Morphological features of lower lumbar degenerative kyphosis.

PURPOSE: Kyphosis in the lower lumbar spine (L4-S1) significantly affects sagittal alignment. However, the characteristics of the spinopelvic parameters and compensatory mechanisms in patients with lower lumbar degenerative kyphosis (LLDK) have not been described in detail. The objective of this retrospective study was to analyze the morphological characteristics in patients with sagittal imbalance due to LLDK. METHODS: In this retrospective study, we reviewed the clinical records of consecutive patients who underwent corrective surgery for adult spinal deformity (ASD) at a single institution. We defined LLDK as (i) kyphotic deformity in lower lumbar spine (L4-S1) or (ii) inappropriate distribution of lordosis (lordosis distribution index < 40%) in the lower lumbar spine. Global spine parameters of ASD patients and MRI findings were compared between those with LLDK (LLDK group) and without LLDK (control group). RESULTS: A total of 95 patients were enrolled in this study, of which the LLDK group included 14 patients (14.7%). Compared to the control, LLDK presented significantly higher pelvic incidence (62.1° vs 52.6°) and pelvic tilt (40.0° vs 33.4°), larger lordosis at the thoracolumbar junction (12.0° vs -19.6°), and smaller thoracic kyphosis (9.3° vs 26.0°). In LLDK, there was significantly less disc degeneration at L2/3 and L3/4. CONCLUSION: LLDK patients had high pelvic incidence, large pelvic tilt, and a long compensatory curve at the thoracolumbar junction and thoracic spine region.

Distal junctional failure after corrective surgery without pelvic fixation for thoracolumbar junctional kyphosis due to osteoporotic vertebral fracture.

BACKGROUND: Thoracolumbar junctional kyphosis (TLJK) due to osteoporotic vertebral fracture (OVF) negatively impacts patients' quality of life. The necessity of pelvic fixation in corrective surgery for TLJK due to OVF remains controversial. This study aimed to: 1) evaluate the surgical outcomes of major corrective surgery for thoracolumbar junctional kyphosis due to osteoporotic vertebral fracture, and 2) identify the risk factors for distal junctional failure to identify potential candidates for pelvic fixation. METHODS: Patients who underwent surgical correction (fixed TLJK>40°, OVF located at T11-L2, the lowermost instrumented vertebra at or above L5) were included. Sagittal vertical axis, pelvic tilt, pelvic incidence, thoracic kyphosis, lumbar lordosis (L1-S1), local kyphosis, and lower lumbar lordosis (L4-S1) were assessed. Proximal and distal junctional kyphosis (P/DJK) and failures (P/DJF) were evaluated. Pre/postoperative spinopelvic parameters were compared between DJF and non-DJF patients. RESULTS: Thirty-one patients (mean age: 72.3 ± 7.9 years) were included. PJK was observed in five patients (16.1%), while DJK in 11 (35.5%). Twelve cases (38.7%) were categorized as failure. Among the patients with PJK, there was only one patient (20%) categorized as PJF and required an additional surgery. Contrary, all of eleven patients with DJK were categorized as DJF, among whom six (54.5%) required additional surgery for pelvic fixation. In comparisons between DJF and non-DJF patients, there was no significant difference in pre/postoperative LK (pre/post, p = 0.725, p = 0.950). However, statistically significant differences were observed in the following preoperative alignment parameters: SVA (p = 0.014), LL (p = 0.001), LLL (p = 0.006), PT (p = 0.003), and PI-LL (p < 0.001). CONCLUSIONS: Spinopelvic parameters, which represent the compensatory function of lumbar hyperlordosis and pelvic retroversion, have notable impacts on surgical outcomes in correction surgery for TLJK due to OVF. Surgeons should consider each patient's compensatory function when choosing a surgical approach.

Does surgical site infection affect patient-reported outcomes after spinal surgery? A multicenter cohort study.

BACKGROUND: Surgical site infections are common in spinal surgeries. It is uncertain whether outcomes in spine surgery patients with vs. without surgical site infection are equivalent. Therefore, we assessed the effects of surgical site infection on postoperative patient-reported outcomes. METHODS: We enrolled patients who underwent elective spine surgery at 12 hospitals between April 2017 and February 2020. We collected data regarding the patients' backgrounds, operative factors, and incidence of surgical site infection. Data for patient-reported outcomes, namely numerical rating scale, Neck Disability Index/Oswestry Disability Index, EuroQol Five-Dimensional questionnaire, and 12-Item Short-Form Health Survey scores, were obtained preoperatively and 1 year postoperatively. We divided the patients into with and without surgical site infection groups. Multivariate logistic regression analyses were performed to identify the risk factors for surgical site infection. Using propensity score matching, we obtained matched surgical site infection-negative and -positive groups. Student's t-test was used for comparisons of continuous variables, and Pearson's chi-square test was used to compare categorical variables between the two matched groups and two unmatched groups. RESULTS: We enrolled 8861 patients in this study; 74 (0.8 %) developed surgical site infections. Cervical spine surgery and American Society of Anesthesiologists physical status classification ≥3 were identified as risk factors; microendoscopy was identified as a protective factor. Using propensity score matching, we compared surgical site infection-positive and -negative groups (74 in each group). No significant difference was found in postoperative pain or dysesthesia of the lower back, buttock, leg, and plantar area between the groups. When comparing preoperative with postoperative pain and dysesthesia, statistically significant improvement was observed for both variables in both groups (p < 0.01 for all variables). No significant differences were observed in postoperative outcomes between the matched surgical site infection-positive and -negative groups. CONCLUSIONS: Patients with surgical site infections had comparable postoperative outcomes to those without surgical site infections.

The influence of COVID-19 epidemic on the number of orthopaedic surgeries in Japan.

BACKGROUND: There is limited data on the impact of COVID-19 epidemic on the number of orthopaedic surgeries in Japan. METHODS: We conducted a nationwide hospital survey asking for the monthly number of orthopaedic surgeries performed at each facility from January 2019 to June 2021. Those facilities that had performed at least 100 surgeries in 2019 were included for analyses. The facilities were further grouped by prefecture and by hospital characteristics. A brief health economic evaluation was also performed. Risk ratios were compared using univariate analyses with P < 0.05 considered statistically significant. RESULTS: Questionnaire was sent to 1988 hospitals with 1671 hospitals (84%) responding. The survey data indicated a total number of orthopaedic surgeries decreased in 2020 compared to 2019 (1,061,541 vs 1,119,955 P < 0.01), and also for the first six months of 2021 compared to the same period in 2019 (530,388 vs 550,378 P < 0.01). In 2020, over 50% of all facilities in nearly all of the prefectures saw a decline in surgical procedures. The risk of incurring more than a 25% decease in the number of surgeries was significantly higher in 2020 for class I designated medical institutions compared to those that were not designated for any types of infectious diseases among the institutions with a tertiary emergency medical center in 2020 (crude risk ratio 2.9: 95% CI 1.2-7.4, p = 0.02) and in 2021 (crude risk ratio 4.7: 95% CI 1 0.9-12.1, p < 0.01). The estimated total nationwide decrease of revenue were in the range of approximately ¥29.2 to ¥116.8 billion per year for orthopaedic surgeries alone. CONCLUSION: There was a statistically significant decrease in the number of orthopaedic surgeries in Japan. The magnitude of the decline varied by prefectures and hospital characteristics, with the greater impact imposed on medical institutions with higher classification functions. The estimated immediate health economic impact was sizable.

Surgical outcomes between posterior decompression alone and posterior decompression with fusion surgery among patients with Meyerding grade 2 degenerative spondylolisthesis: a multicenter cohort study.

BACKGROUND: Whether lumbar decompression with fusion surgery is effective against Meyerding grade 2 degenerative spondylolisthesis (DS) is unknown. Therefore, the current study aimed to compare the surgical outcomes between posterior decompression alone and posterior decompression with fusion surgery among patients with grade 2 DS with central canal stenosis. METHODS: This retrospective cohort study included prospectively registered patients (n = 3863) who underwent surgery for degenerative lumbar spinal canal stenosis at nine high-volume spine centers from April 2017 to July 2019. Patients with grade 2 DS and central canal stenosis were included in the analysis. Patients with radiculopathy, including foraminal stenosis, degenerative scoliosis, and concomitant anterior spinal fusion, and those with a previous history of lumbar surgery were excluded. The participants were divided into the decompression alone group (group D) and decompression with fusion surgery group (group F). Data about patient-reported outcomes, including Numeric Rating Scale (low back pain, leg pain, leg numbness, and foot numbness), Oswestry Disability Index, EuroQol Five-Dimensional questionnaire, and 12-Item Short-Form Health Survey scores, were obtained preoperatively and 2 years postoperatively. RESULTS: In total, 2354 (61%) patients, including 42 (1.8%) with grade 2 DS (n = 18 in group D and n = 24 in group F), completed the 2-year follow-up. Group D had a higher proportion of female patients than group F. However, the two groups did not significantly differ in terms of other baseline demographic characteristics. Group D had a significantly shorter surgical time and lower volume of intraoperative blood loss than group F. Postoperative patient-reported outcomes did not significantly differ between the two groups, although the preoperative degree of low back pain was higher in group F than in group D. The slip degree of group D did not worsen during the follow-up period. CONCLUSION: The surgical outcomes were similar regardless of the addition of fusion surgery among patients with grade 2 DS. Decompression alone was superior to decompression with fusion surgery as it was associated with a lower volume of intraoperative blood loss and shorter surgical time.

Pelvic incidence change on the operating table.

PURPOSE: While a change in the pelvic incidence (PI) after long spine fusion surgery has been reported, no studies have examined the change in the PI on the operating table. The present study examined the PI-change on the operating table and elucidated the patients' background characteristics associated with this phenomenon. METHODS: This study included patients who underwent lumbar posterior spine surgery and had radiographs taken in a full-standing position preoperatively and a pelvic lateral radiograph in the prone position in the operative room. The patients with PI-change on the operating table (PICOT; PICOT group) and without PICOT (control group) were compared for their background characteristics and preoperative radiographic parameters. RESULTS: There were 128 eligible patients (62 males, 66 females) with a mean age (± standard deviation) of 69.9 ± 11.7 (range: 25-93) years old. Sixteen patients (12.5%) showed a decrease in the PI > 10°, which indicated placement in the PICOT group. The preoperative lumbar lordosis (LL) and PI-LL in the PICOT group were significantly worse than those in the control group (LL: 20.8 ± 16.6 vs. 30.6 ± 16.2, p = 0.0251, PI-LL: 33.9 ± 19.0 vs. 17.3 ± 14.8, p < 0.0001). The PICOT group had a higher proportion of patients who underwent fusion surgery than the control group, but the difference was not significant (62.5% vs. 44.6%, p = 0.1799). CONCLUSION: A decreased PI was observed in some patients who underwent lumbar posterior surgery on the operating table before surgery. Patients with a PI decrease on the operating table had a significantly worse preoperative global alignment than those without such a decrease. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Minimum clinically important change for outcome scores among patients aged 75 or over undergoing lumbar spine surgery.

PURPOSE: To elucidate the minimum clinically important change (MCIC) of the physical component summary (PCS) of the Short Form-12, Oswestry Disability Index (ODI), EuroQOL-5 dimensions (EQ-5D), and the Core Outcome Measures Index (COMI) in patients aged ≥ 75 years undergoing lumbar spine surgery. METHODS: We retrospectively reviewed patients aged ≥ 75 years with degenerative lumbar spine disease who underwent lumbar spine decompression or fusion surgery within three levels between April 2017 and June 2018. We also evaluated patients aged < 75 years in the same period as reference. We evaluated the baseline and postoperative PCS, ODI, EQ-5D, and COMI scores. Patients were asked to answer an anchor question regarding health transition for MCICs using the anchor-based method. RESULTS: A total of 247 patients aged ≥ 75 years and 398 patients aged < 75 years were included for analysis. Of patients aged ≥ 75 years, 83.4% showed at least "somewhat improved" outcomes, while 91.0% of patients aged < 75 years reported this outcome. PCS change score was not adequately correlated to health transition in patients aged ≥ 75 years. Receiver operating characteristic curve analyses revealed MCICs of 17.8 for ODI, 0.18 for EQ-5D, and 1.6 for COMI in patients aged ≥ 75 years, and 12.7 for ODI, 0.19 for EQ-5D, and 2.3 for COMI in patients aged < 75 years. CONCLUSION: In patients aged ≥ 75 years, PCS may not be feasible for evaluation of health transition. The MCIC value for ODI score was higher and that for EQ-5D/COMI score was lower in patients aged ≥ 75 years, compared with those in patients aged < 75 years.

Validity of the Japanese core outcome measures index (COMI)-neck for cervical spine surgery: a prospective cohort study.

PURPOSE: To investigate the psychometric properties of the Japanese version of the Core Outcome Measures Index-Neck (COMI-Neck) in patients undergoing cervical spine surgery. METHODS: A total of 177 patients undergoing cervical spine surgery for spinal disorders from April to December 2017 were enrolled. Patient-reported outcomes (PROs) included EuroQOL, Neck Disability Index, and treatment satisfaction. To address whether the questionnaire's scores relate to other outcomes based on a predefined hypothesis, the correlations between the COMI-Neck and the other PROs were measured (Spearman's rank correlation coefficients). The minimum clinically important difference (MCID) of the COMI summary score was calculated using the receiver operating characteristic (ROC) curve with a 7-point Likert scale of satisfaction with the treatment results. To assess reproducibility, another group of 59 volunteers with chronic neck pain were asked to reply to the COMI-Neck twice with an interval of 7-14 days. RESULTS: The COMI summary score showed no floor or ceiling effects preoperatively or postoperatively. Each of the COMI domains and the COMI summary score correlated to the hypothesized extent with the scores of the reference questionnaires (ρ = 0.40-0.79). According to the ROC curve with satisfaction (including "very satisfied" and "satisfied"), the area under the curve and MCID of the COMI summary score were 0.78 and 2.1. The intraclass correlation coefficient and the minimum detectable change (MDC 95%) of the COMI summary score were 0.97 and 0.77. CONCLUSION: The Japanese version of the COMI-Neck is valid and reliable for Japanese-speaking patients with cervical spinal disorders.

Risk factors for worsening sexual function after lumbar spine surgery and characteristics of non-responders to the questionnaire of sex life.

PURPOSE: To precisely assess the Oswestry Disability Questionnaire (ODQ) and its total score (Oswestry Disability Index: ODI) and reveal characteristics of non-responders of the 8th item of ODQ (ODI-8) relating to sexual function. Furthermore, we evaluated risk factors for aggravation of postoperative sexual function. METHODS: We enrolled patients undergoing lumbar spine surgery at eight hospitals between April 2017 and November 2018. Patients' background data and operative factors were collected. We also assessed pain or dysesthesia (lower back, buttock, leg, and plantar area) on a numerical rating scale, EuroQol 5 Dimension, core outcome measures index back, and ODI before and 1 year after surgery. Factor analysis was conducted for the ODQ. Non-responders of the ODI-8 were compared with full-responders using propensity score matching. Risk factors for worsening ODI-8 were evaluated by multivariate logistic regression analysis. RESULTS: Of the 2,610 patients enrolled, 601 (23.0%) answered all but the ODI-8 item; these patients were likely to show better preoperative clinical symptoms than full-responders, even after adjusting for age and gender using propensity scores. Age, spinal deformity, and the American Society of Anesthesiologists physical status (ASA-PS) 3/4 were significant risk factors for postoperative aggravation of the ODI-8. Factor analysis revealed that the ODQ was composed of dynamic and static activities; the ODI-8 was considered a dynamic activity. CONCLUSION: Almost a fourth of the patients skipped the ODI-8. Age, the presence of spinal deformity, and worse ASA-PS were found to be risk factors for postoperative aggravation of sexual function. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Risk factors for deep surgical site infection following posterior instrumented fusion for degenerative diseases in the thoracic and/or lumbar spine: a multicenter, observational cohort study of 2913 consecutive cases.

PURPOSE: Surgical site infection (SSI) is one of the most devastating complications following spinal instrumented fusion surgeries because it may lead to a significant increase in morbidity, mortality, and poor clinical outcomes. Identifying the risk factors for SSI can help in developing strategies to reduce its occurrence. However, data on the risk factors for SSI in degenerative diseases are limited. This study aimed to identify risk factors for deep SSI following posterior instrumented fusion for degenerative diseases in the thoracic and/or lumbar spine in adult patients. METHODS: This was a multicenter, observational cohort study conducted at 10 study hospitals between July 2010 and June 2015. The subjects were consecutive adult patients who underwent posterior instrumented fusion surgery for degenerative diseases in the thoracic and/or lumbar spine and developed SSI. Detailed patient-specific and procedure-specific potential risk variables were prospectively recorded using a standardized data collection chart and retrospectively reviewed. RESULTS: Of the 2913 enrolled patients, 35 developed postoperative deep SSI (1.2%). Multivariable regression analysis identified three independent risk factors: male sex (P = 0.002) and American Society of Anesthesiologists (ASA) score of ≥ 3 (P = 0.003) as patient-specific risk factors, and operation including the thoracic spine (P = 0.018) as a procedure-specific risk factor. CONCLUSION: Thoracic spinal surgery, an ASA score of ≥ 3, and male sex were risk factors for deep SSI after routine thoracolumbar instrumented fusion surgeries for degenerative diseases. Awareness of these risk factors can enable surgeons to develop a more appropriate management plan and provide better patient counseling.

Comparison between microendoscopic laminectomy and open posterior decompression surgery for single-level lumbar spinal stenosis: a multicenter retrospective cohort study.

BACKGROUND: Microendoscopic laminectomy (MEL), in which a 16-mm tubular retractor with an internal scope is used, has shown excellent surgical results for patients with lumbar spinal canal stenosis. However, no reports have directly compared MEL with open laminectomy. This study aimed to elucidate patient-reported outcomes (PROs) and perioperative complications in patients undergoing MEL versus open laminectomy. METHODS: This is a multicenter retrospective cohort study of prospectively registered patients who underwent lumbar spinal surgery at one of the six high-volume spine centers between April 2017 and September 2018. A total of 258 patients who underwent single posterior lumbar decompression at L4/L5 were enrolled in the study. With regard to demographic data, we prospectively used chart sheets to evaluate the diagnosis, operative procedure, operation time, estimated blood loss, and complications. The follow-up period was 1-year. PROs included a numerical rating scale (NRS) for lower back pain and leg pain, the Oswestry Disability Index (ODI), EuroQol 5 Dimension (EQ-5D), and patient satisfaction with the treatment. RESULTS: Of the 258 patients enrolled, 252 (97%) completed the 1-year follow-up. Of the 252, 130 underwent MEL (MEL group) and 122 underwent open decompression (open group). The MEL group required a significantly shorter operating time and sustained lesser intraoperative blood loss compared with the open group. The MEL group showed shorter length of postoperative hospitalization than the open group. The overall complication rate was similar (8.2% in the MEL group versus 7.7% in the open group), and the revision rate did not significantly differ. As for PROs, both preoperative and postoperative values did not significantly differ between the two groups. However, the satisfaction rate was higher in the MEL group (74%) than in the open group (53%) (p = 0.02). CONCLUSIONS: MEL required a significantly shorter operating time and resulted in lesser intraoperative blood loss compared with laminectomy. Postoperative PROs and complication rates were not significantly different between the procedures, although MEL demonstrated a better satisfaction rate.

Adverse effects of surgeon performance after a night shift on the incidence of perioperative complications in elective thoracolumbar spine surgery.

BACKGROUND: Decline in cognitive function after night shift has been well described. However, in the field of spine surgery, the effect of surgeons' sleeplessness on patient outcome is unclear. The purpose of this study was to investigate whether the risk of perioperative complications in elective thoracolumbar spine surgery could be higher if the surgeon had been on a night shift prior to the day of surgery. METHODS: We performed a retrospective review of patients who underwent elective posterior thoracolumbar spine surgery, as indicated in medical records, between March 2015 and September 2018. In total, 1189 patients were included and divided into two groups: the post-nighttime (n = 110) and control groups (n = 1079). A post-nighttime case was defined when the operating surgeon was on nighttime duty on the previous night, and other cases were defined as controls. We evaluated the incidence of perioperative complications (surgical site infection, postoperative hematoma, postoperative paralysis, nerve root injury, and dural tear) in both groups. RESULTS: Overall, we found no significant difference in the major or minor perioperative complication rates between the two groups, but according to the type of complication, the incidence rate of dural tear tended to be higher in the post-nighttime group (13.6% vs 8.2%, P = 0.074). Multivariate analysis showed that post-nighttime status was an independent risk factor of dural tear (adjusted odds ratio, 2.02; 95% confidence interval [CI], 1.10-3.70; P = 0.023). After stratification by surgical complexity, post-nighttime status was an independent risk factor of dural tear only in the surgeries of 3 levels or more (adjusted odds ratio, 2.81; 95% CI, 1.18-6.67; P = 0.019). CONCLUSIONS: Post-nighttime status was generally not a risk factor of perioperative complications in elective posterior thoracolumbar spine surgeries, but was an independent risk factor of dural tear, especially in complex cases.

Microendoscope-Assisted Versus Open Posterior Lumbar Interbody Fusion for Lumbar Degenerative Disease: A Multicenter Retrospective Cohort Study.

Background and objectives: Minimally invasive surgery has become popular for posterior lumbar interbody fusion (PLIF). Microendoscope-assisted PLIF (ME-PLIF) utilizes a microendoscope within a tubular retractor for PLIF procedures; however, there are no published reports that compare Microendoscope-assisted to open PLIF. Here we compare the surgical and clinical outcomes of ME-PLIF with those of open PLIF. Materials and Methods: A total of 155 consecutive patients who underwent single-level PLIF were registered prospectively. Of the 149 patients with a complete set of preoperative data, 72 patients underwent ME-PLIF (ME-group), and 77 underwent open PLIF (open-group). Clinical and radiographic findings collected one year after surgery were compared. Results: Of the 149 patients, 57 patients in ME-group and 58 patients in the open-group were available. The ME-PLIF procedure required a significantly shorter operating time and involved less intraoperative blood loss. Three patients in both groups reported dural tears as intraoperative complications. Three patients in ME-group experienced postoperative complications, compared to two patients in the open-group. The fusion rate in ME-group at one year was lower than that in the open group (p = 0.06). The proportion of patients who were satisfied was significantly higher in the ME-group (p = 0.02). Conclusions: ME-PLIF was associated with equivalent post-surgical outcomes and significantly higher rates of patient satisfaction than the traditional open PLIF procedure. However, the fusion rate after ME-PLIF tended to be lower than that after the traditional open method.

Hypozincemia is associated with human hepatocarcinogenesis in hepatitis C virus-related liver cirrhosis.

AIM: Hypozincemia is associated with the progression of chronic liver diseases, but it is unknown whether hypozincemia promotes human hepatocarcinogenesis. Our aim is to evaluate the serum zinc levels in liver cirrhosis (LC) patients and clarify the relationship between the serum zinc levels and the development of hepatocellular carcinoma (HCC). METHODS: Cirrhotic patients without HCC (n = 299) were enrolled from 14 medical institutes in Japan as a multicenter prospective study (No. 2028). Of the 299 patients, 157 were included in the present study based on reliable and consistent serum zinc levels and no history of oral zinc supplementation. Clinical parameters associated with the development of HCC were determined. Furthermore, the cumulative incidence of HCC was analyzed using Kaplan-Meier methods and was calculated using the log-rank test. A Cox regression analysis was utilized for the multivariate analysis to evaluate the predictors of hepatocarcinogenesis. RESULTS: Thirty of 157 patients (19.1%) developed HCC during an observation period of 3 years. Serum zinc levels were significantly decreased in hepatitis C virus-related LC (C-LC) patients with HCC (0.0180). The risk factors for incidence of HCC were hypozincemia (0.0014), high α-fetoprotein (0.0080), low branched chain amino acids-to-tyrosine ratio (0.0128), or female sex (0.0228). Hypozincemia (hazard ratio 1.61, 0.0324) was the only significant predictor of hepatocarcinogenesis by multivariate Cox regression analysis. CONCLUSIONS: Hypozincemia is associated with hepatocarcinogenesis in C-LC patients.

Discovery of novel pyrazolo[1,5-a]pyridine-based EP1 receptor antagonists by scaffold hopping: Design, synthesis, and structure-activity relationships.

A scaffold-hopping strategy towards a new pyrazolo[1,5-a]pyridine based core using molecular hybridization of two structurally distinct EP1 antagonists, followed by structure-activity relationship-guided optimization, resulted in the identification of potent EP1 antagonists exemplified by 4c, 4f, and 4j, which were shown to reduce pathological intravesical pressure in rats when administered at 1mg/kg iv.

The usefulness of neutrophil CD64 expression for diagnosing infection after orthopaedic surgery in dialysis patients.

BACKGROUND: Dialysis patients undergoing orthopaedic surgery are at high risk for postoperative infection. Diagnosis of postoperative infection is difficult in dialysis patients due to presentation of signs and symptoms similar to infection, such as fever and elevated inflammatory marker levels. Neutrophil CD64 expression (CD64), a marker of infection, is upregulated by microbial wall components and several cytokines (interferon-γ and tumor necrosis factor-α). The purpose of this study is to evaluate the usefulness of CD64 for diagnosing postoperative infection in dialysis patients post orthopaedic surgery. PATIENTS AND METHODS: Between 2013 and 2014, we prospectively studied 36 dialysis patients (18 men, 18 women; mean age 65.9 years; 49 to 83) who underwent orthopaedic surgery. Dialysis patients were classified into three groups according to their postoperative course as follows; non-infected patients, infection suspected patients, and infected patients. Inflammatory markers such as white blood cell count (WBC), C-reactive protein (CRP) and CD64 were measured before operation and one week after surgery. Using the receiver-operating characteristic (ROC) curve and Akaike's Information Criterion (AIC), the cutoff value of CD64 and CRP was calculated leading to a determination of which inflammatory marker is best accurate for detecting postoperative infection. RESULTS: We found that postoperative CD64 and CRP levels presented a statistically significant difference between infected patients and non-infected patients (p < 0.05). Furthermore, comparison of the ROC curve and AIC value between postoperative CD64 and CRP levels exhibited that CD64 was more accurate infectious marker than CRP. CONCLUSION: CD64 is a useful marker for detecting postoperative infection after orthopaedic surgery in dialysis patients.

Prospective multicenter surveillance and risk factor analysis of deep surgical site infection after posterior thoracic and/or lumbar spinal surgery in adults.

BACKGROUND: Surgical site infection is a serious and significant complication after spinal surgery and is associated with high morbidity rates, high healthcare costs and poor patient outcomes. Accurate identification of risk factors is essential for developing strategies to prevent devastating infections. The purpose of this study was to identify independent risk factors for surgical site infection among posterior thoracic and/or lumbar spinal surgery in adult patients using a prospective multicenter surveillance research method. METHODS: From July 2010 to June 2012, we performed a prospective surveillance study in adult patients who had developed surgical site infection after undergoing thoracic and/or lumbar posterior spinal surgery at 11 participating hospitals. Detailed preoperative and operative patient characteristics were prospectively recorded using a standardized data collection format. Surgical site infection was based on the definition established by the Centers for Disease Control and Prevention. RESULTS: A total of 2,736 consecutive adult patients were enrolled, of which 24 (0.9%) developed postoperative deep surgical site infection. Multivariate regression analysis indicated four independent risk factors. Preoperative steroid therapy (P = 0.001), spinal trauma (P = 0.048) and gender (male) (P = 0.02) were statistically significant independent patient-related risk factors, whereas an operating time ≥3 h (P < 0.001) was a surgery-related independent risk factor. CONCLUSION: Preoperative steroid therapy, spinal trauma, male gender and an operating time ≥3 h were independent risk factors for deep surgical site infection after thoracic and/or lumbar spinal surgery in adult patients. Identification of these risk factors can be used to develop protocols aimed at decreasing the risk of surgical site infection.

Branched-chain amino acids prevent hepatocarcinogenesis and prolong survival of patients with cirrhosis.

BACKGROUND & AIMS: Although a low plasma level of branched-chain amino acids (BCAAs) is a marker of cirrhosis, it is not clear whether BCAA supplements affect disease progression. We performed a multicenter study to evaluate the effects of BCAA supplementation on hepatocarcinogenesis and survival in patients with cirrhosis. METHODS: We enrolled 299 patients from 14 medical institutions in Japan in a prospective, multicenter study in 2009; 267 patients were followed through 2011. Patients were given BCAA supplements (5.5-12.0 g/day) for more than 2 years (n = 85) or no BCAAs (controls, n = 182). The primary end points were onset of hepatocellular carcinoma (HCC) and death. Factors associated with these events were analyzed by competing risk analysis. RESULTS: During the study period, 41 of 182 controls and 11 of 85 patients given BCAAs developed HCC. On the basis of the Cox and the Fine and Gray models of regression analyses, level of α-fetoprotein, ratio of BCAA:tyrosine, and BCAA supplementation were associated with development of HCC (relative risk for BCAAs, 0.45; 95% confidence interval, 0.24-0.88; P = .019). Sixteen controls and 2 patients given BCAAs died. Factors significantly associated with death were Child-Pugh score, blood level of urea nitrogen, platelet count, male sex, and BCAA supplementation (relative risk of death for BCAAs, 0.009; 95% confidence interval, 0.0002-0.365; P = .015) in both regression models. CONCLUSIONS: On the basis of a prospective study, amino acid imbalance is a significant risk factor for the onset of HCC in patients with cirrhosis. BCAA supplementation reduces the risk for HCC and prolongs survival of patients with cirrhosis.

Neuromyelitis Optica Spectrum Disorders (NMOSDs) Diagnosed After Surgery for the Ossification of the Posterior Longitudinal Ligament of the Cervical and Thoracic Spine: A Case Report.

Complications of compressive spinal cord myelopathy and demyelinating disease can be difficult to diagnose. A 65-year-old woman gradually lost the ability to walk. Her imaging findings showed multiple spinal canal stenosis and ossification of the posterior longitudinal ligament in the cervical and thoracic spine. Some intramedullary signal changes were seen at sites distant from the spinal cord compression site. Although she underwent cervical and thoracic decompression and fusion surgery relatively early, her lower-extremity strength decreased after surgery. Her aquaporin 4 (AQP4)-antibody was found to be positive postoperatively, and she was diagnosed with NMOSD. Medical treatment for NMOSD improved her walking ability, and she finally became able to walk with a cane. In cases where there is a discrepancy between the site of strong stenosis and intramedullary signal changes, it is necessary to consider an anti-AQP4 antibody test and consultation with a neurologist.

Anterior Protrusion of Hydroxyapatite Blocks During Vertebroplasty for Thoracic Burst Fractures: A Case Report.

Research on complications necessitating reoperation following vertebroplasty related to hydroxyapatite (HA) blocks is limited. We present the case of a 25-year-old woman who underwent posterior fixation and vertebroplasty using HA blocks for a T12 burst fracture. Postoperative computed tomography revealed anterior protrusion of some blocks, with consequent compression of the descending aorta. We removed the protruded blocks viaa transthoracic approach and observed no aortic injuries. Although HA blocks are considered safe for vertebroplasty, surgeons should be aware of the risk of anterior protrusion and potential aortic injury.