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

Vancomycin Antibiotic Prophylaxis Compared to Cefazolin Increases Risk of Surgical Site Infection Following Spine Surgery

Study DesignRetrospective analysis of randomized controlled trial.ObjectivesSurgical site infection (SSI) after spine surgery has severe negative health and financial consequences. Surgical antibiotic prophylaxis (SAP) is a routinely used method to prevent SSIs in the spine patient population. The most commonly used antibiotic is cefazolin, with vancomycin often being substituted in the case of penicillin or cephalosporin allergy. Vancomycin as SAP has been associated with increased SSI in the joint replacement literature, but this is not yet well defined in the spinal surgery population. The purpose of this study was to determine whether vancomycin SAP compared to cefazolin SAP is associated with increased risk of SSI.Methods535 patients, aged 16 years or older, underwent elective multi-level open posterior spinal fusion surgery at the thoracic, thoracolumbar, or lumbar levels. Demographic and operative characteristics as well as post-operative outcomes were compared between the following groups: (1) noninfected-cefazolin, (2) noninfected-vancomycin, (3) infected-cefazolin, and (4) infected-vancomycin. Primary outcomes were superficial and complicated (deep and organ/space) infections.ResultsThe following risk factors for SSI were identified in a logistic regression analysis: vancomycin (OR 2.498, 95% CI, 1.085-5.73, P = 0.031), increasing operating time (OR 1.006, 95% CI, 1.001-1.010 P = 0.010), weight (OR 1.020, 95% CI 1.006-1.034, P = 0.005), revision procedure (OR 2.343, 95% CI 1.283-4.277, P = 0.006), and depression (OR 2.366, 95% CI 1.284-4.360, P = 0.006).ConclusionsIn open posterior approach spinal fusion surgery, vancomycin SAP is associated with increased risk of infection compared to cefazolin SAP.

Vancomycin powder mixed with autogenous bone graft and bone substitute may decrease the deep surgical site infections in elective lumbar instrumented fusion surgery for degenerative disorders: a prospective randomized study

BACKGROUND CONTEXT

Deep surgical site infections (DSSI) following lumbar instrumented fusion surgery are associated with considerable morbidity. Intraoperative application of vancomycin powder (VP) has been widely used to prevent DSSI; however, the effects of VP mixed with local autogenous bone graft (ABG) and bone substitute on DSSI prevention and bone fusion remains unclear.

PURPOSE

To examine the effects of VP mixed with ABG and bone substitute on DSSI and fusion rate.

STUDY DESIGN/SETTING

A prospective randomized case-controlled study at a single medical center. (ClinicalTrials.gov Identifier: NCT03883022) PATIENTS' SAMPLE: Adult patients who underwent decompression along with instrumented fusion surgery for a degenerative lumbar condition were recruited from October 2017 to May 2023. Patients were randomly allocated to vancomycin (n=357) or control (without vancomycin) (n=348) groups. In the vancomycin group, 1 g of antibiotic powder was used for 2- and 3-level fusions (no 1 level fusions?) while 2 g was used for >3-level.

OUTCOMES MEASURES

The primary outcome was DSSI within 90 days after index surgery. Secondary outcomes included surgical and vancomycin-related complications, functional outcomes and bone fusion.

METHODS

All patients were followed up with plain spine radiographs at 1, 2, 3, 6, and 12 months after surgery. The definition of DSSI was based on the Centers for Disease Control and Prevention criteria for SSI. Posterolateral fusion was assessed using the Lenke criteria and interbody fusion was assessed using the Brantigan-Steffee-Fraser (BSF) definition. Solid fusion was defined as an angular change of <5° of the fused segments in supine dynamic flexion and extension lateral radiographs, Lenke grade A and B or BSF-3 definition. Antibiotic concentrations in the vancomycin group were measured in the serum and at the surgical site in the drain on days 1 and 3 after the index surgery. Functional outcomes were evaluated by Oswestry Disability Index (ODI) and visual analog scale (VAS) for leg pain.

RESULTS

In total, 357 and 348 patients were enrolled in the vancomycin and control groups, respectively. Mean patient age was 67.7±11.0 years and 63.0% were female. There were no DSSIs in the vancomycin group and five in the control group (0 vs. 1.4%, p=.029). All five patients with DSSI had diabetes (100%). None of the patients with diabetes in the vancomycin group developed DSSI (0/119 vs. 5/105 in control group, p=.021). Postoperative serum vancomycin levels were undetectable and no vancomycin-related complications were observed. The mean vancomycin concentrations at surgical site in the drain were 524.5±209.9 μg/mL and 217.4±97.2 μg/mL on postoperative days 1 and 3, respectively (measured in a drain?). At the final follow-up, functional outcomes and bone fusion rates were similar between the two groups. Solid posterolateral fusion (Lenke grade A or B) was observed in 79.3% (257/324) of the vancomycin group and 73.5% (233/317) of the control group (p=0.348). Interbody fusion, based on the BSF-3 definition, was observed in 99.4% (326/328) of cages in the vancomycin group and 99.6% (258/259) in the control group (p=1.000). Based on the criteria of angular change of < 5° on dynamic lateral radiographs, the solid fusion rate was 100% in both groups.

CONCLUSIONS

Vancomycin mixed with local ABG and bone substitute maintains high vancomycin level at surgical site and appears safe and effective for preventing DSSI in lumbar degenerative instrumented fusion surgery without affecting bony fusion, especially in diabetic patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03883022.

Viable approach for preventing skin wound infections using bioactive dressing films from chitosan-furfural/α-aminophosphonate nanocomposite

Bioactive chitosan (Cs)-based films containing newly synthesized chitosan-furfural aminophosphonate (F) or chitosan-hydroxymethyl furfural aminophosphonate (HMF) derivatives have been investigated as potential wound dressing material. The chemical structure of the two derivatives was monitored by observing the absorption peaks of P-O-C bonds on the FTIR chart at 883 and 802 cm-1 for F and HMF, respectively. To improve the bioavailability and bio-absorbability, F and HMF nanoemulsions were prepared and loaded separately with three different concentrations (6, 12, and 18 mL) to chitosan solution for obtaining F-loaded Cs films (CsF1, CsF2, and CsF3) and HMF-loaded Cs films (Cs-HMF1, Cs-HMF2, and Cs-HMF3). The F- and HMF-loaded Cs films were investigated via FTIR, XRD, TGA-DTG, SEM-EDX, contact angle, mechanical, and swelling behavior. CsF3 and Cs-HMF3 films (that contain highest concentration of F and HMF nanoemulsion) exhibited optimal texture properties e.g. tensile strength was 8.82 and 8.92 MPa, and swelling ratio was 53.55 and 57.7 % respectively. The films were tested against pathogenic bacteria as a model for skin-causing bacterial infection. The findings signified those films containing F or HMF exhibited larger inhibition zones than bare Cs films. The films exhibited excellent antibacterial activity against skin-infecting pathogens. In addition, Cs-HMF3 films showed exceptional antibiofilm activity against all tested bacterial strains, including multidrug-resistant pathogens. Biocompatibility assessments confirmed the safety and non-toxicity of the films, making them suitable for wound dressings. These findings highlight the potential of F and HMF-modified chitosan films as advanced wound dressing materials with enhanced mechanical properties, antibacterial efficacy, and biocompatibility, offering a promising solution for managing bacterial infections in wound care.

Surgical site infection following isolated lumbar discectomy increases odds of revision lumbar surgery within first 6 months, but not beyond

BACKGROUND CONTEXT

Lumbar discectomy is a commonly performed surgery following which surgical site infection (SSI) may occur. Prior literature has suggested that, following SSI related to lumbar fusion, the rate of subsequent lumbar surgeries is increased over prolonged periods of time. This has not been studied specifically for lumbar discectomy.

PURPOSE

To define factors associated with SSI following lumbar discectomy and determine if subsequently matched cohorts with and without SSI have differential rates of subsequent lumbar surgery beyond irrigation and debridement (I&Ds) over time.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Adult patients undergoing isolated primary lumbar laminotomy/discectomy were identified from the 2010-2021 M157 PearlDiver database. Exclusion criteria included: age<18 years, preoperative diagnosis of infection, neoplastic, or traumatic diagnoses within 90 days prior to index surgery, additional spinal surgeries on the same day as lumbar discectomy, and not being active in the database for at least 90 days postoperative. From this study population, those who developed SSI were identified based on undergoing I&D within 90 days after surgery. Those with versus without SSI were then matched 1:4 based on age, sex, Elixhauser Comorbidity Index (ECI), and obesity.

OUTCOME MEASURES

Following initial I&D, incidence of revision lumbar surgery (revision lumbar discectomy, lumbar laminectomy, lumbar fusion) out to 5 years after lumbar discectomy.

METHODS

Following index isolated lumbar discectomy, those with versus without SSI requiring I&D were matched and compared for incidence of secondary surgery in defined time intervals (0-6 months, 6-12 months, 1-2 years, 2-5 years) using multivariable logistic regression, controlling for patient age, sex, ECI, and obesity status.

RESULTS

Of 323,025 isolated lumbar discectomy patients, SSI requiring I&D was identified for 583 (0.18%). Multivariable analysis revealed several independent predictors of these SSIs: younger age (odds ratio [OR] 0.85 per decade increase), ECI (OR 1.22 per 2-point increase), and obesity (OR 1.30). Following matching of those with versus without SSI requiring I&D, rates of subsequent surgery beyond I&D were compared. Those with SSI had significantly increased odds of lumbar revision in the first six months (OR 5.26, p<.001), but not 6-12 months (p=.462), 1-2 years (p=.515), or 2-5 years (p=.677).

CONCLUSIONS

Overall, SSI requiring I&D is a rare postoperative complication following lumbar discectomy. If occurring, subsequent surgery beyond I&D was higher in the first 6 months, but then not increased at subsequent time points out to five years.

Impact of unplanned readmissions on lumbar surgery outcomes: a national study of 33,447 patients

BACKGROUND CONTEXT

Unplanned readmissions following lumbar spine surgery have immense clinical and financial implications. However, little is known regarding the impact of unplanned readmissions on patient-reported outcomes (PROs) following lumbar spine surgery.

PURPOSE

To evaluate the impact of unplanned readmissions, including specific readmission reasons, on patient reported outcomes 12 months after lumbar spine surgery.

STUDY DESIGN/SETTING

A retrospective cohort study of prospectively collected data was conducted using patients included in the lumbar module of the Quality and Outcomes Database (QOD), a national, multicenter spine registry.

PATIENT SAMPLE

A total of 33,447 patients who underwent elective lumbar spine surgery for degenerative diseases were included. Mean age was 59.8 (SD=14.04), 53.6% were male, 89.5% were white, 45.9% were employed, and 47.5% had private insurance.

OUTCOME MEASURES

Unplanned 90-day readmissions and 12-month patient-reported outcomes (PROs) including numeric rating scale (NRS) scores for back and leg pain, Oswestry Disability Index (ODI) scores, EuroQol-5 Dimension (EQ-5D) scores, and North American Spine Society (NASS) patient-satisfaction scores.

METHODS

The lumbar module of the QOD was queried for adults undergoing elective lumbar spine surgery for degenerative disease. Unplanned 90-day readmissions were classified into 4 groups: medical, surgical, pain-only, and no readmissions. Medical and surgical readmissions were further categorized into primary reason for readmission. 12-month PROs assessing patient back and leg pain (NRS), disability (ODI), quality of life (EQ-5D), and patient satisfaction were collected. Multivariable models predicting 12-month PROs were built controlling for covariates.

RESULTS

A total of 31,430 patients (94%) had no unplanned readmission while 2,017 patients (6%) had an unplanned readmission within 90 days following lumbar surgery. Patients with readmissions had significantly worse 12-month PROs compared with those with no unplanned readmissions in covariate-adjusted models. Using Wald-df as a measure of predictor importance, surgical readmissions were associated with the worst 12-month outcomes, followed by pain-only, then medical readmissions. In separate covariate adjusted models, we found that readmissions for pain, SSI/wound dehiscence, and revisions were among the most important predictors of worse outcomes at 12-months.

CONCLUSIONS

Unplanned 90-day readmissions were associated with worse pain, disability, quality of life, and greater dissatisfaction at 12-months, with surgical readmissions having the greatest impact, followed by pain-only readmissions, then medical readmissions. Readmissions for pain, SSI/wound dehiscence, and revisions were the most important predictors of worse outcomes. These results may help providers better understand the factors that impact outcomes following lumbar spine surgery and promote improved patient counseling and perioperative management.

From drugs to biomaterials: a review of emerging therapeutic strategies for intervertebral disc inflammation

Chronic low back pain (LBP) is an increasingly prevalent issue, especially among aging populations. A major underlying cause of LBP is intervertebral disc degeneration (IDD), often triggered by intervertebral disc (IVD) inflammation. Inflammation of the IVD is divided into Septic and Aseptic inflammation. Conservative therapy and surgical treatment often fail to address the root cause of IDD. Recent advances in the treatment of IVD infection and inflammation range from antibiotics and small-molecule drugs to cellular therapies, biological agents, and innovative biomaterials. This review sheds light on the complex mechanisms of IVD inflammation and physiological and biochemical processes of IDD. Furthermore, it provides an overview of recent research developments in this area, intending to identify novel therapeutic targets and guide future clinical strategies for effectively treating IVD-related conditions.

Healthcare Cost and Outcomes Associated With Surgical Site Infection and Patient Outcomes in Low- and Middle-Income Countries

Surgical site infection (SSI) is a growing global concern. The principal explanation for this is its adverse clinical outcomes, such as morbidity and mortality. However, the link between the economic burden of SSIs and patient outcomes needs to be sufficiently characterized. This review aims to describe the financial implications of SSIs on patient outcomes in low- and middle-income countries (LMIC). Despite the heterogeneity in study designs from multiple LMIC countries, there is a significant correlation between SSI-associated healthcare costs from increased length of stay (LOS), readmissions, reoperations, and adverse patient outcomes. This varies based on the size, degree of infection, or other patient comorbidities. SSIs are much more prevalent in LMICs. The additional financial burden incurred in managing SSIs reinforces the need to prioritize practicing interventions to prevent this complication, which resource-limited health institutions are unequipped to do and consequently have significant adverse patient outcomes.

Surgical site infection in thoracic and lumbar fractures: incidence and risk factors in 11,401 patients from a nationwide administrative database

BACKGROUND CONTEXT

The rate of surgical site infection (SSI) following elective spine surgery ranges from 0.5%‒10%. Published reports suggest a higher SSI rate in non-elective spine surgery such as spine trauma; however, there is a paucity of large database studies examining this issue.

PURPOSE

The objective of this study was to investigate the incidence and risk factors of SSI in patients undergoing spine surgery for thoracic and lumbar fractures in a large population database.

STUDY DESIGN/SETTING

This is a retrospective study utilizing the PearlDiver Patient Claims Database.

PATIENT SAMPLE

Patients undergoing spine surgery for thoracic and lumbar fractures between 2015-2020 were identified in the PearlDiver Patient Claims Database using ICD-10 codes. Patients were excluded who had another surgery either 14 days before or 21 days after the index spine surgery, or pathologic fracture.

OUTCOME MEASURES

Rate of surgical site infection.

METHODS

Clinical data collected from the PearlDiver database based on ICD-10 codes included gender, age, diabetes, smoking status, obesity, Elixhauser Comorbidity Index (ECI), Charlson Comorbidity Index (CCI), and SSI. Univariate analysis was used to assess the association of potential risk factors and SSI. Multivariable analysis was used to identify independent risk factors of SSI. The authors have no conflicts of interest or funding sources to declare.

RESULTS

A total of 11,401 patients undergoing spine surgery for thoracic and lumbar fractures met inclusion criteria, and 1,065 patients were excluded. 860 patients developed SSI (7.5%). Risk factors significantly associated with SSI in univariate analysis included diabetes (OR 1.50; 95% CI, 1.30‒1.73; p<.001), obesity (OR 1.66; 95% CI, 1.44‒1.92; p<.001), increased age (p<.001), ECI (p<.001), and CCI (p<.001). On multivariable analysis, obesity and ECI were independently associated with SSI (p<.001 and p<.001, respectively).

CONCLUSIONS

Non-elective surgery for thoracic and lumbar fractures is associated with a 7.5% risk of SSI. Obesity and ECI are independent predictors of SSI in this population. Limitations include the reliance on accurate insurance coding which may not fully capture all SSI, and in particular superficial SSI. These findings provide a broad overview of the risk of SSI in this population at a national level and may also help counsel patients regarding risk.

Clinical relevance of occult infections in spinal pseudarthrosis revision

Background

Occult infections in spinal pseudarthrosis revisions have been reported in the literature, but the relevance of such an infection on patient outcomes is unknown. We aimed to elucidate clinical outcomes and re-revision risks between patients with and without occult infections in spinal revision surgery for pseudarthrosis.

Methods

In this matched case-control study, we identified 128 patients who underwent thoracolumbar revision surgery from 2014–2019 for pseudarthrosis of the spine. Among them, 13 (10.2%) revealed an occult infection (defined by at least two positive intraoperative tissue samples with the same pathogen), and nine of these 13 were available for follow-up. We selected 18 of the 115 controls using a 2:1 fuzzy matching based on fusion length and length of follow-up. The patients were followed up to assess subsequent re-revision surgeries and the following postoperative patient-reported outcome measures (PROMs): overall satisfaction, Oswestry Disability Index, 5-level EQ-5D, and Short Form 36.

Results

Patient characteristics, surgical data, and length of follow-up were equal between both study groups. The rate of re-revision free survival after the initial pseudarthrosis revision surgery was higher in the occult infection group (77.8%) than the non-infectious controls (44.4%), although not significantly (0.22). The total number of re-revision surgeries, including re-re-revisions, was thirteen (in ten patients) in the control and two (in two patients) in the occult infection group (p = 0.08) after a median follow-up of 24 months (range 13-75). Four cases in the control group underwent re-revision for pseudarthrosis compared to none in the infected group. Satisfactory scores were recorded in all PROMs, with similar scores between the two groups.

Conclusions

The presence of an occult infection accompanying spinal pseudarthrosis revision was not inferior to non-infected pseudarthrosis revisions in a matched, small sample size cohort study. This may be explained due to the possibility of targeted treatment of the identified cause of pseudarthrosis.

Does local vancomycin powder impregnated with autogenous bone graft and bone substitute decrease the risk of deep surgical site infection in degenerative lumbar spine fusion surgery?—An ambispective study

Background

Deep surgical site infection (DSSI) is one of the most challenging complications in lumbar fusion surgery. Few investigations examined the effect of vancomycin powder mixed with autogenic bone graft (ABG) and bone substitutes on preventing DSSI in degenerative lumbar fusion surgeries as well as any interference with bony fusion. The aim of the study was to investigate the effects of ABG along with bone substitutes as a local vancomycin delivery system on preventing DSSI in lumbar instrumented fusion and compared with those who did not use vancomycin powder.

Methods

From January, 2015 through December, 2015, a one-year prospective study using vancomycin powder mixed with ABG and bone substitute for degenerative lumbar fusion surgeries as vancomycin (V) group, 1 gm vancomycin for 2 and 3-level, and 2 gm for more than 3-level instrumentation. From December, 2013 through December 2014, patients received degenerative lumbar fusion surgeries without using vancomycin before the vancomycin protocol were retrospectively enrolled as non-vancomycin (NV) group. Vancomycin concentration was checked at post-operative days 1 and 3 for both the serum and drainage. Patients’ demographic data, microbiology reports, fusion status and functional outcomes were evaluated.

Results

One hundred and ten patients were enrolled prospectively in the V group, and 86 for the NV group. After an average 41 months follow-up (range, 36–54), 3 patients (3.48%) developed postoperative DSSIs in the NV group, thereby requiring revision surgeries and parenteral antibiotics treatment versus no DSSIs (0%, 0/100) in the V group. (p = 0.048). The postoperative serum vancomycin levels were undetectable and no vancomycin related side effects was encountered. The mean vancomycin concentration of drainage at postoperative days 1 and 3 were 517.96 ± 174.4 and 220.14 ± 102.3 μg/mL, respectively. At final follow-up, there was no statistical difference observed in terms of clinical and radiologic outcomes.

Conclusions

Our vancomycin protocol may reduce the incidence of DSSI in degenerative lumbar fusion surgery without affecting bony fusion.

Level of Evidence

Level III ambispective comparative study.

Difficulties, Challenges, and the Learning Curve of Avoiding Complications in Lumbar Endoscopic Spine Surgery

Spinal endoscopy has the stigma of being reserved for only a few surgeons who can figure out how to master the steep learning curve and develop clinical practice settings where endoscopic spine surgery can thrive. In essence, endoscopic treatment of herniated discs specifically and nerve root compression in the lumbar spine in general amounts to replacing traditional open spine surgery protocols with spinal endoscopic surgery techniques. In doing so, the endoscopic spine surgeon must be confident that the degenerative spine's common painful problems can be handled with endoscopic spinal surgery techniques with at least comparable clinical results and complication rates. In this review article, the authors illustrate the difficulties and challenges of the endoscopic lumbar decompression procedure. In addition, they shed light on how to master the learning curve by systematically looking at all sides of the problem, ranging from the ergonomic aspects of the endoscopic platform and its instruments, surgical access planning, challenging clinical scenarios, complications, and sequelae, as well as the training gaps after postgraduate residency and fellowship programs.