Thirty-day readmission rates in spine surgery: systematic review and meta-analysis

OBJECT

The rate of 30-day readmissions is rapidly gaining significance as a quality metric and is increasingly used to evaluate performance. An analysis of the present 30-day readmission rate in the spine literature is needed to aid the development of policies to decrease the frequency of readmissions. The authors examine 2 questions: 1) What is the 30-day readmission rate as reported in the spine literature? 2) What study factors impact the rate of 30-day readmissions?

METHODS

This study was registered with Prospera (CRD42014015319), and 4 electronic databases (PubMed, Cochrane Library, Web of Science, and Google Scholar) were searched for articles. A systematic review and meta-analysis was performed to assess the current 30-day readmission rate in spine surgery. Thirteen studies met inclusion criteria. The readmission rate as well as data source, time from enrollment, sample size, demographics, procedure type and spine level, risk factors for readmission, and causes of readmission were extrapolated from each study.

RESULTS

The pooled 30-day readmission rate was 5.5% (95% CI 4.2%–7.4%). Studies from single institutions reported the highest 30-day readmission rate at 6.6% (95% CI 3.8%–11.1%), while multicenter studies reported the lowest at 4.7% (95% CI 2.3%–9.7%). Time from enrollment had no statistically significant effect on the 30-day readmission rate. Studies including all spinal levels had a higher 30-day readmission rate (6.1%, 95% CI 4.1%–8.9%) than exclusively lumbar studies (4.6%, 95% CI 2.5%–8.2%); however, the difference between the 2 rates was not statistically significant (p = 0.43). The most frequently reported risk factors associated with an increased odds of 30-day readmission on multivariate analysis were an American Society of Anesthesiology score of 4+, operative duration, and Medicare/Medicaid insurance. The most common cause of readmission was wound complication (39.3%).

CONCLUSIONS

The 30-day readmission rate following spinal surgery is between 4.2% and 7.4%. The range, rather than the exact result, should be considered given the significant heterogeneity among studies, which indicates that there are factors such as demographics, procedure types, and individual institutional factors that are important and affect this outcome variable. The pooled analysis of risk factors and causes of readmission is limited by the lack of reporting in most of the spine literature.

Preoperative opioid strength may not affect outcomes of anterior cervical procedures: a post hoc analysis of 2 prospective, randomized trials

OBJECT

The aim of this study is to evaluate the relationship between preoperative opioid strength and outcomes of anterior cervical decompressive surgery.

METHODS

A retrospective cohort of 1004 patients enrolled in 1 of 2 investigational device exemption studies comparing cervical total disc arthroplasty (TDA) and anterior cervical discectomy and fusion (ACDF) for single-level cervical disease causing radiculopathy or myelopathy was selected. At a preoperative visit, opioid use data, Neck Disability Index (NDI) scores, 36-Item Short-Form Health Survey (SF-36) scores, and numeric rating scale scores for neck and arm pain were collected. Patients were divided into strong (oxycodone/morphine/meperidine), weak (codeine/propoxyphene/hydrocodone), and opioid-naïve groups. Preoperative and postoperative (24 months) outcomes scores were compared within and between groups using the paired t-test and ANCOVA, respectively.

RESULTS

Patients were categorized as follows: 226 strong, 762 weak, and 16 opioid naïve. The strong and weak groups were similar with respect to age, sex, race, marital status, education level, Worker's Compensation status, litigation status, and alcohol use. At 24-month follow-up, no differences in change in arm or neck pain scores (arm: strong -52.3, weak -50.6, naïve -54.0, p = 0.244; neck: strong -52.7, weak -50.8, naïve -44.6, p = 0.355); NDI scores (strong -36.0, weak -33.3, naïve -32.3, p = 0.181); or SF-36 Physical Component Summary scores (strong: 14.1, weak 13.3, naïve 21.7, p = 0.317) were present. Using a 15-point improvement in NDI to determine success, the authors found no between-groups difference in success rates (strong 80.6%, weak 82.7%, naïve 73.3%, p = 0.134). No difference existed between treatment arms (TDA vs ACDF) for any outcome at any time point.

CONCLUSIONS

Preoperative opioid strength did not adversely affect outcomes in this analysis. Careful patient selection can yield good results in this patient population.

Opportunistic Osteoporosis Screening - Gleaning Additional Information from Diagnostic Wrist CT Scans

BACKGROUND

Although screening for and treating osteoporosis can prevent subsequent fractures, the rates of such interventions are low following a distal radial fracture. One potential method for identifying metabolic bone disease is via Hounsfield unit (HU) measurements from diagnostic computed tomography (CT) scans. We hypothesized that HU values of the distal aspect of the radius could be used to assess local bone quality and would be predictive of distal radial fracture risk, thereby allowing the identification of patients in need of further management.

METHODS

Measurements of bone mineral density (BMD) were made for 100 patients on the basis of HU values of cancellous portions of the distal aspect of the radius, the ulnar head, and the capitate. The HU values in twenty-five male and twenty-five female patients with an acute distal radial fracture documented on CT were compared with those of age and sex-matched control patients who had a CT scan obtained for other indications.

RESULTS

Among the control patients, HU values decreased as age increased. When assessed on the basis of sex, both male and female patients with a distal radial fracture had significantly lower regional BMD compared with nonfracture control patients. A distal radial HU value of 218 for females and 246 for males optimized sensitivity and specificity; values below this threshold were associated with an increased risk of distal radial fracture.

CONCLUSIONS

HU measurements can be obtained from any diagnostic CT scan using modern software programs and can be obtained by physicians in the office setting with minimal effort and at no additional cost or radiation exposure to the patient. Regardless of imaging indications, we suggest that patients with HU values below the identified thresholds be considered for further metabolic bone disease work-up, such as additional imaging, laboratory assessments, the initiation of osteoporosis treatment, or appropriate referral.

Comparison of dural repair techniques

BACKGROUND CONTEXT

Incidental durotomy occurs in 1% to 17% of lumbar spine surgery. This is treated with watertight suture repair, often combined with a sealant.

PURPOSE

To compare the hydrostatic strength of dural repair using various suture sizes, closure techniques, and adhesives.

STUDY DESIGN

A novel in vitro hydrostatic calf spine model.

OUTCOME MEASURES

Dural leakage as a function of hydrostatic pressure and leak area.

METHODS

We compared surgical repair between 5-0 surgilon and 6-0 prolene suture, continuous locked versus interrupted suture, and the effectiveness of three adhesives hydrogel, cyanoacrylate, and fibrin glue. The leakage flow rate was compared among suture groups using analysis of variance (ANOVA). The percent reduction of leak area was determined for the sealants and compared using ANOVA. The study was funded from an intramural departmental grant.

RESULTS

6-0 Prolene was found to have significantly decreased leakage flow rate than 5-0 surgilon. We found no significant differences in the flow rate between the interrupted and continuous locked sutures. In most cases, leakage occurred from the needle holes around sutures. There was an 80% reduction in leak area with the hydrogel and cyanoacrylic sealants compared with only a 38% reduction with fibrin glue; however, there was no statistical difference between the leak rates using any of the sealants.

CONCLUSION

6-0 Prolene using either interrupted or locked techniques was the best at creating watertight closure of an incidental durotomy. If a watertight seal cannot be obtained, a hydrogel or a fibrin sealant will immediately improve the strength of repair. Newer sutures that have a larger diameter of suture relative to needle should be developed for use in dural repair.

A meta-analysis of cervical foraminotomy: open versus minimally-invasive techniques

BACKGROUND CONTEXT

The posterior cervical foraminotomy (PCF) may be performed using an open or minimally-invasive (MIS) approach using a tubular retractor. Although there are theoretical advantages such as less blood loss and shorter hospitalizations, there is no consensus in the literature regarding the best approach for treatment.

PURPOSE

To assess clinical outcomes of PCF treated with either an open or an MIS approach using a tubular retractor.

STUDY DESIGN

Systematic literature review and meta-analysis of English language studies for the treatment of cervical radiculopathy treated with foraminotomy.

PATIENT SAMPLE

Pooled patient results from Level I studies and Level IV retrospective studies.

OUTCOME MEASURES

Meta-analysis for clinical success as determined by Odom and Prolo criteria, and visual analog scale scores for arm and neck pain.

METHODS

A literature search of three databases was performed to identify investigations performed in the treatment of PCF with an open or MIS approach. The pooled results were performed by calculating the effect size based on the logit event rate. Studies were weighted by the inverse of the variance, which included both within and between-study errors. Confidence intervals (CIs) were reported at 95%. Heterogeneity was assessed using the Q statistic and I-squared, where I-squared is the estimate of the percentage of error due to between-study variation.

RESULTS

The initial literature search resulted in 195 articles, of which, 20 were determined as relevant on abstract review. An open foraminotomy approach was performed in six; similarly, an MIS approach was performed in three studies. The pooled clinical success rate was 92.7% (CI: 88.9, 95.3) for open foraminotomy and 94.9% (CI: 90.5, 97.4) for MIS foraminotomy, which was not statistically significant (p=.418). The open group demonstrated relative homogeneity with Q value of 7.6 and I(2) value of 34.3%; similarly, the MIS group demonstrated moderate study heterogeneity with Q value of 4.44 and I(2) value of 54.94%.

CONCLUSIONS

Patients with symptomatic cervical radiculopathy from foraminal stenosis can be effectively managed with either a traditional open or an MIS foraminotomy. There is no significant difference in the pooled outcomes between the two groups.

Thirty-day readmission rates in orthopedics: a systematic review and meta-analysis

Background

Hospital readmission rates are being used to evaluate performance. A survey of the present rates is needed before policies can be developed to decrease incidence of readmission. We address three questions: What is the present rate of 30-day readmission in orthopedics? How do factors such as orthopedic specialty, data source, patient insurance, and time of data collection affect the 30-day readmission rate? What are the causes and risk factors for 30-day readmissions?

Methods/Findings

A review was first registered with Prospero (CRD42014010293, 6/17/2014) and a meta-analysis was performed to assess the current 30-day readmission rate in orthopedics. Studies published after 2006 were retrieved, and 24 studies met the inclusion criteria. The 30-day readmission rate was extrapolated from each study along with the orthopedic subspecialty, data source, patient insurance, time of collection, patient demographics, and cause of readmission. A sensitivity analysis was completed on the stratified groups. The overall 30-day readmission rate across all orthopedics was 5.4 percent (95% confidence interval: 4.8,6.0). There was no significant difference between subspecialties. Studies that retrieved data from a multicenter registry had a lower 30-day readmission rate than those reporting data from a single hospital or a large national database. Patient populations that only included Medicare patients had a higher 30-day readmission rate than populations of all insurance. The 30-day readmission rate has decreased in the past ten years. Age, length of stay, discharge to skilled nursing facility, increased BMI, ASA score greater than 3, and Medicare/Medicaid insurance showed statistically positive correlation with increased 30-day readmissions in greater than 75 percent of studies. Surgical site complications accounted for 46 percent of 30-day readmissions.

Conclusions

This meta-analysis shows the present rate of 30-day readmissions in orthopedics. Demonstrable heterogeneity between studies underlines the importance of uniform collection and reporting of readmission rates for hospital evaluation and reimbursement.

A Meta-Analysis of the Clinical and Fusion Results following Treatment of Symptomatic Cervical Pseudarthrosis

Study Design Systematic literature review and meta-analysis. Objective This study is a meta-analysis assessing the fusion rate and the clinical outcomes of cervical pseudarthrosis treated with either a posterior or a revision anterior approach. Methods A literature search of PubMed, Cochrane, and Embase was performed. Variables of interest included fusion rate and clinical success. The effect size based on logit event rate was calculated from the pooled results. The studies were weighted by the inverse of the variance, which included both within- and between-study error. The confidence intervals were reported at 95%. Heterogeneity was assessed using the Q statistic and I (2), where I (2) is the estimate of the percentage of error due to between-study variation. Results Sixteen studies reported fusion outcomes; 10 studies reported anterior and/or posterior results. The pooled fusion success was 86.4% in the anterior group and 97.1% in the posterior group (p = 0.028). The anterior group demonstrated significant heterogeneity with Q value of 34.2 and I (2) value of 73.7%; no heterogeneity was seen in the posterior group. The clinical outcomes were reported in 10 studies, with eight reporting results of anterior and posterior approaches. The pooled clinical success rate was 77.0% for anterior and 71.7% for posterior (p = 0.55) approaches. There was significant heterogeneity in both groups (I (2) 16.1; 19.2). Conclusions Symptomatic cervical pseudarthrosis can be effectively managed with either an anterior or a posterior approach. The posterior approach demonstrates a significantly greater fusion rate compared with the anterior approach, though the clinical outcome does not differ between the two groups.

Dependence of anisotropy of human lumbar vertebral trabecular bone on quantitative computed tomography-based apparent density

Most studies investigating human lumbar vertebral trabecular bone (HVTB) mechanical property-density relationships have presented results for the superior-inferior (SI), or "on-axis" direction. Equivalent, directly measured data from mechanical testing in the transverse (TR) direction are sparse and quantitative computed tomography (QCT) density-dependent variations in the anisotropy ratio of HVTB have not been adequately studied. The current study aimed to investigate the dependence of HVTB mechanical anisotropy ratio on QCT density by quantifying the empirical relationships between QCT-based apparent density of HVTB and its apparent compressive mechanical properties--elastic modulus (E(app)), yield strength (σ(y)), and yield strain (ε(y))--in the SI and TR directions for future clinical QCT-based continuum finite element modeling of HVTB. A total of 51 cylindrical cores (33 axial and 18 transverse) were extracted from four L1 human lumbar cadaveric vertebrae. Intact vertebrae were scanned in a clinical resolution computed tomography (CT) scanner prior to specimen extraction to obtain QCT density, ρ(CT). Additionally, physically measured apparent density, computed as ash weight over wet, bulk volume, ρ(app), showed significant correlation with ρ(CT) [ρ(CT) = 1.0568 × ρ(app), r = 0.86]. Specimens were compression tested at room temperature using the Zetos bone loading and bioreactor system. Apparent elastic modulus (E(app)) and yield strength (σ(y)) were linearly related to the ρ(CT) in the axial direction [E(SI) = 1493.8 × (ρ(CT)), r = 0.77, p < 0.01; σ(Y,SI) = 6.9 × (ρ(CT)) − 0.13, r = 0.76, p < 0.01] while a power-law relation provided the best fit in the transverse direction [E(TR) = 3349.1 × (ρ(CT))(1.94), r = 0.89, p < 0.01; σ(Y,TR) = 18.81 × (ρ(CT))(1.83), r = 0.83, p < 0.01]. No significant correlation was found between ε(y) and ρ(CT) in either direction. E(app) and σ(y) in the axial direction were larger compared to the transverse direction by a factor of 3.2 and 2.3, respectively, on average. Furthermore, the degree of anisotropy decreased with increasing density. Comparatively, ε(y) exhibited only a mild, but statistically significant anisotropy: transverse strains were larger than those in the axial direction by 30%, on average. Ability to map apparent mechanical properties in the transverse direction, in addition to the axial direction, from CT-based densitometric measures allows incorporation of transverse properties in finite element models based on clinical CT data, partially offsetting the inability of continuum models to accurately represent trabecular architectural variations.

Bone morphogenetic protein-associated complications in pediatric spinal fusion in the early postoperative period: an analysis of 4658 patients and review of the literature

OBJECT

Use of recombinant human bone morphogenetic protein-2 has risen steadily since its approval by the FDA for use in anterior lumbar interbody fusion in 2002. The FDA has not approved the use of bone morphogenetic protein (BMP) in children. Age less than 18 years or lack of evidence of epiphyseal closure are considered by the manufacturer to be contraindications to BMP use. In light of this, the authors performed a query of the database of one of the nation's largest health insurance companies to determine the rate of BMP use and complications in pediatric patients undergoing spinal fusion.

METHODS

The authors used the PearlDiver Technologies private payer database containing all records from United Health-Care from 2005 to 2011 to query all cases of pediatric spinal fusion with or without BMP use. A review of the literature was also performed to examine the complications associated with BMP use in pediatric spinal fusion.

RESULTS

A total of 4658 patients underwent spinal fusion. The majority was female (65.4%), and the vast majority was age 10-19 years (94.98%) and underwent thoracolumbar fusion (93.13%). Bone morphogenetic protein was used in 1752 spinal fusions (37.61%). There was no difference in the rate of BMP use when comparing male and female patients or age 10 years or older versus less than 10 years. Anterior cervical fusions were significantly less likely to use BMP (7.3%). Complications occurred in 9.82% of patients treated with versus 9.88% of patients treated without BMP. The complication rate was nearly identical in male versus female patients and in patients older versus younger than 10 years. Comparison of systemic, wound-related, CNS, and other complications showed no difference between groups treated with and without BMP. The reoperation rate was also nearly identical.

CONCLUSIONS

Bone morphogenetic protein is used in a higher than expected percentage of pediatric spinal fusions. The rate of acute complications in these operations does not appear to be different in patients treated with versus those treated without BMP. Caution must be exercised in interpreting these data due to the many limitations of the administrative database as a data source, including the short length of follow-up.

Cancer risk from bone morphogenetic protein exposure in spinal arthrodesis

BACKGROUND

The U.S. Food and Drug Administration reported a higher incidence of cancer in patients who had spinal arthrodesis and were exposed to a high dose of recombinant human bone morphogenetic protein-2 (rhBMP-2) compared with the control group in a randomized controlled trial. The purpose of this study was to determine the risk of cancer after spinal arthrodesis with BMP.

METHODS

We retrospectively analyzed the incidence of cancer in 467,916 Medicare patients undergoing spinal arthrodesis from 2005 to 2010. Patients with a preexisting diagnosis of cancer were excluded. The average follow-up duration was 2.85 years for the BMP group and 2.94 years for the control group. The main outcome measure was the relative risk of developing new malignant lesions after spinal arthrodesis with or without exposure to BMP.

RESULTS

The relative risk of developing cancer after BMP exposure was 0.938 (95% confidence interval [95% CI]: 0.913 to 0.964), which was significant. In the BMP group, 5.9% of the patients developed an invasive cancer compared with 6.5% of the patients in the control group. The relative risk of developing cancer after BMP exposure was 0.98 in males (95% CI: 0.94 to 1.02) and 0.93 (95% CI: 0.90 to 0.97) in females. The control group showed a higher incidence of each type of cancer except pancreatic cancer.

CONCLUSIONS

Recent clinical use of BMP was not associated with a detectable increase in the risk of cancer within a mean 2.9-year time window.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Intervertebral disc and stem cells cocultured in biomimetic extracellular matrix stimulated by cyclic compression in perfusion bioreactor

BACKGROUND CONTEXT

Intervertebral disc (IVD) degeneration often causes back pain. Current treatments for disc degeneration, including both surgical and nonsurgical approaches, tend to compromise the disc movement and cannot fully restore functions of the IVD. Instead, cell-based IVD tissue engineering seems promising as an ultimate therapy for IVD degeneration.

PURPOSE

To tissue-engineer an IVD ex vivo as a biological substitute to replace degenerative IVD.

STUDY DESIGN

An extracellular matrix (ECM) structure-mimetic scaffold, cocultured human IVD cells and human mesenchymal stem cells (hMSCs), and mechanical stimulation were used to biofabricate a tissue-engineered IVD.

METHODS

An optimal ratio of human annulus fibrosus (hAF) cells to hMSCs for AF generation within aligned nanofibers, and that of human nucleus pulposus (hNP) cells to hMSCs for NP generation within hydrogels were first determined after comparing different coculture ratios of hAF or hNP cells to hMSCs. Nanofibrous strips seeded with cocultured hAF cells/hMSCs were constructed into multilayer concentric rings, enclosing an inner core of hydrogel seeded with hNP cells/hMSCs. A piece of nonwoven nanofibrous mat seeded with hMSC-derived osteoblasts was assembled on the top of the cellular nanofiber/hydrogel assembly, as an interface layer between the cartilagenous end plate and vertebral body. The final assembled construct was then maintained in an osteochondral cocktail medium and stimulated with compressive loading to further enhance the hAF and hNP cells differentiation and increase the IVD ECM production.

RESULTS

Among all cocultured groups, hAF cells and hMSCs in the ratio of 2:1 cultured in nanofibers showed the closest mRNA expression levels of AF-related markers to positive control hAF cells, whereas hNP cells and hMSCs in the ratio of 1:2 cultured in hydrogels showed the closest expression levels of NP-related markers to positive control hNP cells. The effects of compressive loading on chondrogenesis of hAF or hNP cell and hMSC coculture were dependent on the scaffold structure; the expression of cartilage-related markers in AF nanofibers was downregulated, whereas that in NP hydrogel was upregulated. Interestingly, we found that hMSC-derived osteogenic cells in the interface layer were turned into chondrogenic lineage cells, with decreased expression of osteogenic markers and increased expression of chondrogenic markers.

CONCLUSIONS

We demonstrate a unique approach using a biomimetic scaffold, IVD and stem cell coculture, and mechanical stimulation to tissue-engineer a biological IVD substitute. The results show that our approach provides both favorable physical and chemical cues through cell-matrix and cell-cell interactions and mechanobiological induction to enhance IVD generation ex vivo. Our findings may lead to viable tissue engineering applications of generating a functional biological IVD for the treatment of disc degeneration.

Use of computed tomography for assessing bone mineral density

Assessing local bone quality on CT scans with Hounsfield unit (HU) quantification is being used with increasing frequency. Correlations between HU and bone mineral density have been established, and normative data have been defined throughout the spine. Recent investigations have explored the utility of HU values in assessing fracture risk, implant stability, and spinal fusion success. The information provided by a simple HU measurement can alert the treating physician to decreased bone quality, which can be useful in both medically and surgically managing these patients.

Simulated spinal cerebrospinal fluid leak repair: an educational model with didactic and technical components

BACKGROUND

In the era of surgical resident work hour restrictions, the traditional apprenticeship model may provide fewer hours for neurosurgical residents to hone technical skills. Spinal dura mater closure or repair is 1 skill that is infrequently encountered, and persistent cerebrospinal fluid leaks are a potential morbidity.

OBJECTIVE

To establish an educational curriculum to train residents in spinal dura mater closure with a novel durotomy repair model.

METHODS

The Congress of Neurological Surgeons has developed a simulation-based model for durotomy closure with the ongoing efforts of their simulation educational committee. The core curriculum consists of didactic training materials and a technical simulation model of dural repair for the lumbar spine.

RESULTS

Didactic pretest scores ranged from 4/11 (36%) to 10/11 (91%). Posttest scores ranged from 8/11 (73%) to 11/11 (100%). Overall, didactic improvements were demonstrated by all participants, with a mean improvement between pre- and posttest scores of 1.17 (18.5%; P = .02). The technical component consisted of 11 durotomy closures by 6 participants, where 4 participants performed multiple durotomies. Mean time to closure of the durotomy ranged from 490 to 546 seconds in the first and second closures, respectively (P = .66), whereby the median leak rate improved from 14 to 7 (P = .34). There were also demonstrative technical improvements by all.

CONCLUSION

Simulated spinal dura mater repair appears to be a potentially valuable tool in the education of neurosurgery residents. The combination of a didactic and technical assessment appears to be synergistic in terms of educational development.

Adverse events recording and reporting in clinical trials of cervical total disk replacement

Adverse events reporting in pivotal trials of new technologies, such as cervical total disk replacement, are essential to determine safety. Important questions concerning the adequacy of reporting about such new technologies in peer-reviewed publications have prompted this analysis to assess the safety of cervical disk replacement compared with fusion as presented in peer-reviewed publications and FDA summary reports. Identifying differences among these reports highlight the poor quality of adverse event reporting in the peer-reviewed literature. Nine peer-reviewed studies and five FDA summary reports documented excellent safety for both cervical fusion and disk arthroplasty. No differences in rates of adverse events were found to exist between the two treatments. The methods of recording and the actual reporting of adverse events were poor in peer-reviewed manuscripts, whereas they were comprehensive but difficult to clinically apply in the FDA summaries. Recommendations to improve documentation and reporting of adverse events are presented.

Developing a toolkit for comparing safety in spine surgery

Safety information in spine surgery is important for informed patient choice and performance-based payment incentives, but measurement methods for surgical safety assessment are not standardized. Published reports of complication rates for common spinal procedures show wide variation. Factors influencing variation may include differences in safety ascertainment methods and procedure types. In a prospective cohort study, adverse events were observed in all patients undergoing spine surgery at two hospitals during a 2-year period. Multiple processes for adverse occurrence surveillance were implemented, and the associations between surveillance methods, surgery invasiveness, and observed frequencies of adverse events were examined. The study enrolled 1,723 patients. Adverse events were noted in 48.3% of the patients. Reviewers classified 25% as minor events and 23% as major events. Of the major events, the daily rounding team reported 38.4% of the events using a voluntary reporting system, surgeons reported 13.4%, and 9.1% were identified during clinical conferences. A review of medical records identified 86.7% of the major adverse events. The adverse events occurred during the inpatient hospitalization for 78.1% of the events, within 30 days for an additional 12.5%, and within the first year for the remaining 9.4%. A unit increase in the invasiveness index was associated with an 8.2% increased risk of a major adverse event. A Current Procedural Terminology-based algorithm for quantifying invasiveness correlated well with medical records-based assessment. Increased procedure invasiveness is associated with an increased risk of adverse events. The observed frequency of adverse events is influenced by the ascertainment modality. Voluntary reports by surgeons and other team members missed more than 50% of the events identified through a medical records review. Increased surgery invasiveness, measured from medical records or billing codes, is quantitatively associated with an increased risk of adverse events.

Effect of machined interfacet allograft spacers on cervical foraminal height and area

OBJECT

Iatrogenic foraminal stenosis is a well-known complication in cervical spine surgery. Machined interfacet allograft spacers can provide a large surface area, which ensures solid support, and could potentially increase foraminal space. The authors tested the hypothesis that machined interfacet allograft spacers increase cervical foraminal height and area.

METHODS

The C4-5, C5-6, and C6-7 facets of 4 fresh adult cadavers were exposed, and the cartilage was removed from each facet using customized rasps. Machined allograft spacers were tamped into the joints. The spines were scanned with the O-arm surgical imaging system before and after placement of the spacers. Two individuals independently measured foraminal height and area on obliquely angled sagittal images.

RESULTS

Foraminal height and area were significantly greater following placement of the machined interfacet spacers at all levels. The Pearson correlation between the 2 radiographic reviewers was very strong (r = 0.971, p = 0.0001), as was the intraclass correlation coefficient (ICC = 0.907, p = 0.0001). The average increase in foraminal height was 1.38 mm. The average increase in foraminal area was 18.4% (0.097 cm(2)) [corrected].

CONCLUSIONS

Modest distraction of the facets using machined interfacet allograft spacers can increase foraminal height and area and therefore indirectly decompress the exiting nerve roots. This technique can be useful in treating primary foraminal stenosis and also for preventing iatrogenic foraminal stenosis that may occur when the initially nonlordotic spine is placed into lordosis either with repositioning after central canal decompression or with correction using instrumentation. These grafts may be a useful adjunct to the surgical treatment of cervical spine disease.

An update on modifiable factors to reduce the risk of surgical site infections

BACKGROUND CONTEXT

Despite an increase in physician and public awareness and advances in infection control practices, surgical site infection (SSI) remains to be one of the most common complications after an operation. Surgical site infections have been shown to decrease health-related quality of life, double the risk of readmission, prolong the length of hospital stay, and increase hospital costs.

PURPOSE

To critically evaluate the literature and identify modifiable factors to reduce the risk of SSI.

STUDY DESIGN/SETTING

Systematic review of the literature.

METHODS

A critical review of the literature was performed using OVID, Pubmed, and the Cochrane database and focused on eight identifiable factors: preoperative screening and decolonization of methicillin-sensitive Staphylococcus aureus and methicillin-resistant S. aureus protocols, antiseptic showers, antiseptic cloths, perioperative skin preparation, surgeon hand hygiene, antibiotic irrigation and/or use of vancomycin powder, closed suction drains, and antibiotic suture.

RESULTS

Screening protocols have shown that 18% to 25% of patients undergoing elective orthopedic surgery are nasal carriers of S. aureus and that carriers are more likely to have a nosocomial infection and SSI. The evidence suggests that an institutionalized prescreening program, followed by an appropriate eradication using mupirocin ointment and chlorhexidine soap/shower, will lower the rate of nosocomial S. aureus infections. Based on the current literature, definitive conclusions cannot be made on whether preoperative antiseptic showers effectively reduce the incidence of postoperative infection. The use of a chlorhexidine bathing cloth before surgery may decrease the risk of SSI. There is no definitive clinical evidence that one skin preparation solution effectively lowers the rate of postoperative infection compared with another. The use of dilute betadine irrigation or vancomycin powder in the wound before closure likely decreases the incidence of SSI.

CONCLUSIONS

There is strong evidence in the literature that optimizing specific preoperative, intraoperative, and postoperative variables can significantly lower the risk of developing an SSI.