver donation (LDLD). However, potential risks such as hemodynamic instability are also involved during the procedure. Monitoring of preload or preload responsiveness is therefore crucial during LDLD. The aim of this study was to explore the efficiency of an innovative bioreactance method that introduced the noninvasive cardiac output monitor (NICOM, Cheetah Medical, Vancouver, Wash, United States), as surrogate indicator for preload responsiveness during LDLD. METHODS: Twenty-six patients underwent LDLD and were enrolled in this study. Fluid was restricted until the organ was harvested. The ultrasonic cardiac output monitor (USCOM Ltd, Sydney, Australia) was applied to measure stroke volume (SV) before and after 500 mL of 6% hydroxyethyl starch 130/0.4 (Voluven, Fresenius Kabi, Friedberg, Germany) fluid challenge, and the value of SV variation (SVV) from NICOM was also recorded. Fluid responsiveness was defined if SV increased by more than 15%. Receiver operating characteristic (ROC) curve was performed. RESULTS: The area under the ROC curve was 0.6023. The optimal cutoff value of SVV from NICOM was 12% during LDLD. CONCLUSIONS: Our study has shown that SVV measured from the bioreactance technique is a poor indicator for monitoring preload responsiveness during LDLD.

Corrected flow time is a good indicator for preload responsiveness during living donor liver donation.

BACKGROUND: Corrected flow time (FTc) has been utilized as preload indicator in recent literature. Accurate estimation of preload status during living donor liver donation (LDLD) is important due to fluid restriction. We evaluate the effectiveness of FTc as a surrogate of preload indicator during LDLD. MATERIALS AND METHODS: Twenty-five patients undergoing LDLD were enrolled in the study. Administration of intravenous fluid was restricted before lobectomy was performed. After the organ was harvest, fluid challenge with 500 mL of Voluven (130/0.42, Fresenius, Friedberg, Germany) was performed. Stroke volume (SV) was measured with ultrasonic cardiac output monitor (USCOM; USCOM Pty, Ltd, Sydney, Australia) before and after the fluid challenge. The FTc value obtained with USCOM before fluid challenge was recorded. Fluid responsiveness was defined as an increase in SV of more than 15%. Receiver operating characteristic (ROC) curve was performed. RESULTS: The area under ROC curve was 0.9. The optimal cutoff FTc value was 340 milliseconds during LDLD. CONCLUSIONS: FTc is a noninvasive, easily obtainable, and essentially good preload indicator during LDLD.

A prospective, randomised trial comparing the use of absorbable and metallic screws in the fixation of distal tibiofibular syndesmosis injuries: mid-term follow-up.

Our aim was to compare polylevolactic acid screws with titanium screws when used for fixation of the distal tibiofibular syndesmosis at mid-term follow-up. A total of 168 patients, with a mean age of 38.5 years (18 to 72) who were randomly allocated to receive either polylevolactic acid (n = 86) or metallic (n = 82) screws were included. The Baird scoring system was used to assess the overall satisfaction and functional recovery post-operatively. The demographic details and characteristics of the injury were similar in the two groups. The mean follow-up was 55.8 months (48 to 66). The Baird scores were similar in the two groups at the final follow-up. Patients in the polylevolactic acid group had a greater mean dorsiflexion (p = 0.011) and plantar-flexion of the injured ankles (p < 0.001). In the same group, 18 patients had a mild and eight patients had a moderate foreign body reaction. In the metallic groups eight had mild and none had a moderate foreign body reaction (p < 0.001). In total, three patients in the polylevolactic acid group and none in the metallic group had heterotopic ossification (p = 0.246). We conclude that both screws provide adequate fixation and functional recovery, but polylevolactic acid screws are associated with a higher incidence of foreign body reactions.

[Study of self-threading pins in the preservative restoration of teeth with large area defects].

OBJECTIVE: To investigate the application of self-threading pins in the preservative of teeth with large area defects. METHODS: A follow-up study of 42 out of 50 patients with large area defects in vital teeth were restored by self-threading pins. RESULTS: Among the cases that had been followed up for 5 years, except 2 upper molars which were extracted because of fraction, other cases achieved good effects. CONCLUSION: Self-threading pins are very suitable to restore large area defects of teeth with healthy pulp, and can be widely used because of significant clinical effects.

Reliability of the transepicondylar line as a parameter of femoral axial alignment.

The purpose of this research was to determine the significance of the transepicondylar line as a parameter of femoral axial alignment. Standing full-length X-ray films of 124 knees of 91 patients (63 women, 28 men) with osteoarthritis, rheumatoid arthritis, or osteonecrosis were used in this study, in which the lateral angles formed by the femoral anatomical axis intersecting with the transepicondylar line (angle a'), horizontal line (angle b'), and femoral condylar line (angle r') were measured. The mean value of angle b' in knees with neutral alignment was significantly smaller than that in knees with varus alignment, and significantly larger than that in knees with valgus alignment; no significant difference was found in angle a'. Also, there was no significant difference in angle a' among the patients with osteoarthritis, rheumatoid arthritis, and osteonecrosis. These findings suggest that the transepicondylar line, which is a stable reference of femoral rotation, is also a very reliable parameter of axial alignment of the femur. In the future design of extramedullary guiding for total knee arthroplasty, the transepicondylar line may play an important role as a parameter for proper and accurate implant setting.