Irrigation techniques used in spine surgery for surgical site infection prophylaxis: a systematic review and meta-analysis.

BACKGROUND: The greater likelihood of morbidity, mortality, length of hospital stays and poorer long-term outcomes as a result of surgical site infections secondary to spinal surgery makes prophylactic measures an imperative focus. Therefore, the aim of this review was to evaluate the available research related to the efficacy of different intraoperative irrigation techniques used in spinal surgery for surgical site infection (SSI) prophylaxis. METHODS: We performed a comprehensive search using Ovid Medline, EMBASE, Web of Science and the Cochrane library pertaining to this topic. Our meta-analysis was conducted according to PRISMA guidelines. The inclusion criteria consist of spine surgeries with intraoperative use of any wound irrigation technique, comparison groups with a different intraoperative irrigation technique or no irrigation, SSI identified with bacterial cultures or clinically in the postoperative period, reported SSI rates. Data extracted from eligible studies included, but was not limited to, SSI rates, irrigation technique and control technique. Exclusion criteria consist of articles with no human subjects, reviews, meta-analyses and case control studies and no details about SSI identification or rates. Pooled risk ratios were calculated. A meta-analysis was performed with a forest plot to determine risk estimates' heterogeneity with I2 index, Q-statistic, and p value under a random-effects model. Funnel plot was used to assess publication bias. All databases were last checked on January, 2022. PROBAST tool was used to assess both risk of bias and applicability concerns. RESULTS: After reviewing 1494 titles and abstracts, 18 articles met inclusion criteria. They included three prospective randomized-controlled trials, 13 retrospective cohort studies, two prospective cohort studies. There were 54 (1.8%) cases of SSIs in the povidone-iodine irrigation group (N = 2944) compared to 159 (4.6%) in the control group (N = 3408). Using intraoperative povidone-iodine wound irrigation produced an absolute risk reduction of 2.8%. Overall risk ratio was 0.32 (95% CI 0.20-0.53, p < 0.00001). In a global analysis, study heterogeneity and synthesizing mostly retrospective data were primary limitations. CONCLUSION: The most evidence exists for povidone-iodine and has Level 2 evidence supporting SSI reduction during spinal surgery. Other antiseptic solutions such as dilute chlorhexidine lack published evidence in this patient population which limits the ability to draw conclusions related to its use in spinal surgery. LEVEL OF EVIDENCE: II - Systematic Review with Meta-Analysis.

Chemoprophylactic Anticoagulation 72 Hours After Spinal Fracture Surgical Treatment Decreases Venous Thromboembolic Events Without Increasing Surgical Complications.

Background: Prophylactic anticoagulation is commonly used following operative treatment of spinal fractures to prevent Venous Thromboembolism (VTE) but carries a risk of bleeding complications. The purpose of the study was to compare VTE and bleeding complications for MID (≤72h) versus LATE (>72h) chemoprophylaxis timing after spinal fracture operative intervention. Methods: This is a retrospective review of patients treated for spinal fractures that received anticoagulation chemoprophylaxis between May 2015 and June 2019. Chemoprophylaxis initiation timing (MID vs. LATE) was the primary grouping variable. Patients with traumatic brain injury or evidence of intracranial or intraspinal bleed were excluded. Demographics, injury mechanisms, operative procedures, timing of administration of VTE prophylaxis, Injury Severity Score (ISS) and Spine Abbreviated Injury Scale (AIS), and complications including VTE and bleeding complications were collected. Predictors of VTE were identified using a binary logistic regression. Results: Eighty-eight patients (65M, 23F) met inclusion criteria. The median age was 55 years, and median Injury Severity Score (ISS) was 14. MID had 68 patients and LATE had 20. Nine patients developed VTE (6 LATE, 3 MID, p<0.01). Three patients developed bleeding complications, and all occurred in the LATE group (p=0.01). ISS (p<0.01) and GCS (p<0.01) also correlated with an increased VTE rate. Conclusions: Chemoprophylactic anticoagulation at 72 hours in surgically treated spinal fracture patients demonstrates a lower VTE rate without increasing complications. VTE prophylaxis can be initiated at 72 hours following spine fixation to decrease postinjury morbidity and mortality in this high-risk patient population.

Indications and timing of revision spine surgery in adults after adolescent surgery for idiopathic scoliosis.

STUDY DESIGN: Retrospective case series. PURPOSE: To characterize the indications and timing of revision spine surgery in adulthood after adolescent surgery for idiopathic scoliosis. Previous studies have shown that revision usually occurs within 3 months or more than 5 years after the index operation. It is not clear what the indications for and timeline to revision surgery are in these patients during adulthood. METHODS: 421 patients with idiopathic scoliosis were seen as adults over a 15-year period. 81 patients who had scoliosis surgery prior to age 18 were identified. This cohort was studied for indications and time from index to revision operation. Their clinical presentation and a description of their revision operation was also documented. RESULTS: Of the 81 patients, 18 (22.2%) had a revision surgery as an adult. Indications for revision in order of prevalence were implant malposition, subjacent segment degeneration and stenosis, pseudoarthrosis, delayed deep wound infection, spondylolisthesis, and symptomatic implants. Revisions were indicated generally within 15 years or more than 30 years after the initial operation. CONCLUSIONS: The timeline for revision spine surgery in idiopathic scoliosis was bimodal, with revisions occurring within 15 years or over 30 years after the initial operation. Implant malposition and subjacent segment degeneration were the most prevalent indications for adulthood revision. LEVEL OF EVIDENCE: Prognostic-IV.

Better Functional Recovery After Single-Level Compared With Two-Level Posterolateral Lumbar Fusion.

Background Multiple studies describe the outcomes of patients undergoing single-level and multilevel posterolateral lumbar fusion (PLF). However, a comparison of outcomes between single-level and two-level PLF is lacking. The aim of this prospective cohort study was to compare outcomes between single-level and two-level instrumented PLF. Methods A total of 42 patients were enrolled at nine US centers between October 2015 and June 2017. Data included radiologic outcomes, visual analog scale (VAS) Back and Leg Pain, disability per the Oswestry Disability Index (ODI), and health-related quality of life (QoL) per 36-Item Short Form Survey version 2.0 (SF-36v2) at six weeks and three, six, 12, and 24 months. Results Twelve-month and 24-month follow-ups were completed by 38 (90.5%) and 32 (76.2%) subjects, respectively. The average age was 67 years, and 54.8% were female. Twenty-six received single-level PLF, and 16 received two-level PLF. In the single-level group, there was one reoperation, two postoperative infections, and one dural tear. In the two-level group, there was one postoperative infection. The surgeon computed tomography (CT)-based evaluation of fusion rate was 67.6% (25/37) at 12-month follow-up and 94.1% (32/34) at 24-month follow-up. The third-party evaluation of fusion rate was 52.8% (19/36) at six months, 81.1% (30/37) at 12 months, and 86.5% (32/37) at 24 months. There was a tendency toward a higher fusion rate in single-level compared with two-level PLF. The ODI, SF-36v2 Mental Component Score (MCS), and VAS Back Pain and Leg Pain outcomes improved by the first follow-up visit in both the single-level and two-level groups. Improvement in the ODI was 5.86 (95% confidence interval (CI): 0.03-11.69) points greater in the single-level group compared with the two-level group. Conclusions Compared with the two-level PLF subjects, single-level PLF subjects had better functional outcomes and reported higher satisfaction with the outcome of surgery but showed similar fusion, pain, and generic health-related quality of life outcomes. Both single-level and two-level PLF subjects demonstrated high fusion rates in association with improvements in pain, functional, and quality of life outcomes, as well as high satisfaction levels.

Lumbar interbody fusion: recent advances in surgical techniques and bone healing strategies.

PURPOSE: Lumbar interbody fusion (LIF) is a treatment option for low back pain secondary to lumbar instability and/or deformity. This review highlights recent studies of surgical techniques and bone healing strategies for LIF. METHODS: Relevant articles were identified by searching the PubMed database from January 1948 to April 2020, with a focus on the last 5 years, using the following keywords: LIF approach, LIF cage, stem cells for LIF, biomaterials for LIF, and osteobiologics for LIF. RESULTS: LIF procedures were traditionally performed through either a posterior approach (PLIF), or an anterior approach. Later, the transforaminal LIF approach gained popularity over the PLIF as it entailed less nerve retraction. To minimize paraspinal muscle dissections, alternative approaches including lateral LIF, oblique LIF, and minimally invasive approaches have been developed and utilized. These modifications have improved the surgical outcomes of LIF. However, the most recent rates of non-union after LIF procedures still ranged from 7 to 20% with an even higher incidence in patients with osteoporosis. This review summarizes the advantages and disadvantages of each surgical approach and current efforts to enhance LIF by improving fusion cage material properties and developing novel osteobiologic products that contain nanomaterials for controlled release of effective osteogenic proteins and mesenchymal stem cells. CONCLUSIONS: There have been significant advances in surgical technologies for LIF over the past decades. Post-operative non-union remains a major challenge, which could be addressed by development of more effective surgical techniques, fusion cages, and bone healing products through joint efforts from spine surgeons, bone biologists, and material engineers.

Impact of unoperated adolescent idiopathic scoliosis in adulthood: a 10-year analysis.

STUDY DESIGN: Retrospective, cross-sectional. OBJECTIVE: To evaluate the impact of unoperated adolescent idiopathic scoliosis (AIS) in adulthood on pain, quality of life, and need for operative management. BACKGROUND: Long-term studies of AIS in adulthood demonstrate most patients function well, though some have increased disability. The Oswestry Disability Index (ODI) and SRS-22r are validated questionnaires for assessing back disability and quality of life. Correlation of these questionnaires to patient outcomes and necessity for surgery have not been fully defined. METHODS: Unoperated adults with AIS seen in a tertiary deformity clinic from 2008-2018 were identified. Variables included demographics, comorbidities, family history, curve size/location, pain score, ODI, SRS-22r, and previous treatment. ODI and SRS-22r scores were analyzed across three age groups: 20-39, 40-59, and ≥ 60. RESULTS: 275 eligible patients were identified and 255 (93%) patients had an ODI and/or SRS-22r score. ODI scores (220 patients) had a positive correlation with age, BMI, and curve size (p < .001). SRS-22r (204 patients) pain score was worse in all age-gender-matched domains (p < .05). Of the 255 patients in the study, 10% underwent surgery after presentation. In 118 patients with surgical-size curves (thoracic ≥ 50°; thoracolumbar ≥ 40°), no difference was seen in age or curve size between surgical and non-surgical patients; however, ODI and SRS-22r scores (excluding mental health) were significantly worse in surgical patients (p ≤ .01). CONCLUSIONS: Patients with AIS have SRS-22r scores that are lower than age-gender-matched controls in most domains. ODI had a positive linear correlation with age, body mass index, and curve size. Only 10% of adults with surgical-size curves evaluated for scoliosis elected to undergo surgery. Patients treated surgically reported worse preoperative quality-of-life scores than their non-surgical counterparts. These results can help healthcare providers when counseling patients and families concerning management options. LEVEL OF EVIDENCE: III.

Biomechanics of prophylactic tethering for proximal junctional kyphosis: effects of cyclic loading on tether strength and failure properties.

STUDY DESIGN: Biomechanical evaluation of woven polyester tethers. OBJECTIVES: To quantify changes in tether elongation, stiffness, and failure characteristics after cyclic loading. Ligamentous augmentation is gaining interest as a technique to prevent proximal junctional kyphosis (PJK) in adult spinal fusions. There are a lack of data regarding the effects of cyclic loading on polyester tether mechanical properties. Tether stretch may lead to loss of stabilization and increased risk of tether failure. Biomechanical data are needed to determine the effects of cyclic loading on tether integrity. METHODS: Testing was done in two materials: (1) a synthetic cortical bone composite to determine baseline mechanical properties, and (2) nine cadaveric L1 spinous processes. 5 mm woven polyester tethers were looped through 2.5 mm holes drilled in each material. First, five tethers were tested directly to failure in the synthetic bone to establish baseline failure properties. Next, tethers were tested at one of the three cyclic load ranges [5%, 25%, and 50% (n = 5 each) of baseline failure] for 1000 cycles and then loaded to failure. Cadaveric tests were done at the 25% range and compared to synthetic bone tests at the same range. Cadaveric failure tests were classified as either tether failure or spinous process bone failure. RESULTS: Greater cyclic loading range had a significant effect on tether loop elongation, increased stiffness, and decreased ultimate tensile force. Among the cadaveric failure tests, 56% resulted in tether failure and the remaining 44% resulted in bone failure. CONCLUSIONS: Polyester tethers stretch significantly when loaded to physiological ranges. Anticipation of tether stretch may be an important consideration for a tethering strategy to prevent PJK. Improved understanding of tether material properties can provide guidance for the evaluation of clinical outcomes associated with techniques to reduce the risk of PJK caused by ligamentous laxity. LEVEL OF EVIDENCE: Biomechanical study.

Preoperative full-length standing radiographs and revision rates in lumbar degenerative scoliosis.

OBJECTIVE Full-length (36-inch) standing spine radiographs are commonly used by spine surgeons to evaluate patients with lumbar degenerative scoliosis (LDS). Despite this practice, the impact of these images on preoperative decision making and the rate of revision surgery has not been analyzed. The purpose of this study is to determine if preoperative full-length standing spine radiographs improve surgical decision making by decreasing the rate of revision surgery in patients with LDS. METHODS From the Health Care Service Corporation administrative claims database, the authors identified patients 50-80 years of age with LDS who had undergone surgery including posterior lumbar decompression and fusion over 2-6 levels and with at least 5 years of continuous coverage after the index surgery. Patients were stratified into the following groups, according to the preoperative imaging studies performed within 6 months before their index surgery: lumbar spine MRI studies only, lumbar spine MRI studies and standard lumbar spine radiographs, CT myelograms, and full-length standing spine radiographs. Survival analysis was performed with the occurrence of a revision within 5 years of the index surgery as the outcome of interest. RESULTS A total of 411 patients were included in the study after applying the inclusion and exclusion criteria. Revision surgery within 5 years after the index procedure was most frequent in the patients with preoperative MRI only (41.8%), followed by the patients with a CT myelogram (30.4%) and those with MRI and standard radiographs (24.8%). The lowest revision rate was seen among those with long-cassette standing radiographs (11.1%). Patients whose preoperative evaluation included full-length standing radiographs (OR 0.353, p = 0.034) and MRI studies plus radiographs (OR 0.650, p = 0.022) were less likely to require revision surgery at 5 years after the index procedure. CONCLUSIONS An assessment of standing alignment using full-length (36-inch) standing radiographs may be beneficial in reducing the risk of revision surgery in patients with lumbar scoliosis. This observation was not limited to patients with large curves or substantial deformity.

Spinal Trauma in the Pediatric Polytrauma Patient.

Pediatric spine trauma, although relatively uncommon, encompasses several spinal injuries that may be associated with substantial neurologic injury and multiple traumatic injuries. Spinal injuries may have considerable lifelong effects on pediatric patients; therefore, early diagnosis and management of spinal injuries in pediatric patients is imperative to ensure optimal outcomes. Anatomic features unique to the pediatric spine predispose pediatric patients to injury patterns that are not frequently observed in adults. Careful assessment of the injury pattern and the associated anatomy aids in selection of the optimal treatment method for pediatric patients with a spinal injury.

Microsphere-Based Osteochondral Scaffolds Carrying Opposing Gradients Of Decellularized Cartilage And Demineralized Bone Matrix.

Extracellular matrix (ECM) "raw materials" such as demineralized bone matrix (DBM) and cartilage matrix have emerged as leading scaffolding materials for osteochondral regeneration owing to their capacity to facilitate progenitor/resident cell recruitment, infiltration, and differentiation without adding growth factors. Scaffolds comprising synthetic polymers are sturdy yet generally lack cues for guiding cell differentiation. We hypothesized that opposing gradients of decellularized cartilage (DCC) and DBM in polymeric microsphere-based scaffolds would provide superior regeneration compared to polymer-only scaffolds in vivo. Poly(D,L-lactic-co-glycolic acid) (PLGA) microsphere-based scaffolds were fabricated, either with opposing gradients of DCC and DBM encapsulated (GRADIENT) or without DCC and DBM (BLANK control), and implanted into rabbit osteochondral defects in medial femoral condyles. After 12 weeks, gross morphological evaluation showed that the repair tissue in about 30% of the implants was either slightly or significantly depressed, hinting toward rapid polymer degradation in scaffolds from both of the groups. Additionally, no differences were observed in gross morphology of the repair tissue between the BLANK and GRADIENT groups. Mechanical testing revealed no significant differences in model parameter values between the two groups. Histological observations demonstrated that the repair tissue in both of the groups was fibrous in nature with the cells demonstrating notable proliferation and matrix deposition activity. No adverse inflammatory response was observed in any of the implants from the two groups. Overall, the results emphasize the need to improve the technology in terms of altering the DBM and DCC concentrations, and tailoring the polymer degradation to these concentrations.