Weijun Wang

Nutrition support with glutamine dipeptide in patients undergoing liver transplantation.

AIM The effect of total parenteral nutrition (TPN) support supplemented with alanyl-glutamine (Ala-Gln) dipeptide was investigated in a randomized, controlled clinical trial. METHODS Sixty-five patients with the diagnosis of end-stage liver disease or hepatic cellular carcinoma admitted for orthotopic liver transplantation were randomly divided into 3 groups: diet group (n = 21), TPN group (n = 22), and Gln group (n = 22). Patients in the TPN and Gln groups received isocaloric and isonitrogenous TPN for 7 days. Venous heparin blood samples were obtained for assay on days 2 and 9 after surgery; we performed routine pathologic tests. RESULTS Compared with the results on day 9 in the TPN group, there was a significant increase in the prognostic nutrition index and in prealbumin among the Gln group. Aspartate aminotransferase improved significantly by Gln treatment compared with traditional TPN support (P < .05). The pathologic results also showed Gln supplementation to reduce hepatic cell injury. A significant decrease in postoperative hospital stay was observed in the Gln group. CONCLUSIONS Posttransplant TPN support greatly improved protein metabolism and nutritional state of patients. TPN with Ala-Gln helped to improve synthetic function and to reduce the injury to a transplanted liver.

Different Curve Pattern and Other Radiographical Characteristics in Male and Female Patients With Adolescent Idiopathic Scoliosis

Study Design. Retrospective radiographical study. Objective. To compare the sex differences in curve patterns and radiographical characteristics in patients who have adolescent idiopathic scoliosis (AIS). Summary of Background Data. Sex differences in AIS have been documented in the incidence of curve progression, response to bracing, and outcomes of surgical treatment. However, limited information is available about the relation between sex and scoliosis curve patterns and radiographical presentations. Methods. A total of 359 male and 999 female patients with AIS with major curve of 20° or more were recruited. Standard posteroanterior and lateral radiographs of spine were reviewed to classify scoliosis curve patterns as typical or atypical and to measure curve severity and thoracic kyphosis. In 351 surgically treated patients, side-bending films were used to assess curve flexibility. Comparisons between male and female patients were made by subgrouping patients according to curve patterns and severity. Results. Atypical curves were more frequently observed in male (19.8%) than in female patients (8.9%) (P < 0.01). Sex differences were also found in the distribution of curve types. Main thoracic curve was the most common curve type in both sexes. Furthermore, significantly higher incidence of main thoracic curve in patients with severe AIS than in patients with moderate AIS was found in male (P < 0.001) but not in female patients. In patients with severe AIS who had typical curve patterns that included a major thoracic curve, male patients had larger magnitude of thoracic curve, more severe thoracic kyphosis, and more rigid thoracic and lumbar curves than female patients. Conclusion. Atypical curve patterns were more predominant in male than in female patients with AIS. The thoracic curve in male patients with AIS might have higher incidence of progression than that in female patients. The higher rigidity of both thoracic and lumbar curves in male patients with AIS with severe curves might contribute to the lower curve correction rate and poor response to brace than in female cases.

The position of the aorta changes with altered body position in single right thoracic adolescent idiopathic scoliosis: a magnetic resonance imaging study.

Study Design. A prospective clinical magnetic resonance imaging study. Objective. To explore the differences in the position of the aorta relative to the spine in patients with single right thoracic adolescent idiopathic scoliosis (RT-AIS) in 2 different body positions (supine and prone). Summary of Background Data. Pedicle screws are used widely in scoliosis surgery. With an increase in the incidence of vascular complications that result from misplaced pedicle screws, studies regarding the spatial relationship of the aorta and the vertebral body have also gradually increased and show that the aorta is positioned more posteriorly in patients with RT-AIS than in normal subjects. In these imaging studies, the patients received computed tomographic or magnetic resonance (MR) scans in the supine position. Recent studies of subjects without a spinal deformity found that the aorta moves from a posterolateral to an anteromedial position when the subject changes from a supine position to a prone position. However, no studies investigated aorta shifting with changing body position in patients with AIS. Methods. Twenty-six patients with single RT-AIS were recruited into this study. Each patient received an axial MR scan from T5 through L3 in both the supine and prone positions. In the Cartesian coordinate system, the left pedicle-aorta (LtP-Ao) angle, LtP-Ao distance, and vertebral rotation angle were measured from T5 through L3 in the axial plane MR images. We also simulated misplacement of the pedicle screw with commonly used length and 20° direction error, and the potential risk of aorta impingement was defined as the virtual pedicle screw crossing the aorta. The paired sample t test was used to compare these parameters between the 2 body positions. Results. The mean LtP-Ao angle and mean LtP-Ao distance differed between the body positions at each level. At the T5–T10 levels, the patients in the prone position exhibited significantly smaller LtP-Ao angles (26.2° vs. 38.8°; P, 0.01) and distances (27.0 vs. 30.7 mm; P, 0.01) than those in the supine position. The vertebral rotation angle was larger in the prone position than in the supine position at periapical levels, although this difference did not reach statistical significance (P . 0.05). The percentage of potential risk of aorta impingement was significantly higher in the prone position than in the supine position at the T5–T10 levels (19.7% vs. 6.6%, respectively; P, 0.05). Conclusion. The aorta shifts more anteromedially and more closely to the spine at the T5–T10 levels when patients with RT-AIS change from the supine to the prone position. Thus, in the prone position, the aorta is potentially at a higher risk for injury from anterior and lateral cortex penetration by the left pedicle screws. The spinal surgeon should be aware of these altered conditions to avoid injury to the aorta during pedicle screw insertion in patients with RT-AIS who are in the prone position.

Accuracy of thoracic vertebral screw insertion in adolescent idiopathic scoliosis: a comparison between thoracoscopic and mini-open thoracotomy approaches.

Study Design. A cross-sectional study with axial computed tomography (CT) to compare the accuracy of vertebral screw insertion in the thoracic spine for adolescent idiopathic scoliosis (AIS) between the thoracoscopic and the mini-open thoracotomy approach. Objective. To evaluate the safety of vertebral screw placement in anterior instrumentation for thoracic AIS. Summary of Background Data. Thoracoscopic anterior instrumentation has been used with good results for AIS. It is technically demanding especially for the insertion of vertebral screws. The important issue of whether the screws inserted thoracoscopically is as accurate and safe as those inserted through thoracotomy approach has not been well studied. Methods. Thirty-one patients with thoracic AIS receiving thoracoscopic or mini-open thoracotomy anterior instrumentation were included in this study. They were divided into Group A and B, respectively. Postoperative sequential CT scanning on the thoracic vertebral screws was carried out. The relative position between screws and the spinal canal, the aorta, and the bicortical purchase were analyzed with CT images. The percentage of screws in good position was defined and further analyzed. Results. Seventy-three and 162 thoracic vertebral screws were inserted in 10 patients in Group A and 21 patients in Group B, respectively. Eighty-nine percent of screw tips in Group A and 80.2% in Group B were distant from the aorta, 89.0% and 87.0% of screws achieved bicortical purchase in Group A and B, respectively. No significant difference was found in all thoracic levels including the upper thoracic, periapical, or lower thoracic vertebrae. Seventy-four percent and 66.7% of screws were in good positions in Group A and B, respectively and there was no statistically significant difference between the 2 groups. Conclusion. The vertebral screws inserted through thoracoscopic approach were as accurate as those inserted through a mini-open thoracotomy approach. The accuracy could be enhanced by using screws with smaller increments, with special attention to the possible migration of aorta with anterior spinal instrumentation.

Characteristics of the pelvic axial rotation in adolescent idiopathic scoliosis: a comparison between major thoracic curve and major thoracolumbar/lumbar curve

BACKGROUND CONTEXT As the biomechanical foundation of the spine, the pelvis was found to display rotation in the transverse plane in adolescent idiopathic scoliosis (AIS). However, the possible factors influencing the pelvic axial rotation (PAR) and its mechanism in patients with AIS remain unclear. PURPOSE To characterize the PAR in AIS patients with right major thoracic (MT) or major left thoracolumbar/lumbar (TL/L) curve and to explore the associated influencing factors and probable mechanism of compensation by analyzing the association between PAR and other spinal radiographic parameters. STUDY DESIGN Retrospective study. PATIENT SAMPLE All patients with the primary diagnosis of AIS from January 2008 to November 2009 were retrieved from our scoliosis database. OUTCOME MEASURES Age, Cobb angle, and apex rotation of the main curve and the compensatory curve, curve flexibility, and PAR. METHODS One-hundred thirty-two patients with right MT (14.7±1.8 years, 48±6.9°) and 83 patients with left major TL/L (14.7±1.5 years, 46±6.6°) were retrospectively reviewed. On standing full-spine posteroanterior radiographs, the PAR was quantified by the left/right hemi-pelvis width ratio (L/R ratio); then the subjects in both MT and major TL/L groups were divided into two subgroups: L/R ratio ≤1 (pelvis rotated to the right, R-PAR group); and L/R ratio >1 (pelvis rotated to the left, L-PAR group). Comparisons of all variables were performed between the L- and R-PAR subgroups; correlation and regression analysis were carried out to identify the influencing factors of PAR. RESULTS The majority of the MT and major TL/L patients (75.8% vs. 60.2%) displayed right pelvic rotation, which was in the same direction as the thoracic curve. The incidence of R-PAR was greater in the MT patients than the major TL/L ones (p=.016). Lumbar flexibility in MT patients with R-PAR was greater than in MT patients with L-PAR (0.96±0.27 vs. 0.81±0.33, p=.038), which was contrary to the findings in the major TL/L patients (L-PAR>R-PAR, 0.79±0.15 vs. 0.70±0.22, p=.024). In the MT patients with R-PAR, the L/R ratio showed significant positive correlations with the lumbar Cobb angle (r=0.424) as well as with the apex rotation (r=0.488), which was further identified as an influencing factor (R=0.418) of the PAR. Significant positive correlations between L/R ratio and thoracic apex rotation (r=0.361) also were detected. CONCLUSION The majority of AIS patients with right MT or left major TL/L curves were found to have PAR to the right, in the same direction as the thoracic curve. The lumbar flexibility and apex rotation significantly influenced the PAR direction and magnitude. Moreover, the pelvis might be involved in compensation for the MT deformity through its connection with the lumbar spine.

Transcription factor Runx2 in the low bone mineral density of girls with adolescent idiopathic scoliosis.

The molecular mechanism of low bone mass in girls with adolescent idiopathic scoliosis (AIS) has not been ascertained. Runx2 is a critical transcription factor regulating osteoblast differentiation and maturation. The present study aimed to explore the possible relationship between Runx2 expression in osteoblasts and bone mineral density (BMD) in subjects with AIS.

Influence of prone positioning on potential risk of aorta injury from pedicle screw misplacement in adolescent idiopathic scoliosis patients.

Study Design: A prospective magnetic resonance imaging (MRI) study. Objective: The aim of this study was to quantitatively analyze the potential risks of aorta injury from thoracic pedicle screw (TPS) misplacement in right thoracic adolescent idiopathic scoliosis (RT-AIS) patients who are in the prone position. Summary of Background Data: The aorta injuries are rare during posterior spinal surgery, but they can result in catastrophic complications when they do occur. However, we are aware of no prior studies that have used MRI images obtained with patients in the prone position for the purpose of systematically evaluating the potential risks of aorta injury due to TPS misplacement. Materials and Methods: This prospective study included 38 RT-AIS patients who underwent MRI scans in the prone position. We evaluated on the MRI images the aorta position relative to the scoliotic spine, and simulated placement of a left TPS with a lateral deviation different from the medium trajectory using Surgimap Spine imaging software. The maximum error of lateral direction was set to 10, 20, or 30 degrees (3 scenarios), and the length of the TPS was set at 30, 35, or 40 mm (3 scenarios). Sensitivity analysis was performed by variable direction errors and TPS lengths. The potential risk of aorta impingement was defined as the virtual TPS crossing the aorta. The percentages of potential risk of aorta impingement were calculated at each level in 9 scenarios. Results: In the RT-AIS patients, the aorta shifted gradually from the left side of the vertebrae at midthoracic levels to a more anterior position at the lower thoracic levels, and was close to the vertebral body at T5–T6 and far away from the left cortex of vertebrae at T12. In 9 scenarios, with the increment of the lengths or/and direction errors of the simulated TPS, the risks of aorta impingement were consistently elevated at all the levels. The simulated 40 mm TPS at T5, T6, and T11 posed a higher potential risk of aorta injury (66%–74%) with a 30-degree lateral direction error. Conclusions: Prone positioning may increase the potential risk of aorta injury in RT-AIS patients, particularly at T5–T6 and T11 even if a left TPS just barely touches the anteriolateral or lateral cortex of the vertebrae. Laterally misplaced TPSs should be removed at these high aorta-at-risk levels.

Distal Femoral Fractures in Post-poliomyelitis Patients Treated with Locking Compression Plates

Treatment of distal femoral fracture in post‐polio patients is difficult because the bone is usually osteopenic, small and deformed. This retrospective study aimed to investigate the outcomes of distal femoral fracture in post‐polio patients treated by locking compression plates (LCP).

Sagittal alignment of the spine-pelvis-lower extremity axis in patients with severe knee osteoarthritis: A radiographic study

Objectives Normal sagittal spine-pelvis-lower extremity alignment is crucial in humans for maintaining an ergonomic upright standing posture, and pathogenesis in any segment leads to poor balance. The present study aimed to investigate how this sagittal alignment can be affected by severe knee osteoarthritis (KOA), and whether associated changes corresponded with symptoms of lower back pain (LBP) in this patient population. Methods Lateral radiograph films in an upright standing position were obtained from 59 patients with severe KOA and 58 asymptomatic controls free from KOA. Sagittal alignment of the spine, pelvis, hip and proximal femur was quantified by measuring several radiographic parameters. Global balance was accessed according to the relative position of the C7 plumb line to the sacrum and femoral heads. The presence of chronic LBP was documented. Comparisons between the two groups were carried by independent samples t-tests or chi-squared test. Results Patients with severe KOA showed significant backward femoral inclination (FI), hip flexion, forward spinal inclination, and higher prevalence of global imbalance (27.1% versus 3.4%, p < 0.001) compared with controls. In addition, patients with FI of 10° (n = 23) showed reduced lumbar lordosis and significant forward spinal inclination compared with controls, whereas those with FI > 10° (n = 36) presented with significant pelvic anteversion and hip flexion. A total of 39 patients with KOA (66.1%) suffered from LBP. There was no significant difference in sagittal alignment between KOA patients with and without LBP. Conclusions The sagittal alignment of spine-pelvis-lower extremity axis was significantly influenced by severe KOA. The lumbar spine served as the primary source of compensation, while hip flexion and pelvic anteversion increased for further compensation. Changes in sagittal alignment may not be involved in the pathogenesis of LBP in this patient population. Cite this article: W. J. Wang, F. Liu, Y.W. Zhu, M.H. Sun, Y. Qiu, W. J. Weng. Sagittal alignment of the spine-pelvis-lower extremity axis in patients with severe knee osteoarthritis: A radiographic study. Bone Joint Res 2016;5:198–205. DOI:10.1302/2046-3758.55.2000538.

Body composition in males with adolescent idiopathic scoliosis: a case-control study with dual-energy X-ray absorptiometry.

BackgroundIn contrast to the well-characterized body growth and development of females with adolescent idiopathic scoliosis (AIS), the pubertal growth pattern of male patients has not been well-documented. Recently, significantly lower body weight (BW) and body mass index (BMI) were reported in males with AIS, and were thought to be related to curve progression. A case–control study was carried out to characterize the body composition and bone status of males with AIS, with the aim of gaining a better understanding of lower BW among these patients.MethodsForty-seven males with AIS and forty age- and gender-matched healthy controls were recruited. Standing height (SH) and BW were measured. The SH of the males who had AIS was corrected using Bjure’s equation, and then the BMI was calculated. Body composition, including subcranial fat mass (FM), lean mass (LM), and bone mineral content (BMC), and bone mineral density (BMD) were analyzed using dual-energy X-ray absorptiometry. The LM index (LMi) and the FM index (FMi) were calculated by dividing the FM and LM by the square of the SH. Logistic regression analysis was employed for comparison between AIS and controls.ResultsThe AIS patients had comparable age and Tanner staging for pubic hair as the controls. After adjustment for age, the AIS patients showed comparable SH but significantly lower BW and BMI than that of the controls. The LM, LMi, BMC and BMD were also significantly lower in the AIS patients than in the controls. However, the difference in BMC between two groups was not significant by adjusting for age, FM and LM.ConclusionThe male AIS patients showed abnormal body composition, presenting as significantly lower LM than the controls. The lower BMC observed in the patients might due to the abnormal body composition.