Bailing Chen

Transpedicular Fixation in Management of Thoracolumbar Burst Fractures: Monosegmental Fixation versus Short-segment Instrumentation

Study Design. A prospective clinical trial was conducted. Objective. To compare the clinical and radiologic late results of monosegmental transpedicular fixation versus short-segment pedicle instrumentation (SSPI) in management of thoracolumbar burst fractures and evaluate the efficacy of monosegmental transpedicular fixation. Summary of Background Data. SSPI (1 level above and 1 below the fracture level) are accepted by many surgeons as an accepted technique for the treatment of thoracolumbar burst fractures. To preserve more motion segments, some authors have advocated monosegmental pedicle instrumentation (MSPI). The recent developments showed that MSPI yielded good clinical results; however, there were no report about comparison of clinical outcome between monosegmental and biosegmental transpedicular fixation in management of thoracolumbar burst fractures. Methods. Eighty-five patients with thoracolumbar burst fractures fulfilling the inclusion criteria were included in the study. The patients were randomized by a simple method into 2 groups. Group 1 were treated with monosegmental transpedicular fixation (n = 47), and group 2 were treated with biosegmental transpedicular fixation (n = 38). Clinical (Low Back Outcome Score and Oswestry Disability Index) and radiologic (load-sharing classification index, sagittal index, and percentage of anterior body height compression) outcomes were analyzed. Results. The 2 groups were similar in age, follow-up period, and severity of the deformity and fracture. The postoperative and follow-up sagittal index, local kyphosis, percentage of anterior body height compression, and average correction loss in local kyphosis in both groups were not significantly different. The failure rate between the 2 surgical approaches was also not significantly different (group 1 = 6.38% and group 2 = 5.26%). Oswestry Disability Index improved in both groups by >25 points in a similar amount (P = 0.23). The average follow-up Low Back Outcome Score was 74.9 and 60.2 for group 1 and group 2, respectively (P = 0.033). Conclusion. In conclusion, radiologic parameters demonstrated that both MSPI and SSPI are the effective and reliable operative techniques for selected thoracolumbar burst fractures. MSPI shortened the operative time and decreased the amount of blood loss significantly and, thus, offered better clinical results. Nevertheless, long-term studies are supposed to be performed to support the outcomes.

Low-magnitude high-frequency loading via whole body vibration enhances bone-implant osseointegration in ovariectomized rats†

Osseointegration is vital to avoid long‐time implants loosening after implantation surgery. This study investigated the effect of low‐magnitude high‐frequency (LMHF) loading via whole body vibration on bone‐implant osseointegration in osteoporotic rats, and a comparison was made between LMHF vibration and alendronate on their effects. Thirty rats were ovariectomized to induce osteoporosis, and then treated with LMHF vibration (VIB) or alendronate (ALN) or a control treatment (OVX). Another 10 rats underwent sham operation to establish Sham control group. Prior to treatment, hydroxyapatite (HA)‐coated titanium implants were inserted into proximal tibiae bilaterally. Both LMHF vibration and alendronate treatment lasted for 8 weeks. Histomorphometrical assess showed that both group VIB, ALN and Sham significantly increased bone‐to‐implant contact and peri‐implant bone fraction (p < 0.05) when compared with group OVX. Nevertheless the bone‐to‐implant contact and peri‐implant bone fraction of group VIB were inferior to group ALN and Sham (p < 0.05). Biomechanical tests also revealed similar results in maximum push out force and interfacial shear strength. Accordingly, it is concluded that LMHF loading via whole body vibration enhances bone‐to‐implant osseointegration in ovariectomized rats, but its effectiveness is weaker than alendronate.

Monosegmental transpedicular fixation for selected patients with thoracolumbar burst fractures.

Study Design A prospective cohort study on selected consecutive patients. Objective To evaluate the efficacy of an innovative operative technique called monosegmental transpedicular fixation for the treatment of some thoracolumbar burst fractures. Summary of Background Data Short-segment pedicle screw instrumentation is accepted by many spinal surgeons as an acceptable technique for the treatment of thoracolumbar burst fractures. Preoperative evaluation using the spinal load-sharing makes this technique more reliable. To preserve more motion segments, some authors have advocated using monosegmental pedicle screw instrumentation (MSPI) to treat thoracolumbar fractures. However, up until now this kind of maneuver is only performed in cases of flexion distraction injuries. Methods A cohort of 20 patients with thoracolumbar burst fractures fulfilling the inclusion criteria were prospectively submitted to surgical treatment of monosegmental transpedicular fixation plus posterior fusion. All instrumentations were performed with pedicle screws inserted bilaterally into the fractured level and 1 adjacent level, either superior or inferior depending on the locating side of the intact endplate. All patients were followed up. The preoperative radiographs, the postoperative radiographs within 1 week of operation, and the radiographs of the most recent follow-up were evaluated for kyphosis correction recorded in the Sagittal Index and Load-Sharing Classification (LSC) index. The postoperative functional outcomes were evaluated using the Frankel Performance Scale together with the Denis Pain Scale. Results Eighteen patients were followed up successfully with an average final follow-up of 24.7±8.0 months. The focal kyphotic angulations were corrected satisfactorily with the mean Sagittal Index of preoperative 16.5±6.6 degrees, initial postoperative 4.0±2.4 degrees, and latest follow-up 4.8±4.0 degrees. No obvious loss of correction occurred except for 2 patients who both scored 8 points on the LSC Score. Postoperatively, most patients attained both functional neurologic improvement and pain relief, and only a few complications were noted. Conclusions For selected thoracolumbar burst fractures, MSPI can provide the same or better fixation and preserve more motion segments than other methods of posterior pedicle instrumentation. With preoperative evaluation using the spinal LSC system, MSPI is effective and reliable for the treatment of thoracolumbar burst fractures when properly indicated.

Systematic back muscle exercise after percutaneous vertebroplasty for spinal osteoporotic compression fracture patients: a randomized controlled trial:

Objective: To analyze the clinical significance of postoperative back muscle exercises after percutaneous vertebroplasty for spinal osteoporotic compression fracture patients. Design: Clinical randomized controlled trials of parallel group nonpharmacologic study. Setting: Patients practised back muscle exercises in the spinal surgery department, rehabilitation department and at their residences. Subjects: Osteoporotic compression fracture patients who had undergone percutaneous vertebroplasty and processed sufficient muscle strength to participate in the training were studied. Interventions: Patients were randomized into two groups, which were titled A and B. General postoperation therapy, including antiosteoporotic medications and education, was offered to all patients. Group B patients received additional systematic back muscle exercise. Main measures: Both Oswestry Disability Index (ODI) and visual analogue scale (VAS) were recorded preoperatively and postoperatively at three-day, one-month, six-month, one-year and two-year follow-up. Results: From January 2006 to January 2009, a total of 82 patients were assessed for eligibility, 60 patients were enrolled and randomized into two groups. Forty-two (70%) patients (20 of 30 in Group A and 22 of 30 in Group B) were successfully followed-up for two years. Systematic back muscle exercises resulted in a significant advantage in both measurements. The ODI of Group B was significantly better than Group A at the six-month, one-year and two-year follow-ups (P < 0.05). The pain level of Group B was significantly lower than in Group A at the one- and two-year follow-ups (P < 0.05). At the end of our study, the mean (SD) of the ODI in Groups A and B were 39.1 (9.14) and 23.4 (5.62); the mean (SD) of the VAS in Groups A and B were 3.4 (1.15) and 2.1 (0.84), respectively. Conclusions: Our findings suggest that the benefit of the exercises required at least six months to be observed; however, the favourable effects could last for two years. Therefore, systematic back muscle exercise should be recommended as one of the treatment guidelines for postpercutaneous vertebroplasty patients.

Associations between dietary patterns and psychological factors: a cross-sectional study among Chinese postmenopausal women.

Objective:The aim of this study is to explore the association of dietary patterns with depression, perceived stress, and self-esteem among postmenopausal Chinese women. Methods:A cross-sectional study was conducted among 906 participants who attended the screening visits for two soy trials. Dietary data were collected using a validated food frequency questionnaire containing 85 food items. Principal component factor analysis was used to derive dietary patterns based on 11 food groups. Psychological factors were assessed by the Center for Epidemiologic Studies Depression Scale, Perceived Stress Scale, and Rosenberg Self-esteem Scale. Results:We identified three dietary patterns as follows: processed foods (refined grains, preserved foods, fat meat, fried foods, and sweets), whole plant foods (whole grains, vegetables, and fruits), and animal foods (fish, lean meat, and milk products). Multivariable linear regression analyses indicated that whole plant food intake was negatively associated with depression score (P = 0.030). Processed food intake was positively associated with perceived stress (P = 0.025) and depression (P = 0.073), and negatively associated with scores of self-esteem (P = 0.046). The highest tertile of processed foods score was associated with 79.3% increased risk of depression (P for trend = 0.006), whereas the highest tertile of whole plant food score was associated with 26% reduction of depression (P for trend = 0.023) relative to the lowest tertile. Conclusions:Dietary patterns featuring a low intake of processed foods and/or a high intake of whole plant foods were associated with a reduced risk of depression and perceived stress.

Comparison of the Wake-up Test and Combined TES-MEP and CSEP Monitoring in Spinal Surgery.

Study Design: A retrospective clinical analysis. Objective: The aim of this study was to compare the effectiveness of the wake-up test with that of combined monitoring of transcranial electrical stimulation motor evoked potentials (TES-MEP) and cortical somatosensory evoked potentials (CSEP) in spinal surgery. Summary of Background Data: TES-MEP/CSEP combined monitoring is being increasingly recognized as the ideal approach to detect spinal neurophysiological compromise during spinal surgery; however, as a result the merit of the wake-up test is now in doubt. Materials and Methods: TES-MEP/CSEP combined monitoring was performed simultaneously in 426 patients who underwent spinal surgery at our department, and wake-up tests were conducted on 23 patients because of positive neurophysiological monitoring results with uncertain causes or persistent positive monitoring findings after all potential causes had been resolved. Preoperative and postoperative neurological examinations were performed as the gold standard to detect irreversible spinal function compromise. All data were collected to compare the efficiency of TES-MEP/CSEP combined monitoring with that of the wake-up test. Results: Positive results of TES-MEP/CSEP combined monitoring were recorded in 64 cases. Among them, the positive monitoring findings agreed with the results of the neurological examination in 51 cases, and the monitoring results did not match that of neurological examination in 13 cases. No false-negative result was observed. The sensitivity of TES-MEP/CSEP monitoring was 100%, the specificity was 96.5%, and the Youden index was 0.965. Wake-up tests were conducted in 23 cases. In 8 patients the positive monitoring findings completely matched the postoperative neurological examination results. In contrast, in the other 15 cases with negative neurophysiological monitoring results, only 9 patients retained intact neurological function and 6 patients suffered compromised neurological function. The sensitivity of the wake-up test was 57.1%, the specificity was 100%, and the Youden index was 0.571. Conclusions: Combined TES-MEP and CSEP monitoring, with its high sensitivity and specificity, is an effective method for monitoring spinal function during surgery and should be the preferred choice. The wake-up test is a useful complementary method for monitoring because of its high specificity.

Association of Circulating 25(OH)D and Lower Urinary Tract Symptoms: A Four-Year Prospective Study among Elderly Chinese Men

The role of vitamin D in relation to lower urinary tract symptoms (LUTS) remains inconclusive. This four-year longitudinal study aims to explore the association of circulating 25(OH)D and LUTS in elderly Chinese men. Two thousand Chinese men aged 65 and older were recruited from a local community, of which 1998 (99.9%) at baseline and 1564 (78.2%) at four-year follow-up reported data on LUTS, and 988 of the randomly chosen subpopulation were assayed for serum 25(OH)D by radioimmunoassay at baseline. LUTS were evaluated by a validated International Prostate Symptoms Scale (IPSS). Data on demographic characteristics, lifestyle factors, health, and medications were collected. Serum parathyroid and sex steroid hormones and genotypes of vitamin D receptors were assayed. The association of serum 25(OH)D and LUTS was examined by using multivariable regression models. Serum 25(OH)D was not significantly associated with the changes of IPSS or the risk of LUTS in overall participants. However, among men with 25(OH)D ≤ 60 nmol/L, each 10 nmol/L increase of 25(OH)D over 0 nmol/L was significantly associated with 1.3 lower points of IPSS or a 51.6% decreased risk for moderate/severe LUTS four years later. Adjustment for serum androstenedione (p = 0.019) and dehydropiandrosterone (p = 0.037) attenuated the associations. Our study suggested that among individuals with low vitamin D status, the increase of the 25(OH)D level may be associated with a lowered risk of LUTS.

Dietary acrylamide exposure was associated with mild cognition decline among non-smoking Chinese elderly men

The aim of the study is to explore the longitudinal association of dietary acrylamide exposure with cognitive performance in Chinese elderly. The analysis was conducted among 2534 non-smoking elderly men and women based on a prospective study, Mr. and Ms. OS Hong Kong. Dietary acrylamide intake was assessed by food frequency questionnaires with data on local food contamination, derived from the first Hong Kong Total Diet Study. Global cognitive function was assessed by Cantonese version of Mini-Mental State Exam (MMSE) at the baseline and the 4th year of follow-up. Multivariable-adjusted linear and logistic regression models were used to assess the associations of dietary acrylamide with MMSE score changes or risk of poor cognition. The results indicated that among men with MMSE ≥ 18, each one SD increase of acrylamide decreased MMSE score by 7.698% (95%CI: −14.943%, −0.452%; p = 0.037). Logistic regression revealed an increased risk of poor cognition (MMSE ≤ 26) in men with HR of 3.356 (1.064~10.591, p = 0.039). The association became non-significance after further adjustment for telomere length. No significant association was observed in women. Dietary acrylamide exposure was associated with a mild cognitive decline or increased risk of poor cognition over a 4-year period in non-smoking Chinese elderly men.

Comparison of Ten Creatinine-based Equations for Estimation of Glomerular Filtration Rate in Chinese Postmenopausal Women with Normal or Mildly Reduced Renal Function

Background and aim: The aim of the study was to compare the agreement of the commonly used creatininebased equations with simple cystatin C (cysC) equation (100/serum cysC) for estimation of glomerular filtration rate (GFR) in Chinese postmenopausal women with normal or mildly decreased renal function. Materials and methods: Total 936 twenty-four-hour urine and 837 fasting serum samples were tested for creatinine and serum cysC. GFR was estimated by 10 creatinine based equations which included the CockcroftGault equation (CG), the Modification of Diet in Renal Disease equation (MDRD), the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI), 24 h urine creatinine clearance (CrCl), as well as six Asian equations (Asia, Japan, Korean, Thai, China1 and China2). The agreement of the creatinine based equations with cysC equation was assessed for correlation, bias, precision and accuracy. Results: The equations of Korea (r=0.784), China2 (r=0.694), CKD-EPI (r=0.686) and CG (r=0.676) indicated higher intra-correlation with simple cysC GFR than other equations. CG and Korean formulas showed minimal bias from cysC GFR. Bland and Altman plot suggested a significant smaller limit of agreement to cysC GFR was achieved by Japan (52.7%), CKD-EPI (39%), Korean (45.2%) and China2 (46.3%) equations than CrCl (106.8%). Receiver operating characteristic (ROC) analysis indicated the better predictive performance in CG, CKD-EPI and China2 equations to cysC equation. Conclusions: Estimation of GFR using the equations of CKD-EPI, Korean, China2 and Japan has comparable precision and accuracy with simple cysC calculated GFR among Chinese postmenopausal women with normal or mildly decreased renal function.