Analysis of Postoperative Thoracolumbar Spine Infections in a Prospective Randomized Controlled Trial Using the Centers for Disease Control Surgical Site Infection Criteria

Prognostic and therapeutic interest of a new classification in inferior hip dislocation: a systematic review of the literature

INTRODUCTION

Reported cases of inferior dislocation in the literature are found under several names (inferior, anteroinferior, obturator, or erecta), which may be source of confusion. The purpose of this comprehensive review of the literature is to collect as many cases of inferior dislocation as possible to determine better therapeutic strategies, outcome after reduction, complications, and prognostic factors.

METHODS

In April 2020, a literature search was performed in Pubmed, Medline, Scopus, Cochrane, and Embase databases. The MeSH keywords were "OBTURATOR DISLOCATION HIP" or "ANTERIOR DISLOCATION HIP" or "INFERIOR DISLOCATION HIP." Authors independently selected articles that met the selection criteria, with no time limit.

RESULTS

Out of the 97 articles selected, there were 119 cases of primary inferior hip dislocations. This review of the literature has allowed us to differentiate 3 radiographic subtypes of inferior dislocations, which correspond to 3 different anatomical positions of the femoral head: "obturator" dislocation, "proximal anterior-inferior" dislocation, and "distal anterior-inferior" dislocation. Our subtype classification yielded 39 obturator subtype inferior dislocations (32.8%), 66 proximal anteroinferior subtypes (55.4%), and 14 distal anteroinferior (11.8%). The obturator subtype is at risk of reduction failure and femoral neck fracture during the reduction manoeuver.

CONCLUSIONS

Our study identified 3 subtypes with different prognosis, with obturator and distal anteroinferior dislocations having a poorer prognosis because of their pre- and post-reduction complications. We were unable to determine the correct manoeuver to reduce inferior dislocations without taking the risk of femoral neck fracture, but each of these subtypes may require a different manoeuver.

The Intraoperative Use of Defensive Antibacterial Coating (DAC®) in the Form of a Gel to Prevent Peri-Implant Infections in Orthopaedic Surgery: A Clinical Narrative Review

Periprosthetic joint infections (PJIs) in arthroplasty and osteosynthesis-associated infections (OAIs) in reconstructive surgery still represent a challenging complication in orthopaedics and traumatology causing a burden worsening the patient's quality of life, for caregiver and treating physicians, and for healthcare systems. PJIs and OAIs are the result of bacterial adhesion over an implant surface with subsequent biofilm formation. Therefore, the clinical pathological outcome is a difficult-to-eradicate persistent infection. Strategies to treat PJIs and OAIs involve debridement, the replacement of internal fixators or articular prostheses, and intravenous antibiotics. However, long treatments and surgical revision cause discomfort for patients; hence, the prevention of PJIs and OAIs represents a higher priority than treatment. Local antibiotic treatments through coating-release systems are becoming a smart approach to prevent this complication. Hydrophilic coatings, loaded with antibiotics, simultaneously provide a barrier effect against bacterial adhesion and allow for the local delivery of an antibiotic. The intraoperative use of a hyaluronan (HY)-derivative coating in the form of a gel, loaded with antibiotics to prevent PJI, has recently raised interest in orthopaedics. Current evidence supports the use of this coating in the prophylaxis of PJI and IRIs in terms of clinical outcomes and infection reduction. Thus, the purpose of this narrative review is to assess the use of a commercially available HY derivative in the form of a gel, highlighting the characteristics of this biomaterial, which makes it attractive for the management of PJIs and IRIs in orthopaedics and traumatology.

Cutibacterium spp. Infections after Instrumented Spine Surgery Have a Good Prognosis Regardless of Rifampin Use: A Cross-Sectional Study

Infection after spinal instrumentation (IASI) by Cutibacterium spp. is being more frequently reported. The aim of this study was to analyse the incidence, risk factors, clinical characteristics, and outcome of a Cutibacterium spp. IASI (CG) compared with non-Cutibacterium IASI (NCG) infections, with an additional focus on the role of rifampin in the treatment. All patients from a multicentre, retrospective, observational study with a confirmed IASI between January 2010 and December 2016 were divided into two groups: (CG and NCG) IASI. Baseline, medical, surgical, infection treatment, and follow-up data were compared for both groups. In total, 411 patients were included: 27 CG and 384 NCG. The CG patients were significantly younger. They had a longer median time to diagnosis (23 vs. 13 days) (p = 0.025), although 55.6% debuted within the first month after surgery. Cutibacterium patients were more likely to have the implant removed (29.6% vs. 12.8%; p = 0.014) and received shorter antibiotic regimens (p = 0.014). In 33% of Cutibacterium cases, rifampin was added to the baseline therapy. None of the 27 infections resulted in treatment failure during follow-up regardless of rifampin use. Cutibacterium spp. is associated with a younger age and may cause both early and late IASIs. In our experience, the use of rifampin to improve the outcome in the treatment of a Cutibacterium spp. IASI is not relevant since, in our series, none of the cases had therapeutic failure regardless of the use of rifampin.

Evidence-based guideline for the prevention and management of perioperative infection

BACKGROUND

We have updated the guideline for preventing and managing perioperative infection in China, given the global issues with antimicrobial resistance and the need to optimize antimicrobial usage and improve hospital infection control levels.

METHODS

We conducted a comprehensive evaluation of the evidence for prevention and management of perioperative infection, based on the concepts of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The strength of recommendations was graded and voted using the Delphi method and the nominal group technique. Revisions were made to the guidelines in response to feedback from the experts.

RESULTS

There were 17 questions prepared, for which 37 recommendations were made. According to the GRADE system, we evaluated the body of evidence for each clinical question. Based on the meta-analysis results, recommendations were graded using the Delphi method to generate useful information.

CONCLUSIONS

This guideline provides evidence to perioperative antimicrobial prophylaxis that increased the rational use of prophylactic antimicrobial use, with substantial improvement in the risk-benefit trade-off.

Potential side effects of antibacterial coatings in orthopaedic implants: A systematic review of clinical studies

Objective: The systematic review aimed to determine the potential side effects of antibacterial coatings in orthopaedic implants. Methods: Publications were searched in the databases of Embase, PubMed, Web of Science and Cochrane Library using predetermined keywords up to 31 October 2022. Clinical studies reporting side effects of the surface or coating materials were included. Results: A total of 23 studies (20 cohort studies and three case reports) reporting the concerns about the side effects of antibacterial coatings were identified. Three types of coating materials, silver, iodine and gentamicin were included. All of studies raised the concerns regarding safety of antibacterial coatings, and the occurrence of adverse events was observed in seven studies. The main side effect of silver coatings was the development of argyria. For iodine coatings, only one anaphylactic case was reported as an adverse event. No systemic or other general side effects were reported for gentamicin. Conclusion: Clinical studies on the side effects of antibacterial coatings were limited. Based on the available outcomes, the most reported side effects of antibacterial coatings in clinical use were argyria with silver coatings. However, researchers should always pay attention to the potential side effects of antibacterial materials, such as systematic or local toxicity and allergy.

Does Postoperative Spine Infection Bacterial Gram Type Affect Surgical Debridement or Antibiotic Duration?

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

The aim was to evaluate differences in readmission rates, number of debridements, and length of antibiotic therapy when comparing bacterial gram type following lumbar spinal fusion infections.

SUMMARY OF BACKGROUND DATA

Surgical site infections (SSIs) after spinal fusion serve as a significant source of patient morbidity. It remains to be elucidated how bacterial classification of the infecting organism affects the management of postoperative spinal SSI.

METHODS

Patients who underwent spinal fusion with a subsequent diagnosis of SSI between 2013 and 2019 were retrospectively identified. Patients were grouped based on bacterial infection type (gram-positive, gram-negative, or mixed infections). Poisson regressions analyzed the relationship between the type of bacterial infection and the number of irrigation and debridement (I&D) reoperations, and the duration of intravenous (IV) antibiotic therapy. Significance was set at P <0.05.

RESULTS

Of 190 patients, 92 had gram-positive (G+) infections, 57 had gram-negative (G-) infections, and 33 had mixed (M) infections. There was no difference in 30 or 90-day readmissions for infection between groups (both P =0.051). Patients in the M group had longer durations of IV antibiotic treatment (G+: 46.4 vs. G-: 41.0 vs. M: 55.9 d, P =0.002). Regression analysis demonstrated mixed infections were 46% more likely to require a greater number of debridements ( P =0.001) and 18% more likely to require an increased duration of IV antibiotic therapy ( P <0.001), while gram-negative infections were 10% less likely to require an increased duration of IV antibiotic therapy ( P <0.001) when compared with G- infections.

CONCLUSION

Spinal SSI due to a mixed bacterial gram type results in an increased number of debridements and a longer duration of IV antibiotics required to resolve the infection compared with gram-negative or gram-positive infections.

LEVEL OF EVIDENCE

Level III.

Surgical Site Infections after Spinal Surgery in a Tropical Area: A Prospective Monocentric Observational Study

To date, no study has described the microbiological profile of surgical site infections (SSIs) after spine surgery in a tropical environment. The main objective of this study is to describe the microbiology and the risk factors of SSI after spinal surgery in a tropical climate. Our hypothesis is that the microbiology of SSIs in tropical areas is different to what is mainly described in temperate countries. As a consequence, the recommendation for antibiotic prophylaxis administered in the operative room, which mainly relays on the literature, might not be adequate in such countries. We included 323 consecutive patients who underwent a spinal intervention between 2017 and 2019, with a 2-year minimum follow-up. Objective ISO criteria were established in accordance with the criteria accepted by the Center of Disease Control in Atlanta. The identification of risk factors for SSI was carried out by uni- and multivariate analysis with a significance threshold of P < 0.05. The incidence of SSI was 7.7%. A total of 54.8% were in favor of a predominantly digestive origin of germs with an average of 1.68 bacteria found by ISO. Inadequate antibiotic prophylaxis was found in 54.8%. Age and body mass index were found to be independent risk factors for SSI. We report here an unusual microbiological profile of SSI with a predominance of gram-negative bacteria and a low proportion of Staphylococcus aureus and Staphylococcus epidermidis.

Development of Silver-Containing Hydroxyapatite-Coated Antimicrobial Implants for Orthopaedic and Spinal Surgery

The prevention of surgical site infections is directly related to the minimization of surgical invasiveness, and is in line with the concept of minimally invasive spine therapy (MIST). In recent years, the incidence of postoperative infections has been increasing due to the increased use of spinal implant surgery in patients at high risk of infection, including the elderly and easily infected hosts, the limitations of poor bone marrow transfer of antibiotics, and the potential for contamination of surgical gloves and instruments. Thus, the development of antimicrobial implants in orthopedic and spinal surgery is becoming more and more popular, and implants with proven antimicrobial, safety, and osteoconductive properties (i.e., silver, iodine, antibiotics) in vitro, in vivo, and in clinical trials have become available for clinical use. We have developed silver-containing hydroxyapatite (Ag-HA)-coated implants to prevent post-operative infection, and increase bone fusion capacity, and have successfully commercialized antibacterial implants for hip prostheses and spinal interbody cages. This narrative review overviews the present status of available surface coating technologies and materials; describes how the antimicrobial, safety, and biocompatibility (osteoconductivity) of Ag-HA-coated implants have been demonstrated for commercialization; and reviews the clinical use of antimicrobial implants in orthopedic and spinal surgery, including Ag-HA-coated implants that we have developed.

Predictive Factors for Successful Treatment of Deep Incisional Surgical Site Infections following Instrumented Spinal Surgeries: Retrospective Review of 1832 Cases

Background: Surgical site infection (SSI) is a major complication in spinal instrumentation that is often difficult to treat. The purpose of this study was to identify and determine prognostic indicators for successful treatment of spine instrumentation SSI. Methods: Retrospectively, spine surgery cases were examined on SSI diagnosis. Post-instrumentation SSI patients were categorized as “Successful” if SSI subsided after single debridement. Patients in whom SSI did not subsided and/or required removal of instrumentation were classified as “Challenging”. We investigated the relation of treatment outcomes to patients and treatment factors. Results: A total of 1832 spinal instrumentation cases were recognized with 44 (2.40%) SSI cases. White blood cell count, C-reactive protein (CRP) levels, causative bacteria (i.e., S. Aureus or MRSA), trauma injury, and early-stage antimicrobial agent sensitivity correlated with treatment prognosis. Multivariate analysis highlighted CRP levels and applying early-stage sensitive antibiotics as potential impactful predictive factors for successful treatment. Conclusions: Our results demonstrated that early selection of sensitive antimicrobial agents is critical and emphasizes the potential for early-stage classification methods such as Gram staining. Additionally, S. Aureus and MRSA SSI formed significantly more challenging infections to treat, thus requiring consideration when deciding on instrumentation retention. These factors offer promising aspects for further large-scale studies.

Factors Affecting Operation Duration in Posterior Spinal Fusion (PSF) Using Dual Attending Surgeon Strategy Among Lenke 1 and 2 Adolescent Idiopathic Scoliosis (AIS) Patients

STUDY DESIGN

This was a retrospective study.

SUMMARY OF BACKGROUND DATA

Prolonged operation duration in adolescent idiopathic scoliosis (AIS) surgery was associated with increased perioperative complications. However, the factors affecting operation duration in AIS surgery were unknown.

OBJECTIVE

The aim of the study was to investigate the factors affecting operation duration in posterior spinal fusion (PSF) surgery using a dual attending surgeon strategy among Lenke 1 and 2 AIS patients.

METHODS

In all, 260 AIS patients with Lenke 1 and 2 curves who underwent PSF were retrospectively reviewed. Preoperative and intraoperative factors affecting operation duration such as age, sex, height, weight, body mass index, Risser grade, Lenke subtypes, number of fusion level, number of screws, screw density, wound length, upper and lowest instrumented vertebrae level, preoperative Cobb angle, and flexibility of the major curve were assessed using univariate and multivariate linear regression analyses. Independent factors were determined when P-value <0.05.

RESULTS

The mean operation duration was 122.2±28.6 minutes. Significant independent factors affecting operation duration in PSF among Lenke 1 and 2 AIS patients were Lenke 2 subtypes (β=8.86, P=0.008), number of screws (β=7.01, P<0.001), wound length (β=1.14, P=0.009), and flexibility of the major curve (β=-0.25, P=0.005). The overall model fit was R2=0.525. Operation duration can be predicted using the formula: (8.86×Lenke subtypes)+(7.01×number of screws)+(1.14×wound length)-(0.25×flexibility)-0.54, where Lenke 2=1 and Lenke 1=0.

CONCLUSION

The factors affecting operation duration in PSF among Lenke 1 and 2 AIS patients were Lenke 2 curves, number of screws, wound length, and curve flexibility. The knowledge of these factors enables the spinal deformity surgeons to plan and estimate the operation duration before AIS surgery.

The Impact of Surgical Site Infection on Patient Outcomes After Open Posterior Instrumented Thoracolumbar Surgery for Degenerative Disorders

BACKGROUND

Few reports in the literature have described the long-term outcome of postoperative infection from the patient perspective. The aim of the present study was to determine if complicated surgical site infection (SSI) affects functional recovery and surgical outcomes up to 2 years after posterior instrumented thoracolumbar surgery for the treatment of degenerative disorders.

METHODS

This retrospective cohort study involved patients who had been enrolled in a previous randomized controlled trial that examined antibiotic use for open posterior multilevel thoracolumbar or lumbar instrumented fusion procedures. In the present study, patients who had SSI (n = 79) were compared with those who did not (n = 456). Patient-reported outcome measures (PROMs) included the Oswestry Disability Index (ODI), leg and back pain scores on a numeric rating scale, Short Form-12 (SF-12) summary scores, and satisfaction with treatment at 1.5, 3, 6, 12, and 24 months. Surgical outcomes included adverse events, readmissions, and additional surgery.

RESULTS

The median time to infection was 15 days. Of the 535 patients, 31 (5.8%) had complicated infections and 48 (9.0%) had superficial infections. Patients with an infection had a higher body mass index (BMI) (p = 0.001), had more commonly received preoperative vancomycin (p = 0.050), were more likely to have had a revision as the index procedure (p = 0.004), had worse preoperative mental functioning (mental component summary score, 40.7 ± 1.6 versus 44.1 ± 0.6), had more operatively treated levels (p = 0.024), and had a higher rate of additional surgery (p = 0.001). At 6 months after surgery, patients who developed an infection scored worse on the ODI by 5.3 points (95% confidence interval [CI], 0.4 to 10.1 points) and had worse physical functioning by -4.0 points (95% CI, -6.8 to -1.2 points). Comparison between the groups at 1 and 2 years showed no difference in functional outcomes, satisfaction with treatment, or the likelihood of achieving the minimum clinically important difference (MCID) for the ODI.

CONCLUSIONS

SSI more than doubled the post-discharge emergency room visit and additional surgery rates. Patients with SSI initially (6 months) had poorer overall physical function representing the delay to recovery; however, the negative impact resolved by the first postoperative year.

LEVEL OF EVIDENCE

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

Bacterial adhesion on spinal implants: An in vitro study of "hot spots"

Few studies evaluated bacterial colonization of spinal implants from a "topographic" point of view. This lack of knowledge could hinder the development of more effective strategies in the prevention and treatment of postoperative spinal infections. The aim of this in vitro study was the analysis of the adhesion pattern of sessile cells on conventional spinal implants, to identify "hot spots" on implants where bacterial adhesion could be favored. Clinically relevant Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa isolates were grown on commercially available end product spinal implants. To identify sessile cells attached to implant surfaces, confocal laser scan microscopy was used. Different areas from the spinal instrumentations (both Ti and CoCr) were selected for biofilm quantification. Bacterial biofilm was markedly increased in the cut of the rods, both Ti and CoCr, as the uneven surface deriving from the cut might foster cell adhesion. Though not statistically significant, a difference was observed between the rod and the area of the notch, possibly as a consequence of the smoothening effect deriving from the bending of the rod. Finally, the amount of biofilm produced on cobalt-chromium surfaces was always more significant than that formed on titanium surfaces. This study highlights how bacterial adhesion through biofilm formation is favored on the surfaces of higher irregularity and that staphylococci are able to increase sessile biomass on CoCr surfaces. These preliminary results show how surface modifications on the implants may play a key role in bacterial adhesion, opening an exciting field for future research.

Intraoperative blood loss as indicated by haemoglobin trend is a predictor for the development of postoperative spinal implant infection-a matched-pair analysis

Background

With a reported rate of 0.7–20%, postoperative spinal implant infection (PSII) is one of the most common complications after spine surgery. While in arthroplasty both haematoma formation and perioperative blood loss have been identified as risk factors for developing periprosthetic joint infections and preoperative anaemia has been associated with increased complication rates, literature on the aetiology of PSII remains limited.

Methods

We performed a matched-pair analysis of perioperative haemoglobin (Hb) and haematocrit (Hct) levels in aseptic and septic spine revision surgeries. 317 patients were included, 94 of which were classified as septic according to previously defined criteria. Patients were matched according to age, body mass index, diabetes, American Society of Anesthesiologists score and smoking habits. Descriptive summaries for septic and aseptic groups were analysed using Pearson chi-squared for categorical or Student t test for continuous variables.

Results

Fifty patients were matched and did not differ significantly in their reason for revision, mean length of hospital stay, blood transfusion, operating time, or number of levels operated on. While there was no significant difference in preoperative Hb or Hct levels, the mean difference between pre- and postoperative Hb was higher in the septic group (3.45 ± 1.25 vs. 2.82 ± 1.48 g/dL, p = 0.034).

Conclusions

We therefore show that the intraoperative Hb-trend is a predictor for the development of PSII independent of the amount of blood transfusions, operation time, number of spinal levels operated on and hospital length of stay, which is why strategies to reduce intraoperative blood loss in spine surgery need to be further studied.

Risk factors associated with surgical site infections after thoracic or lumbar surgery: a 6-year single centre prospective cohort study

BACKGROUND

Surgical site infection (SSI) is a risk in every operation. Infections negatively impact patient morbidity and mortality and increase financial demands. The aim of this study was to analyse SSI and its risk factors in patients after thoracic or lumbar spine surgery.

METHODS

A six-year single-centre prospective observational cohort study monitored the incidence of SSI in 274 patients who received planned thoracic or lumbar spinal surgery for degenerative disease, trauma, or tumour. They were monitored for up to 30 days postoperatively and again after 1 year. All patients received short antibiotic prophylaxis and stayed in the eight-bed neurointensive care unit (NICU) during the immediate postoperative period. Risk factors for SSI were sought using multivariate logistic regression analysis.

RESULTS

We recorded 22 incidences of SSI (8.03%; superficial 5.84%, deep 1.82%, and organ 0.36%). Comparing patients with and without SSI, there were no differences in age (p=0.374), gender (p=0.545), body mass index (p=0.878), spine diagnosis (p=0.745), number of vertebrae (p=0.786), spine localization (p=0.808), implant use (p=0.428), American Society of Anesthesiologists (ASA) Score (p=0.752), urine catheterization (p=0.423), drainage (p=0.498), corticosteroid use (p=0.409), transfusion (p=0.262), ulcer prophylaxis (p=0.409) and diabetes mellitus (p=0.811). The SSI group had longer NICU stays (p=0.043) and more non-infectious hospital wound complications (p<0.001). SSI risk factors according to our multivariate logistic regression analysis were hospital wound complications (OR 20.40, 95% CI 7.32-56.85, p<0.001) and warm season (OR 2.92, 95% CI 1.03-8.27, p=0.044).

CONCLUSIONS

Contrary to the prevailing literature, our study did not identify corticosteroids, diabetes mellitus, or transfusions as risk factors for the development of SSI. Only wound complications and warm seasons were significantly associated with SSI development according to our multivariate regression analysis.

Pathway for enhanced recovery after spinal surgery-a systematic review of evidence for use of individual components

Background

Enhanced recovery in spinal surgery (ERSS) has shown promising improvements in clinical and economical outcomes. We have proposed an ERSS pathway based on available evidence. We aimed to delineate the clinical efficacy of individual pathway components in ERSS through a systematic narrative review.

Methods

We included systematic reviews and meta-analysis, randomized controlled trials, non-randomized controlled studies, and observational studies in adults and pediatric patients evaluating any one of the 22 pre-defined components. Our primary outcomes included all-cause mortality, morbidity outcomes (e.g., pulmonary, cardiac, renal, surgical complications), patient-reported outcomes and experiences (e.g., pain, quality of care experience), and health services outcomes (e.g., length of stay and costs). Following databases (1990 onwards) were searched: MEDLINE, EMBASE, and Cochrane Library (Cochrane Database of Systematic Reviews and CENTRAL). Two authors screened the citations, full-text articles, and extracted data. A narrative synthesis was provided. We constructed Evidence Profile (EP) tables for each component of the pathway, where appropriate information was available. Due to clinical and methodological heterogeneity, we did not conduct a meta-analyses. GRADE system was used to classify confidence in cumulative evidence for each component of the pathway.

Results

We identified 5423 relevant studies excluding duplicates as relating to the 22 pre-defined components of enhanced recovery in spinal surgery. We included 664 studies in the systematic review. We identified specific evidence within the context of spinal surgery for 14/22 proposed components. Evidence was summarized in EP tables where suitable. We performed thematic synthesis without EP for 6/22 elements. We identified appropriate societal guidelines for the remainder of the components.

Conclusions

We identified the following components with high quality of evidence as per GRADE system: pre-emptive analgesia, peri-operative blood conservation (antifibrinolytic use), surgical site preparation and antibiotic prophylaxis. There was moderate level of evidence for implementation of prehabilitation, minimally invasive surgery, multimodal perioperative analgesia, intravenous lignocaine and ketamine use as well as early mobilization. This review allows for the first formalized evidence-based unified protocol in the field of ERSS.

Further studies validating the multimodal ERSS framework are essential to guide the future evolution of care in patients undergoing spinal surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01281-1.

A Multicenter Trial Demonstrating Presence or Absence of Bacterial Contamination at the Screw-Bone Interface Owing to Absence or Presence of Pedicle Screw Guard, Respectively, During Spinal Fusion

STUDY DESIGN

A prospective multicenter study.

OBJECTIVE

The objective of this study was to assess bacterial contamination in current practices of pedicle screw handling and comparing it to a novel method of using an intraoperative, sterile implant guard for screws.

SUMMARY OF BACKGROUND DATA

Postoperative infections occur at the higher end of 2%-13%, as cited in the literature, and are underestimated due to various reasons in such publications. Despite concerns associated with vancomycin application immediately before closure, it is theoretically impossible to irrigate the screw-bone interface postimplantation. Consequently, any contamination of pedicle screw before implantation is permanent, and has the potential to cause deep-bone infection, or hardware loosening due to encapsulation of biofilm between the bone and the screw. Therefore, continued vigilance and effective preventive measures should be undertaken if available.

MATERIALS AND METHODS

Two groups of presterile individually-packaged pedicle screws, one incased in a sterile, protective guard (group 1: G) and the other without such a guard (group 2: NG), 31 samples in each group were distributed over 28 spinal fusion surgeries at 5 independent hospitals groups. Each were loaded onto the insertion device by the scrub tech and left on the sterile table. Twenty minutes later, the lead surgeon who had just finished preparing the surgical site, handles the pedicle screw, to check the fit with the insertion device. Then, instead of implantation, it was transferred to a sterile container using fresh sterile gloves for bacterial analysis.

RESULTS

The standard unguarded pedicle screws presented bioburden in the range of 10 to 10 colonies forming units per screw, whereas the guarded pedicle screws showed no bioburden.

CONCLUSION

Standard, current, handling of pedicle screws leads to bacterial contamination, which can be avoided if the screws are sterilely prepackaged with an intraoperative guard (preinstalled).

Implant contamination as a cause of surgical site infection in spinal surgery: are single-use implants a reasonable solution? - a systematic review

Background

In spine surgery, surgical site infection (SSI) is one of the main perioperative complications and is associated with a higher patient morbidity and longer patient hospitalization. Most factors associated with SSI are connected with asepsis during the surgical procedure and thus with contamination of implants and instruments used which can be caused by pre- and intraoperative factors. In this systematic review we evaluate the current literature on these causes and discuss possible solutions to avoid implant and instrument contamination.

Methods

A systematic literature search of PubMed addressing implant, instrument and tray contamination in orthopaedic and spinal surgery from 2001 to 2019 was conducted following the PRISMA guidelines. All studies regarding implant and instrument contamination in orthopaedic surgery published in English language were included.

Results

Thirty-five studies were eligible for inclusion and were divided into pre- and intraoperative causes for implant and instrument contamination. Multiple studies showed that reprocessing of medical devices for surgery may be insufficient and lead to surgical site contamination. Regarding intraoperative causes, contamination of gloves and gowns as well as contamination via air are the most striking factors contributing to microbial contamination.

Conclusions

Our systematic literature review shows that multiple factors can lead to instrument or implant contamination. Intraoperative causes of contamination can be avoided by implementing behavior such as changing gloves right before handling an implant and reducing the instruments’ intraoperative exposure to air. In avoidance of preoperative contamination, there still is a lack of convincing evidence for the use of single-use implants in orthopaedic surgery.

Implant Retention or Removal for Management of Surgical Site Infection After Spinal Surgery

STUDY DESIGN

A literature review.

OBJECTIVE

To summarize the implant removal rate, common bacterial organisms found, time of onset, ratio of superficial to deep infection, and regurgitating the prevalence among all the retrospective and prospective studies on management and characterization of surgical site infections (SSIs).

METHODS

PubMed was searched for articles published between 2000 and 2018 on the management or characterization of SSIs after spinal surgery. Only prospective and retrospective studies were included.

RESULTS

A total of 49 articles were found relevant to the objective. These studies highlighted the importance of implant removal to avoid recurrence of SSI. The common organisms detected were methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermis, Staphylococcus epidermis, Staphylococcus aureus, and Propionibacterium acnes, with prevalence of 1% to 15%. A major proportion of all were deep SSI, with minority reporting on late-onset SSI.

CONCLUSION

Long-term antibiotics administration, and continuous irrigation and debridement were common suggestion among the authors; however, the key measure undertaken or implied by most authors to avoid risk of recurrence was removal or replacement of implants for late-onset SSI.

Decompression With or Without Fusion for Lumbar Stenosis: A Cost Minimization Analysis

STUDY DESIGN

Retrospective database review.

OBJECTIVE

Compare 1-year episode of care costs between single-level decompression and decompression plus fusion for lumbar stenosis.

SUMMARY OF BACKGROUND DATA

Lumbar stenosis is the most common indication for surgery in patients over 65. Medicare direct hospital costs for lumbar surgery reached $1.65 billion in 2007. Despite stenosis being a common indication for surgery, there is debate as to the preferred surgical treatment. Cost-minimization analysis is a framework that identifies potential cost savings between treatment options that have similar outcomes. We performed a cost-minimization analysis of decompression versus decompression with fusion for lumbar stenosis from the payer perspective.

METHODS

An administrative claims database of privately insured patients (Humana) identified patients who underwent decompression (n = 5349) or decompression with fusion (n = 8540) for lumbar stenosis with and without spondylolisthesis and compared overall costs. All patients were identified and costs identified for a 1-year period. Complication rates and costs were described using summary statistics.

RESULTS

Mean treatment costs at 1 year after surgery were higher for patients who underwent decompression and fusion compared to patients who underwent decompression alone ($20,892 for fusion vs. $6329 for decompression; P < 0.001). Facility costs (P < 0.001), surgeon costs (P < 0.001), and physical therapy costs (P < 0.001) were higher in the fusion group. Cost differences related to infection or durotomy reached significance (P < 0.04). No difference in cost was identified for supplies.

CONCLUSION

Decompression had significantly lower costs for the treatment of lumbar stenosis, including treatment for postoperative complications. If cost minimization is the primary goal, decompression is favored for surgical treatment of lumbar stenosis. Other factors including shared decision-making directed toward patient's values, patient-reported outcomes, and preferences should also be recognized as drivers of healthcare decisions.

LEVEL OF EVIDENCE

3.

Updates on Evidence-Based Practices to Reduce Preoperative and Intraoperative Contamination of Implants in Spine Surgery: A Narrative Review

The current communication seeks to provide an updated narrative review on latest methods of reducing implant contaminations used during spine surgery. Recent literature review has shown that both preoperative reprocessing and intraoperative handling of implants seem to contaminate implants. In brief, during preoperative phase, the implants undergo repeated bulk cleaning with dirty instruments from the OR, leading to residue buildup at the interfaces and possibly on the surfaces too. This, due to its concealed nature, remains unnoticed by the SPD (sterile processing department) or other hospital staff. Nevertheless, these can be avoided by using individually prepackaged presterilized implants. In the intraoperative phase, the implants (in the sterile field) are directly touched by the scrub tech with soiled (assisting the surgeon dispose the tissues from the instruments in use) gloves for loading onto an insertion device. It is then kept exposed on the working table (either separately or next to the used instruments as the pedicles hole are being prepared). Latest investigation has shown that by the time it is implanted in the patient, it can harbor up to 10e7 bacterial colony-forming units. The same implants were devoid of such colony-forming units, when sheathed by an impermeable sterile sheath around the sterile implant.

Outcomes of an Intraoperative Povidone-Iodine Irrigation Protocol in Spinal Surgery for Surgical Site Infection Prevention

STUDY DESIGN

This was a retrospective observational study.

OBJECTIVE

The aim of this study was to evaluate the efficacy of our new protocol for preventing postoperative surgical site infection (SSI) following spinal surgery.

SUMMARY OF BACKGROUND DATA

SSI following spinal surgery is a serious postoperative complication. Several studies have recently assessed the effectiveness of wound irrigation with povidone-iodine (PVP-I) for SSI prevention, but no consensus has been reached as to how PVP-I should be used in clinical practice. We formed a PVP-I irrigation protocol focusing on the pharmacological properties of PVP-I. This study aimed to evaluate the efficacy and safety of our protocol for preventing SSI.

MATERIALS AND METHODS

All cases of spinal surgery at our hospital between October 2011 and September 2016 were retrospectively reviewed. The exclusion criteria were PVP-I allergy, prior surgical debridement for infection, and implant removal surgery. The patients were subdivided into those who had received normal saline irrigation after 90 seconds of 1% PVP-I pooling every 1.5 hours (study group) or only routine saline irrigation every 1.5 hours (control group). The study and control groups comprised of 177 and 146 patients, respectively. This study compared the rate of SSI with and without the use of the PVP-I irrigation protocol.

RESULTS

The SSI rates were 1.7% for the study group (3/177 patients) and 3.4% for the control group (5/146 patients), showing no significant statistical difference (P=0.32). There were no cases of deep SSI in the study group, whereas there were 4 cases in the control group. The deep SSI rate significantly decreased in the study group (P=0.027). No adverse events occurred in the study group.

CONCLUSION

In this study, 90 seconds of 1% PVP-I pooling every 1.5 hours followed by saline irrigation demonstrated the effectiveness of our protocol for the prevention of postoperative deep SSI after spinal surgery.

The Effect of Prolonged Postoperative Antibiotic Administration on the Rate of Infection in Patients Undergoing Posterior Spinal Surgery Requiring a Closed-Suction Drain: A Randomized Controlled Trial

BACKGROUND

Closed-suction drains are frequently used following posterior spinal surgery. The optimal timing of antibiotic discontinuation in this population may influence infection risk, but there is a paucity of evidence. The aim of this study was to determine whether postoperative antibiotic administration for 72 hours (24 hours after drain removal as drains were removed on the second postoperative day) decreases the incidence of surgical site infection compared with postoperative antibiotic administration for 24 hours.

METHODS

Patients undergoing posterior thoracolumbar spinal surgery managed with a closed-suction drain were prospectively randomized into 1 of 2 groups of postoperative antibiotic durations: (1) 24 hours, or (2) 24 hours after drain removal (72 hours). Drains were discontinued on the second postoperative day. The duration of antibiotic administration was not blinded. All subjects received a single dose of preoperative antibiotics, as well as intraoperative antibiotics if the surgical procedure lasted >4 hours. The primary outcome was the rate of complicated surgical site infection (deep or organ or space) within 1 year of the surgical procedure.

RESULTS

The trial was terminated at an interim analysis, when 552 patients were enrolled, for futility with respect to the primary outcome. In this study, 282 patients were randomized to postoperative antibiotics for 24 hours and 270 patients were randomized to postoperative antibiotics for 72 hours. A complicated infection developed in 17 patients (6.0%) in the 24-hour group and in 14 patients (5.2%) in the 72-hour group (p = 0.714). The superficial infection rate did not differ between the groups (p = 0.654): 9.6% in the 24-hour group compared with 8.1% in the 72-hour group. Patients in the 72-hour group had a median hospital stay that was 1 day longer (p < 0.001). At 1 year, patient-rated outcomes including leg and back pain and physical and mental functioning were not different between the groups.

CONCLUSIONS

The extension of postoperative antibiotics for 72 hours, when a closed-suction drain is required, was not associated with a reduction in the rate of complicated surgical site infection after posterior thoracolumbar spinal surgery.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of Levels of Evidence.

Harboring Contaminants in Repeatedly Reprocessed Pedicle Screws

STUDY DESIGN

It consisted of evaluation of the pedicle screws for presence of residual nonmicrobial contaminants and tabulation of the minimum steps and time required for reprocessing implants as per guidelines and its comparison with actual practice.

OBJECTIVE

An evaluation of the nonmicrobial contaminants prevalent on the pedicle screws used for spine surgery and the underlying practice cause behind the source.

METHODS

The first component consisted of a random selection of 6 pedicle screws and its assessment using optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. The second component consisted of review of implant reprocessing guidelines and its applicability.

RESULTS

Three types of contaminants were identified: corrosion, saccharide of unknown origin, and soap residue mixed with and were mostly present at the interfaces with low permeability. In addition, manufacturer's guideline recommends 19 hours of reprocessing, whereas the real-time observation revealed a turnaround time of 1 hour 17 minutes.

CONCLUSION

Repeatedly reprocessed pedicle screws host corrosion, carbohydrate, fat, and soap, which could be a cause of surgical site infection and inflammatory responses postsurgery. The cause behind it is the impracticality of repeated cleaning and inspection of such devices.

Efficacy of Intraoperative Implant Prophylaxis in Reducing Intraoperative Microbial Contamination

STUDY DESIGN

A prospective single-center study.

OBJECTIVES

Assess to what degree contamination of pedicle screws occur in standard intraoperative practice and if use of an impermeable guard could mitigate or reduce such an occurrence.

METHODS

Two groups of sterile prepackaged pedicle screws, one with an intraoperative guard (group 1) and the other without such a guard (group 2), each consisting of 5 samples distributed over 3 time points, were loaded onto the insertion device by the scrub tech and left on the sterile table. Approximately 20 minutes later, the lead surgeon who had just finished preparing the surgical site touches the pedicle screw. Then instead of implantation it was transferred to a sterile container using fresh clean gloves for bacterial and gene analysis. Guarded screw implies that even after unwrapping from the package, the screw carries an impermeable barrier along its entire length, which is only removed seconds prior to implantation.

RESULTS

The standard unguarded pedicle screws presented bioburden in the range of 10⁵ to 10⁷ (colony forming units/implant) with bacterial genus mostly consisting of Staphylococcus and Micrococcus, the 2 most common genera found in surgical site infection reports. The common species among them were Staphylococcus epidermis, Staphylococcus aureus, Micrococcus luteus, and Staphylococcus pettenkoferi, whereas the guarded pedicle screws showed no bioburden.

CONCLUSIONS

Shielding the pedicle screws intraoperatively using a guard provides a superior level of asepsis than currently practiced. All unshielded pedicles screws were carrying bioburden of virulent bacterial species, which provides an opportunity for the development of postoperative infections.

Implant Prophylaxis: The Next Best Practice Toward Asepsis in Spine Surgery

STUDY DESIGN

A literature review.

OBJECTIVES

An evaluation of the contaminants prevalent on implants used for surgery and the aseptic methods being employed against them.

METHODS

PubMed was searched for articles published between 2000 and 2017 for studies evaluating the contaminants present on spine implants, and associated pre- and intraoperative implant processing and handling methodology suggested to avoid them. Systematic reviews, observational studies, bench-top studies, and expert opinions were included.

RESULTS

Eleven studies were identified whose major focus was the asepsis of implants to reduce the incidence of surgical site infection incidences during surgery. These studies measured the colony forming units of bacteria on sterilized implants and/or gloves from the surgeon, scrub nurse, and assistants, as well as reductions of surgical site infection rates in spine surgery due to changes in implant handling techniques. Additionally, the search included assessments of endotoxins and carbohydrates present on reprocessed implants. The suggested changes to surgical practice based on these studies included handling implants with only fresh gloves, keeping implants covered until the immediate time of use, reducing operating room traffic, avoiding reprocessing of implants (ie, providing terminally sterilized implants), and avoiding touching the implants altogether.

CONCLUSIONS

Both reprocessing (preoperative) and handling (intraoperative) of implants seem to lead to contamination of sterilized implants. Using a terminally sterilized device may mitigate reprocessing (preoperative implant prophylaxis), whereas the use of fresh gloves for handling each implant and/or a permanent shielding technique (intraoperative implant prophylaxis) could potentially avoid recontamination at the theatre.

A Paradigm Shift Toward Terminally Sterilized Devices

Given the complexity of the sterilization process, and the risk involved in absence of strict adherence to the protocol described by the medical device manufacturers, terminally sterilized devices are emerging and being promoted in the field of medical practices. The characteristics associated with conventional reprocessing are demanding logistics, costs of delay, operations and adverse events, and unacceptable liability. Demanding logistics were a result of decoupled staff between the operating room and sterilize processing department, understaffed and high-volume processing with an additional burden due to inventory management and inefficient training. Other costs arose from upkeep, delay in operating room, and surgical-site infections. Liability arose from the repeatedly use of an unquantifiable process thus adding uncertainties, limited shelf life of the reprocessed implants, contingency of flash sterilization and introduction of newer technology with higher demand on cleaning performances. In contrast, terminally sterilized single-use devices do not carry any of the aforementioned-characteristics, deeming it to be the simplest solution to the current conundrum. This review serves to provide an evaluation of logistics, costs, and potential adverse effects, both directly and indirectly, associated with current practices in the sterile processing department, and also describes as to how the use of terminally sterilized devices can help circumvent those.

Defining the "Critical Elements" for the Most Common Procedures in Spine Surgery: A Consensus of Orthopedic and Neurosurgical Surgeons

STUDY DESIGN

Survey.

OBJECTIVE

To define the critical elements of common spine surgeries.

SUMMARY OF BACKGROUND DATA

Despite significant relevance to the field of spine surgery, the term "critical element" of surgery has not been clearly defined. Every surgical procedure involves numerous steps, each with its own potential for complications and harm to the patient. Despite its crucial role in surgical training, billing, and the ethicality of concurrent surgery, the term "critical element" of surgery has not been defined.

METHODS

A survey was administered to surgeons associated with AO Spine North America and the Society for Minimally Invasive Spine Surgery to determine the critical elements for four common spine procedures: open lumbar laminectomy and fusion, microdiscectomy, anterior cervical discectomy and fusion (ACDF), and posterior cervical laminectomy and fusion. Respondents were asked which steps necessitated their direct supervision. Surgical subspecialty, level of experience, and practice demographics were also recorded.

RESULTS

For all applicable procedures, decompression, instrumentation, and fusion were designated as critical elements. Patient positioning and fascial closure were not. Radiographic localization was considered critical for all procedures, except posterior cervical laminectomy and fusion. Exposure was not considered critical for any procedures, except ACDF. Certain substeps of decompression in ACDF and open lumbar laminectomy and fusion were not considered critical. Orthopaedic surgeons considered exposure and fusion in ACDF procedures to be critical whereas neurosurgeons did not. Surgeons operating in private practice considered every step of these common procedures to be critical elements.

CONCLUSION

Decompression, instrumentation, and fusion were considered critical elements of common spine surgeries. There were significant differences in responses according to surgical specialty and practice setting. Future research is necessary to determine the implications of these findings and guide the definition of the "critical portions" of surgery.

LEVEL OF EVIDENCE

1.

Relationship between preoperative serum rapid turnover proteins and early-stage surgical wound infection after spine surgery

PURPOSE

Malnutrition is one of the important risk factors for postoperative complications. Transferrin, prealbumin, and retinol-binding protein, so-called rapid turnover proteins (RTPs), may be the better indicators for early detection of nutritional deficits. However, few studies have described the impact of serum RTP levels on postoperative surgical site infection (SSI) in spine surgery. The purpose of this study was to investigate the relationship between preoperative serum RTPs and postoperative SSI.

METHODS

The data of 105 patients (64 male, 41 female; average age 64.4 years; age range 20-88 years) who underwent spine surgery in a single institution between 2014 and 2015 were retrospectively analyzed. Preoperative total lymphocyte count, serum albumin, transferrin, prealbumin, retinol-binding protein, pre-and postopeartive C-reactive protein (CRP), white blood cell count (WBC), and total lymphocyte count were evaluated. Postoperative CRP, WBC, and total lymphocyte count were repeated two or three times/week until hospital discharge. A broad spectrum penicillin or second generation cephalosporin was administered as a prophylactic antibiotic to each patient. When repeated CRP elevation or lymphopenia (no more than 10% or 1000/μL) after postoperative day 3 or 4 was observed, possible SSI was diagnosed. Variables between possible SSI group and non-SSI group were compared using Mann-Whitney U or Chi square test. All variables on univariate analysis were included in multiple logistic regression analysis to identify risk factors for possible postoperative SSI.

RESULTS

Thirty-five patients were diagnosed with possible SSI. The mean operative time of possible SSI group was significantly longer (p = 0.036), preoperative total lymphocyte count and serum prealbumin level of possible SSI group were significantly lower (p = 0.002, p = 0.048, respectively) than that of non-SSI group. On univariate analysis, operative time (p = 0.012), preoperative total lymphocyte count (p = 0.041), serum albumin level (p = 0.038), and serum prealbumin level (p = 0.044) were significant contributors to possible SSI, and multiple logistic regression analysis revealed that operative time was the significant contributor to possible SSI (odds ratio 1.008, 95% confidence interval (CI) 1.001-1.015, p = 0.024).

CONCLUSIONS

A low prealbumin level is a possible risk factor for early-stage SSI in spine surgery, though it was not statistically significant; operative time was the most important indicator of SSI on multivariate analysis.