Incidence and risk factors of wound complications in long segment instrumented thoracolumbar spinal fusions: a retrospective study

Retrospective analysis of medium-term outcomes following anterior lumbar interbody fusion surgery performed in a tertiary spinal surgical centre

INTRODUCTION

Anterior lumbar interbody fusion (ALIF) can treat spondylolisthesis, degenerative disc disease and pseudoarthrosis. This approach facilitates complete discectomy, disc space distraction, indirect decompression of neural foramina and placement of large interbody devices. Several intra- and postoperative complications can be attributed to the anterior approach: vascular/visceral injury, hypogastric plexus injury and urogenital consequences. Spine-specific complications include implant migration, graft failure, pseudoarthrosis and persistent symptomology.

METHODS

This retrospective study reviewed patient demographics, medium-term outcomes and complication rates following ALIF surgery performed over a 5-year period. A total of 110 consecutive patients had undergone ALIF surgery at a single tertiary spinal centre. The database was reviewed with a primary outcome of identifying postoperative 90-day complications and whether a revision anterior operation was required after primary ALIF.

RESULTS

No patients required revision anterior operation after their primary ALIF surgery by final follow-up. Out of 110 patients, 11 (10%) recorded a complication attributed to the anterior stage of their operation within 90 days.

CONCLUSIONS

Our 90-day complication rate of 10% lies within the 2.6% acute complication and 40% overall complications rates described in previous literature. The risk of vascular/visceral injury is significant (3%) and we recommend that ALIF be performed as a dual surgeon procedure with a vascular-trained access surgeon accompanying the spinal surgeon. ALIF is a valid revision surgical option for failed posterior approaches leading to complications such as pseudoarthrosis. In our sample, 89% of patients were managed with posterior fixation to augment the anterior fusion as, biomechanically, this is a proven construct.

Impact of obesity on adult spinal deformity (ASD) long-segment spinal fusion radiographic and clinical outcomes

STUDY DESIGN

Retrospective chart review of patients receiving long-segment fusion during a five-year period.

OBJECTIVE

To determine whether obese patients receive comparable benefits when receiving long-segment fusion compared to non-obese patients and to identify factors that may predict hardware failure and post-surgical complications among obese patients.

METHODS

Demographic, spinopelvic radiographic, patient-reported outcome measures (PROMs), and complications data was retrospectively collected from 120 patients who underwent long-segment fusion during a five-year period at one tertiary care medical center. Radiographic measurements were pelvic incidence, pelvic tilt (PT), lumbar lordosis, L4-S1 lordosis, thoracic kyphosis, sagittal vertical axis, PI-LL mismatch, and proximal junction cobb angle at upper instrumented vertebrae + 2 (UIV+2). PROMs were Oswestry disability index, numeric rating scale (NRS) Back Pain, NRS Leg Pain, RAND SF-36 pain, and RAND SF-36 physical functioning. Included patients were adults and had at least 2-years of postoperative follow-up. Descriptive and multivariate statistical analysis was performed with α = 0.05.

RESULTS

Patients with a BMI ≥ 30 (n=63) and patients with a BMI < 30 (n=57) demonstrated comparable improvements (P>0.05) for all spinopelvic radiographic measurements and PROMs. Each cohort demonstrated significant improvements from pre-assessment to post-assessment on nearly all spinopelvic radiographic measurements and PROMs (P<0.05), except PT and L4-S1 lordosis where neither group improved (p=0.95 and 0.58 for PT and P=0.23 and 0.11 for L4-S1 lordosis fornon-obese and obese cohorts respectively) and SF-36 physical functioning where the non-obese cohort not statistically improve (P=0.08). Patients with a BMI ≥ 30 demonstrated an increased incidence of cardiovascular complications (P=0.0293), acute kidney injury (P=0.0241), rod fractures (P=0.0293), and reoperations (P=0.0241) when compared to patients with a BMI < 30.

CONCLUSION

This study adds to a growing body of evidence linking demographic factors with risks of hardware failure. Further, this data challenges the assumption that obese patients may not receive sufficient benefit to be long-segment surgical candidates. However, given their elevated risk for post-operative and delayed hardware complications, obese patients should be appropriately counseling before undergoing surgery.

A New Predictive Nomogram for the Risk of Delayed Incision Healing After Open Posterior Lumbar Surgery: A Retrospective Study

STUDY DESIGN

This was a primary research study.

OBJECTIVE

A risk nomogram was established and externally validated by exploring the related risk factors for delayed incision healing in patients undergoing open posterior lumbar surgery.

SUMMARY OF BACKGROUND DATA

The use of a nomogram model to predict prognosis in patients with delayed incision healing is an evolving field given the complex presentation of patients with this condition.

PATIENTS AND METHODS

This study reviewed 954 patients with data collected from January 2017 to December 2021 who were randomized into a training set and a validation set (7:3). We built a prediction model based on a training set of 616 patients. The "least absolute shrinkage and selection operator" regression model was applied to screen out the optimal prediction features, and binary logistic regression was used to develop a prediction model. The discrimination, calibration, and clinical applicability of the prediction model were assessed by using the area under the curve, C -index, calibration curve, and decision curve analysis.

RESULTS

Postoperative delayed incision healing occurred in 214 (24.4%) patients. The least absolute shrinkage and selection operator regression model showed that smoking, white blood cell count, infection, diabetes, and obesity were involved in delayed incision healing ( P ≠ 0). A binary logistic regression model confirmed that smoking [odds ratio (OR) = 3.854, 95% CI: 1.578~9.674, P = 0.003], infection (OR = 119.524, 95% CI: 59.430~263.921, P < 0.001), diabetes (OR = 3.935, 95% CI: 1.628~9.703, P = 0.003), and obesity (OR = 9.906, 95% CI: 4.435~23.266, P < 0.001) were predictors of delayed incision healing, and a nomogram model was established. The area under the curve was 0.917 (95% CI: 0.876-0.959). The calibration curve showed good consistency. Decision curve analysis showed that when the risk threshold of delayed incision healing was >5%, the use of this nomogram was more clinically valuable.

CONCLUSIONS

Smoking, infection, diabetes, and obesity are risk factors for delayed incision healing. The nomogram model could be used to predict the risk of delayed incision healing and could provide a reference for early clinical intervention.

Risk factors for incisional complications after lumbar internal fixation via posterior midline approach: A case-control study of 455 consecutive cases

To analyse the clinical data of patients who developed incisional complications and those who did not develop incisional complications after lumbar internal fixation, and investigate the risk factors for incisional complications in patients after lumbar internal fixation with posterior midline incision. A standardised data collection form was used to collect the clinical data of patients who were admitted and underwent lumbar internal fixation in our hospital from July 2018 to July 2021. Patients who experienced any one of the incisional complications, such as incision exudates, swelling, blisters, bruising, superficial/deep incisional infections, poor healing and scarring, after surgery were included in the incisional complication group, and patients who did not develop the above-mentioned incisional complications were included in the control group. Univariate logistic regression analysis was first performed to identify potential risk factors, significant factors from univariate analysis were then included in multivariable logistic regression analysis to identify independent risk factors for incisional complications after lumbar spine surgery. Among 455 patients included in the study, postoperative incision complications occurred in 82 patients, with an incidence rate of 18.02%. Multivariate regression analysis identified seven independent risk factors for incisional complications: age, body mass index, preoperative albumin level, hypertension, diabetes mellitus, operation time and local anaesthetic infiltration at the incision site after surgery. Our findings documented that age, body mass index, preoperative albumin level, hypertension, diabetes mellitus, operation time, and postoperative local anaesthetic infiltration at the incision site were risk factors for incisional complications after lumbar internal fixation with posterior median incision. Awareness of these risk factors can enable surgeons to develop a more appropriate perioperative management plan for patients undergoing lumbar internal fixation, thus helping them recover faster.

Plastic Surgery Closure of Complex Spinal Wounds

Wound breakdown and infection are common complications after complex spine surgery and may occur in up to 40% of high-risk patients. These are challenging scenarios which can result in a prolonged hospital stay, revision surgery, and elevated costs. Reconstructive specialists can do prophylactic closures for high-risk groups to potentially reduce the risk of developing a wound complication. These plastic surgery techniques often involve multilayered closure, with the addition of local muscle and/or fasciocutaneous flaps. The goal of this study was to review the literature for risks associated with wound complications, identification of high-risk patients, and the advantages of using plastic surgery techniques. In addition, we elaborate on the multilayered and flap closure technique for complex spine surgery which is done at our institution.

Surgical and Clinical Outcomes Associated With the Use of Barbed Sutures and Self-Adhering Mesh System and Polymeric Glue for Wound Closure in Multilevel or Revision Spinal Surgery: A Matched Cohort Comparative Study With Conventional Wound Closure Procedure

OBJECTIVE

Multilevel or revisional posterior spinal surgery is prone to infection and delayed wound healing, related with the wound closure time and suture strength. Knotless barbed suture is an innovative self-locking, multianchor suture. This study aims to evaluate the safety and efficacy of the knotless barbed suture and self-adhering mesh with polymeric glue in multilevel or revisional posterior spinal surgery.

METHODS

This is a single-center retrospective matched cohort study. Patients were divided into 2 groups based on the wound closure method: barbed suture group with novel wound closure, and conventional suture group with conventional wound closure, 1:1 matched by the level of surgery and sex, resulting in 120 subjects each. Total operation time and wound closure time were measured intraoperatively, and perioperative clinical outcome parameters including postoperative wound complication were investigated for the first 3 months postoperatively. The distribution of continuous variables was assessed for normality by Shapiro-Wilk test, then parametric or nonparametric tests were applied accordingly (paired t-test or Wilcoxon signed-rank test).

RESULTS

Wound closure time was significantly shorter with the novel barbed suture than with conventional suture in all subgroups divided by the level of spinal surgery: 3-5, 6-9, ≥ 10 levels (p < 0.001). The 2 groups showed no significant differences in surgical complications (p = 1.000). Specially, total operation time and wound-closing time were significantly shorter in revisional subgroup.

CONCLUSION

Absorbable knotless barbed suture and self-adhering mesh with polymeric glue can shorten spinal wound closure time with noninferiority in complications for multilevel or revisional spinal surgery.

Risk Factors for Surgical Site Complications After Outpatient Lumbar Spine Surgery

Background: With the recent increase of minor lumbar spine surgeries being performed in the outpatient setting, there is a need for information on factors that contribute to post-operative complications for these surgeries. Patients and Methods: This was a prospective observational study examining risk factors for self-reported post-operative drainage in patients who underwent lumbar spine surgery. Patient surveys and the hospital's electronic medical records were used to collect data on patient demographic, patient lifestyle, and surgical variables. Univariable and multivariable analyses in addition to a random forest classifier were performed. Results: A total of 146 patients were enrolled in the study with 111 patients included in the final analysis. The average age and body mass index (BMI) of these patients was 66 and 27.8, respectively. None of the 146 patients in this study developed surgical site infection. Older age, no steroid use, no pet ownership, and spine surgery involving two or more levels were all found to be risk factors for wound drainage. Conclusions: This study evaluated lifestyle, environmental, and traditional risk factors for surgical site drainage that have not been explored cohesively related to outpatient orthopedic surgery. Consistent with the existing literature, outpatient spine surgery involving two or more levels was most strongly associated with surgical site drainage after surgery.

Obesity and Spine Surgery: A Qualitative Review About Outcomes and Complications. Is It Time for New Perspectives on Future Researches?

STUDY DESIGN

Literature review.

OBJECTIVES

An increasing number of obese patients requires operative care for degenerative spinal disorders. The aim of this review is to analyze the available evidence regarding the role of obesity on outcomes after spine surgery. Peri-operative complications and clinical results are evaluated for both cervical and lumbar surgery. Furthermore, the contribution of MIS techniques for lumbar surgery to play a role in reducing risks has been analyzed.

METHODS

Only articles published in English in the last 10 years were reviewed. Inclusion criteria of the references were based on the scope of this review, according to PRISMA guidelines. Moreover, only paper analyzing obesity-related complications in spine surgery have been selected and thoroughly reviewed. Each article was classified according to its rating of evidence using the Sacket Grading System.

RESULTS

A total number of 1636 articles were found, but only 130 of them were considered to be relevant after thorough evaluation and according to PRISMA checklist. The majority of the included papers were classified according to the Sacket Grading System as Level 2 (Retrospective Studies).

CONCLUSION

Evidence suggest that obese patients could benefit from spine surgery and outcomes be satisfactory. A higher rate of peri-operative complications is reported among obese patients, especially in posterior approaches. The use of MIS techniques plays a key role in order to reduce surgical risks. Further studies should evaluate the role of multidisciplinary counseling between spine surgeons, nutritionists and bariatric surgeons, in order to plan proper weight loss before elective spine surgery.

Is the Use of Intraoperative 3D Navigation for Thoracolumbar Spine Surgery a Risk Factor for Post-Operative Infection?

Pedicle screw fixation is a technique used to provide rigid fixation in thoracolumbar spine surgery. Safe intraosseous placement of pedicle screws is necessary to provide optimal fixation as well as to avoid damage to adjacent anatomic structures. Despite the wide variety of techniques available, none thus far has been able to fully eliminate the risk of malpositioned screws. Intraoperative 3-dimensional navigation (I3DN) was developed to improve accuracy in the placement of pedicle screws. To our knowledge, no previous studies have investigated whether infection rates are higher with I3DN. A single-institution, retrospective study of patients age > 18 undergoing thoracolumbar fusion and instrumentation was carried out and use of I3DN was recorded. The I3DN group had a significantly greater rate of return to the operating room for culture-positive incision and drainage (17 (4.1%) vs. 1 (0.6%), p = 0.025). In multivariate analysis, the use of I3DM did not reach significance with an OR of 6.49 (0.84−50.02, p = 0.073). Post-operative infections are multifactorial and potential infection risks associated with I3DN need to be weighed against the safety benefits of improved accuracy of pedicle screw positioning.

Risk factors for surgical site infection following spinal surgery: A meta-analysis

STUDY DESIGN

A meta-analysis.

BACKGROUND

We performed a meta-analysis to explore risk factors of surgical site infection (SSI) following spinal surgery.

METHODS

An extensive search of literature was performed in English database of PubMed, Embase, and Cochrane Library and Chinese database of CNKI and WANFANG (up to October 2020). We collected factors including demographic data and surgical factor. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

RESULTS

Totally, 26 studies were included in the final analysis. In our study, the rate of SSI after spinal surgery was 2.9% (1222 of 41,624). Our data also showed that fusion approach (anterior vs posterior; anterior vs combined), osteotomy, transfusion, a history of diabetes and surgery, hypertension, surgical location (cervical vs thoracic; lumbar vs thoracic), osteoporosis and the number of fusion levels were associated with SSI after spinal surgery. However, age, sex, a history of smoking, body mass index, fusion approach (posterior vs combined), surgical location (cervical vs lumbar), duration of surgery, blood loss, using steroid, dural tear and albumin were not associated with development of SSI.

CONCLUSIONS

In our study, many factors were associated with increased risk of SSI after spinal surgery. We hope this article can provide a reference for spinal surgeons to prevent SSI after spinal surgery.

Impact of Obesity on Complications and Surgical Outcomes of Adult Degenerative Scoliosis with Long- Segment Spinal Fusion

INTRODUCTION

The relationship between obesity and outcome of spine surgery has been controversial. The impact of obesity on surgical outcomes of patients undergoing long- segment (6 vertebrae or more) spinal fusion have not been studied. This study was designed to define the influence of obesity on the outcomes of patients undergoing long-segment spinal fusion.

METHODS AND MATERIALS

A retrospective study of patients undergoing long-segment (6 vertebrae or more) spinal fusion was realized. Patients were divided into non-obese group and obese group. Variables such as blood loss, operative time, length of stay, complications, reoperation rates, and clinical outcome were compared between the two groups.

RESULTS

Thirty-four non-obese patients (BMI: 26.43 ± 0.87) and 27 obese ones (BMI: 35.35 ± 1.81) were recruited. Number of fused levels in non-obese group was not significantly different from obese group (9.06±0.57 vertebrae vs 8.85±0.68 vertebrae, p=0.65). There was no significant difference between non-obese group and obese group in the blood loss during surgery (p= 0.12), the operating time (p=0.46) and the length of hospitalization (p=0.64). Similarly, no significant difference was found in surgical complications (p= 0.76) and medical complications (p=0.82) between the two groups. The rate of ambulatory improvement is similar between non-obese group and obese group (p=0.64).

CONCLUSION

Our study showed that there was no relationship between obesity and adverse surgical outcomes in ADS surgery with long-segment (6 vertebrae or more) spinal fusion.

Surgical Site Infection, Readmission, and Reoperation After Posterior Long Segment Fusion

STUDY DESIGN

Retrospective case series.

OBJECTIVE

We sought to identify risk factors associated with surgical site infection (SSI) after posterior long segment spinal fusion (PLSF).

SUMMARY OF BACKGROUND DATA

Patients who undergo PLSF may be at elevated risk of SSI. Identifying factors associated with SSI in these operations can help risk stratify patients and tailor management.

METHODS

We analyzed PLSFs-seven or more levels-at our institution from 2000 to 2015. Data on patients' clinical characteristics, procedural factors, and antimicrobial management were collected. Multivariable analysis identified factors independently associated with outcomes of interest.

RESULTS

In 628 cases, SSI was associated with steroid use (P = 0.024, odds ratio [OR] = 2.54) and using cefazolin (P < 0.001, OR = 4.37) or bacitracin (P = 0.010, OR 3.49) irrigation, as opposed to gentamicin or other irrigation. Gram-positive infections were more likely with staged procedures (P = 0.021, OR 4.91) and bacitracin irrigation (P < 0.001, OR = 17.98), and less likely with vancomycin powder (P = 0.050, OR 0.20). Gram-negative infections were more likely with a history of peripheral arterial disease (P = 0.034, OR = 3.21) or cefazolin irrigation (P < 0.001, OR 25.47). Readmission was more likely after staged procedures (P = 0.003, OR = 3.31), cervical spine surgery (P = 0.023, OR = 2.28), or cefazolin irrigation (P = 0.039, OR = 1.85). Reoperation was more common with more comorbidities (P = 0.022, OR 1.09), staged procedures (P < 0.001, OR = 4.72), cervical surgeries (P = 0.013, OR = 2.36), more participants in the surgery (P = 0.011, OR = 1.06), using cefazolin (P < 0.001, OR = 3.12) or bacitracin (P = 0.009, OR = 3.15) irrigation, and higher erythrocyte sedimentation rate at readmission (P = 0.009, OR = 1.04). Washouts were more likely among patients with more comorbidities (P = 0.013, OR = 1.16), or who used steroids (P = 0.022, OR = 2.92), and less likely after cervical surgery (P = 0.028, OR = 0.24). Instrumentation removal was more common with bacitracin irrigation (p = 0.013, OR = 31.76).

CONCLUSION

Patient factors, whether a procedure is staged, and choice of antibiotic irrigation affect the risk of SSI and ensuing management required.Level of Evidence: 4.

Complex wound closure by plastic surgery following resection of spinal neoplasms minimizes postoperative wound complications in high-risk patients

OBJECTIVE

Wound breakdown and infection are common postoperative complications following resection of spinal neoplasms. Accordingly, it has become common practice at some centers for plastic surgeons to assist with closure of large posterior defects after spine tumor resection. In this study, the authors tested the hypothesis that plastic surgery closure of complex spinal defects improves wound outcomes following resection of spinal neoplastic disease.

METHODS

Electronic medical records of consecutive patients who underwent resection of a spinal neoplasm between June 2015 and January 2019 were retrospectively reviewed. Patients were separated into two subpopulations based on whether the surgical wound was closed by plastic surgery or neurosurgery. Patient demographics, preoperative risk factors, surgical details, and postoperative outcomes were collected in a central database and summarized using descriptive statistics. Outcomes of interest included rates of wound complication, reoperation, and mortality. Known preoperative risk factors for wound complication in spinal oncology were identified based on literature review and grouped categorically. The presence of each category of risk factors was then compared between groups. Univariate and multivariate linear regressions were applied to define associations between individual risk factors and wound complications.

RESULTS

One hundred six patients met inclusion criteria, including 60 wounds primarily closed by plastic surgery and 46 by neurosurgery. The plastic surgery population included more patients with systemic metastases (58% vs 37%, p = 0.029), prior radiation (53% vs 17%, p < 0.001), prior chemotherapy (37% vs 15%, p = 0.014), and sacral region tumors (25% vs 7%, p = 0.012), and more patients who underwent procedures requiring larger incisions (7.2 ± 3.6 vs 4.5 ± 2.6 levels, p < 0.001), prolonged operative time (413 ± 161 vs 301 ± 181 minutes, p = 0.001), and greater blood loss (906 ± 1106 vs 283 ± 373 ml, p < 0.001). The average number of risk factor categories present was significantly greater in the plastic surgery group (2.57 vs 1.74, p < 0.001). Despite the higher relative risk, the plastic surgery group did not experience a significantly higher rate of wound complication (28% vs 17%, p = 0.145), reoperation (17% vs 9%, p = 0.234), or all-cause mortality (30% vs 13%, p = 0.076). One patient died from wound-related complications in each group (p = 0.851). Regression analyses identified diabetes, multilevel instrumentation, and BMI as the factors associated with the greatest wound complications.

CONCLUSIONS

Involving plastic surgery in the closure of spinal wounds after resection of neoplasms may ameliorate expected increases in wound complications among higher-risk patients.

Consensus on the Role of Antibiotic Use in SSI Following Spinal Surgery

In July of 2018, the Second International Consensus Meeting (ICM) on Musculoskeletal Infection convened in Philadelphia, PA was held to discuss issues regarding infection in orthopedic patients and to provide consensus recommendations on these issues to practicing orthopedic surgeons. During this meeting, attending delegates divided into subspecialty groups to discuss topics specifics to their respective fields, which included the spine. At the spine subspecialty group meeting, delegates discussed and voted upon the recommendations for 63 questions regarding the prevention, diagnosis, and treatment of infection in spinal surgery. Of the 63 questions, 17 focused on the use of antibiotics in spine surgery, for which this article provides the recommendations, voting results, and rationales.

Strategies of management of deep spinal infection: from irrigation and debridement to vacuum-assisted closure treatment

Postoperative surgical site problems (PSSPs) following spinal surgery may lead to patient mortality, increased treatment costs and possible recurrent medical interventions. Despite efforts to reduce spinal surgery-related infection rates, complications are common and significantly increased by patient comorbidities. Since PSSPs occur regardless of deterrent measures, it is essential to distinguish the related risk factors. Different treatment conventions for PSSPs, for example, antibiotic treatment, debridement, soft tissue care and removal of implants have been prescribed with blended outcomes. The utilization of the wound vacuum-assisted closure (VAC) system has gained increasing popularity in the management of deep wound infections after deformity surgery.

Impact of medical student involvement on outcomes following spine surgery: A single center analysis of 6485 patients

Medical student (MS) observation and assistance in the operating room (OR) is a critical component of medical education. Though participation in the operating room has many benefits to the medical student, the potential cost of these experiences to the patients must be taken into account. Other studies have shown differences in outcomes with resident involvement, but the effect of medical students in the OR has been poorly understood. The objective of this study was to understand how medical students and residents impacted surgical outcomes in posterior spinal fusions, anterior cervical discectomy and fusions (ACDFs), and lumbar discectomies. We conducted a retrospective study of patients undergoing posterior spinal fusions, ACDFs, and lumbar discectomies over 15 years. There were 6485 patients met the inclusion criteria of either undergoing a posterior fusion, ACDF or lumbar discectomy (1250 posterior fusion, 1381 ACDF, 3854 lumbar discectomies). Overall, little difference was observed when a medical student was present for surgical outcomes including length of stay, infection, and readmission. For ACDFs, having a medical student present had a significantly longer procedure durations (OR = 1.612, p = 0.001) than cases without. Besides slightly longer operative time (in posterior fusions), there were no major differences in outcomes when a medical student was present in the OR.