Spine infections: variations in incidence during the academic year

Ankle fracture surgery performed by orthopaedic residents without supervision has comparable outcomes to surgery performed by fellowship trained orthopaedic surgeons

BACKGROUND

Unstable fractures often necessitate open reduction and internal fixation (ORIF), which generally yield favourable outcomes. However, the impact of surgical trainee autonomy on healthcare quality in these procedures remains uncertain. We hypothesized that surgery performed solely by residents, without supervision or participation of an attending surgeon, can provide similar outcomes to surgery performed by trauma or foot and ankle fellowship-trained orthopaedic surgeons.

METHODS

A single-center cohort of an academic level-1 trauma center was retrospectively reviewed for all ankle ORIF between 2015 and 2019. Data were compared between surgery performed solely by post-graduate-year 4 to 6 residents, and surgery performed by trauma or foot and ankle fellowship-trained surgeons. Demographics, surgical parameters, preoperative and postoperative radiographs, and primary (mortality, complications, and revision surgery) and secondary outcome variables were collected and analyzed. Univariate analysis was performed to evaluate outcomes.

RESULTS

A total of 460 ankle fractures were included in the study. Nonoperative cases and cases operated by senior orthopaedic surgeons who are not trauma or foot and ankle fellowship-trained orthopaedic surgeons were excluded. The average follow-up time was 58.4 months (SD ± 12.5). Univariate analysis of outcomes demonstrated no significant difference between residents and attendings in complications and reoperations rate (p = 0.690, p = 0.388). Sub-analysis by fracture pattern (Lauge-Hansen classification) and the number of malleoli involved and fixated demonstrated similar outcomes. surgery time was significantly longer in the resident group (p < 0.001).

CONCLUSION

The current study demonstrates that ankle fracture surgery can be performed by trained orthopaedic surgery residents, with similar results and complication rates as surgery performed by fellowship-trained attendings. These findings provide valuable insights into surgical autonomy in residency and its role in modern clinical training and surgical education.

LEVEL OF EVIDENCE

Level III - retrospective cohort study.

Total hip arthroplasty performed in summer is not associated with increased risk of revision due to prosthetic joint infection: a cohort study on 58 449 patients with osteoarthritis from the Danish Hip Arthroplasty Register

Aims: Danish surveillance data indicated a higher risk of revision due to prosthetic joint infection (PJI) following total hip arthroplasty (THA) performed during the summer season. We investigated the association between summer and revision risk following primary THA. Methods: This study identified 58 449 patients from the Danish Hip Arthroplasty Register (DHR) with unilateral primary THA due to osteoarthritis from 2010-2018. From Danish Health Registries, we retrieved information on Charlson Comorbidity Index (CCI), immigration, and death and microbiological data on intraoperative biopsies and cohabitation status. Meteorological data were received from the Danish Meteorological Institute. Summer was defined as June-September, and THAs performed during October-May were used as controls. The primary outcome was revision due to PJI: the composite of revision with ≥ 2 culture-positive biopsies or reported PJI to the DHR. The secondary outcome was any revision. The cumulative incidences of revision and the corresponding adjusted relative risk (RR) with 95 % confidence intervals (CI) were calculated by season of the primary THA. Results: A total of 1507 patients were revised, and 536 were due to PJI. The cumulative incidence for THAs performed during summer and the rest of the year was 1.1 % (CI 1.0-1.3) and 1.1 % (CI 1.0-1.2) for PJI revision and 2.7 % (CI 2.5-3.0) and 2.5 % (CI 2.4-2.7) for any revision, respectively. The adjusted RR for THAs performed during summer vs. the rest of the year for PJI revision and any revision was 1.1 (CI 0.9-1.3) and 1.1 (CI 1.0-1.2), respectively. Conclusion: We found no association between summer and the risk of PJI revision or any revision in a northern European climate.

An evaluation of seasonal maternal-neonatal morbidity related to trainee cycles

BACKGROUND

The existence of the "July phenomenon" (worse outcomes related to the presence of new physician trainees in teaching hospitals) has been debated in the literature and media. Previous studies of the phenomenon in obstetrics are limited by the quality and detail of data.

OBJECTIVE

To evaluate whether the months of June to August, when transitions in trainees occur, are associated with increased maternal and neonatal morbidity.

STUDY DESIGN

Secondary analysis of an observational cohort of 115,502 mother-infant pairs that delivered at 25 hospitals from March 2008 to February 2011. Inclusion criteria were an individual who had a singleton, nonanomalous live fetus at the onset of labor, and delivered at a hospital with trainees. The primary outcomes were composites of maternal and neonatal morbidity. We evaluated the outcomes by academic quarter during which the delivery occurred, beginning July 1, and by duration of the academic year as a continuous variable. To account for clustering in outcomes at a given delivery location, we applied hierarchical logistic regression with adjustment for hospital as a random effect.

RESULTS

Of 115,502 deliveries, 99,929 met the inclusion criteria. Race and ethnicity, insurance, body mass index, drug use, and the availability of 24/7 maternal-fetal medicine, anesthesia, and neonatology varied by quarter. In adjusted analysis, the frequency of the composite maternal and neonatal morbidity did not differ by quarter. No differences in composite morbidity were observed when using day of the year as a continuous variable (maternal morbidity adjusted odds ratio, 1.00; 95% confidence interval, 0.99-1.00 and neonatal morbidity adjusted odds ratio, 1.00; 95% confidence interval, 1.00-1.01) and after adjustment for hospital as a random effect. Odds of major surgical complications in quarter 2 were twice those in quarter 1. Neonatal injury and intensive care unit were less frequent in later quarters.

CONCLUSION

Maternal and neonatal morbidity in teaching hospitals was not associated with the academic quarter during which delivery occurred, and there was no evidence of a "July phenomenon".

Seasonal and Temperature-associated Effect on Infection in Implant-based Breast Reconstruction

BACKGROUND AND OBJECTIVES

Despite advances in medicine, infection at the surgical site is an impregnation problem that most surgeons confront. Although studies on the seasonality of infection have been conducted in various areas, no study has confirmed the relationship between seasonal temperature and infection after breast reconstruction.

METHODS

From 2008 to 2018, a retrospective study was conducted on patients who underwent implant-based breast reconstruction. Patient demographics, intraoperative data, postoperative data, and temperature information were collected. Temperature differences between cases with and without infection were examined. The differences in the incidence and risk of infection by season were estimated according to the hot season (July to August) and the nonhot season (September to June).

RESULTS

Of the 460 cases enrolled, 42 cases developed an infection. Among them, 15 (35.71%) cases developed infection during the hot season (P = 0.003). According to the logistic regression model, the risk of infection was 2.639 times higher in the hot season than in the nonhot season (95% confidence interval, 1.282-5.434; P = 0.008). When the temperature was higher than 25°C, the risk of infection increased by 45.2% for every 1°C increase, which was statistically significant (odds ratio, 1.452; 95% confidence interval, 1.198-1.76; P < 0.001).

CONCLUSION

In conclusion, the hot season or average temperatures higher than 25°C increase the risk of infection in patients undergoing implant-based breast reconstruction. It is essential to focus on skin hygiene during the healing of the incision site.

Seasonality in surgical outcome data: a systematic review and narrative synthesis

BACKGROUND

Seasonal trends in patient outcomes are an under-researched area in perioperative care. This systematic review evaluates the published literature on seasonal variation in surgical outcomes worldwide.

METHODS

MEDLINE, Embase, Cochrane, CINHAL, and Web of Science were searched for studies on major surgical procedures, examining mortality or other patient-relevant outcomes, across seasonal periods up to February 2019. Major surgery was defined as a procedure requiring an overnight stay in an inpatient medical facility. We included studies exploring variation according to calendar and meteorological seasons and recurring annual events including staff turnover. Quality was assessed using an adapted Downs and Black scoring system.

RESULTS

The literature search identified 82 studies, including 22 210 299 patients from four continents. Because of the heterogeneity of reported outcomes and literature scope, a narrative synthesis was undertaken. Mass staff changeover was investigated in 37 studies; the majority (22) of these did not show strong evidence of worse outcomes. Of the 47 studies that examined outcomes across meteorological or calendar seasons, 33 found evidence of seasonal variation. Outcomes were often worse in winter (16 studies). This trend was particularly prominent amongst surgical procedures classed as an 'emergency' (five of nine studies). There was evidence for increased postoperative surgical site infections during summer (seven of 12 studies examining this concept).

CONCLUSION

This systematic review provides tentative evidence for an increased risk of postoperative surgical site infections in summer, and an increased risk of worse outcomes after emergency surgery in winter and during staff changeover times.

CLINICAL TRIAL REGISTRATION

PROSPERO CRD42019137214.

Seasonal variation in incidence and causal organism of surgical site infection after PLIF/TLIF surgery: A multicenter study

BACKGROUND

Postoperative SSI is a common and potentially serious complication in spine surgery. Seasonal variation occurs in rates of nosocomial infection, with higher rates found in the summer, during which hot, humid conditions may be optimal for proliferation of bacteria. This might also influence the rate of SSI. The purpose of the study was to examine seasonal variation in SSI after PLIF/TLIF surgery, including relationships with experience of surgeons and causal organisms.

METHODS

Cases with SSI after PLIF/TLIF surgery at 10 facilities between January 1, 2012, and December 31, 2014 were retrieved from a database. Infection was defined based on CDC guidelines for SSIs. Patients were followed for at least two years after surgery. Surgeries were examined in spring (April-June), summer (July-September), autumn (October-December), and winter (January-March). Seasonal variation and other factors with a potential association with SSIs were evaluated.

RESULTS

A total of 1174 patients (607 males, 567 females) who underwent PLIF/TLIF surgery were identified. The operations were PLIF (n = 667), TLIF (n = 443), MIS-PLIF (n = 27), and MIS-TLIF (n = 37). The total SSI rate for the 2-year period was 2.5% (29/1174), and the 2-year average SSI rates for surgeries in each season were spring, 2.6% (7/266); summer, 3.9% (13/335); fall, 1.3% (4/302); winter, 1.8% (5/271). The SSI rate was significantly higher in summer than non-summer (3.9% vs. 1.9%, p < 0.05). SSIs were caused by a variety of pathogens, including Gram-positive cocci, and Staphylococcus aureus was the most common pathogenic organism to cause SSI.

CONCLUSION

Seasonality should be taken into account in strategies for SSI prevention, with particular attention on mitigation of increased temperature and humidity in the summer and on infection caused by Gram-positive cocci and S. aureus.

"July Effect" Revisited: July Surgeries at Residency Training Programs are Associated with Equivalent Long-term Clinical Outcomes Following Lumbar Spondylolisthesis Surgery

STUDY DESIGN

Retrospective analysis of a prospective registry.

OBJECTIVE

We utilized the Quality Outcomes Database (QOD) registry to investigate the "July Effect" at QOD spondylolisthesis module sites with residency trainees.

SUMMARY OF BACKGROUND DATA

There is a paucity of investigation on the long-term outcomes following surgeries involving new trainees utilizing high-quality, prospectively collected data.

METHODS

This was an analysis of 608 patients who underwent single-segment surgery for grade 1 degenerative lumbar spondylolisthesis at 12 high-enrolling sites. Surgeries were classified as occurring in July or not in July (non-July). Outcomes collected included estimated blood loss, length of stay, operative time, discharge disposition, complications, reoperation and readmission rates, and patient-reported outcomes (Oswestry Disability Index [ODI], Numeric Rating Scale [NRS] Back Pain, NRS Leg Pain, EuroQol-5D [EQ-5D] and the North American Spine Society [NASS] Satisfaction Questionnaire). Propensity score-matched analyses were utilized to compare postoperative outcomes and complication rates between the July and non-July groups.

RESULTS

Three hundred seventy-one surgeries occurred at centers with a residency training program with 21 (5.7%) taking place in July. In propensity score-matched analyses, July surgeries were associated with longer operative times ( average treatment effect = 22.4 minutes longer, 95% confidence interval 0.9-449.0, P = 0.041). Otherwise, July surgeries were not associated with significantly different outcomes for the remaining perioperative parameters (estimated blood loss, length of stay, discharge disposition, postoperative complications), overall reoperation rates, 3-month readmission rates, and 24-month ODI, NRS back pain, NRS leg pain, EQ-5D, and NASS satisfaction score (P > 0.05, all comparisons).

CONCLUSION

Although July surgeries were associated with longer operative times, there were no associations with other clinical outcomes compared to non-July surgeries following lumbar spondylolisthesis surgery. These findings may be due to the increased attending supervision and intraoperative education during the beginning of the academic year. There is no evidence that the influx of new trainees in July significantly affects long-term patient-centered outcomes.Level of Evidence: 3.

Seasonal impact on surgical site infections and wound healing disturbance in carpal tunnel surgery: A retrospective cohort study

Carpal tunnel syndrome is the most common entrapment syndrome of a peripheral nerve. The gold standard treatment is open carpal tunnel release which has a high success rate, a low complication rate, and predictable postoperative results. However, it has not been analysed yet if there is a seasonal influence on complications for carpal tunnel release, a highly elective procedure. In this retrospective study, we determine whether there is a seasonal impact on surgical site infections (SSI) and wound healing disorders (WHD) in primary carpal tunnel syndrome surgery. Between 2014 and 2018, we have assessed 1385 patients (65% female, 35% male) at a mean age of 61.9 (SD 15.3) years, which underwent open carpal tunnel release because of primary carpal tunnel syndrome. The seasonal data such as the warm season (defined as the period from 1st of June until 15th of September), the average daily and monthly temperature, and the average relative humidity were analysed. Patient demographics were examined including body mass index, alcohol and nicotine abuse, the use of anticoagulants and antiplatelet drugs as well as comorbidities. These data were correlated regarding their influence to the rate of surgical site infections and wound healing disorders in our study collective. A postoperative SSI rate of 2.4% and a WHD rate of 7% were detected. Our data confirms the warm season, the average monthly temperature, and male sex as risk factors for increasing rates of WHDs. Serious SSIs with subsequent revision surgery could be correlated with higher age and higher relative humidity. However there is no seasonal impact on SSIs. We therefore advise considering the timing of this elective surgery with scheduling older male patients preferably during the cold season to prevent postoperative WHDs.

The July Effect for Total Joint Arthroplasty Procedures

The "July effect" refers to the assumed increased risk of complications during the months when medical school graduates transition to residency programs. The actual existence of a July effect is controversial. With this study, the authors sought to determine whether evidence exists for the presence of a July effect among total joint arthroplasty (TJA) procedures. The 2013 and 2014 Nationwide Readmission Databases were combined and all index primary and revision arthroplasty procedures were identified, and then patients from December were excluded. Thirty-day readmission rates, time to readmission, and readmission costs were analyzed by index procedure month and index procedure type. A total of 1,193,034 procedures (index primary: n=1,107,657; revision arthroplasty: n=85,377) were identified. Among all procedure types, 46,674 (3.9%) 30-day readmissions were observed. Among all procedures, an index procedure with a discharge in July resulted in the highest monthly readmission rate of the year (4.2%), which was significantly higher than the mean annual readmission rate (P<.0001). This effect was most pronounced for primary total knee arthroplasty (3.9% vs 3.6%, P<.0001). When stratifying results into teaching vs nonteaching hospitals, the highest readmission rate occurred if the index procedure occurred at a nonteaching hospital in July (4.5%, P<.0001). These data provide evidence that a July effect appears to exist for TJA procedures and is most pronounced at nonteaching institutions. Based on published mean readmission costs, the total annualized cost variation attributable to the higher readmission rate for primary TJA procedures in July is approximately $18.6 million. [Orthopedics. 2020;43(6):e543-e548.].

Deep Brain Stimulation-Related Infections: Analysis of Rates, Timing, and Seasonality

BACKGROUND

Infection is one of the most common complications of deep brain stimulation (DBS). Long-term infection rates beyond the immediate postoperative period are rarely evaluated.

OBJECTIVE

To study short- and long-term DBS-related infection rates; to evaluate any potential seasonality associated with DBS-related infections.

METHODS

We retrospectively reviewed all DBS surgeries performed in a 5-yr period at 1 hospital by a single surgeon. Infection rates and clinical characteristics were analyzed. Postoperative "infections" were defined as occurring within 6 mo of implantation of DBS hardware, while "erosions" were defined as transcutaneous exposure of hardware at ≥6 mo after implantation. Based on the date of surgery preceding an infection, rates of infection were calculated on a monthly and seasonal basis and compared using Chi square and logistic regression analyses.

RESULTS

A total of 443 patients underwent 592 operations; 311 patients underwent primary DBS placement with 632 electrodes. Primary DBS placement infection incidence was 2.6%. DBS procedure infection and infection rate by electrode were 2.9% and 3.2%, respectively. Infectious complications presented later than 6 mo postoperatively in 38% of infected patients Summer (July-September) infection rate was significantly higher than other seasons (P = .002). The odds ratio of an infection related to a surgery performed in August was found to be 4.15 compared to other months (P = .021).

CONCLUSION

There is a persistent risk of DBS infection and erosion beyond the first year of DBS implantation. Start of the academic year was associated with increased infection rate at our institution.

Association between higher ambient temperature and orthopaedic infection rates: a systematic review and meta-analysis

INTRODUCTION

Many infectious diseases display seasonal variation corresponding with particular conditions. In orthopaedics a growing body of evidence has identified surges in post-operative infection rates during higher temperature periods. The aim of this research was to collate and synthesize the current literature on this topic.

METHODS

A systematic review and meta-analysis was performed using five databases (PubMed, Embase, CINAHL, Web of Science and Central (Cochrane)). Study quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation method. Odds ratios (ORs) were calculated from monthly infection rates and a pooled OR was generated using the DerSimonian and Lairds method. A protocol for this review was registered with the National Institute for Health Research International Prospective Register of Systematic Reviews (CRD42017081871).

RESULTS

Eighteen studies analysing over 19 000 cases of orthopaedic related infection met inclusion criteria. Data on 6620 cases and 9035 controls from 12 studies were included for meta-analysis. The pooled OR indicated an overall increased odds of post-operative infection for patients undergoing orthopaedic procedures during warmer periods of the year (pooled OR 1.16, 95% confidence interval 1.04-1.30).

CONCLUSION

A small but significantly increased odds of post-operative infection may exist for orthopaedic patients who undergo procedures during higher temperature periods. It is hypothesized that this effect is geographically dependent and confounded by meteorological factors, local cultural variables and hospital staffing cycles.

Trends of surgical treatment for spinal degenerative disease in China: a cohort of 37,897 inpatients from 2003 to 2016

Purpose

Given the aging Chinese population and the inevitable degenerative process of the spine, more elderly patients with spinal degenerative disease (SDD) are surgical candidates, placing a significant burden on health care resources. Few studies have investigated recent trends in hospital admissions and procedures for SDD in China. This study aimed to identify the trends, if any, in the number of surgical procedures undertaken for SDD in a large patient cohort.

Materials and methods

This retrospective cohort analysis used data from inpatient medical records at Peking University Third Hospital between 2003 and 2016. Descriptive statistical analysis, regression models, and a Holt–Winters seasonal model were used to analyze trends.

Results

Altogether, 38,676 surgery records from 37,897 SDD patients who had undergone surgical treatment were included in our study, among whom 49.60%, 47.81%, and 2.59% were treated because of cervical, lumbar, and thoracic degenerative disease, respectively. There was an increasing trend for spinal surgery performance with an increasing mean age at surgery, from 50.65 years of age in 2003 to 55.29 years in 2016. We also revealed interesting seasonal variation in our study – that is, most of the spinal procedures were performed during the winter and spring months.

Conclusion

Our study showed a significantly increasing surgical workload for addressing SDD in China. Both the public and the health care system should be aware of this increase in chronic degenerative disease in the aging population.

Surgical Infection after Posterolateral Lumbar Spine Arthrodesis: CT Analysis of Spinal Fusion

OBJECTIVE

To determine the incidence of infection after instrumented lumbar spine surgery, the demographic and surgical variables associated with acute infection, and the influence of infection and debridement on the consolidation of spinal fusion.

METHODS

After obtaining approval from the hospital ethics committee, an observational study was made on a prospective cohort of consecutive patients surgically treated by posterolateral lumbar spine arthrodesis (n = 139, 2005-2011). In all cases, the minimum follow-up period was 18 months. The following bivariate analysis was conducted of demographic and surgical variables: non-infection group (n = 123); infection group (n = 16). Fusion rates were determined by multislice CT. Logistic regression analysis was performed.

RESULTS

Incidence of deep infection requiring debridement: 11.51% (95% confidence interval, 5.85-17.18]). Bivariate analysis: differences were observed in hospital stay (7.0 days [range, 4-10] vs 14.50 days [range, 5.25-33.75]; P = 0.013), surgical time (3.15 h vs 4.09 h; P = 0.004), body mass index (25.11 kg/m² [22.58-27.0] vs 26.02 kg/m² [24.15 to 29.38]; P = 0.043), Charlson comorbidity index (median, 0 vs 1; P = 0.027), and rate of unsuccessful consolidation according to CT (18.4% vs 72.7%; P = 0.0001). In a model of multivariate logistic regression, taking as the dependent variable unsuccessful arthrodesis after 1 year, and adjusting for the other independent variables (infection, body mass index, Charlson comorbidity index, and surgical time), the only variable that was significantly associated with an outcome of unsuccessful spinal fusion after 1 year was infection, with OR = 12.44 (95% confidence interval, 2.50-61.76).

CONCLUSION

Deep infection after instrumented lumbar spine arthrodesis is a common complication that compromises the radiographic outcome of surgery. Patients who develop a postoperative infection and require debridement surgery are 12 times less likely to achieve satisfactory radiological fusion.

Involvement of Residents Does Not Increase Postoperative Complications After Open Reduction Internal Fixation of Ankle Fractures: An Analysis of 3251 Cases

Ankle fractures are common injuries frequently treated by foot and ankle surgeons. Therefore, it has become a core competency for orthopedic residency training. Surgical educators must balance the task of training residents with optimizing patient outcomes and minimizing morbidity and mortality. The present study aimed to determine the effect of resident involvement on the 30-day postoperative complication rates after open reduction and internal fixation of ankle fractures. A second objective of the present study was to determine the independent risk factors for complications after this procedure. We identified patients in the American College of Surgeons National Surgical Quality Improvement Program database who had undergone open reduction internal fixation for ankle fractures from 2005 to 2012. Propensity score matching was used to help account for a potential selection bias. We performed univariate and multivariate analyses to identify the independent risk factors associated with short-term postoperative complications. A total of 3251 open reduction internal fixation procedures for ankle fractures were identified, of which 959 (29.4%) had resident involvement. Univariate (2.82% versus 4.54%; p = .024) and multivariate (odds ratio 0.71; p = .75) analyses demonstrated that resident involvement did not increase short-term complication rates. The independent risk factors for complications after open reduction internal fixation of ankle fractures included insulin-dependent diabetes, increasing age, higher American Society of Anesthesiologists score, and longer operative times.

Impact of Resident Involvement in Neurosurgery: An American College of Surgeons' National Surgical Quality Improvement Program Database Analysis of 33,977 Patients

OBJECTIVE

There is conflicting and limited literature on the effect of intraoperative resident involvement on surgical outcomes. Our study assessed effects of resident involvement on outcomes in patients undergoing neurosurgery.

METHODS

We identified 33,977 adult neurosurgical cases from 374 hospitals in the 2006-2012 National Surgical Quality Improvement Program, a prospectively collected national database with established reproducibility and validity. Outcomes were compared according to resident involvement before and after 1:1 matching on procedure and perioperative risk factors.

RESULTS

Resident involvement was documented in 13,654 cases. We matched 10,170 resident-involved cases with 10,170 attending-alone. In the matched sample, resident involvement was associated with increased surgery duration (average, 34 minutes) and slight increases in odds for prolonged hospital stay (odds ratio, 1.2; 95% confidence interval [CI], 1.2-1.3) and complications (odds ratio, 1.2; 95% CI, 1.1-1.3) including infections (odds ratio, 1.4; 95% CI, 1.2-1.7). Increased risk for infections persisted after controlling for surgery duration (odds ratio, 1.3; 95% CI, 1.1-1.5). The majority of cases were spine surgeries, and resident involvement was not associated with morbidity or mortality for malignant tumor and aneurysm patients. Training level of residents was not associated with differences in outcomes.

CONCLUSION

Resident involvement was more common in sicker patients undergoing complex procedures, consistent with academic centers undertaking more complex cases. After controlling for patient and intraoperative characteristics, resident involvement in neurosurgical cases continued to be associated with longer surgical duration and slightly higher infection rates. Longer surgery duration did not account for differences in infection rates.

Season of the year influences infection rates following total hip arthroplasty

AIM

To research the influence of season of the year on periprosthetic joint infections.

METHODS

We conducted a retrospective review of the entire Medicare files from 2005 to 2014. Seasons were classified as spring, summer, fall or winter. Regional variations were accounted for by dividing patients into four geographic regions as per the United States Census Bureau (Northeast, Midwest, West and South). Acute postoperative infection and deep periprosthetic infections within 90 d after surgery were tracked.

RESULTS

In all regions, winter had the highest incidence of periprosthetic infections (mean 0.98%, SD 0.1%) and was significantly higher than other seasons in the Midwest, South and West (P < 0.05 for all) but not the Northeast (P = 0.358). Acute postoperative infection rates were more frequent in the summer and were significantly affected by season of the year in the West.

CONCLUSION

Season of the year is a risk factor for periprosthetic joint infection following total hip arthroplasty (THA). Understanding the influence of season on outcomes following THA is essential when risk-stratifying patients to optimize outcomes and reduce episode of care costs.

Impact of resident and fellow changeovers on patient outcomes: a nationwide cross-sectional study

Background

Findings regarding the association of cohort changeovers with patient outcomes are mixed. We sought to examine the association of resident and fellow changeovers with a comprehensive set of indicators.

Methods

We performed a cross-sectional comparative study including all French teaching and non-teaching hospitals. All-cause mortality and length of stay were assessed. Focused analysis for three medical conditions (myocardial infarction, intestinal hemorrhage, stroke) and three surgical procedures (colorectal, vascular and spine surgery) was performed regarding other quality and efficiency indicators (readmissions, intensive care unit admission, transfers).

Results

Overall, 34 330 716 patients were admitted in 2011 and 2012. Within the month following cohort changeovers, no increase in mortality was observed in teaching hospitals. Length of stay was longer in May and November in teaching hospitals (P < 0.0001) whereas it was shorter in the private sector. When focusing on six selected causes of hospitalization, we observed significant differences associated with resident changeovers, suggesting a decreased efficiency. In particular, readmissions rates and lengths of stay were found to be significantly higher (P < 0.0005) after intestinal hemorrhage and with a trend toward worse efficiency (P < 0.005) after colorectal surgery and stroke in teaching hospitals.

Conclusion

Our findings provide some reassurance regarding cohort changeover and mortality even if they suggest a loss of efficiency in some cases.

Surgical resident involvement in foot and ankle surgery

BACKGROUND

Surgical resident participation in the operating room is necessary for education and progression toward safe and independent practice. However, the impact of resident involvement on patient outcomes in foot and ankle surgery is unknown.

METHODS

The American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database (2005-2012) was used to identify common foot and ankle procedures (by Current Procedural Taxonomy (CPT) code) performed by orthopedic surgeons. Resident participation was determined using the NSQIP-collected variable 'pgy'; cases missing the pgy variable were excluded. Multivariate regression models were constructed to determine an association between resident involvement and 30-day morbidity (total, medical, and surgical complications) and 30-day mortality, when controlling for patient demographics, comorbidities, American Society for Anesthesiologist (ASA) status, body mass index (BMI), and smoking status.

RESULTS

A total of 13,685 cases were analyzed for 24 common foot and ankle operations. Overall mortality rate was 3.60%. Overall complication rate was 16.9%; 10.9% had medical and 8.3% had surgical complications. Residents were involved in 55.6% of cases. In unadjusted analyses, resident cases were less likely to be emergent, but were performed on more complicated patients (i.e. higher comorbidity burden, higher ASA scores). Resident cases had increased total morbidity (18.8% vs. 14.6%, p<0.001), medical complications (12.5% vs. 9.0%, p<0.001), and surgical complications (8.7% vs. 7.7%, p=0.03), but similar mortality frequency (3.8% vs. 3.3%, p=0.2). In multivariable analyses, resident cases did not correlate with 30-day mortality, 30-day total morbidity, or 30-day surgical complications; resident cases were, however, associated with increased medical complications [Odds Ratio (OR) 1.18 (95% Confidence Interval (CI) 1.02-1.37, p=0.03)] and longer length of stay [Coeff 2.38 (1.68-3.09), p<0.001]. Subgroup analyses of orthopedic-only cases demonstrated no statistical association between resident involvement and mortality, total morbidity, or medical complications; a decrease in surgical complications was observed for open reduction internal fixation cases [OR 0.23 (0.06-0.82), p=0.02].

CONCLUSIONS

Resident involvement in foot and ankle surgery is not associated with changes in 30-day mortality, 30-day total morbidity, or 30-day surgical complication rates. Residents operate on more medically complex patients who experience higher medical complication rates and longer postoperative length of stay; however, the cause and directionality of this relationship remains to be determined. Efforts to improve the quality of foot and ankle surgery with resident involvement should target reductions in post-operative medical complications.

LEVEL OF EVIDENCE

Prognostic study, Level II.

Novel approaches to surgical site infections: what recommendations can be made?

INTRODUCTION

Surgical site infections (SSI) are one of the most frequent healthcare-associated infections worldwide, representing a substantial burden on the healthcare system and the individual patient. Various risk factors for SSI have been identified, which can be separated into patient-related, procedure-related and other risk factors. Areas covered: Other risk factors relevant for SSI are the season in which surgery is performed, the volume of surgeries in a department, the working atmosphere in the operating room and the indications for surgery. Overall, the risk of SSI is higher during summertime. Higher-volume departments appear to be protective against SSI as does a calm working atmosphere. The frequency of certain types of surgery differs greatly among European countries. The decision to perform surgery appears to be dependent on the patient's condition as well as the healthcare system and financial incentives. Expert commentary: When possible, elective surgery should not be executed during summertime but during cooler times of year. Departments with a high volume of surgical procedures should be given preference. The establishment of a calm working atmosphere is beneficial to a surgeon's performance and can reduce SSI rates. The indications for performing surgery should be carefully reevaluated whenever possible.

Presence of Modic type 1 change increases risk of postoperative pyogenic discitis following decompression surgery for lumbar canal stenosis

STUDY DESIGN

Multicenter retrospective study.

BACKGROUND

Postoperative surgical site infection is one of the most serious complications following spine surgery. Previous studies do not appear to have investigated pyogenic discitis following lumbar laminectomy without discectomy. This study aimed to identify risk factors for postoperative pyogenic discitis following lumbar decompression surgery.

METHODS

We examined data from 2721 patients undergoing lumbar laminectomy without discectomy in five hospitals from April 2007 to March 2012. Patients who developed postoperative discitis following laminectomy (Group D) and a 4:1 matched cohort (Group C) were included. Fisher's exact test was used to determine risk factors, with values of p < 0.05 considered statistically significant.

RESULTS

The cumulative incidence of postoperative discitis was 0.29% (8/2721 patients). All patients in Group D were male, with a mean age of 71.6 ± 7.2 years. Postoperative discitis was at L1/2 in 1 patient, at L3/4 in 3 patients, and at L4/5 in 4 patients. Except for 1 patient with discitis at L1/2, every patient developed discitis at the level of decompression. The associated pathogens were methicillin-resistant Staphylococcus aureus (n = 3, 37.5%), methicillin-susceptible Staphylococcus epidermidis (n = 1, 12.5%), methicillin-sensitive S. aureus (n = 1, 12.5%), and unknown (n = 3, 37.5%). In the analysis of risk factors for postoperative discitis, Group D showed a significantly lower ratio of patients who underwent surgery in the winter and a significantly higher ratio of patients who had Modic type 1 in the lumbar vertebrae compared to Group C.

CONCLUSIONS

Although further prospective studies, in which other preoperative modalities are used for the evaluation, is needed, our data suggest the presence of Modic type 1 as a risk factor for discitis following laminectomy. Latent pyogenic discitis should be carefully ruled out in patients with Modic type 1. If lumbar laminectomy is performed for such patients, more careful observation is necessary to prevent the development of postoperative discitis.

Seasonal Variations in the Risk of Reoperation for Surgical Site Infection Following Elective Spinal Fusion Surgery: A Retrospective Study Using the Japanese Diagnosis Procedure Combination Database

STUDY DESIGN

A retrospective study of data abstracted from the Diagnosis Procedure Combination (DPC) database, a national representative database in Japan.

OBJECTIVE

The aim of this study was to examine seasonal variations in the risk of reoperation for surgical site infection (SSI) following spinal fusion surgery.

SUMMARY OF BACKGROUND DATA

Although higher rates of infection in the summer than in other seasons were thought to be caused by increasing inexperience of new staff, high temperature, and high humidity, no studies have examined seasonal variations in the risk of SSI following spinal fusion surgery in the country where medical staff rotation timing is not in summer season. In Japan, medical staff rotation starts in April.

METHODS

We retrospectively extracted the data of patients who were admitted between July 2010 and March 2013 from the DPC database. Patients were included if they were aged 20 years or older and underwent elective spinal fusion surgery. The primary outcome was reoperation for SSI during hospitalization. We performed multivariate analysis to clarify the risk factors of primary outcome with adjustment for patient background characteristics.

RESULTS

We identified 47,252 eligible patients (23,659 male, 23,593 female). The mean age of the patients was 65.4 years (range, 20-101 yrs). Overall, reoperation for SSI occurred in 0.93% of the patients during hospitalization. The risk of reoperation for SSI was significantly higher in April (vs. February; odds ratio, 1.93; 95% confidence interval, 1.09-3.43, P = 0.03) as well as other known risk factors. In subgroup analysis with stratification for type of hospital, month of surgery was identified as an independent risk factor of reoperation for SSI among cases in an academic hospital, although there was no seasonal variation among those in a nonacademic hospital.

CONCLUSION

This study showed that month of surgery is a risk factor of reoperation for SSI following elective spinal fusion surgery, nevertheless, in the country where medical staff rotation timing is not in summer season.

LEVEL OF EVIDENCE

3.

Operative Intervention of Supracondylar Humerus Fractures More Complicated in July: Analysis of the July Effect

BACKGROUND

The "July Effect" involves the influx of new interns and residents early in the academic year (July and August), which may have greater potential for poorer patient outcomes. Current orthopaedic literature does not demonstrate the validity of this concept in arthroplasty, spine, hand, and arthroscopy. No study has investigated the possibility of this effect on common pediatric orthopaedic procedures, such as closed reduction and percutaneous pin fixation of supracondylar humerus fractures.

METHODS

A retrospective review of all type II or III supracondylar humerus fractures that underwent primary closed reduction and percutaneous pin fixation (CPT code 24538) at a single pediatric level 1 trauma center from July 2009 to June 2013. Patients were grouped according to time in the academic year: early (July and August) and late (May and June). Demographic data included length of follow-up, age at surgery, sex, side of injury, and Wilkin's modified Gartland classification. Outcomes included length of operation, number of pins used, length of stay, complications, and the need for repeat surgery.

RESULTS

There were 245 patients, 101 in the early and 144 in the late group. There was no increase in surgical time [33.32±24.74 (early) vs. 28.63±10.06 (late) min, P=0.07) or complication rates [7.0% (early) vs. 2.1% (late), P=0.06) between the early and the late groups. Cases performed with junior residents demonstrated longer operative (31.72±17.07 vs. 28.96±18.71 min, P=0.02) and fluoroscopy (48.63±30.96 vs. 34.12±27.38 s, P=0.01) times.

CONCLUSIONS

The academic orthopaedic surgeon must ensure the education of residents, while providing the highest level of safety to patients. Our study shows that education of young residents early in the academic year results in no increase in operative times, radiation exposure, or complications.

LEVEL OF EVIDENCE

Level III.

Hydrogen Peroxide Wound Irrigation in Orthopaedic Surgery

As the burden of deep hardware infections continues to rise in orthopaedics, there is increasing interest in strategies for more effective debridement of colonized tissues and biofilm. Hydrogen peroxide has been used medically for almost a century, but its applications in orthopaedic surgery have yet to be fully determined. The basic science and clinical research on the antiseptic efficacy of hydrogen peroxide have demonstrated its efficacy against bacteria, and it has demonstrated potential synergy with other irrigation solutions such as chlorhexidine and povidone-iodine. While hydrogen peroxide is effective in infection reduction, there are concerns with wound healing, cytotoxicity, and embolic phenomena, and we recommend against hydrogen peroxide usage in the treatment of partial knee replacements, hemiarthroplasties, or native joints. Additionally, due to the potential for oxygen gas formation, hydrogen peroxide should not be used in cases of dural compromise, when pressurizing medullary canals, or when irrigating smaller closed spaces to avoid the possibility of air embolism. Finally, we present our protocol for irrigation and debridement and exchange of modular components in total joint arthroplasty, incorporating hydrogen peroxide in combination with povidone-iodine and chlorhexidine.

Postoperative Bone Graft Displacement: An Unusual Sign of Infection Following Posterior Spinal Fusion

We describe a case of a spinal fusion site infection, which was first suggested on plain radiographs due to interval displacement and partial dissolution of the bone graft material. These radiographic findings occurred 4 weeks before the infection became clinically evident. Cultures taken during eventual surgical debridement grew Aspergillus fumigatus. This case emphasizes the importance of noting changes in bone graft material in addition to the routine evaluation of alignment and hardware in patients who have undergone posterior spinal fusion.

Efficiency of Hyperbaric Oxygen Therapy in Iatrogenic Spinal Infections

STUDY DESIGN

Retrospective clinical study.

OBJECTIVE

The aim of this study is to reveal the effectiveness of HBO therapy in iatrogenic spinal infections intractable to antibiotic therapy alone.

SUMMARY OF BACKGROUND DATA

The efficiency of hyperbaric oxygen (HBO) therapy, which is currently being used in many areas, has been proven in infections in deep and superficial locations and in osteomyelitis. The aim of this study is to reveal effectives of HBO therapy in iatrogenic spinal infections intractable to antibiotic alone therapy.

METHODS

HBO therapy was given to 19 cases of iatrogenic spinal infection between 2008 and 2013. Adjuvant HBO therapy was applied to cases that had exhibited no improvement in clinical and laboratory findings despite medical treatment for at least 3 weeks. Several parameters including demographic characteristics, surgical area, etiology and the surgical treatment modality, microbiology (culture material and causative organism), clinical and laboratory results, duration of HBO therapy, and outcome were reviewed.

RESULTS

The mean age was 54.6 years (range: 32-75 years). Iatrogenic spinal infections were most frequent in the lumbar region. It occurred after spine instrumentation in 12 cases and after micro-discectomy in 7 cases. The average number of HBO therapy sessions applied was 20.1 (range: 10-40). Wound discharge and clinical and laboratory findings recovered in all cases at the end of the therapy course. No revision or removal of the instrumentation was necessary in the instrumented cases.

CONCLUSION

HBO therapy is a treatment modality, which is safe and efficient as an adjuvant therapy in the treatment of infections. It was also seen to be effective in the prevention of revision procedures and instrumentation failures in iatrogenic osteomyelitis cases, which had occurred following spinal instrumentation.

LEVEL OF EVIDENCE

4.

Postoperative infection in spine surgery: does the month matter?

OBJECT

The relationship between time of year and surgical site infection (SSI) following neurosurgical procedures is poorly understood. Authors of previous reports have demonstrated that rates of SSI following neurosurgical procedures performed during the summer months were higher compared with rates during other seasons. It is unclear, however, if this difference was related to climatological changes or inexperienced medical trainees (the July effect). The aim of this study was to evaluate for seasonal variation of SSI following spine surgery in a network of nonteaching community hospitals.

METHODS

The authors analyzed 6 years of prospectively collected surveillance data (January 1, 2007, to December 31, 2012) from all laminectomies and spinal fusions from 20 hospitals in the Duke Infection Control Outreach Network of community hospitals. Surgical site infections were defined using National Healthcare Safety Network criteria and identified using standardized methods across study hospitals. Regression models were then constructed using Poisson distribution to evaluate for seasonal trends by month. Each analysis was first performed for all SSIs and then for SSIs caused by specific organisms or classes of organisms. Categorical analysis was performed using two separate definitions of summer: June through September (definition 1), and July through September (definition 2). The prevalence rate of SSIs during the summer was compared with the prevalence rate during the remainder of the year by calculating prevalence rate ratios and 95% confidence intervals.

RESULTS

The authors identified 642 SSIs following 57,559 neurosurgical procedures (overall prevalence rate = 1.11/100 procedures); 215 occurred following 24,466 laminectomies (prevalence rate = 0.88/100 procedures), and 427 following 33,093 spinal fusions (prevalence rate = 1.29/100 procedures). Common causes of SSI were Staphylococcus aureus (n = 380; 59%), coagulase-negative staphylococci (n = 90; 14%), and Escherichia coli (n = 41; 6.4%). Poisson regression models demonstrated increases in the rates of SSI during each of the summer months for all SSIs and SSIs due to gram-positive cocci, S. aureus, and methicillin-sensitive S. aureus. Categorical analysis confirmed that the rate of SSI during the 4-month summer period was higher than the rate during the remainder of the year, regardless of which definition for summer was used (definition 1, p = 0.008; definition 2, p = 0.003). Similarly, the rates of SSI due to grampositive cocci and S. aureus were higher during the summer months than the remainder of the year regardless of which definition of summer was used. However, the rate of SSI due to gram-negative bacilli was not.

CONCLUSIONS

The rate of SSI following fusion or spinal laminectomy/laminoplasty was higher during the summer in this network of community hospitals. The increase appears to be related to increases in SSIs caused by gram-positive cocci and, more specifically, S. aureus. Given the nonteaching nature of these hospitals, the findings demonstrate that increases in the rate of SSI during the summer are more likely related to ecological and/or environmental factors than the July effect.

Holospinal epidural abscess of the spinal axis: two illustrative cases with review of treatment strategies and surgical techniques

Despite the increasing prevalence of spinal infections, the subcategory of holospinal epidural abscesses (HEAs) is extremely infrequent and requires unique management. Panspinal imaging (preferably MRI), modern aggressive antibiotic therapy, and prompt surgical intervention remain the standard of care for all spinal axis infections including HEAs; however, the surgical decision making on timing and extent of the procedure still remain ill defined for HEAs. Decompression including skip laminectomies or laminoplasties is described, with varied clinical outcomes. In this review the authors present the illustrative cases of 2 patients with HEAs who were treated using skip laminectomies and epidural catheter irrigation techniques. The discussion highlights different management strategies including the role of conservative (nonsurgical) management in these lesions, especially with an already identified pathogen and the absence of mass effect on MRI or significant neurological defects. Among fewer than 25 case reports of HEA published in the past 25 years, the most important aspect in deciding a role for surgery is the neurological examination. Nearly 20% were treated successfully with medical therapy alone if neurologically intact. None of the reported cases had an associated cranial infection with HEA, because the dural adhesion around the foramen magnum prevented rostral spread of infection. Traditionally a posterior approach to the epidural space with irrigation is performed, unless an extensive focal ventral collection is causing cord compression. Surgical intervention for HEA should be an adjuvant treatment strategy for all acutely deteriorating patients, whereas aspiration of other infected sites like a psoas abscess can determine an infective pathogen, and appropriate antibiotic treatment may avoid surgical intervention in the neurologically intact patient.

Resident involvement does not influence complication after total hip arthroplasty: an analysis of 13,109 cases

Our study aimed to determine the impact of resident involvement on the 30-day postoperative complication rates following primary total hip arthroplasty (THA). Using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database, 13,109 primary THAs were identified, of which 3462 (26.4%) had resident involvement. Neither univariate (4.45% vs 4.52%, P = 0.86) nor multivariate (OR 1.04, P = 0.75) analyses demonstrated an increased complication rate with resident involvement following THA. We did find, however, that increased operative time, comorbidities, age, obesity, prior history of stroke and/or cardiac surgery were all independent risk factors for short-term complication. Our findings suggest that resident involvement does not increase 30-day complication rates following primary THA.

Does resident involvement impact post-operative complications following primary total knee arthroplasty? An analysis of 24,529 cases

Little is known about the impact of resident involvement on complication rates following total knee arthroplasty (TKA). The goal of our study was to determine the impact of resident involvement on complications following primary TKA. Using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database (2005-2012) we identified 24,529 patients who underwent primary TKA. Of these, 5960 (24.3%) had a resident involved in a primary TKA. Using a multivariate logistic regression which incorporated propensity score adjustment, no differences were seen in morbidity and mortality following those cases with resident involvement (OR: 1.15, P = 0.129). In the first large scale, comprehensive analysis of resident impact on short-term morbidity and mortality, no increase in complications was observed with resident involvement in primary TKA.

Is there a "July effect" in surgery for adolescent idiopathic scoliosis?

BACKGROUND

Prior studies in various medical and surgical specialties have suggested that the changeover of medical trainees in the United States at the end of the academic year, or so-called "July effect," negatively impacts the quality of patient care, including increasing morbidity and decreasing efficiency. We analyzed whether the outcomes of surgery for adolescent idiopathic scoliosis involving physicians-in-training as first assistants were affected by the time of year the surgery was performed.

METHODS

We performed a multicenter retrospective study with use of a prospectively collected database to examine outcomes following instrumented posterior spinal fusion in patients with adolescent idiopathic scoliosis. The minimum duration of follow-up was two years. The outcomes of procedures performed by twelve surgeons whose first assistants were all surgeons-in-training were analyzed on the basis of the month of year that the surgery was performed. Variables assessed included blood loss, operative time, length of hospitalization, radiographic outcomes, Scoliosis Research Society (SRS-22) scores, and complications.

RESULTS

Five hundred and seventy-five surgical procedures for adolescent idiopathic scoliosis were performed, most in June (14%) and July (13%) (p ≤ 0.001). Preoperative radiographic characteristics were similar across all months as were postoperative radiographic outcomes. Preoperative and two-year SRS-22 scores were also similar across all months, with the exception of scores in the preoperative pain domain, which showed worse pain for patients who underwent surgery in February. No significant differences in blood loss, operative time, or length of hospital stay were observed when these variables were analyzed on the basis of the month in which the surgery was performed. The rate of patients experiencing any complication (23.5% overall) was not associated with the month of surgery, nor were the rates for the specific subcategories of neurologic, pulmonary, gastrointestinal, instrumentation, or surgical site-related complications. With the exception of three gastrointestinal complications that were observed in July, the odds of a patient having a complication from surgery in July/August were unchanged from other months.

CONCLUSIONS

Overall, the data did not provide evidence to support a July effect. Our results suggest that surgery for adolescent idiopathic scoliosis during July and August yields safety and outcomes equal to that of other months.

Perioperative characteristics and outcomes of patients undergoing anterior cervical fusion in July: analysis of the "July effect"

STUDY DESIGN

Retrospective national database analysis.

OBJECTIVE

A national population-based database was analyzed to characterize the "July effect" on the perioperative outcomes of anterior cervical fusions (ACFs).

SUMMARY OF BACKGROUND DATA

Perception biases exist regarding the outcomes of cervical spine surgery based upon the month of admission.

METHODS

The Nationwide Inpatient Sample database was queried from 2009-2011. Patients who underwent an ACF in teaching and nonteaching hospitals were identified and separated into cohorts. Patients who were admitted in July were then compared with non-July admissions in both cohorts. Demographics, Charlson Comorbidity Index, length of stay, costs, postoperative complications, and mortality were assessed.

RESULTS

A total of 52,499 ACF cases were identified in the Nationwide Inpatient Sample of which 26,831 (51.2%) were performed in teaching hospitals and 25,668 (48.8) in nonteaching institutions. July admissions represented 6.8% and 7.4% of cases in the teaching and nonteaching hospital cohorts, respectively. Among July admissions, the teaching cohort incurred a longer hospitalization than the nonteaching cohort (P < 0.05). In contrast, no significant differences in mortality or total hospital costs were demonstrated. In teaching institutions, the in-hospital complications associated with July patients included deep vein thrombosis and surgical site infection (P < 0.05), but this did not reach significance in nonteaching hospitals. Postoperative dysphagia and deep vein thromboses were also significantly more prevalent among July admissions in teaching hospitals compared with nonteaching institutions.

CONCLUSION

This national study demonstrated that the early resident academic year was associated with a greater length of stay among July patients in teaching hospitals. This study did not demonstrate an increase in mortality or total hospital costs among July patients in either hospital cohort. In teaching hospitals, ACF-treated patients in July were associated with a greater incidence of postoperative thromboses and surgical site infection. In addition, the incidence of dysphagia was significantly greater among July patients in teaching hospitals than nonteaching hospitals.

Selection of an optimal antiseptic solution for intraoperative irrigation: an in vitro study

BACKGROUND

With increasing bacterial antibiotic resistance and an increased infection risk due to more complicated surgical procedures and patient populations, prevention of surgical infection is of paramount importance. Intraoperative irrigation with an antiseptic solution could provide an effective way to reduce postoperative infection rates. Although numerous studies have been conducted on the bactericidal or cytotoxic characteristics of antiseptics, the combination of these characteristics for intraoperative application has not been addressed.

METHODS

Bacteria (Staphylococcus aureus and S. epidermidis) and human cells were exposed to polyhexanide, hydrogen peroxide, octenidine dihydrochloride, povidone-iodine, and chlorhexidine digluconate at various dilutions for two minutes. Bactericidal properties were calculated by means of the quantitative suspension method. The cytotoxic effect on human fibroblasts and mesenchymal stromal cells was determined by a WST-1 metabolic activity assay.

RESULTS

All of the antiseptics except for polyhexanide were bactericidal and cytotoxic at the commercially available concentrations. When diluted, only povidone-iodine was bactericidal at a concentration at which some cell viability remained. The other antiseptics tested showed no cellular survival at the minimal bactericidal concentration.

CONCLUSIONS

Povidone-iodine diluted to a concentration of 1.3 g/L could be the optimal antiseptic for intraoperative irrigation. This should be established by future clinical studies.

The impact of resident involvement on post-operative morbidity and mortality following orthopaedic procedures: a study of 43,343 cases

BACKGROUND

Few studies have addressed the role of residents' participation in morbidity and mortality after orthopaedic surgery. The present study utilized the 2005-2010 National Surgical Quality Improvement Program (NSQIP) dataset to assess the risk of 30-day post-operative complications and mortality associated with resident participation in orthopaedic procedures.

METHODS

The NSQIP dataset was queried using codes for 12 common orthopaedic procedures. Patients identified as having received one of the procedures had their records abstracted to obtain demographic data, medical history, operative time, and resident involvement in their surgical care. Thirty-day post-operative outcomes, including complications and mortality, were assessed for all patients. A step-wise multivariate logistic regression model was constructed to evaluate the impact of resident participation on mortality- and complication-risk while controlling for other factors in the model. Primary analyses were performed comparing cases where the attending surgeon operated alone to all other case designations, while a subsequent sensitivity analysis limited inclusion to cases where resident participation was reported by post-graduate year.

RESULTS

In the NSQIP dataset, 43,343 patients had received one of the 12 orthopaedic procedures queried. Thirty-five percent of cases were performed with resident participation. The mortality rate, overall, was 2.5 and 10 % sustained one or more complications. Multivariate analysis demonstrated a significant association between resident participation and the risk of one or more complications [OR 1.3 (95 % CI 1.1, 1.4); p < 0.001] as well as major systemic complications [OR 1.6 (95 % CI 1.3, 2.0); p < 0.001] for primary joint arthroplasty procedures only. These findings persisted even after sensitivity testing.

CONCLUSIONS

A mild to moderate risk for complications was noted following resident involvement in joint arthroplasty procedures. No significant risk of post-operative morbidity or mortality was appreciated for the other orthopaedic procedures studied.

LEVEL OF EVIDENCE

II (Prognostic).

The "July effect" does not have clinical relevance in liver transplantation

In the beginning of the academic year, medical errors are often attributed to inexperienced medical staff. This potential seasonal influence on health care outcomes is termed the "July effect." No study has demonstrated the July effect in liver transplantation. We reviewed retrospectively collected data from the United Network for Organ Sharing for patients who underwent liver transplantation from October 1987 to June 2011 to determine if surgical outcomes were worse in July compared with rest of the year. We found no clinical difference in early graft survival (91.11% vs. 90.72%, p = 0.045) and no difference in early patient survival (94.71% vs. 94.42%, p = 0.057). Survival at 1 year, 3 years, and 5 years was also compared and no notable differences were detected. Because the Model for End-stage Liver Disease (MELD) score implementation in 2002 affected the acuity of liver transplant recipients, we further stratified our data to compare pre- and post-MELD survival to remove subjectivity as a confounding factor. MELD stratification revealed no seasonal difference in outcomes. There was no difference in rate of graft failure and acute and chronic rejection between groups. Our findings show no evidence of the July effect in liver transplantation. Each July, thousands of medical residents take on new responsibilities in patient care. It has been suggested that these new practitioners may produce errors that contribute to worse patient outcomes in the beginning of the academic year-a phenomenon called the "July effect." Currently, there are few research studies with controversial evidence of poorer outcomes in July, and no articles address the effect of new medical staff in the setting of liver transplantation. Our study compares short-, medium-, and long-term graft and patient survival between July and August and the remaining months using national data. We also examine survival before and after the implementation of the MELD scoring system to determine its effect on outcomes in the beginning of the academic year.

Impact of admission month on outcomes in spontaneous subarachnoid hemorrhage: evidence against the march effect

Objective

We attempted to identify the presence of a so called 'March effect (or phenomenon)' (which had long been known as a 'July effect' in western countries), a transient increase in adverse outcomes during an unskilled period for new interns and residents in a teaching hospital, among a cohort of patients with spontaneous subarachnoid hemorrhage (sSAH).

Methods

A total of 455 consecutive patients with sSAH from our department database from 2008 to 2010 were enrolled retrospectively and the admission month, patient demographics and clinical characteristics, treatment modalities and discharge outcomes were analyzed. Multivariate regression analysis was used to determine whether unfavorable discharge and in-hospital mortality showed a significant increase during the unskilled months for new interns and residents (from March to May) in a pattern suggestive of a "March effect".

Results

Among 455 patients with sSAH, 113 patients were treated during the unskilled period (from March to May) and the remaining 342 patients were treated during the skilled period (from June until February of the next year). No statistically significant difference in demographics and clinical characteristics was observed between patients treated during these periods. In addition, the mortality and unfavorable discharge rates of the un-skilled period were 16.8% and 29.7% and those of the skilled period were 15.5% and 27.2%, respectively. However, no statistically significant difference was observed between them.

Conclusions

Findings of our study suggest that there was no 'March effect' on the mortality rate and unfavorable discharge rate among patients with sSAH in our hospital during the study period.

A methodological, systematic review of evidence-based independent risk factors for surgical site infections after spinal surgery

OBJECTIVE

To identify the independent risk factors, based on available evidence in the literature, for patients developing surgical site infections (SSI) after spinal surgery.

METHODS

Non-interventional studies evaluating the independent risk factors for patients developing SSI following spinal surgery were searched in Medline, Embase, Sciencedirect and OVID. The quality of the included studies was assessed by a modified quality assessment tool that had been previously designed for observational studies. The effects of studies were combined with the study quality score using a best-evidence synthesis model.

RESULTS

Thirty-six observational studies involving 2,439 patients with SSI after spinal surgery were identified. The included studies covered a wide range of indications and surgical procedures. These articles were published between 1998 and 2012. According to the quality assessment criteria for included studies, 15 studies were deemed to be high-quality studies, 5 were moderate-quality studies, and 16 were low-quality studies. A total of 46 independent factors were evaluated for risk of SSI. There was strong evidence for six factors, including obesity/BMI, longer operation times, diabetes, smoking, history of previous SSI and type of surgical procedure. We also identified 8 moderate-evidence, 31 limited-evidence and 1 conflicting-evidence factors.

CONCLUSION

Although there is no conclusive evidence for why postoperative SSI occurs, these data provide evidence to guide clinicians in admitting patients who will have spinal operations and to choose an optimal prophylactic strategy. Further research is still required to evaluate the effects of these above risk factors.

A methodological systematic review on surgical site infections following spinal surgery: part 1: risk factors

STUDY DESIGN

A methodological systematic review.

OBJECTIVE

To critically appraise the validity of risk factors for surgical site infection (SSI) after spinal surgery.

SUMMARY OF BACKGROUND DATA

SSIs lead to higher morbidity, mortality, and increased health care costs. Understanding which factors lead to an increased risk of SSI is important for the development of prophylactic protocols to counter this risk. To date, however, no review appraising the methodological quality of studies evaluating risk factors for spinal SSIs has been published.

METHODS

Contemporary studies identifying risk factors for SSI after spinal surgery were searched through the Medline and EMBASE databases (January 2001 to December 2010). References were retrieved and bias-prone study features were abstracted individually and independently by 2 authors.

RESULTS

Twenty-four eligible studies were identified, including 9 (nested) case-control studies and 15 case series. Included studies covered wide variations of indications and surgical procedures. A total of 73 different types of factors were evaluated for the risk of an SSI of which 34 (47%) were reported to be significantly related to at least 1 study. Only the following risk factors-diabetes mellitus, obesity, and previous SSI-were confirmed more often (n = 11, 8, and 3, respectively) as a significant risk factor for an SSI than they were disproved (n = 7, 6, and 1, respectively). Various sources of heterogeneity were observed, including patient selection, selection and analysis of putative risk factors, and definitions of SSI outcomes.

CONCLUSION

There is an abundance of conflicting data on risk factors for SSI after spinal surgery. Given various sources of heterogeneity observed in observational literature, there is a paucity of solid evidence for the proof of robust risk factors. The authors recommend the introduction, validation, and use of a standardized set of strongly justified eligibility criteria and well-defined candidate risk factors and spinal SSI outcomes.

The seasonality of postoperative infection in spine surgery

OBJECT

Studies from many disciplines have found an association with the summer months, elevated temperature, humidity, and an increased rate of infection. The "July effect," a hypothesis that the inexperience of new house staff at the beginning of an academic year leads to an increase in wound complications, has also been considered. Finally, an increase in trauma-related admissions in the summer months is likely to result in an increased incidence of postoperative infections. Two previous studies revealed mixed results concerning perioperative spinal wound infections in the summer months. The purpose of this study was to determine the months and/or seasons of the year that display significant fluctuation of postoperative infection rate in spine surgery. Based on the idea that infection rates are susceptible to seasonal factors, the authors hypothesized that spinal infections would increase during the summer months.

METHODS

Inclusion criteria were all spine surgery cases at a single tertiary referral institution between January 2005 and December 2009; 8122 cases were included. Patients presenting with a contaminated wound or active infection were excluded. Infection rates were calculated on a monthly and seasonal basis and compared.

RESULTS

A statistically significant increase in the infection rate was present on both a seasonal and monthly basis (p = 0.03 and p = 0.024) when looking at the seasonal change from spring to summer. A significant decrease in the infection rate was seen on a seasonal basis during the change from fall to winter (p = 0.04). The seasonal rate of infection was highest in the summer (4.1%) and decreased to the lowest point in the spring (2.8%) (p = 0.03).

CONCLUSIONS

At the authors' institution, spine surgeries performed during the summer and fall months were associated with a significantly higher incidence of wound infection compared with the winter and spring. These data support the existence of a seasonal effect on perioperative spinal infection rates, which may be explained by seasonal variation in weather patterns and house staff experience, among other factors.

Prophylactic intraoperative powdered vancomycin and postoperative deep spinal wound infection: 1,512 consecutive surgical cases over a 6-year period

PURPOSE

The purpose of this study is to evaluate the effect of intraoperative powdered vancomycin on the rates of postoperative deep spinal wound infection. The use of intraoperative powdered vancomycin as a prophylactic measure in an attempt to reduce the incidence of postoperative spinal wound infection has not been sufficiently evaluated in the existing literature. A retrospective review of a large clinical database was performed to determine the rates of deep wound infection associated with the use of intraoperative operative site powdered vancomycin.

MATERIALS AND METHODS

During the period from 2005 to 2010, 1,512 consecutive spinal surgery cases were performed by the same fellowship-trained spinal surgeon (RWM) at a level 1 trauma-university medical center. One gram of powdered vancomycin was placed in all surgical sites prior to wound closure. Eight hundred forty-nine cases were uninstrumented, 478 cases were instrumented posterior thoracic or lumbar, 12 were instrumented anterior thoracic or lumbar, 126 were instrumented anterior cervical, and 47 were instrumented posterior cervical cases. Fifty-eight cases were combined anterior and posterior surgery and 87 were revision surgeries. A retrospective operative database and medical record review was performed to evaluate for evidence of postoperative deep wound infection.

RESULTS

15 of the 1,512 patients (0.99%) were identified as having evidence of postoperative deep wound infection. At least one pre-existing risk factor for deep infection was present in 8/15 pts (54%). Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) were the most commonly identified organisms (11/15 cases). The rate of deep wound infection was 1.20% (8/663) for instrumented spinal surgeries, and 0.82% (7/849) for uninstrumented surgeries. Deep infection occurred in only 1.23% (4/324) of multilevel instrumented posterior spinal fusions, 1.37% (1/73) of open PLIF procedures, and 1.23% (1/81) of single-level instrumented posterior fusions. Deep infection was not observed in any patient who had uninstrumented spinal fusion (0/64). The deep infection rate for revision surgeries was 1.15% (1/87) and 0.55% (1/183) for trauma surgery. Increased rates of complications related to powdered vancomycin use were not identified in this series. Conclusion In this series of 1,512 consecutive spinal surgeries, the use of 1 g of powdered intraoperative vancomycin placed in the wound prior to wound closure appears to associated with a low rate deep spinal wound infection for both instrumented and uninstrumented cases. Rates of deep infection for instrumented fusion surgery, trauma, and revision surgery appear to be among the lowest reported in the existing literature. Further investigation of this prophylactic adjunctive measure is warranted.

A July spike in fatal medication errors: a possible effect of new medical residents

BACKGROUND

Each July thousands begin medical residencies and acquire increased responsibility for patient care. Many have suggested that these new medical residents may produce errors and worsen patient outcomes-the so-called "July Effect;" however, we have found no U.S. evidence documenting this effect.

OBJECTIVE

Determine whether fatal medication errors spike in July.

DESIGN

We examined all U.S. death certificates, 1979-2006 (n = 62,338,584), focusing on medication errors (n = 244,388). We compared the observed number of deaths in July with the number expected, determined by least-squares regression techniques. We compared the July Effect inside versus outside medical institutions. We also compared the July Effect in counties with versus without teaching hospitals.

OUTCOME MEASURE

JR = Observed number of July deaths / Expected number of July deaths.

RESULTS

Inside medical institutions, in counties containing teaching hospitals, fatal medication errors spiked by 10% in July and in no other month [JR = 1.10 (1.06-1.14)]. In contrast, there was no July spike in counties without teaching hospitals. The greater the concentration of teaching hospitals in a region, the greater the July spike (r = .80; P = .005). These findings held only for medication errors, not for other causes of death.

CONCLUSIONS

We found a significant July spike in fatal medication errors inside medical institutions. After assessing competing explanations, we concluded that the July mortality spike results at least partly from changes associated with the arrival of new medical residents.

Incidence, prevalence, and analysis of risk factors for surgical site infection following adult spinal surgery

STUDY DESIGN

A retrospective cohort study to identify rates and analyze the risk factors for postoperative spinal wound infection.

OBJECTIVE

To determine significant risk factors for postoperative spinal wound infection by comparing those patients who developed a postoperative wound infection with the rest of the cohort.

SUMMARY OF BACKGROUND DATA

A surgical site infection (SSI) is a common complication after spinal surgery. SSI leads to higher morbidity, mortality, and healthcare costs. To develop strategies to reduce the risk for SSI, independent risk factors for SSI should be identified.

METHODS

The electronic patient record of all 3174 patients who underwent orthopedic spinal surgery at out institution were abstracted. Individual patient and perioperative characteristics were stored in an electronic database.

RESULTS

In total, 132 (4.2%) patients were found to have an SSI with 84 having deep based infection. Estimated blood loss over 1 liter (P = 0.017), previous SSI (P = 0.012) and diabetes (P = 0.050) were found to be independent statistically significant risk factors for SSI. Obesity (P = 0.009) was found to significantly increase the risk of superficial infection, whereas anterior spinal approach decreased the risk (P = 0.010). Diabetes (P = 0.033), obesity (P = 0.047), previous SSI (P = 0.009), and longer surgeries (2-5 hours [P = 0.023] and 5 or more hours [P = 0.009]) were found to be independent significant risk factors for deep SSI.

CONCLUSION

SSI is commonly seen after spinal surgery. In our study, we identified independent risk factors for both deep and superficial SSI. Identification of these risk factors should allow us to design protocols to decrease the risk of SSE in future patients.

Perioperative outcomes and complications related to teaching residents and fellows in scoliosis surgery

STUDY DESIGN

Single-surgeon retrospective case series of 303 consecutive operative patients with idiopathic scoliosis (IS).

OBJECTIVE

The purpose of this study is to evaluate the perioperative outcomes in patients undergoing surgery for IS as a function of the experience level of the surgical assistant.

SUMMARY OF BACKGROUND DATA

The experience level of the surgical assistant, who is often a resident or fellow, has never before been evaluated as an independent factor in predicting perioperative outcomes and morbidity in scoliosis surgery. We hypothesize that there is no difference in perioperative outcomes with varying experience level of the surgical assistant.

METHODS

We evaluated the clinical, radiographic, and operative records from 303 consecutive operative patients from consecutive patients with IS. Group I was comprised of residents or spine fellows as assistants (teaching service, n = 175), and Group II consisted of junior or senior attendings as assistants (private practice service, n = 128). Multivariable linear regression was used to evaluate the relationship between experience level of the assistant and curve correction, operative time, estimated blood loss (EBL), complications, transfusions, and length of stay.

RESULTS

In the posterior spinal fusion group (PSF, n = 164), there were no statistically significant differences in operative times between Groups I and II. Group I operative time was significantly increased, however, in patients undergoing anterior spinal surgery (ASF, P = 0.01), video-assisted thoracoscopic surgery (P = 0.0004), and combined anterior/posterior surgeries (ASF/PSF, P = 0.0063). There were no differences in EBL in ASF, video-assisted thoracoscopic surgery, or PSF surgeries, however, Group I had significantly higher EBL in the ASF/PSF group (P = 0.0016). No group differences were detected with respect to curve correction, transfusion rates, length of stay, or early complication rates.

CONCLUSION

The experience level of surgical assistant had little bearing on perioperative morbidity or radiographic outcomes in scoliosis surgery. Marginally increased operative times and EBL, without an increase in transfusions or complications, is an acceptably safe tradeoff for educating orthopedic residents and fellows.

Infectious complications after the Nuss repair in a series of 863 patients

PURPOSE

A nemesis of surgical implants is infection. We evaluated the various infectious complications after Nuss repair of pectus excavatum in 863 patients over 18 years.

METHODS

After institutional review board approval, a retrospective review of a prospectively gathered database of patients was performed who underwent minimally invasive repair of pectus excavatum and developed an infection. All patients received intravenous antibiotics before surgery continuing until discharge. Patients with a persistent fever after operation were discharged with oral antibiotics.

RESULTS

From January 1987 to September 2005, 863 patients underwent a minimally invasive pectus excavatum repair and 13 (1.5%) developed postoperative infections. These included 6 bar infections, 4 cases of cellulitis, and 3 stitch abscesses. Cellulitis was defined as erythema and warmth which responded to a single course of antibiotics. Bar infections were defined as an abscess in contact with the bar. Surgical drainage and long-term antibiotics resolved 3 of these abscesses, whereas 3 patients required early bar removal (1 after 3 months and 2 after 18 months). Cultures identified a single organism in each case and Staphylococcus aureus was the most common organism (83%) identified, and all being methicillin sensitive. All infections occurred on the side of the stabilizer if a stabilizer had been placed.

CONCLUSIONS

Infectious complications after Nuss repair are uncommon and occurred in 1.5% of our patients. Published rates of postoperative infection range from 1.0% to 6.8%. Superficial infections responded to antibiotics alone. Bar infection occurred in only 0.7% and required surgical drainage and long-term antibiotics. Only 3 of these (50% of bar infections and 0.34% overall) required early bar removal at 3 and 18 months because of recurring infections. Early bar removal should be a rare morbidity with the Nuss repair.

Is there a "July phenomenon" in pediatric neurosurgery at teaching hospitals?

OBJECT

Concern for patient safety, among other reasons, recently prompted sweeping changes in resident work policies in the US. Some have speculated that the arrival of new interns and residents at teaching hospitals each July might cause an annual transient increase in poor patient outcomes and inefficient care.

METHODS

Data were analyzed for 4323 craniotomies for tumor resection and 22,072 shunt operations performed in pediatric patients between 1988 and 2000 in US nonfederal hospitals (Nationwide Inpatient Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality, Rockville, MD). In-hospital mortality rates, discharge outcome, complications, and efficiency measures (length of stay [LOS] and hospital charges) for patients treated in July and August were compared with similar data for patients in other months. There were no significant increases in any adverse end point for either tumor or shunt operations in July and August. Odds ratios (95% confidence interval [CI]) for outcome of tumor craniotomies performed in July and August compared with outcome for tumor craniotomies performed in other months were as follows: for mortality rate, 0.43 (0.14-1.32); for adverse discharge disposition, 1.03 (0.71-1.51); for neurological complications, 1.00 (0.63-1.59); for transfusion, 0.70 (0.41-1.19). Hospital charges were 0.5% lower (range -6 to 5%) in July and August, and LOS was 3% shorter (range -8 to 3%). Odds ratios (95% CI) for July or August shunt surgery compared with shunt surgery performed in other months were as follows: for mortality rate, 0.96 (0.58-1.60); for adverse discharge disposition, 0.85 (0.66-1.11); for neurological complications, 1.27 (0.75-2.16); for transfusion, 0.81 (0.48-1.37). Hospital charges were 0.2% higher in July and August (range -3 to 3%), and LOS was 3% shorter (range -5 to 0.5%).

CONCLUSIONS

Although moderate increases in some adverse end points could not be excluded, there was no evidence that brain tumor or shunt surgery performed in pediatric patients at US teaching hospitals during July and August is associated with more frequent adverse patient outcome or inefficient care than similar surgery performed during other months.