Search Results (164)

Background: To investigate the risk factors for and prognostic implications of massive blood loss during posterior spinal instrumentation and fusion (PSIF) in pediatric patients with scoliosis. Methods: We retrospectively analyzed the electronic medical records of 460 children who underwent scheduled PSIF under general anesthesia between June 2021 and January 2024. Patients were grouped based on intraoperative blood loss: massive (estimated blood loss [EBL]/estimated blood volume [EBV] ≥ 30%) and nonmassive (EBL/EBV < 30%). Perioperative parameters were compared. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for massive intraoperative blood loss. Results: Among the 460 patients with scoliosis who underwent PSIF, 188 were male and 272 were female (mean age 9.4 ± 4.1 years). Massive intraoperative blood loss occurred in 126 (27%) patients. Factors associated with massive blood loss included age, preoperative Cobb angle, history of heart disease or neurofibromatosis, number of previous scoliosis surgeries, operative time, number of fused levels, number of pedicle screws inserted, and whether osteotomy was performed. Multivariate analysis identified younger age (odds ratios [OR] = 0.829, 95% confidence interval [CI], 0.751–0.914, p < 0.001), history of heart disease (OR = 4.338, 95% CI: 1.637–11.498, p = 0.003), greater number of fused levels (OR = 1.118, 95% CI: 1.014–1.233, p = 0.025), and longer operative time (OR = 1.008, 95% CI: 1.005–1.012, p < 0.001) as independent risk factors. Additionally, the massive blood loss group had a longer postoperative hospital stay (p = 0.008) and a higher rate of postoperative allogeneic blood transfusion (7.1% vs. 1.2%, p = 0.002) than the nonmassive blood loss group. Conclusions: Younger age, preexisting heart disease, a greater number of fused levels, and longer operation duration are independent risk factors for massive intraoperative blood loss in children undergoing PSIF for scoliosis. Full article

Background/Objectives: Extraforaminal lumbar interbody fusion provides indirect decompression without entering the spinal canal, but its uptake has been limited by poor visualization and risk of exiting nerve root injury. We describe a minimally invasive exoscopic extraforaminal lumbar interbody fusion (exELIF) technique and evaluate its clinical and radiological outcomes. This study aims to describe the exELIF technique and report its early clinical and radiological outcomes. Methods: Twenty-six patients with lumbar degenerative diseases underwent exELIF using a 3D exoscope (ORBEYE). The procedure was performed through bilateral 30–40 mm posterior incisions. Clinical outcomes were assessed using the Japanese Orthopedic Association score preoperatively and at 1-year follow-up. Postoperative computed tomography evaluated interbody fusion. Operative time, blood loss, and complications were recorded. Results: Mean operative time was 131 ± 51 min, and mean estimated blood loss was 82 ± 99 mL. The mean JOA score improved from 15.2 ± 2.2 to 24.3 ± 2.6, with a mean recovery rate of 66% at 1 year. Interbody fusion was achieved in 96%. In an exploratory CUSUM analysis of 18 single-level fluoroscopy-guided cases, a transition in operative time was observed at approximately the 10th case; operative time and estimated blood loss decreased from 141.5 ± 39.2 min and 89.0 ± 77.8 mL in cases 1–10 to 80.1 ± 6.7 min and 21.2 ± 18.1 mL in cases 11–18 (p < 0.001 and p = 0.035, respectively), indicating a reduction of operative time with accumulated experience rather than a formally established learning curve. Three patients developed transient exiting nerve root symptoms that resolved spontaneously during follow-up. One patient at the L5/S level required revision surgery due to left L5 nerve root palsy caused by posterior migration of the bone graft; this complication led to a modification of the technique, with posterior bone grafting no longer performed at L5/S. Partial screw loosening was observed in 5 patients (19%), all of which were asymptomatic and required no additional intervention. Conclusions: ExELIF provides excellent visualization in deep surgical fields, allowing the use of conventional surgical instruments through minimally invasive incisions. This is an early feasibility report of a single-institution retrospective case series with a heterogeneous cohort and no control group; the present data therefore do not establish superiority over conventional or endoscopic ELIF. Within these limits, exELIF was associated with acceptable early clinical improvement and a high interbody fusion rate, and progressive reduction in operative time with experience suggests that it may be a technically feasible minimally invasive option for selected patients with lumbar degenerative disease and for revision surgery after lumbar decompression. Full article

Background: Implant-related mechanical failure remains a clinically relevant concern following posterior decompression and fusion in elderly patients with lumbar spinal stenosis (LSS). The relative contribution of host-related versus construct-related factors to failure risk requires further clarification. Methods: This retrospective single-center cohort study included 118 patients aged ≥65 years who underwent single-level hemilaminectomy with posterolateral fusion (PLF) for isolated L4–5 central LSS, with a minimum follow-up of 48 months (mean 51.0 ± 2.0 months). All procedures were performed using a standardized posterior technique with uniform 6.5-mm titanium rods and 6.5-mm pedicle screws. Mechanical failure was defined as revision surgery due to radiographically and clinically confirmed hardware-related complications in the absence of infection. Exploratory univariable analyses were conducted to evaluate associations between baseline variables and mechanical failure. Clinical outcomes were assessed using validated patient-reported outcome measures. The Oswestry Disability Index (ODI), Roland Morris Disability Questionnaire (RMDQ), and Visual Analog Scale (VAS) for pain were recorded. Results: Overall revision rate was 13.6% (16/118), including 14 cases (11.9%) of implant-related mechanical failure and 2 cases (1.7%) of infection-related revision. Higher age (p = 0.005), higher body mass index (BMI) (p = 0.005), lower bone mineral density (BMD) (p < 0.001), active smoking (p < 0.001), and diabetes mellitus (DM) (p = 0.023) were significantly associated with mechanical failure. Functional outcomes (ODI, RMDQ, VAS) improved significantly at final follow-up (all p < 0.001). Conclusions: Mechanical failure following hemilaminectomy with PLF appears to be predominantly influenced by host-related factors rather than construct characteristics when a standardized surgical technique is applied. Bone quality and modifiable systemic risk factors may play a critical role in long-term construct durability. Full article

The aim of the present study was to compare the cost-effectiveness of 3DMorphic’s spinal 3DFusion Lumbar (3DFL) cages versus Off-The-Shelf (OTS) cages for patients undergoing lumbar interbody fusion in an Australian healthcare setting. 3DFL cages differ from generic OTS cages in that they are Patient-Specific Interbody Cages (PSICs). While several studies have discussed the clinical benefits of PSIC versus OTS cages, no studies have evaluated the cost-effectiveness of this technology. Without a direct randomised controlled trial between the two implant categories, an indirect treatment comparison was performed. The indirect comparison was informed by a clinical trial of 3DFL cages, the Australian Spine Registry and an analysis of reoperation rates for patients undergoing spinal fusion in an Australian cohort. In conclusion, the PSICs were demonstrated to be clinically superior to OTS cages as measured by Health Related Quality of Life (HRQoL) and reoperation rates. The cost-utility analysis demonstrated that 3DFL cages were cost-effective compared to OTS cages in an Australian healthcare setting. Full article

Background: Posterior decompression with instrumented fusion (PDF) is a conventional surgical procedure performed in patients with massive ossification of the posterior longitudinal ligament (OPLL); however, it is invasive to the posterior cervical tissues. In this report, we introduce a novel PDF technique, exoscopic minimally invasive open-door laminoplasty with pedicle screw fixation (exLAPPS), to treat cervical OPLL, while minimizing posterior tissue damage. Methods: ExLAPPS was indicated for patients with K-line (−) OPLL or a canal occupying a ratio of ≥50%, allowing decompression from C3 to C7. A small midline incision was used for the navigation reference placement and exoscopic minimally invasive open-door laminoplasty, whereas bilateral lateral incisions were utilized for posterior fixation, including pedicle screw insertion, based on the minimally invasive cervical pedicle screw technique. Results: A total of 7 patients with K-line (-) or a canal occupancy ≥50% underwent exLAPPS for cervical OPLL. The mean operative time was 248 min (range, 165–342 min) and the mean blood loss was 320 mL (range, 50–740 mL). Postoperative imaging demonstrated adequate spinal cord decompression in all patients. A total of 52 pedicle screws were inserted, with a pedicle screw deviation rate of 1.9%. Conclusions: ExLAPPS is a minimally invasive surgical technique designed for posterior decompression and fixation in patients with cervical OPLL. In this preliminary case series, the procedure was successfully performed with acceptable operative time, blood loss, and screw placement accuracy. Although the present study did not include a direct comparison with conventional procedures, these preliminary observations suggest that ExLAPPS is a feasible surgical option for selected patients with cervical OPLL. Full article

Lumbar interbody fusion is widely performed for degenerative, deformity-related, and instability-associated spinal conditions. Yet, reported outcomes remain variable across grafting strategies and surgical techniques. While advances in instrumentation and cage design improve immediate construct stability, successful arthrodesis depends on early graft behavior within the interbody environment. This includes positional stability, interface contact, and load transfer prior to mature bone formation. Synthetic bone graft substitutes are commonly used to supplement or replace autograft. However, the clinical literature describing these materials is heterogeneous with respect to composition, structural presentation, surgical context, and outcome reporting. This narrative review synthesizes clinical, translational, and biomechanical studies published between 2019 and 2025 that evaluate synthetic bone graft substitutes used in adult lumbar interbody fusion. Rather than comparing individual products or reported fusion rates, grafts are organized by material class and examined through early mechanical events such as graft migration, loss of graft–endplate contact, and cage subsidence. Across recent studies, variability in fusion definitions, imaging modalities, postoperative timepoints, and documentation of early mechanical events limits direct comparison and quantitative synthesis. These findings highlight the need for improved reporting consistency and greater emphasis on engineering-relevant variables in future investigations. Full article

Background/Objectives: Adult degenerative scoliosis (ADS) is a spinal disease causing pain and reduced mobility, often occurring with degenerative lumbar spinal stenosis (DLSS). While fusion stabilizes the spine, it has drawbacks like loss of motion and adjacent segment degeneration. Minimally invasive techniques, such as tubular unilateral laminotomy for bilateral decompression (tULBD), provide a less invasive alternative, but their impact on ADS with DLSS is underexplored. This study examines the short-term effects of navigated tULBD on radiological and clinical outcomes in this patient population. Methods: This retrospective single-center study analyzed patients aged ≥18 years with DLSS and ADS (Cobb angle ≥ 10°), with or without grade I spondylolisthesis, who underwent navigated tULBD between June 2019 and October 2022. Radiological parameters were assessed pre- and post-operatively using AI-powered FXA™ Version 1.33, Raylytic Software GmbH, Leipzig, Germany, while clinical outcomes were evaluated using the Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) for back and leg pain. Statistical analyses were conducted with R Studio. Results: This study included 20 patients (mean age 74.6 ± 7.6 years, body mass index [BMI] 26.08 ± 3.7 kg/m²), with a median follow-up of 2 months. Most underwent single-level decompression (45%), with a median of 2 surgical levels (IQR: 1–3). Radiological parameters showed no significant changes (p > 0.05). Clinically, the median NRS back improved from 5 (IQR: 3–9) preoperatively to 2 (IQR: 0–2) postoperatively (p = 0.009) and 1 (IQR: 0–4.5) at follow-up (p = 0.004). NRS leg scores dropped from 3.5 (IQR: 0–5) to 0 postoperatively and at follow-up (p = 0.02, p = 0.04). ODI improved from 37.8 (IQR: 29–42.5) preoperatively to 17.5 (IQR: 5–24) at follow-up (p = 0.04). There were no neurological complications. Conclusions: Navigated tULBD is a promising, minimally invasive option for mild ADS and DLSS. It provides significant pain and disability relief without adversely affecting stability and alignment. Long-term studies are needed to confirm durability and efficacy, particularly in severe cases. Full article

Background/Objectives: This study aimed to evaluate the effect of preoperative halo-gravity traction (HGT) on surgical outcomes in adolescents with severe idiopathic scoliosis (AIS), comparing posterior spinal fusion (PSF) performed with versus without traction in terms of curve correction, complication rates, and overall surgical efficacy. Methods: A retrospective cohort study was conducted on 46 adolescents (mean age 14.6 ± 1.9 years) with severe AIS (Cobb > 65°) treated at a single tertiary center between 2011 and 2024. Sixteen patients underwent primary PSF, and 30 received preoperative HGT followed by PSF. Radiographic parameters—including Cobb angle and Risser grade—were analyzed pre- and postoperatively. Statistical tests (t-test, Mann–Whitney U, and multivariable linear regression) assessed differences in correction and predictors of outcome, with p < 0.05 considered significant. Results: Baseline characteristics were comparable between groups (mean preoperative Cobb: 83.6° ± 11.2° vs. 83.1° ± 15.6°, p = 0.91). The traction cohort achieved significantly smaller postoperative Cobb angles (30.9° ± 7.8° vs. 42.7° ± 18.9°, p = 0.027), greater absolute correction (52.7° ± 7.4° vs. 40.4° ± 10.5°, p < 0.001), and higher percentage correction (63.3% ± 6.7% vs. 50.0% ± 14.0%, p = 0.002). Regression analysis confirmed HGT as an independent predictor of improved correction (+14.6%, 95% CI +6.9–22.3%, p = 0.00047). No neurological or major complications occurred, and most correction was achieved within the first three weeks of traction. Conclusions: Preoperative halo-gravity traction significantly enhances deformity correction and surgical safety in severe AIS without added morbidity. Most benefit occurs within 21 days, supporting shorter, standardized traction protocols. HGT remains a valuable adjunct for optimizing outcomes in rigid scoliosis prior to posterior spinal fusion. Full article

Background: Quantifying intraoperative nociceptive responses under general anesthesia remains challenging, particularly during complex procedures such as spinal surgery. The Nociception Level (NoL) index is a multiparametric tool designed to reflect the dynamic balance between nociception and analgesia in anesthetized patients. This study aimed to evaluate NoL fluctuations during predefined phases of spinal surgery and assess their relationship to anesthetic administration. Methods: This prospective observational study enrolled 44 adult patients undergoing lumbar discectomy, laminectomy, or spinal fusion under remifentanil–propofol anesthesia. Continuous NoL monitoring was performed using the PMD100™ system. Sixteen anatomically and procedurally defined surgical phases were analyzed. The primary outcome was the mean NoL value in each phase. The secondary outcome was the association between NoL values and intraoperative infusion rates of remifentanil and propofol. Repeated-measures ANOVA with Bonferroni correction was used for phase comparisons. Results: Mean NoL values remained within the target range (10–25) in most phases. However, significant elevations were observed during pedicle screw insertion (mean 27.9, SD ± 17.7), cage insertion (27.6, SD ± 10.5), and flavectomy (28.0, SD ± 27.0), indicating increased nociceptive burden. The lowest NoL values occurred during skin closure (16.6, SD ± 11.2) and discectomy (18.0, SD ± 2.8). Propofol and remifentanil infusion rates remained within standard clinical ranges but were slightly elevated during high-NoL phases. Conclusions: Despite standardized anesthesia, distinct nociceptive peaks were observed during specific stages of spinal surgery. These findings suggest that NoL monitoring may help identify high-nociception phases and guide tailored analgesic strategies. Future randomized trials are warranted to assess whether protocolized NoL-guided anesthesia improves intraoperative management and postoperative outcomes. Full article

Background/Objectives: Endoscopic lumbar interbody fusion (ELIF) represents a key milestone in minimally invasive spinal surgery, offering reduced tissue trauma, lower complication rates, and faster recovery compared with open fusion. However, its steep learning curve remains a major barrier to widespread adoption. This systematic review aimed to synthesize current evidence on the ELIF learning curve and identify factors that influence the acquisition of surgical proficiency. Methods: A comprehensive literature search of PubMed, Embase, and the Cochrane Library was conducted for studies reporting quantitative analyses of the ELIF learning curve. Eligible articles included clinical data describing operative performance, complication rates, and learning curve cutoff points. Study quality was evaluated using the Newcastle–Ottawa Scale. Pooled data were analyzed to determine the mean cutoff point between the early and proficient phases and to compare outcomes across surgical approaches. Results: Five eligible studies encompassing 425 patients were included. Operative time was the most frequently assessed outcome, followed by hospital stay and complication rates. The pooled cutoff point for operative time was 23.4 ± 8.9 (range, 12–29) cases. Full-endoscopic ELIF tended to require longer operative times but resulted in shorter hospital stays than biportal techniques. Conclusions: ELIF reflects the evolution of endoscopic fusion techniques. The proficiency threshold varies according to the outcome parameters and the type of endoscopic system. Structured training programs and standardized educational pathways are essential for optimizing the learning process and ensuring safe and efficient implementation. Full article

Background: Osteoporosis and low bone mineral density are highly prevalent among patients undergoing spinal fusion, contributing to higher rates of hardware failure, revision surgery, and poor postoperative outcomes. Despite clear risks, perioperative screening and treatment for osteoporosis remain inconsistent. Bone Health Clinics (BHCs) and Fracture Liaison Services (FLSs) have emerged as multidisciplinary models to address this care gap. We describe the implementation of a dedicated BHC at a single academic center and evaluate perioperative pharmacotherapy patterns, treatment barriers, and surgical outcomes among spine patients. Methods: We retrospectively reviewed 174 consecutive perioperative spine patients referred to our institutional BHC between October 2019 and April 2024. Demographics, surgical characteristics, bone health status, laboratory and DXA results, pharmacologic management, contraindications, insurance-related barriers, and medication sequencing were collected. Surgical outcomes included hardware failure and revision surgery. Bone health response was assessed by follow-up DXA scans. Results: The cohort was predominantly female (78.2%) with a mean age of 71.9 years. Most patients were referred by neurosurgery (53.4%) or orthopedics (41.4%). Based on DXA and fragility fracture history, 27.0% had osteopenia, 56.3% osteoporosis, and 13.8% severe osteoporosis. Pharmacotherapy was prescribed in 146 patients (83.9%), most commonly romosozumab (32.9%), denosumab (22.6%), and abaloparatide (21.2%). Twenty-eight patients (16.1%) did not receive medication, primarily due to contraindications. Insurance-related barriers disproportionately affected anabolic agents, whereas denosumab had the lowest denial rate (15.2%, p = 0.0124). Sequential therapy was common (32.1%), most frequently romosozumab followed by denosumab. Hardware failure occurred in 11.5% of patients, with 5.7% requiring revision surgery. Among the 80 patients (46.0%) with follow-up DXA, 60% demonstrated improved bone mineral density, with an average T-score gain of 0.6 ± 0.5. Conclusions: Integration of a multidisciplinary BHC into perioperative spine care was feasible, associated with high rates of pharmacotherapy initiation, and demonstrated favorable early surgical outcomes compared to published complication rates in this population. Insurance and contraindications remain key barriers to anabolic therapy access, driving prescribing toward denosumab. Prospective studies are needed to confirm the impact of perioperative bone optimization on surgical durability, cost-effectiveness, and patient-centered outcomes. Full article

Spinal sarcomas are rare, aggressive tumors requiring wide resection that creates large, challenging defects. Conventional reconstruction using allografts or metallic implants is prone to failure in compromised settings like irradiated or infected tissue. This narrative review synthesizes the literature on biologic reconstruction strategies, focusing on vascularized bone grafts (VBGs) and the ‘spinoplastic’ reconstruction approach, to provide a clinical framework for their application. We performed a narrative literature review using PubMed and Scopus to synthesize clinical studies describing biologic spinal reconstruction in compromised host beds. The main findings show that pedicled VBGs (e.g., rib, iliac crest) and free VBGs (e.g., fibula) function as living structural components. ‘Spinoplastic’ reconstruction leverages these grafts to promote biologic fusion, with clinical series reporting high union rates, even in irradiated or revision settings, offering a durable alternative to avascular constructs. Biologic reconstruction using VBGs is a critical strategy for achieving durable spinal stability in these challenging scenarios, and future directions point toward hybrid strategies combining 3D-printed implants with the biologic power of VBGs. Full article

Persistent postoperative opioid use (PPOU) is an emerging challenge in pediatric perioperative care, with rates as high as 4.7% in opioid-naive adolescents. Despite advances in multimodal analgesia, current protocols often fail to prevent long-term opioid exposure, particularly after high-risk surgeries such as spinal fusions. While multiple strategies exist to reduce PPOU in children, including regional anesthesia and non-opioid analgesics, this review specifically focuses on methadone and pharmacogenomic-guided opioid prescribing as promising approaches. Methadone, a long-acting opioid with mu-opioid agonism, NMDA antagonism, and monoamine reuptake inhibition, has shown encouraging outcomes in adult and emerging pediatric studies but remains underutilized due to concerns over safety, variability, and familiarity. This narrative review explores the intersection of methadone pharmacology, pharmacogenomic (PGx)-guided opioid prescribing, and their potential to reduce PPOU and optimize perioperative pain control in children. We examine methadone’s unique pharmacokinetic profile, extended half-life, and ability to reduce central sensitization and opioid tolerance. Data from pediatric trials in cardiac, spinal, and major abdominal surgeries are reviewed, highlighting methadone’s potential to lower total opioid use, stabilize postoperative pain trajectories, and improve recovery. The review also discusses the role of PGx testing, particularly CYP2D6, CYP3A4, UGT2B7, and OPRM1 variants, in tailoring methadone dosing to individual metabolic profiles, reducing adverse effects, and improving analgesic efficacy. There are no well accepted generalizable perioperative methadone dose, number of doses and dosing intervals due to limited large multicenter studies in children. We outline challenges, including QTc prolongation, dosing variability, lack of pediatric-specific PGx guidelines, and ethical considerations around genetic testing in minors. The review calls for multidisciplinary perioperative teams, expanded PGx implementation, and real-world data from registries and AI-integrated models to support precision opioid strategies. Preventing PPOU in children is critical. Integration of methadone-based multimodal analgesia in high-risk painful in-patient procedures and future integration of PGx represent positive steps toward personalized, effective, and safer pain management in pediatric surgical patients, an urgent need as opioid stewardship becomes a clinical and public health imperative. Full article

Background/Objectives: Screw placement accuracy with robotic guidance shows better results than freehand techniques, yet there is scant data for region-specific outcomes, fusion rates, and complication profiles in different populations. The purpose of this study is to assess and describe screw-rod accuracy, fusion rates, and complications of robot-assisted pedicle screw placement in a Spanish cohort. Methods: Robotic-guided technique for thoracolumbar fusion in 115 patients (July 2020–January 2025) using ExcelsiusGPS^® platform (Globus Medical Inc., Audubon, PA, USA). Inclusion criteria: adults (≥18 years) with postoperative CT to assess accuracy. Primary outcomes were screw accuracy (assessed on the Gertzbein–Robbins scale), fusion rates, and complications (infection, osteolysis, and subsidence). Jamovi 2.6 was employed for statistical analysis. Results: Of a total of 726 screws implanted, 590 screws (95 patients) were studied: 584 (99%) Grade A, 5 (0.8%) Grade B, and 1 (0.2%) Grade C. Fusion was achieved in 85 out of 95 patients (89.5%). Complications included superficial infections (3/115 patients, 2.6%) and asymptomatic osteolysis (8/95 patients, 8.4%, mostly at S1). There was no screw subsidence or removal. Conclusions: Robotic-guided pedicle screw placement demonstrated exceptional accuracy (99% Grade A), high fusion success (89.5%), and minimal complications in this Spanish cohort, supporting its clinical utility for spinal instrumentation. Full article

Background/Objectives: Surgical Site Infections (SSIs) are among the most common complications of Posterior Spinal Fusion (PSF) in children and adolescents. The rate of SSIs after PSF varies from 0.9% to 3% for idiopathic scoliosis and can be as high as 8.7% for neuromuscular scoliosis due to cerebral palsy. Major factors associated with SSIs include patient’s underlying pathology and comorbidities, the complexity of the procedure, and many extrinsic factors such as the expertise of the surgeon, perioperative antibiotic prophylaxis, length of hospitalisation, and perhaps environmental factors in the operating theatre and the hospital infections rates of the centre at which the procedure is being performed. We sought to identify the overall rate of SSI and possible modifiable risk factors for SSI in children and adolescents treated with PSF in Penteli Children’s Hospital. Methods: A total of 46 consecutive patients accounting for 67 surgeries performed between 2019 and 2024 were included in this retrospective observational study. Inclusion criteria were as follows: patient’s age at the time of surgery less than 22 years, patients treated with PSF only, and more than 9 months postoperative observation. SSI was defined as infection occurring within 90 days of the index procedure. Results: The rate of deep SSI in our department was 6.0%. Older age at the time of surgery and a history of previous spine surgery were risk factors for developing an SSI. Conclusions: Between 2019 and 2024 four cases of deep SSI occurred in our institution, leading to a rate of 6.0% among all PSF cases for this specific time period. Higher age and a history of previous spine surgery were risk factors for SSI in this cohort of patients. Full article