Surgical site infection rates after minimally invasive spinal surgery

Single-Level Unilateral Biportal Endoscopic versus Tubular Microdiscectomy: Comparing Surgical Outcomes and Opioid Consumption

BACKGROUND

Unilateral biportal endoscopic (UBE) microdiscectomy is an emerging minimally invasive surgery technique for treating symptomatic lumbar disc herniation. There is limited literature regarding outcomes. Here, we assess surgical outcomes and pain medication consumption for UBE vs. tubular lumbar microdiscectomy.

METHODS

This was a retrospective cohort study of adult patients undergoing primary, single-level UBE or tubular lumbar microdiscectomy surgery at a high-volume institution between 2018 and 2023. Variables of interest included operative time, complications and reoperations, as well as postoperative opioid and nonopioid pain medication consumption from discharge to 6 months. Opioid consumption was converted to morphine milligram equivalents. Standard statistical analyses were performed for comparative analyses.

RESULTS

One hundred two patients-48 UBE and 54 tubular-were included. Average operative time (minutes) was higher for UBE patients (133.1 UBE vs. 86.6 tubular, P < 0.001), which trended downward over time but did not reach statistical significance (P = 0.07). There were no differences in complication or reoperation rates. Average daily MME was lower from discharge to 2-week follow-up in the UBE group (11.1 v. 14.1, P = 0.02), but were comparative thereafter. Nonopioid medication prescription was lower in the UBE cohort from discharge to 2 weeks (70.8% vs. 92.6%, P = 0.01) and 2 to 6 weeks (52.1% vs. 85.2%, P < 0.001), with no significant differences thereafter.

CONCLUSIONS

UBE microdiscectomy is associated with longer operating times. Both opioid and nonopioid pain medication consumption were lower for UBE patients during the initial postoperative period, perhaps owing to the less-invasive nature of the surgery.

Complications in Minimally Invasive Spine Surgery in the Last 10 Years: A Narrative Review

OBJECTIVE

Minimally invasive spine surgery (MISS) employs small incisions and advanced techniques to minimize tissue damage while achieving similar outcomes to open surgery. MISS offers benefits such as reduced blood loss, shorter hospital stays, and lower costs. This review analyzes complications associated with MISS over the last 10 years, highlighting common issues and the impact of technological advancements.

METHODS

A systematic review following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines was conducted using PubMed, MEDLINE, Embase via OVID, and Cochrane databases, covering publications from January 2013 to March 2024. Keywords related to MISS and complications were used. Studies on adult patients undergoing MISS with tubular, uniportal, or biportal endoscopy, reporting intraoperative or postoperative complications, were included. Non-English publications, abstracts, and small case series were excluded. Data on MISS approach, patient demographics, and complications were extracted and reviewed by 2 independent researchers.

RESULTS

The search identified 880 studies, with 137 included after screening and exclusions. Key complications in cervical MISS were hematomas, transient nerve root palsy, and dural tears. In thoracic MISS, complications included cerebrospinal fluid leaks and durotomy. In lumbar MISS, common complications were incidental dural injuries, postoperative neuropathic conditions, and disc herniation recurrences. Complications varied by surgical approach.

CONCLUSION

MISS offers reduced anatomical disruption compared to open surgery, potentially decreasing nerve injury risk. However, complications such as nerve injuries, durotomies, and hardware misplacement still occur. Intraoperative neuromonitoring and advanced technologies like navigation can help mitigate these risks. Despite variability in complication rates, MISS remains a safe, effective alternative with ongoing advancements enhancing its outcomes.

Dose-response relationship between perioperative allogeneic blood transfusion and surgical site infections following spinal surgery

BACKGROUND CONTEXT

Perioperative allogeneic transfusion was generally considered to be safe. However, there had been some literatures reporting a potential association between surgical site infections (SSI) and blood transfusion.

PURPOSE

To determine whether perioperative blood transfusion increased the risk of SSI and to further explored whether there was a dose-response relationship.

DESIGN

Retrospective nested case-control study.

PATIENT SAMPLE

We retrospectively analyzed consecutive patients who underwent spinal fusion surgery at our institution between July 2011 and July 2021.

OUTCOME MEASURE

In the current study, the primary outcome measure was SSI.

METHODS

All consecutive patients who underwent elective spinal surgery at our institution between July 2011 and July 2021 formed the retrospective cohort. Electronic patient record and radiographic data were reviewed retrospectively in our electronic database. To examine the effects of mismatched variables, we further adjusted for possible confounding factors using conditional logistic regression models. Then, we explored the nonlinear relationship between perioperative blood transfusion and SSI by a smoothed curve, with the adjustments for potential confounders. If a nonlinear relationship was observed, a two-piecewise regression model would be performed to calculate the threshold effect.

RESULTS

The average time from surgery to diagnosis of SSI was 20.5 days. We matched 248 controls to 124 SSI cases. Of the 124 patients who developed SSI, 84 patients (67.7%) had deep SSI, 40 patients (32.3%) had superficial SSI. In the fully adjusted model, the risk of SSI increased by 27% for each additional unit of blood transfusion. It can be seen from the curve fitting plot that the risk of SSI has a greater increase after blood transfusion >3U. Subsequent piecewise regression identified an inflection point of 3U.

CONCLUSION

We determined that 3U was a threshold volume of allogeneic blood transfusion that shifted the risk of SSI following spinal surgery, and there was a dose-response effect.

Wound healing after intracutaneous vs. staple-assisted skin closure in lumbar, non-instrumented spine surgery: a multicenter prospective randomized trial

PURPOSE

Superficial surgical site infection (SSSI) is a prominent problem in spine surgery. Intracutaneous sutures and staple-assisted closure are two widely used surgical techniques for skin closure. Yet, their comparative impact on wound healing and infection rates is underexplored. Our goal was to address this gap and compare wound healing between these two techniques.

METHODS

This study was a multicenter international prospective randomized trial. Patient data were prospectively collected at three large academic centers, patients who underwent non-instrumented lumbar primary spine surgery were included. Patients were intraoperatively randomized to either intracutaneous suture or staple-assisted closure cohorts. The primary endpoint was SSSI within 30 days after surgery according to the wound infection Centers for Disease Control and Prevention (CDC) classification system.

RESULTS

Of 207 patients, 110 were randomized to intracutaneous sutures and 97 to staple-assisted closure. Both groups were homogenous with respect to epidemiological as well as surgical parameters. Two patients (one of each group) suffered from an A1 wound infection at the 30-day follow up. Median skin closure time was faster in the staple-assisted closure group (198 s vs. 13 s, p < 0,001).

CONCLUSION

This study showed an overall low superficial surgical site infection rate in both patient cohorts in primary non instrumented spine surgery.

A novel endoscope-port unit for lumbar microendoscopic surgery: a single-center case series review

Minimally invasive spinal surgery has shown benefits not only from a clinical standpoint but also in some cost-effectiveness metrics. Microendoscopic procedures combine optical advantages of endoscopy with the preservation of bimanual surgical maneuvers that are not feasible with full percutaneous endoscopic procedures. TELIGEN is a new endoscopic platform designed to optimize these operations. Our aim was to present a retrospective review of surgical data from the first consecutive cases applying this device in our institution and describe some of its technical details. 25 patients have underwent procedures using this device at our institution to the date, with a mean follow-up of 341.7 ± 45.1 days. 17 decompression-only procedures, including microendoscopic discectomies (MED) and decompression of stenosis (MEDS), with or without foraminotomies (± MEF) and 8 microendoscopic transforaminal lumbar interbody fusions (ME-TLIF) were performed. Mean age and body mass index (BMI) were respectively 58.8 ± 17.4 years and 27.6 ± 5.3 kg/m2. Estimated blood loss (13 ± 4.8, 12.8 ± 6.98 and 76.3 ± 35.02 mL), postoperative length of hospital stay (11.2 ± 21.74, 22.1 ± 26.85 and 80.7 ± 44.60 h), operative time (130.3 ± 58.53, 121 ± 33.90 and 241.5 ± 45.27 min) and cumulative intraprocedural radiation dose (14.2 ± 6.36, 15.4 ± 12.17 and 72.8 ± 12.26 mGy) are reported in this paper for MED ± MEF, MEDS ± MEF and ME-TLIF, respectively. TELIGEN affords an expanded surgical field of view with unique engineered benefits that provide a promissing platform to enhance minimally invasive spine surgery.

New Technique for Treatment of Spondylolysis and Contralateral Facet Fracture Using Navigation and Robotics: A Case Report

CASE

A healthy 15-year-old male competitive hockey player presented with acute-on-chronic lower back pain was found to have a bilateral pars defect. After conservative treatment, subsequent computed tomography imaging demonstrated partial healing of the right-sided facet fracture but persistent left-sided pars fracture. A novel technique was performed, using robotic navigation to assist in laminar screw placement and to determine the optimal trajectory for subsequent microscopic surgery and bone grafting.

CONCLUSION

Robotic navigation can be safely used to not only guide precise laminar screw placement for fixation and direct repair but also to provide guidance for microscopic tubular bone grafting of the pars defect.

Innovations in the Treatment of Spinal Cerebrospinal Fluid Leaks

Spontaneous spinal cerebrospinal fluid (CSF) leaks are uncommon but can be neurologically debilitating. When initial treatments fail, definitive repair or closure of the leak is indicated. Depending upon the type of leak present, innovative strategies for their treatment have been developed. Among them are open surgical techniques using a transdural approach for the closure of ventral CSF leaks, minimally invasive tubular techniques for the reduction and repair of lateral meningeal diverticula, and endovascular embolization of CSF-venous fistulas. Illustrative cases demonstrating the indications for and implementation of these techniques are provided.

Effect of wound drainage on the wound infection and healing in patients undergoing spinal surgery: A meta-analysis

A meta-analysis was conducted to comprehensively evaluate the impact of wound drainage on postoperative wound infection and healing in patients undergoing spinal surgery. Computer searches were performed, from database inception to October 2023, in EMBASE, Google Scholar, Cochrane Library, PubMed, Wanfang and China National Knowledge Infrastructure databases for studies related to the application of wound drainage in spinal surgery. Two researchers independently screened the literature, extracted data and conducted quality assessments. Stata 17.0 software was employed for data analysis. Overall, 11 articles involving 2102 spinal surgery patients were included. The analysis showed that, compared to other treatment methods, the use of wound drainage in spinal surgery patients significantly shortened the wound healing time (standardized mean difference [SMD]: -1.35, 95% confidence intervals [CI]: -1.91 to -0.79, p < 0.001). However, there was no statistical difference in the incidence of wound infection (odds ratio: 1.35, 95% CI: 0.83-2.19, p = 0.226). This study indicates that wound drainage in patients undergoing spinal surgery is effective, can accelerate wound healing and is worth promoting in clinical practice.

Pros and Cons of Minimally Invasive Spine Surgery

This paper reviews current knowledge on minimally invasive spine surgery (MISS). Although it has significant advantages, such as less postoperative pain, short hospital stay, quick return to work, better cosmetics, and less infection rate, there are also disadvantages. The long learning curve, the need for special instruments and types of equipment, high costs, lack of tactile sensation and biplanar imaging, some complications that are hard to treat, and more radiation to the surgeon and surgical team are the disadvantages.Most studies remark that the outcomes of MISS are similar to traditional surgery. Although patients demand it more than surgeons, we predict the broad applications of MISS will replace most of our classical surgical approaches.

Thermographic assessment of skin temperature after lumbar spine surgery: Useful method for detection of wound complications? A pilot study

BACKGROUND

Wound complications after lumbar spine surgery may result in prolonged hospitalization and increased morbidity. Early identification can trigger appropriate management.

OBJECTIVE

The aim of this study was to investigate the efficacy of infrared-based wound assessment (FLIR) after lumbar spine surgery in the context of identifying wound healing disorders.

METHODS

62 individuals who underwent lumbar spine surgery were included. The immediate postoperative course was studied, and the patient's sex, age, body mass index (BMI), heart rate, blood pressure, body temperature, numeric rating scale for pain (NRS), C-reactive protein (CRP), leukocyte, and hemoglobin levels were noted and compared to thermographic measurement of local surface temperature in the wound area.

RESULTS

Measurement of local surface temperature in the wound area showed a consistent temperature distribution while it was uneven in case of wound healing disorder. In this instance, the region of the wound where the wound healing disorder occured had a lower temperature than the surrounding tissue (p> 0.05).

CONCLUSIONS

This study demonstrates the ongoing importance of clinical wound assessment for early detection of complications. While laboratory parameter measurement is crucial, FLIR may serve as a cost-effective supplemental tool in clinical wound evaluation. Patient safety risks appear minimal since local ST is measured without touch.

New technique and case report: Robot-assisted intralaminar screw fixation of spondylolysis in an adolescent

Introduction

Management of spondylolysis in adolescents is generally successful with conservative management. Uncommonly, surgical fixation is necessary for refractory cases. Direct repair with intralaminar screws is one commonly utilized technique. Recently, less invasive spinal procedures are becoming viable with the enabling of technologies, including robotics.

Case description

A 14-year-old baseball player and surfer presented with low back pain, diagnosed by MRI as bony edema and stress fractures of the posterior spinal elements. After 18 months, the pain was unresponsive to rest, physical therapy, and bracing. There was no radicular pain or neurologic symptoms. Computed tomography (CT) revealed bilateral, chronic nonhealing pars defects at L5. He underwent outpatient, robot-assisted percutaneous intralaminar fixation with hydroxyapatite-coated screws through a 2 cm skin incision.

Outcome

On postoperative day 1, the patient reported relief of his preoperative pain and he was ambulating without difficulty. At 2 weeks follow-up, the patient was completely pain free and surfing. At 2 months follow-up, low-dose CT demonstrated partial incorporation of the hydroxyapatite-coated screws, and the patient returned to sports. At 6 months follow-up, the patient had no pain and was swinging his baseball bat with full force. Low-dose CT revealed complete healing of the defects with full incorporation of the hydroxyapatite-coated screws.

Conclusions

A novel minimally invasive robotic percutaneous approach for direct spondylolysis repair using hydroxyapatite-coated screws is a potential surgical treatment option for non-healing pars defects in adolescent patients.

The Utility and Appropriateness of Single-Position Circumferential Lumbar Interbody Fusion Using O-Arm-Based Navigation in the Novel Oblique Position

PURPOSE

Single-position surgery with patients in a lateral position, which involves inserting percutaneous pedicular screws (PPS) and lateral interbody fusion (LIF) to avoid changing the position, has been reported. The purpose of the present study was to evaluate the utility and appropriateness of single-position LIF-PPS using O-arm-based navigation in the innovative oblique position.

METHODS

This study involved a retrospective analysis of 92 consecutive patients with lumbar spondylolisthesis who underwent LIF-PPS using O-arm-based navigation. Thirty-five subjects demonstrated surgery with repositioning, as well as 24 in the lateral decubitus position, and 33 in the oblique during PPS, where the position was changed to the lateral decubitus position using bed rotation without resetting. We compared these three groups in terms of the surgery time, blood loss, and the accuracy of the screw placement.

RESULTS

The operative time was significantly shorter in the single-position surgery, both in the lateral and oblique positions, compared to surgery in a dual position. The blood loss was significantly increased in the lateral position compared to the dual and oblique positions. The screw trajectory angle on the downside was significantly smaller in the lateral position, and the accuracy of the screw placement on the downside was significantly lower in the lateral position compared to the dual and oblique positions.

CONCLUSION

Single-position surgery could reduce the average surgery time by about 60 min. The present study indicated the oblique position during PPS insertion might make single-position surgery more useful to improve the accuracy of PPS on the downside, with less blood loss.

Ten-step minimally invasive slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation

BACKGROUND

Unilateral laminotomy for bilateral decompression (ULBD) is a MIS surgical technique that offers safe and effective decompression of lumbar spinal stenosis (LSS) with a long-term resolution of symptoms. Advantages over conventional open laminectomy include reduced expected blood loss, muscle damage, mechanical instability, and less postoperative pain. The slalom technique combined with navigation is used in multi-segmental LSS to improve the workflow and effectiveness of the procedure.

METHODS

We outline ten technical steps to achieve a slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation. In a retrospective case series, we included patients with multi-segmental LSS operated in our institution using the sULBD between 2020 and 2022. The primary outcome was a reduction in pain measured by Visual Analogue Scale (VAS) for back pain and leg pain and Oswestry Disability Index (ODI).

RESULTS

In our case series (N = 7), all patients reported resolution of initial symptoms on an average follow-up of 20.71 ± 9 months. The average operative time and length of hospital stay were 196.14 min and 1.67 days, respectively. On average, VAS (back pain) was 4.71 pre-operatively and 1.50 on long-term follow-up of an average of 19.05 months. VAS (leg pain) decreased from 4.33 to 1.21. ODI was reported as 33% pre-operatively and 12% on long-term follow-up.

CONCLUSION

The sULBD with navigation is a safe and effective MIS surgical procedure and achieves the resolution of symptoms in patients presenting with multi-segmental LSS. Herein, we demonstrate the ten key steps required to perform the sULBD technique. Compared to the standard sULBD technique, the incorporation of navigation provides anatomic localization without exposure to radiation to staff for a higher safety profile along with a fast and efficient workflow.

Risk Factors for Surgical Site Infection in Spinal Surgery and Interventions: A Retrospective Study

BACKGROUND

Surgical site infection following spinal surgery causes prolonged delay in recovery after surgery, increases cost, and sometimes leads to additional surgical procedures. We investigated risk factors for the occurrence of surgical site infection events in terms of patient-related, surgery-related, and postoperative factors.

METHODS

This retrospective study included 1000 patients who underwent spinal surgery in our hospital between April 2016 and March 2019.

RESULTS

Patient-related factors were dementia, length of preoperative hospital stay (≥ 14 days), and diagnosis at the time of surgery (traumatic injury or deformity). The one surgery-related factor was multilevel surgery (≥ 9 intervertebral levels), and the one postoperative factor was time to ambulation (≥ 7 days) were statistically significant risk factors for spinal surgical site infection.

CONCLUSION

One risk factor identified in this study that is amenable to intervention is time to ambulation. As delayed ambulation is a risk factor for postoperative surgical site infection, how medical staff can intervene in postoperative ambulation to further reduce the incidence of surgical site infection is a topic for future research.

Surgery for Metastatic Spinal Disease in Octogenarians and Above: Analysis of 78 Patients

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

Octogenarians living with spinal metastases are a challenging population to treat. Our objective was to identify the rate, types, management, and predictors of complications and survival in octogenarians following surgery for spinal metastases.

METHODS

A retrospective review of a prospectively collected cohort of patients aged 80 years or older who underwent surgery for metastatic spinal tumor treatment between 2008 and 2019 were included. Demographic, intraoperative, complications, and postoperative follow-up data was collected. Cox proportional hazards regression and logistic regression were used to associate variables with overall survival and postoperative complications, respectively.

RESULTS

78 patients (mean 83.6 years) met inclusion criteria. Average operative time and blood loss were 157 minutes and 615 mL, respectively. The median length of stay was 7 days. The overall complication rate was 31% (N = 24), with 21% considered major and 7% considered life-threatening or fatal. Blood loss was significantly associated with postoperative complications (OR = 1.002; P = 0.02) and mortality (HR = 1.0007; P = 0.04). Significant associations of increased risk of death were also noted with surgeries with decompression, and cervical/cervicothoracic index level of disease. For deceased patients, median time to death was 4.5 months. For living patients, median follow-up was 14.5 months. The Kaplan-Meier based median overall survival for the cohort was 11.6 months (95% CI: 6.2-19.1).

CONCLUSIONS

In octogenarians undergoing surgery with instrumentation for spinal metastases, the median overall survival is 11.6 months. There is an increased complication rate, but only 7% are life-threatening or fatal. Patients are at increased risk for complications and mortality particularly when performing decompression with stabilization, with increasing intraoperative blood loss, and with cervical/cervicothoracic tumors.

Biomechanical Comparison of Multilevel Stand-Alone Lumbar Lateral Interbody Fusion With Posterior Pedicle Screws: An In Vitro Study

OBJECTIVE

Lumbar lateral interbody fusion (LLIF) allows placement of large interbody cages while preserving ligamentous structures important for stability. Multiple clinical and biomechanical studies have demonstrated the feasibility of stand-alone LLIF in single-level fusion. We sought to compare the stability of 4-level stand-alone LLIF utilizing wide (26 mm) cages with bilateral pedicle screw and rod fixation.

METHODS

Eight human cadaveric specimens of L1-5 were included. Specimens were attached to a universal testing machine (MTS 30/G). Flexion, extension, and lateral bending were attained by applying a 200 N load at a rate of 2 mm/sec. Axial rotation of ± 8° of the specimen was performed at 2°/sec. Three-dimensional specimen motion was recorded using an optical motion-tracking device. Specimens were tested in 4 conditions: (1) intact, (2) bilateral pedicle screws and rods, (3) 26-mm stand-alone LLIF, (4) 26-mm LLIF with bilateral pedicle screws and rods.

RESULTS

Compared to the stand-alone LLIF, bilateral pedicle screws and rods had 47% less range of motion in flexion-extension (p < 0.001), 21% less in lateral bending (p < 0.05), and 20% less in axial rotation (p = 0.1). The addition of bilateral posterior instrumentation to the stand-alone LLIF resulted in decreases of all 3 planes of motion: 61% in flexion-extension ( p < 0.001), 57% in lateral bending (p < 0.001), 22% in axial rotation (p = 0.002).

CONCLUSION

Despite the biomechanical advantages associated with the lateral approach and 26 mm wide cages, stand-alone LLIF for 4-level fusion is not equivalent to pedicle screws and rods.

Does Tobacco Smoking Affect the Postoperative Outcome of MIS Lumbar Decompression Surgery?

BACKGROUND

Tobacco smoking is a major cause of morbidity and mortality worldwide. Several authors reported a significant negative impact of smoking on the outcome of spinal surgeries. However, comparative studies on the effect of smoking on the outcome of minimally invasive (MIS) spinal decompression are rare with conflicting results. In this study, we aimed to evaluate clinical outcomes and postoperative complications following MIS decompression in current and former smoking patients compared to those of non-smoking patients.

METHODS

We used our prospectively collected database to retrospectively analyse the records of 188 consecutive patients treated with MIS lumbar decompression at our institution between November 2013 and July 2017. Patients were divided into groups of smokers (S), previous smokers (PS) and non-smokers (N). The S group and the PS group comprised 31 and 40 patients, respectively. The N group included 117 patients. The outcome measures included perioperative complications, revision surgery and length of stay. Patient-reported outcome measures included a visual analogue scale (VAS) for back pain and leg pain, as well as the Oswestry disability index (ODI) for evaluating functional outcomes.

RESULTS

Demographic variables, comorbidity and other preoperative variables were comparable between the three groups. A comparison of perioperative complications and revision surgery rates showed no significant difference between the groups. All groups showed significant improvement in their ODI and VAS scores at 12 and 24 months following surgery. As shown by a multivariate analysis, current smokers had lower chances of improvement, exceeding the minimal clinical important difference (MCID) in ODI and VAS for leg pain at 12 months but not 24 months postoperatively.

CONCLUSIONS

Our findings show that except for a possible delay in improvement in leg pain and disability, tobacco smoking has no substantial adverse impact on complications and revision rates following MIS spinal decompressions.

Surgical Management of the Metastatic Spine Disease: A Review of the Literature and Proposed Algorithm

STUDY DESIGN

Narrative Review. The spine remains the most common site for bony metastasis. It is estimated that up to 70% of cancer patients harbor secondary spinal disease. And up to 10% will develop a clinically significant lesion. The last two decades have seen a substantial leap forward in the advancements of the management of spinal metastases. What once was a death sentence is now a manageable, even potentially treatable condition. With marked advancements in the surgical treatment and post-operative radiotherapy, a standardized approach to stratify and manage these patients is both prudent and now feasible.

OBJECTIVES

This article looks to examine the best available evidence in the stratification and surgical management of patients with spinal metastases. So the aim of this review is to offer a standardized approach for surgical management and surgical planning of patients with spinal metastases.

Radiological Assessment of Postoperative Paraspinal Muscle Changes After Lumbar Interbody Fusion With or Without Minimally Invasive Techniques

STUDY DESIGN

Retrospective cohort study.

BACKGROUND

Percutaneous pedicle screws (PPS) have the advantage of being able to better preserve the paraspinal muscles when compared with a traditional open approach. However, the nature of changes in postoperative paraspinal muscle after damage by lumbar fusion surgery has remained largely unknown. It is clinically important to clarify and compare changes in paraspinal muscles after the various surgeries.

OBJECTIVE

(1) To determine postoperative changes of muscle density and cross-sectional area using computed tomography (CT), and (2) to compare paraspinal muscle changes after posterior lumbar interbody fusion (PLIF) with traditional open approaches and minimally invasive lateral lumbar interbody fusions (LLIF) with PPS.

METHODS

We included data from 39 consecutive female patients who underwent open PLIF and 23 consecutive patients who underwent single-staged treatment with LLIF followed by posterior PPS fixation at a single level (L4-5). All patients underwent preoperative, 6 months postoperative, and 1-year postoperative CT imaging. Measurements of the cross-sectional area (CSA) and muscle densities of paraspinal muscles were obtained using regions of interest defined by manual tracing.

RESULTS

We did not find any decrease of CSA in any paraspinal muscles. We did find a decrease of muscle density in the multifidus at 1 year after surgery in patients in the PILF group, but not in those in LLIF/PPS group.

CONCLUSIONS

One year after surgery, a significant postoperative decrease of muscle density of the multifidi was observed only in patients who underwent open PLIF, but not in those who underwent LLIF/PPS.

Full-endoscopic spine surgery diminishes surgical site infections - a propensity score-matched analysis

BACKGROUND CONTEXT

Surgical site infections (SSI) are one the most frequent and costly complications following spinal surgery. The SSI rates of different surgical approaches need to be analyzed to successfully minimize SSI occurrence.

PURPOSE

The purpose of this study was to define the rate of SSIs in patients undergoing full-endoscopic spine surgery (FESS) and then to compare this rate against a propensity score-matched cohort from the National Surgical Quality Improvement Program (NSQIP) database.

DESIGN

This is a retrospective multicenter cohort study using a propensity score-matched analysis of prospectively maintained databases.

PATIENT SAMPLE

One thousand two hundred seventy-seven non-instrumented FESS cases between 2015 and 2021 were selected for analysis. In the nonendoscopic NSQIP cohort we selected data of 55,882 patients.

OUTCOME MEASURES

The occurrence of any SSI was the primary outcome. We also collected any other perioperative complications, demographic data, comorbidities, operative details, history of smoking, and chronic steroid intake.

METHODS

All FESS cases from a multi-institutional group that underwent surgery from 2015 to 2021 were identified for analysis. A cohort of cases for comparison was identified from the NSQIP database using Current Procedural Terminology of nonendoscopic cervical, thoracic, and lumbar procedures from 2015 to 2019. Trauma cases as well as arthrodesis procedures, surgeries to treat pathologies affecting more than 4 levels or spine tumors that required surgical treatment were excluded. In addition, nonelective cases, and patients with wounds worse than class 1 were also not included. Patient demographics, comorbidities, and operative details were analyzed for propensity matching.

RESULTS

In the non-propensity-matched dataset, the endoscopic cohort had a significantly higher incidence of medical comorbidities. The SSI rates for nonendoscopic and endoscopic patients were 1.2% and 0.001%, respectively, in the nonpropensity match cohort (p-value <.011). Propensity score matching yielded 5936 nonendoscopic patients with excellent matching (standard mean difference of 0.007). The SSI rate in the matched population was 1.1%, compared to 0.001% in endoscopic patients with an odds ratio 0.063 (95% confidence interval (CI) 0.009-0.461, p=.006) favoring FESS.

CONCLUSIONS

FESS compares favorably for risk reduction in SSI following spinal decompression surgeries with similar operative characteristics. As a consequence, FESS may be considered the optimal strategy for minimizing SSI morbidity.

Complication Avoidance in Spine Surgery

The outcomes of spine surgery are closely related to postoperative morbidity. Therefore, an experienced surgeon must be aware of various complications and should apply all necessary preventive measures to avoid them. It is widely considered that complications of spine surgery are underreported and that their real incidence is much higher than expected. This review highlights methods to prevent various types of morbidity that may be encountered during different spinal procedures, considering general complications, approach-related complications, fusion- and implant-related complications, and systemic complications.

The Role of Diskectomy in Reducing Infectious Complications after Surgery for Lumbar Spondylodiscitis

BACKGROUND

 Surgery for pyogenic Spondylodiscitis as an adjunct to antibiotic therapy is an established treatment. However, the technique and extent of surgical debridement remains a matter of debate. Some propagate diskectomy in all cases. Others maintain that stand-alone instrumentation is sufficient.

METHODS

 We reviewed charts of patients who underwent instrumentation for pyogenic Spondylodiscitis with a minimum follow-up of 1 year. Patients were stratified according to whether they underwent diskectomy plus instrumentation or posterior instrumentation alone. Outcome measures included the need for surgical revision due to recurrent epidural intraspinal infection, wound revision, and construct failure.

RESULTS

 In all, 257 patients who underwent surgery for pyogenic Spondylodiscitis were identified. Diskectomy and interbody procedure (group A) was performed in 102 patients, while 155 patients underwent instrumentation surgery for Spondylodiscitis without intradiskal debridement (group B). The mean age was 67 ± 12 years, and 102 patients (39.7%) were females. No significant differences were found in the need for epidural abscess recurrence therapy (group A [2.0%] and 5 cases in group B [3%; p = 0.83]) and construct failure (p = 0.575). The need for wound revisions showed a tendency toward higher rates in the posterior instrumentation-only group, which failed to reach significance (p = 0.078).

CONCLUSIONS

 Overall, intraspinal relapse of surgically treated pyogenic diskitis was low in our retrospective series. The choice of surgical technique was not associated with a significant difference. However, a somewhat higher rate of wound infections requiring revision in the group where no diskectomy was performed has to be weighed against a longer duration of surgery in an already ill patient population.

Full-endoscopic versus microscopic unilateral laminotomy for bilateral decompression of lumbar spinal stenosis at L4-L5: comparative study

PURPOSE

Full-endoscopic spine surgery for degenerative lumbar diseases is growing in popularity and has shown favourable outcomes. Lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has been used to treat lumbar spinal stenosis (LSS). However, studies comparing LE-ULBD to microscopic ULBD are lacking. This study compared the clinical efficacy and radiological outcomes between the LE-ULBD and microscopic ULBD.

METHODS

The study retrospectively enrolled patients undergoing either LE-ULBD or microscopic ULBD for spinal stenosis at the L4-L5 level. The demographic data, operative details, radiological images, clinical outcomes, and complications of patients from the two groups were compared through matched-pairs analysis. The minimum follow-up duration was 24 months.

RESULTS

There were 93 patients undergoing either LE-ULBD (n = 42) or microscopic ULBD (n = 51). The patient demographics were similar between the two groups. The LE-ULBD group had significantly less estimated blood loss, less analgesic use, and shorter hospitalization duration (P < .05). The endoscopic group had a significantly lower visual analog scale for back pain at all follow-up intervals compared with the microscopic group (P < .05). There were no significant differences in leg pain or Oswestry Disability Index. The cross-section area of the spinal canal was significantly wider after microscopic ULBD. There were no significant differences in post-operative degenerative changes in disc height, translational motion, or facet preservation rate.

CONCLUSIONS

LE-ULBD is comparable in clinical and radiological outcomes with enhanced recovery for single-level LSS. The endoscopic approach might further minimize tissue injury and enhance post-operative recovery.

Minimally invasive discectomy versus open laminectomy and discectomy for the treatment of cauda equina syndrome: A preliminary study and case series

Background

Cauda Equina syndrome (CES) is a potentially devastating condition and is treated usually with urgent open surgical decompression of the spinal canal. Currently, the role of minimally invasive discectomy (MID) as an alternative surgical technique for CES is unclear.

Objective

The purpose of this study was to compare clinical outcomes following MID and open laminectomy and discectomy for the treatment of CES.

Methods

The study cohort included patients that underwent surgery due to CES at our institute. Patients' outcomes included: surgical complications, length of hospitalization, postoperative lower extremity motor score (LEMS), Numerical Rating Scale (NRS) for leg and back pain, Oswestry disability index (ODI), and the EQ-5D health-related quality of life questionnaire.

Results

Twelve patients underwent MID and 12 underwent open laminectomy and discectomy. Complications and revisions rates were comparable between the groups. Postoperative urine incontinence and saddle dysesthesia improved in 50% of patients in both groups. LEMS improved from 47.08 ± 5.4 to 49.27 ± 0.9 in the MID group and from 44.46 ± 5.9 to 49.0 ± 1.4 in the open group. Although, leg pain improved in both groups from 8.4 ± 2.4 to 3 ± 2.1 in the MID and from 8.44 ± 3.3 to 3.88 ± 3 in the open group, significant improvement in back pain was found only in the MID group. Final functional scores were similar between groups.

Conclusions

Our preliminary results suggest that minimally invasive discectomy is an effective and safe procedure for the treatment of CES when compared to open laminectomy and discectomy. However, MID in these cases should only be considered by surgeons experienced in minimally invasive spine surgery. Further studies with bigger sample sizes and long-term follow-ups are needed.

Assessment of MRI and US Screening for Tethered Cord Syndrome in Patients Diagnosed With Esophageal Atresia/Tracheoesophageal Fistula

INTRODUCTION

Infants with esophageal atresia and/or tracheoesophageal fistula (EA/TEF) undergo screening for tethered cord syndrome (TCS) via ultrasound and magnetic resonance imaging. Existing literature lacks data to guide optimal timing of screening and magnetic resonance imaging (MRI) is often delayed until 3-6 mo of age, when it is frequently forgotten. Detethering surgery has a high rate of success in patients with TCS and is often performed prophylactically due to potential irreversible deficits. This study aims to improve screening procedure for infants with EA/TEF.

METHODS

A retrospective chart review was done of all EA/TEF patients treated over 6 y (n = 79). The study examined how often each imaging modality was performed and identified a TCS lesion, as well as age of screening/surgical intervention.

RESULTS

Screening for TCS was done with MRI 58% of the time and US 15% of the time. However, 38% of patients did not undergo any screening. Out of the patients with TCS on MRI (n = 19, 41.3%), 73.7% had neurosurgery. Of patients who underwent US (n = 12), nine patients also had MRI later: two reported TCS lesions and subsequently had neurosurgery. Surgical infection rates and complications were 0/14.

CONCLUSIONS

MRI demonstrated a higher rate of detecting TCS lesions than US, and patients with TCS frequently had detethering. Patients with ≥3 VACTERL or vertebral anomalies had a higher incidence of TCS on MRI. Patients with vertebral anomalies reported false negative ultrasounds in two cases, suggesting the potential superiority of MRI screening in this subgroup. A third of children did not undergo any imaging and this will require a process improvement.

30-day postoperative sepsis risk factors following laminectomy for intradural extramedullary tumors

BACKGROUND

Posterior laminectomy (LA) for resection of intradural extramedullary tumors (IDEMTs) is associated with postoperative complications, including sepsis. Sepsis is an uncommon but serious complication that can lead to increased morbidity and mortality, prolonged hospital stays, and greater costs. Given the susceptibility of a solid tumor patients to sepsis-related complications, it is important to recognize IDEMT patients as a unique population when assessing the risk factors for sepsis after laminectomy.

METHODS

The study design was a retrospective cohort study. Adult patients undergoing LA for IDEMTs from 2012 to 2018 were identified in the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database. Baseline patient characteristics/comorbidities, operative and hospital variables, and 30-day postoperative complications were collected.

RESULTS

Of 2,027 total patients undergoing LA for IDEMTs, 38 (2%) had postoperative sepsis. On bivariate analysis sepsis was associated with superficial surgical site infection [odds ratio (OR) 11.62, P<0.001], deep surgical site infection (OR 10.67, P<0.001), deep vein thrombosis (OR 10.75, P<0.001), pulmonary embolism (OR 15.27, P<0.001), transfusion (OR 6.18, P<0.001), length of stay greater than five days (OR 5.41, P<0.001), and return to the operating room within thirty days (OR 8.72, P<0.001). Subsequent multivariate analysis identified the following independent risk factors for sepsis and septic shock: operative time ≥50th percentile (OR 2.11, P=0.032), higher anesthesia class (OR 1.76, P=0.046), dependent functional status (OR 2.23, P=0.001), diabetes (OR 2.31, P=0.037), and chronic obstructive pulmonary disease (OR 3.56, P=0.037).

CONCLUSIONS

These findings can help spine surgeons identify high-risk patients and proactively deploy measures to avoid this potentially devastating complication in individuals who may be more vulnerable than the general elective spine population.

A Modified Approach for Minimally Invasive Tubular Microdiscectomy for Far Lateral Disc Herniations: Docking at the Caudal Level Transverse Process

Background and Objectives: The use of minimally invasive retractor systems has significantly decreased the amount of tissue dissection and blood loss, and the duration of post-operative recovery after far-lateral disc herniations (FLDH). In this technical note, the technique of docking the tubular retractor on the caudal transverse process is described for an efficient approach with a decreased need for manipulation of the exiting nerve root. Materials and Methods: The case reported is that of a woman affected by a right-sided FLDH at the L4–5 level causing an L4 radiculopathy with weakness and numbness. A review of the literature for FLDH regarding the key anatomy used during a far lateral approach was also performed. Results: The patient showed a significant improvement of her dorsiflexion weakness and radiating leg pain at her 2-week and 5-week post-operative visits, and at a 6-month follow-up she had near-complete relief of her symptoms, including resolution of foot numbness. Prior techniques for tubular microdiscectomy for FLDH report docking on the facet joint, pars interarticularis, and the cranial transverse process. Conclusions: This technical note details that the utility of docking a tubular retractor at the caudal transverse process improves upon already established techniques for minimally invasive tubular discectomy for FLDH.

Lumbar surgical drains do not increase the risk of infections in patients undergoing spine surgery

PURPOSE

The aim of this study was to characterize if the use of surgical drains or length of drain placement following spine surgery increases the risk of post-operative infection.

METHODS

Records of patients undergoing elective spinal surgery at a tertiary care center were collected between May 5, 2016 and August 16, 2018. Pre-operative baseline characteristics were recorded including patient's demographics and comorbidities. Intraoperative procedure information was documented related to procedure type, blood loss, and antibiotics used. Following surgery, patients were then further subdivided into two groups: patients who were discharged with a spinal surgical site drain and patients who did not receive a drain. Post-operative surgical variables included length of stay (LOS), drain length, number of antibiotics given, and type of post-operative infection. Univariate and multivariate statistical analysis was conducted.

RESULTS

A total of 671 patients were included in the current study, 386 (57.5%) with and 285 (42.5%) without the drain. The overall infection rate was 5.7% with 6.22% among patients with the drain compared to 4.91% in patients without drain. The univariate analysis identified the following variables to be significantly associated with the infection: total number of surgical levels, spinal region, blood loss, redosing of antibiotics, length of stay, length of drain placement, and number of antibiotics (P < 0.05). However, the multivariate analysis none of the predictors was significant.

CONCLUSIONS

The current study shows that the placement of drain does not increase rate of infection, irrespective of levels, length of surgery, or approach.

Design and clinical application of injectable hydrogels for musculoskeletal therapy

Musculoskeletal defects are an enormous healthcare burden and source of pain and disability for individuals. With an aging population, the proportion of individuals living with these medical indications will increase. Simultaneously, there is pressure on healthcare providers to source efficient solutions, which are cheaper and less invasive than conventional technology. This has led to an increased research focus on hydrogels as highly biocompatible biomaterials that can be delivered through minimally invasive procedures. This review will discuss how hydrogels can be designed for clinical translation, particularly in the context of the new European Medical Device Regulation (MDR). We will then do a deep dive into the clinically used hydrogel solutions that have been commercially approved or have undergone clinical trials in Europe or the United States. We will discuss the therapeutic mechanism and limitations of these products. Due to the vast application areas of hydrogels, this work focuses only on treatments of cartilage, bone, and the nucleus pulposus. Lastly, the main steps toward clinical translation of hydrogels as medical devices are outlined. We suggest a framework for how academics can assist small and medium MedTech enterprises conducting the initial clinical investigation and post‐market clinical follow‐up required in the MDR. It is evident that the successful translation of hydrogels is governed by acquiring high‐quality pre‐clinical and clinical data confirming the device mechanism of action and safety.

Development and Internal Validation of Supervised Machine Learning Algorithms for Predicting the Risk of Surgical Site Infection Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

Purpose: Machine Learning (ML) is rapidly growing in capability and is increasingly applied to model outcomes and complications in medicine. Surgical site infections (SSI) are a common post-operative complication in spinal surgery. This study aimed to develop and validate supervised ML algorithms for predicting the risk of SSI following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

Methods: This single-central retrospective study included a total of 705 cases between May 2012 and October 2019. Data of patients who underwent MIS-TLIF was extracted by the electronic medical record system. The patient's clinical characteristics, surgery-related parameters, and routine laboratory tests were collected. Stepwise logistic regression analyses were used to screen and identify potential predictors for SSI. Then, these factors were imported into six ML algorithms, including k-Nearest Neighbor (KNN), Decision Tree (DT), Support Vector Machine (SVM), Random Forest (RF), Multi-Layer Perceptron (MLP), and Naïve Bayes (NB), to develop a prediction model for predicting the risk of SSI following MIS-TLIF under Quadrant channel. During the training process, 10-fold cross-validation was used for validation. Indices like the area under the receiver operating characteristic (AUC), sensitivity, specificity, and accuracy (ACC) were reported to test the performance of ML models.

Results: Among the 705 patients, SSI occurred in 33 patients (4.68%). The stepwise logistic regression analyses showed that pre-operative glycated hemoglobin A1c (HbA1c), estimated blood loss (EBL), pre-operative albumin, body mass index (BMI), and age were potential predictors of SSI. In predicting SSI, six ML models posted an average AUC of 0.60–0.80 and an ACC of 0.80–0.95, with the NB model standing out, registering an average AUC and an ACC of 0.78 and 0.90. Then, the feature importance of the NB model was reported.

Conclusions: ML algorithms are impressive tools in clinical decision-making, which can achieve satisfactory prediction of SSI with the NB model performing the best. The NB model may help access the risk of SSI following MIS-TLIF and facilitate clinical decision-making. However, future external validation is needed.

The Potential Cost-Effectiveness of a Cell-Based Bioelectronic Implantable Device Delivering Interferon-β1a Therapy Versus Injectable Interferon-β1a Treatment in Relapsing-Remitting Multiple Sclerosis

BACKGROUND

Current first-line disease-modifying therapies (DMT) for multiple sclerosis (MS) patients are injectable or oral treatments. The Optogenerapy consortium is developing a novel bioelectronic cell-based implant for controlled release of beta-interferon (IFNβ1a) protein into the body. The current study estimated the potential cost effectiveness of the Optogenerapy implant (hereafter: Optoferon) compared with injectable IFNβ1a (Avonex).

METHODS

A Markov model simulating the costs and effects of Optoferon compared with injectable 30 mg IFNβ1a over a 9-year time horizon from a Dutch societal perspective. Costs were reported in 2019 Euros and discounted at a 4% annual rate; health effects were discounted at a 1.5% annual rate. The cohort consisted of 35-year-old, relapsing-remitting MS patients with mild disability. The device is implanted in a daycare setting, and is replaced every 3 years. In the base-case analysis, we assumed equal input parameters for Optoferon and Avonex regarding disability progression, health effects, adverse event probabilities, and acquisition costs. We assumed reduced annual relapse rates and withdrawal rates for Optoferon compared with Avonex. Sensitivity, scenario, value of information, and headroom analysis were performed.

RESULTS

Optoferon was the dominant strategy with cost reductions (- €26,966) and health gains (0.45 quality-adjusted life-years gained). A main driver of cost differences are the acquisition costs of Optoferon being 2.5 times less than the costs of Avonex. The incremental cost-effectiveness ratio was most sensitive to variations in the annual acquisition costs of Avonex, the annual withdrawal rate of Avonex and Optoferon, and the disability progression of Avonex.

CONCLUSION

Innovative technology such as the Optoferon implant may be a cost-effective therapy for patients with MS. The novel implantable mode of therapeutic protein administration has the potential to become a new mode of treatment administration for MS patients and in other disease areas. However, trials are needed to establish safety and effectiveness.

Stable Low-Grade Degenerative Spondylolisthesis Does Not Compromise Clinical Outcome of Minimally Invasive Tubular Decompression in Patients with Spinal Stenosis

Background and Objectives: In recent literature, the routine addition of arthrodesis to decompression for lumbar spinal stenosis (LSS) with concomitant stable low-grade degenerative spondylolisthesis remains controversial. The purpose of this study is to compare the clinical outcome, complication and re-operation rates following minimally invasive (MIS) tubular decompression without arthrodesis in patients suffering from LSS with or without concomitant stable low-grade degenerative spondylolisthesis. Materials and Methods: This study is a retrospective review of prospectively collected data. Ninety-six consecutive patients who underwent elective MIS lumbar decompression with a mean follow-up of 27.5 months were included in the study. The spondylolisthesis (S) group comprised 53 patients who suffered from LSS with stable degenerative spondylolisthesis, and the control (N) group included 43 patients suffering from LSS without spondylolisthesis. Outcome measures included complications and revision surgery rates. Pre- and post-operative visual analog scale (VAS) for both back and leg pain was analyzed, and the Oswestry Disability Index (ODI) was used to evaluate functional outcome. Results: The two groups were comparable in most demographic and preoperative variables. VAS for back and leg pain improved significantly following surgery in both groups. Both groups showed significant improvement in their ODI scores, at one and two years postoperatively. The average length of hospital stay was significantly higher in patients with spondylolisthesis (p-value< 0.01). There was no significant difference between the groups in terms of post-operative complications rates or re-operation rates. Conclusions: Our results indicate that MIS tubular decompression may be an effective and safe procedure for patients suffering from LSS, with or without degenerative stable spondylolisthesis.

Safety and efficacy of the transoral approach for cheek volumization with hyaluronic acid: A pilot study

BACKGROUND

With aging, there is a decrease in the volume of facial fat compartments, which can be restored using injectable biodegradable fillers.

AIMS

The objective of this study was to assess the efficacy and safety of an ultrasound-guided transoral injection versus the traditional percutaneous approach for cheek volumization with hyaluronic acid.

PATIENTS/METHODS

This is a pilot, single-center, comparative, prospective study conducted in Spain in which the hemifaces were randomized to receive an injection with each technique, and the duration of follow-up was 1 year. Results were assessed using the GAIS and the procedure satisfaction survey. The degree of pain experienced was evaluated using a VAS for pain.

RESULTS

This study included 20 women with a mean age of 45.3 years (SD 5.1, range of 38-53). No significant differences were observed in esthetic improvement scores or in the satisfaction surveys. There were significant differences in the transoral approach assessment at V3 (p = 0.0362) and in both procedures at V6 (p = 0.0026) between patients and evaluators. Of all patients, 55% (n = 11/20) reported less pain with the transoral approach, and 15% (n = 3/20) did not perceive pain with any techniques. No side effects different than those expected were observed, and they all resolved without the need for treatment.

CONCLUSION

The transoral approach for cheek volumization with hyaluronic acid was shown as a safe, effective technique that provides more comfort and minor sensation of pain than the traditional percutaneous approach but with equivalent esthetic outcomes.

Spinal metastasis: The rise of minimally invasive surgery

INTRODUCTION

Bone is the third most common site of metastatic cancer, of which the spine is the most frequently involved. As metastatic cancer prevalence rises and surgical techniques advance, operative intervention for spinal metastases is expected to rise. In the first operative cohort of spinal metastasis in Ireland, we describe the move towards less invasive surgery, the causative primary types and post-operative survival.

METHODS

This is a retrospective cohort study of all operative interventions for spinal metastasis in a tertiary referral centre over eight years. Primary spinal tumours and local invasion to the spine were excluded. Median follow up was 1895 days.

RESULTS

225 operative procedures in 196 patients with spinal metastasis were performed over eight years. Average cases per year increased form 20 per year to 29 per year. Percutaneous procedures became more common, accounting for the majority (53%) in the final two years. The most common primary types were breast, myeloma, lung, prostate and renal. Overall survival at 1 year was 51%. Primary type was a major determinant of survival, with breast and the haematological cancers demonstrating good survival, while lung had the worst prognosis.

CONCLUSION

This is the first descriptive cohort of operative interventions for spinal metastasis in an Irish context. Surgery for spinal metastasis is performed at an increasing rate, especially through minimally-invasive means. The majority of patients survive for at least one year post-operatively. Prudent resource planning is necessary to prepare for this growing need.

A narrative review of infection prevention techniques in adult and pediatric spinal deformity surgery

Spinal infections associated with pediatric and adult spinal deformity surgery are associated with postoperative morbidity and mortality along with elevated health-care costs. Prevention requires meticulous technique by the spine surgeon throughout the perioperative period. There is significant variability in the current practices of spinal deformity surgeons with regard to infection prevention, stemming from the lack of reliable evidence available in the literature. There has also been a lack of literature detailing the difference in infection rates and risk factors between pediatric and adult patients undergoing deformity correction surgery. In this narrative review we looked at 60 studies in the adult population and 9 studies in the pediatric population. Most of these studies of surgical site infections (SSI) in spinal deformity surgery have been performed in adult patients, however it is clear that the pediatric neuromuscular patient requires particular attention that we discuss in detail. This narrative review of the literature outlines evidence and compares and contrasts data for preventive strategies and modifiable risk factors to decrease rates of SSI in the pediatric and adult spinal deformity patient populations. In this review we discuss techniques relating to preoperative cleansing protocols, antibiotic administration, gentle soft tissue handling, appropriate closure, drain usage, and intraoperative technique itself to minimize EBL and operative time.

Risk of reoperation and infection after percutaneous endoscopic lumbar discectomy and open lumbar discectomy : a nationwide population-based study

AIMS

Open discectomy (OD) is the standard operation for lumbar disc herniation (LDH). Percutaneous endoscopic lumbar discectomy (PELD), however, has shown similar outcomes to OD and there is increasing interest in this procedure. However despite improved surgical techniques and instrumentation, reoperation and infection rates continue and are reported to be between 6% and 24% and 0.7% and 16%, respectively. The objective of this study was to compare the rate of reoperation and infection within six months of patients being treated for LDH either by OD or PELD.

METHODS

In this retrospective, nationwide cohort study, the Korean National Health Insurance database from 1 January 2007 to 31 December 2018 was reviewed. Data were extracted for patients who underwent OD or PELD for LDH without a history of having undergone either procedure during the preceding year. Individual patients were followed for six months through their encrypted unique resident registration number. The primary endpoints were rates of reoperation and infection during the follow-up period. Other risk factors for reoperation and infection were also evalulated.

RESULTS

Out of 549,531 patients, 522,640 had undergone OD (95.11%) and 26,891 patients had undergone PELD (4.89%). Reoperation rates within six months were 2.28% in the OD group, and 5.38% in the PELD group. Infection rates were 1.18% in OD group and 0.83% in PELD group. The risk of reoperation was lower for patients with OD than for patients with PELD (adjusted hazard ratio (HR) 0.38). The risk of infection was higher for patients with OD than for patients undergoing PELD (HR, 1.325).

CONCLUSION

Compared with the OD group, the PELD group showed higher reoperation rates and lower infection rates. Cite this article: Bone Joint J 2021;103-B(8):1392-1399.

Reasons for revision following stand-alone anterior lumbar interbody fusion and lateral lumbar interbody fusion

OBJECTIVE

Anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) are alternative and less invasive techniques to stabilize the spine and indirectly decompress the neural elements compared with open posterior approaches. While reoperation rates have been described for open posterior lumbar surgery, there are sparse data on reoperation rates following these less invasive procedures without direct posterior decompression. This study aimed to evaluate the overall rate, cause, and timing of reoperation procedures following anterior or lateral lumbar interbody fusions without direct posterior decompression.

METHODS

This was a retrospective cohort study of all consecutive patients indicated for an ALIF or LLIF for lumbar spine at a single academic institution. Patients who underwent concomitant posterior fusion or direct decompression surgeries were excluded. Rates, causes, and timing of reoperations were analyzed. Patients who underwent a revision decompression were matched with patients who did not require a reoperation, and preoperative imaging characteristics were analyzed to assess for risk factors for the reoperation.

RESULTS

The study cohort consisted of 529 patients with an average follow-up of 2.37 years; 40.3% (213/529) and 67.3% (356/529) of patients had a minimum of 2 years and 1 year of follow-up, respectively. The total revision rate was 5.7% (30/529), with same-level revision in 3.8% (20/529) and adjacent-level revision in 1.9% (10/529) of patients. Same-level revision patients had significantly shorter time to revision (7.14 months) than adjacent-level revision patients (31.91 months) (p < 0.0001). Fifty percent of same-level revisions were for a posterior decompression. After further analysis of decompression revisions, an increased preoperative canal area was significantly associated with a lower risk of further decompression revision compared to the control group (p = 0.015; OR 0.977, 95% CI 0.959-0.995).

CONCLUSIONS

There was a low reoperation rate after anterior or lateral lumbar interbody fusions without direct posterior decompression. The majority of same-level reoperations were due to a need for further decompression. Smaller preoperative canal diameters were associated with the need for revision decompression.

Minimally invasive posterior lumbar surgery in the morbidly obese, obese and non-obese populations: A single institution retrospective review

BACKGROUND

There is a paucity of information regarding outcomes in minimally invasive surgical (MIS) approaches to posterior lumbar surgery in morbidly obese patients. We seek to determine if there are differences in operative variables and early complication rates in morbidly obese patients undergoing MIS posterior lumbar surgery compared to obese and non-obese patients.

METHODS

A single institution retrospective review of patients undergoing MIS posterior lumbar surgery (decompression and/or fusion) between 2013 and 2016 was performed. Morbidly obese patients (BMI ≥ 40) were compared to obese (BMI 30-39.9) and non-obese (BMI < 30) cohorts. Postoperative complication rates and perioperative variables including estimated blood loss, operative time, and outcome measures including length of stay (LOS), in-hospital complications, readmission, and disposition were assessed.

RESULTS

47 morbidly obese, 135 obese and 224 non-obese patients underwent posterior MIS instrumented fusion. 59 morbidly obese, 182 obese and 314 non-obese patients underwent posterior MIS decompression. The morbidly obese group experienced a greater rate of deep vein thrombosis and had an increased hospital LOS (p < 0.05). Morbidly obese patients who underwent MIS decompression experienced increased postoperative complications (p < 0.01), and increased LOS (p < 0.0001) compared to obese and non-obese patients. There were no differences in revision rates, readmissions, and other complications including surgical site infection. Morbid obesity was an independent predictor of overall complications and increased LOS on multivariate analysis.

CONCLUSION

Morbidly obese patients undergoing posterior MIS fusion had a higher rate of complications and increased LOS. While weight loss should be encouraged, complication rates remains acceptably low in morbidly obese patients and MIS posterior lumbar surgery should still be offered.

Application of Spinal Robotic Navigation Technology to Minimally Invasive Percutaneous Treatment of Spinal Fractures: A Clinical, Non-Randomized, Controlled Study

Objective

To introduce a new robotic navigation system that assists pedicle screw implantation and verify the accuracy and stability of the system.

Methods

Pedicle screw placements were performed on the thoracic vertebrae (T)9–Lumbar vertebrae (L)5 thoracolumbar vertebrae of cadavers using robotic guidance. The operative duration, puncture success, correction, and correction time were assessed. Additionally, a total of 30 thoracolumbar fractures from September 2017 until June 2019 were included in a clinical study. Two groups were evaluated: the robotic guidance group and freehand group. Both sexes were evaluated. Mean ages were 47.0 and 49.1 years, respectively, in the robotic and freehand groups. Inclusion criteria was age >18 years and a thoracolumbar fracture. Intervention was the operative treatment of thoracolumbar fractures. Outcome parameters were the operation time, intraoperative bleeding, and fluoroscopic data. The accuracy of the pedicle screw placement and screw penetration rate of the two groups were compared using intraoperative fluoroscopic axial images.

Results

The success rate for 108 one‐time nail placements in cadavers was 88% and two‐time nail placement was 100%. Vertebral punctures at L5 took the longest to perform and achieve correction. Clinically, there were no significant differences in patients' sex, body mass index, age distribution, or intraoperative bleeding between the groups. The average X‐ray exposure time for patients and operators were 37.69 ± 9.24 s and 0 s in the robotic group (significantly lower than in the freehand group: 81.24 ± 6.97 s vs 56.29 ± 7.93 s, respectively). Success rates for one‐time screw placements were 98.64 and 88.46% in the robotic and freehand groups, respectively, which is significant. Screw penetration rates (1.36% vs 11.54%, robotic vs freehand), were significantly different.

Conclusions

The robotic system improved the accuracy and safety of pedicle screw internal fixation and reduced patients' and operators' intraoperative radiation exposure.

C-reactive protein in spinal surgery: more predictive than prehistoric

PURPOSE

In spinal surgery, surgical site infections (SSI) after dorsal spondylodesis lead to severe short- and long-term complications. Despite various clinical and serological evidence, the detection of a postoperative SSI remains crucial. In this retrospective cohort study, we determined the prognostic value of C-reactive protein (CRP) kinetics after open reduction and dorsal spondylodesis in the development of a SSI.

METHODS

We retrospectively analyzed 192 patients from 2016 to 2018 undergoing open reduction and dorsal spondylodesis with and without SSI for 20 days at a level-I trauma center and assessed their serological and clinical characteristics.

RESULTS

On day 7 and 8 after surgery, patients who developed a SSI displayed significantly higher CRP levels. A second peak after the initial maximum of CRP and a restricted failure to decline as well as a maximum CRP of more than 225 mg/l predict an infectious complication with a sensitivity of 92.9%, and a specificity of 78.2%. A binary logistic regression leads to 85.7% and 69.7%, respectively. A one-phase decay exponential regression can predict 75.6% of the variance after the initial peak of CRP.

CONCLUSION

Our study demonstrates a high value of postoperative CRP kinetics in SSI detection after dorsal spondylodesis. Moreover, we observed typical CRP levels with a specific course as indicative predictors that may facilitate an early SSI detection in clinical practice.

Postoperative Prophylactic Antibiotics in Spine Surgery: A Propensity-Matched Analysis

BACKGROUND

Surgical site infections are common and costly complications after spine surgery. Prophylactic antibiotics are the standard of care; however, the appropriate duration of antibiotics has yet to be adequately addressed. We sought to determine whether the duration of antibiotic administration (preoperatively only versus preoperatively and for 24 hours postoperatively) impacts postoperative infection rates.

METHODS

All patients undergoing inpatient spinal procedures at a single institution from 2011 to 2018 were evaluated for inclusion. A minimum of 1 year of follow-up was used to adequately capture postoperative infections. The 1:1 nearest-neighbor propensity score matching technique was used between patients who did and did not receive postoperative antibiotics, and multivariable logistic regression analysis was conducted to control for confounding.

RESULTS

A total of 4,454 patients were evaluated and, of those, 2,672 (60%) received 24 hours of postoperative antibiotics and 1,782 (40%) received no postoperative antibiotics. After propensity-matched analysis, there was no difference between patients who received postoperative antibiotics and those who did not in terms of the infection rate (1.8% compared with 1.5%). No significant decrease in the odds of postoperative infection was noted in association with the use of postoperative antibiotics (odds ratio = 1.17; 95% confidence interval, 0.620 to 2.23; p = 0.628). Additionally, there was no observed increase in the risk of Clostridium difficile infection or in the short-term rate of infection with multidrug-resistant organisms.

CONCLUSIONS

There was no difference in the rate of surgical site infections between patients who received 24 hours of postoperative antibiotics and those who did not. Additionally, we found no observable risks, such as more antibiotic-resistant infections and C. difficile infections, with prolonged antibiotic use.

LEVEL OF EVIDENCE

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

Is Decompression and Partial Discectomy Advantageous Over Decompression Alone in Microendoscopic Decompression Of Monosegmental Unilateral Lumbar Recess Stenosis?

BACKGROUND

Endoscopic techniques are well accepted as surgical technique for decompression of lumbar lateral recess stenosis (LRS). It is uncertain if there is a difference in clinical outcome for decompression alone (DA) or decompression with partial discectomy (DPD) for the treatment of LRS.

METHODS

All files of patients who underwent an endoscopic procedure for lumbar LRS were identified from a prospectively collected database. Preoperative magnetic resonance imaging and endoscopic video were analyzed with special focus on the technique of nerve root decompression. Clinical outcome was assessed via a personal examination, a standardized questionnaire including the numeric rating scale (NRS) for leg and back pain, the Oswestry disability index (ODI), and the modified MacNab criteria to assess functional outcome and clinical success.

RESULTS

Sixty-six patients were identified of which 57 attended for evaluation (86.4%). DA was performed in 15 (26.3%) patients and DPD in 42 patients (73.7%). The mean follow-up was 45.0 months (range: 16-82 months). Fifty-two patients reported to be free of leg pain (91.1%), 42 patients had no noticeable back pain (73.7%), 49 patients had full muscle strength (85.9%), and 48 patients had no sensory disturbance (84.2%). The mean NRS for leg pain was 1, the mean NRS for back pain was 2, mean ODI was 16% (range: 0%-60%). Clinical success was noted in 49 patients (85.9%) and it was significantly higher for patients following DPD (P = .024). The overall repeat procedure rate was 12% with reoperation rate at the index segment in 10.5% of cases. There were no significant differences with respect to leg and back pain, ODI, and reoperation between both groups.

CONCLUSION

Microendoscopic DPD of LRS achieves a 92% clinical success rate which is significantly higher compared to 67% clinical success achieved by DA. There was no significant difference for the rate of reoperation, leg and back pain, and ODI.

LEVEL OF EVIDENCE

4.

Adolescent Disc Disease: Risk Factors and Treatment Success-Related Factors

OBJECTIVE

A paucity of literature is available discussing the associated risk factors, treatment options (including the use of minimally invasive surgery), and outcomes related to lumbar disc herniation (LDH) in children. We have discussed the risk factors for disc disease among pediatric patients and evaluated the efficacy of the minimally invasive approach.

METHODS

A retrospective review of pediatric patients with lumbar disc disease who had undergone microdiscectomy at our institution from 2005 to 2016 was conducted. The preoperative presentation, hospital course, postoperative course, and follow-up data (≥3 years) were reviewed. We evaluated the risk factors for LDH and the surgical outcomes for both groups.

RESULTS

A total of 52 pediatric patients had undergone 61 lumbar disc surgeries for LDH in our department from 2005 to 2016. Their average age at surgery was 16.65 years. Of the 61 procedures, 48 (78.7%) had been performed via the minimally invasive spine microdiscectomy approach and 13 (21.3%) via the open microdiscectomy approach. The average body mass index for all cases was 29.3 kg/m². The average interval to diagnosis was 7.9 months. Of the 61 cases, 21 (34.4%) had been required for patients who were competitive athletes. In addition, 15 had been for LDH related to trauma (24.6%). In 46 of the 61 cases, complete resolution of the symptoms had occurred at the 1-year follow-up visit (79.2% of minimally invasive spine microdiscectomy vs 61.5% of open microdiscectomy).

CONCLUSION

Risk factors similar to those for adult LDH, such as an elevated body mass index, can be seen in the pediatric population. However, some unique risk factors such as post-traumatic LDH were found in the pediatric age group. Minimally invasive techniques are demonstrably safe and useful in this patient population.

Accuracy of fluoroscopic guidance with the coaxial view of the pedicle for percutaneous insertion of lumbar pedicle screws and risk factors for pedicle breach

OBJECTIVE

In this study the authors aimed to evaluate the rate of malposition, including pedicle breach and superior facet violation, after percutaneous insertion of pedicle screws using the coaxial fluoroscopic view of the pedicle, and to assess the risk factors for pedicle breach.

METHODS

In total, 394 percutaneous screws placed in 85 patients using the coaxial fluoroscopic view of the pedicle between January 2014 and September 2017 were assessed, and 445 pedicle screws inserted in 116 patients using conventional open procedures were used for reference. Pedicle breach and superior facet violation were evaluated by postoperative 0.4-mm slice CT.

RESULTS

Superior facet violation was observed in 0.5% of the percutaneous screws and 1.8% of the conventionally inserted screws. Pedicle breach occurred more frequently with percutaneous screws (28.9%) than with conventionally inserted screws (11.9%). The breaches in percutaneous screws were minor and did not reduce the interbody fusion rate. The angle difference between the percutaneous and conventionally inserted screws was comparable. Insertion at the L3 or L4 level, right-sided insertion, placement around a trefoil canal, smaller pedicle angle, and a small difference between the screw and pedicle diameters were found to be risk factors for pedicle breach by percutaneous pedicle screws.

CONCLUSIONS

Percutaneous pedicle screw placement using the coaxial fluoroscopic view of the pedicle carries a low risk of superior facet violation. The screws should be placed carefully considering the level and side of insertion, canal shape, and pedicle angle.

Comprehensive treatment algorithm of postoperative spinal implant infection

Postoperative spinal implant infection (PSII) is a commonly found and serious complication after instrumented spinal surgery. Whereas early-onset PSII usually can be diagnosed by clinical symptoms, the diagnosis of late-onset PSII can be often made only by examination of intraoperatively collected samples. The treatment of PSII consists of surgical and antibiotic therapy schemes. In case of early PSII, the retention of spinal implants is a feasible option, whereas late PSII is usually treated by one-staged exchange of the spinal implants. Radical debridement of surrounding tissue should be performed in any case of PSII. The antibiotic treatment depends on either the implants can be removed or need to be retained or exchanged, respectively. If the causative pathogens are sensitive for biofilm-active antibiotic agents, the duration of antibiotic treatment amounts to 12 weeks with retention of spinal implants. In case of problematic pathogens, the application of antibiotics needs to be prolonged for an individual duration. Antibiotic treatment should always be initiated with an intravenous application for at least 2 weeks.

Minimally Invasive Scoliosis Correction in Parkinson Disease: Retrospective Case Series

BACKGROUND

Parkinson disease (PD) is the second most common neurodegenerative disease in the United States. In the context of the disability inherent to PD, the additional physical challenges and pain from scoliosis can be debilitating for these patients. However, the magnitude of surgery required to correct the deformity combined with the medical co-morbidities and frailty in this population of patients makes surgery very risky.

OBJECTIVE

To investigate clinical presentations and outcomes of patients with PD that underwent minimally invasive long-segment fusion for scoliosis correction.

METHODS

A retrospective chart review was performed over the years 2007 to 2017 for patients diagnosed with PD undergoing long-segment spinal fusion (5 or more levels) with the use of circumferential minimally invasive spine surgery techniques. Data including age, sex, race, medical co-morbidities, presenting symptoms, radiographic findings, surgical procedure, case history, and complications were collected from the medical record.

RESULTS

Retrospective chart review revealed three patients that met the inclusion criteria. They included 2 males and 1 female, with a mean age of 68.7 yr (range 63-75 yr). Ability to maintain upright posture, return to activities of daily living, and visual analog scale (VAS)-back improved in all patients at 1-yr follow-up. Results were durable at 2-yr follow-up. No medical complications were observed.

CONCLUSION

The generally positive results suggest that minimally invasive technique could have significant benefits in this high-risk group of patients.

Evaluating the role of methicillin-resistant Staphylococcus aureus (MRSA)-specific antibiotic prophylaxis for neurosurgical patients

OBJECTIVE

Surgical site infection (SSI) in neurosurgical patients increases morbidity. Despite the rise of methicillin-resistant Staphylococcus aureus (MRSA) colonization, there is little consensus regarding antibiotic prophylaxis for SSI in MRSA-colonized neurosurgical patients. Our objective was to examine the incidence of SSI in MRSA-colonized neurosurgical patients and interrogate whether MRSA-specific antibiotic prophylaxis reduces SSIs.

METHODS

We performed a retrospective analysis of adult patients undergoing neurosurgical procedures between 2013 and 2018. The primary outcome was SSI in patients with MRSA colonization receiving MRSA-specific antibiotics. Secondary outcomes included predictors of SSI, including whether broad use of MRSA-specific antibiotics affects SSI rate.

RESULTS

Of 9739 procedures, 376 had SSI (3.9 %). Seven hundred forty-four procedures (7.6 %) were performed on patients screened preoperatively for MRSA, including 54 procedures on MRSA-colonized patients. MRSA-colonized patients were more likely than MRSA-non-colonized patients to receive MRSA-specific antibiotics (35.2 % vs. 17.8 %, p = 0.002) for prophylaxis. Nevertheless, MRSA-colonized patients had higher SSI rates compared to MRSA-non-colonized patients (22.2 % vs. 6.4 %, p = 0.00002). MRSA-colonization led to 3.49 greater odds (95 % CI 1.52-7.65, p = 0.002) of SSI relative to MRSA-non-colonization. MRSA-colonized patients receiving MRSA-specific antibiotics, compared to those receiving non-MRSA-specific antibiotics, had lower SSI rates, but this difference was not statistically significant (15.8 % vs. 25.7 %, p = 0.40). In the non-screened population, those receiving MRSA-specific antibiotics, compared to those receiving non-MRSA-specific antibiotics, had significantly higher SSI rates (6.9 % vs. 3.0 %, p = 0.00001). The use of MRSA-specific antibiotic prophylaxis in the non-screened population increased the odds of SSI (OR 1.90, 95 % CI 1.45-2.46, p = 0.0001).

CONCLUSION

MRSA-colonized neurosurgical patients had a higher SSI rate compared to MRSA-non-colonized patients. While MRSA-specific antibiotics may benefit those with MRSA colonization, the difference in SSI rate between MRSA-colonized patients receiving MRSA-specific antibiotics vs. non-specific antibiotics requires further investigation. The broader use of MRSA-specific antibiotics may paradoxically confer an increased risk of SSI in a non-screened neurosurgical population.