Postoperative spinal wound infection: a review of 2,391 consecutive index procedures

Fulminating septicemia secondary to oxygen-ozone therapy for lumbar disc herniation: case report

STUDY DESIGN

A case report and clinical discussion.

OBJECTIVE

To describe a rare but fatal complication secondary to oxygen-ozone therapy for the treatment of herniated lumbar disc.

SUMMARY OF BACKGROUND DATA

Previously reported complications secondary to oxygen-ozone therapy are rarely reported. Septic discitis and epidural abscesses have been reported after myelography, lumbar puncture, paravertebral injections, epidural anesthesia, acupuncture, and intradiscal therapy with chymopapain. We report the first case of a local infection with systemic fatal dissemination secondary to this treatment.

METHODS

A 57-year-old man previously treated with oxygen-ozone therapy presented low back and bilateral pain. The lumbar computed tomography revealed the presence of L4-L5 and L5-S1 herniated discs.

RESULTS

Three days after admission in the hospital, the patient developed a fulminant septicemia. An abdominal-pelvic and chest computed tomography and blood culture led to the diagnosis of pyogenic lumbar muscle involvement, accompanied with septic pulmonary embolism secondary to Escherichia coli infection.

CONCLUSIONS

This case report identifies a rare and fatal complication of oxygen-ozone therapy in the treatment of a herniated lumbar disc. Acute fatal septicemia should be considered among the major complications of the oxygen-ozone therapy in the treatment of a herniated lumbar disc.

Infectious complications after the Nuss repair in a series of 863 patients

PURPOSE

A nemesis of surgical implants is infection. We evaluated the various infectious complications after Nuss repair of pectus excavatum in 863 patients over 18 years.

METHODS

After institutional review board approval, a retrospective review of a prospectively gathered database of patients was performed who underwent minimally invasive repair of pectus excavatum and developed an infection. All patients received intravenous antibiotics before surgery continuing until discharge. Patients with a persistent fever after operation were discharged with oral antibiotics.

RESULTS

From January 1987 to September 2005, 863 patients underwent a minimally invasive pectus excavatum repair and 13 (1.5%) developed postoperative infections. These included 6 bar infections, 4 cases of cellulitis, and 3 stitch abscesses. Cellulitis was defined as erythema and warmth which responded to a single course of antibiotics. Bar infections were defined as an abscess in contact with the bar. Surgical drainage and long-term antibiotics resolved 3 of these abscesses, whereas 3 patients required early bar removal (1 after 3 months and 2 after 18 months). Cultures identified a single organism in each case and Staphylococcus aureus was the most common organism (83%) identified, and all being methicillin sensitive. All infections occurred on the side of the stabilizer if a stabilizer had been placed.

CONCLUSIONS

Infectious complications after Nuss repair are uncommon and occurred in 1.5% of our patients. Published rates of postoperative infection range from 1.0% to 6.8%. Superficial infections responded to antibiotics alone. Bar infection occurred in only 0.7% and required surgical drainage and long-term antibiotics. Only 3 of these (50% of bar infections and 0.34% overall) required early bar removal at 3 and 18 months because of recurring infections. Early bar removal should be a rare morbidity with the Nuss repair.

Postoperative spinal wound infections and postprocedural diskitis

BACKGROUND/OBJECTIVE

Postprocedural infections are a significant cause of morbidity after spinal interventions.

METHODS

Literature review. An extensive literature review was conducted on postprocedural spinal infections. Relevant articles were reviewed in detail and additional case images were included.

RESULTS

Clinical findings, laboratory markers, and imaging modalities play important roles in the detection of postprocedural spinal infections. Treatment may range from biopsy and antibiotics to multiple operations with complex strategies for soft tissue management.

CONCLUSIONS

Early detection and aggressive treatment are paramount in managing postprocedural spinal infections and limiting their long-term sequelae.

Postoperative infections of the thoracic and lumbar spine: a review of 18 cases

We retrospectively reviewed 18 consecutive patients (age range, 19-81 years; average age, 55 years) with postoperative infections of the spine. Postdiscectomy-laminectomy infections confined to the disc space (n = 2) were treated with percutaneous transpedicle drainage. Open débridement was performed in patients with an epidural or paraspinal abscess (n = 3). Infections after posterior instrumentation that manifested during the first postoperative month were treated with single (n = 3) or multiple débridements and delayed closure (n = 7), with preservation of instrumentation. Infections that presented more than 9 months after the initial operation (n = 3) were treated with open débridement and removal of instrumentation. The minimum followup was 1 year (mean 2 years, range, 1-4 years). Infections in 17 of the 18 patients resolved effectively and one patient with metastatic cancer died of sepsis. Transpedicle drainage resulted in immediate relief of back pain. Instrumentation can be retained safely in patients with infections that manifest during the first month after implantation. Single surgical débridement is effective in selected cases. After repeated débridements, the presence of healthy granulation tissue in the wound and decreasing C-reactive protein activity were associated with safe and effective wound closure. Despite radiographic evidence of hardware loosening in infections manifested more than 9 months after implantation, we removed hardware without destabilizing the spine.

Surgical site infections following spinal surgery at a tertiary care center in Lebanon: incidence, microbiology, and risk factors

Surgical site infections (SSIs) following spinal surgery are associated with significant morbidity and long-term complications. The epidemiology of these infections has not been previously studied in Lebanon. This nested case-control study was conducted between 2001 and 2003 at the American University of Beirut Medical Center. Cases were defined as patients who developed surgical site infection within 30 d of surgery. Controls were patients with no evidence of infection. There were 27 cases of surgical site infections among 997 surgeries with an incidence of 2.7%. Compared to controls, cases were older (mean age 59 vs 47 y, p=0.001), and were more likely to have diabetes (OR = 4.0; 95% CI 1.2-12.8) and foreign body implantation (OR = 3.4; 95% CI 1.3-9.3). Antibiotic prophylaxis was given for a range of 0-6 d in cases and 0-7 d in controls. Coagulase-negative staphylococci were the most commonly isolated organisms. Hospital stay was significantly longer in cases than controls. The rates of surgical site infections following spinal surgery at our center are comparable to worldwide rates. There is unjustified overuse of prophylactic antibiotics in our patients that has the potential of inducing emergence of antimicrobial resistance.

Postoperative infection

Infectious disease complicating surgery involving the musculoskeletal system is one of the most important causes of postoperative morbidity and mortality. Timely detection and accurate localization of infectious processes have important clinical implications and are critical to appropriate patient management. Imaging studies can play an important role in the detection of infection and can help guide appropriate clinical management. The diagnosis of postoperative infection can be made by a variety of imaging modalities. This article reviews the various methods and modalities available for the detection of postoperative infection.

Wound conditioning by vacuum assisted closure (V.A.C.) in postoperative infections after dorsal spine surgery

The use of vacuum assisted closure (V.A.C.) therapy in postoperative infections after dorsal spinal surgery was studied retrospectively. Successful treatment was defined as a stable healed wound that showed no signs of acute or chronic infection. The treatment of the infected back wounds consisted of repeated debridement, irrigation and open wound treatment with temporary closure by V.A.C. The instrumentation was exchanged or removed if necessary. Fifteen patients with deep subfascial infections after posterior spinal surgery were treated. The implants were exchanged in seven cases, removed completely in five cases and left without changing in one case. In two cases spinal surgery consisted of laminectomy without instrumentation. In two cases only the wound defects were closed by muscle flap, the remaining ones were closed by delayed suturing. Antibiotic treatment was necessary in all cases. Follow up was possible in 14 patients. One patient showed a new infection after treatment. The study illustrates the usefulness of V.A.C. therapy as a new alternative management for wound conditioning of complex back wounds after deep subfascial infection.

Surgical infections in the traumatized spine

Patients with acute spinal injury who require operative intervention may be at increased risk for postoperative surgical-site infection when compared with patients having elective spinal surgery. Various local, systemic, and iatrogenic factors predispose this unique population of patients to post-surgical infection. Nonmodifiable risk factors for surgical-site infection in spine trauma include age, medical comorbidities, and neurologic status. Modifiable risk factors include poor postoperative nutritional status, delay from time of injury to surgical intervention, posterior surgical approach, higher number of levels stabilized, length of postoperative stay in the intensive care unit, and treatment by a single specialty team (versus treatment by successive orthopaedic and neurosurgical teams). When treating patients with spine trauma, a high index of suspicion should be maintained for patients with multiple risk factors for infection and every effort should be made to minimize the modifiable risk factors.

LEVEL OF EVIDENCE

Level V (expert opinion). Please see the Guidelines for Authors for a complete description of levels of evidence.

Postoperative infections in interbody fusion for degenerative spinal disease

Scant literature exists on the treatment of infection after interbody fusion. Some authors advocate removal of the interbody grafts. Salvage of the grafts was possible in 92.3% (12 of 13) of the infections in a series of 326 consecutive patients with degenerative spinal diseases treated by three surgeons. Posterior interbody fusion and posterolateral instrumented fusion was performed in 267 patients and anterior interbody fusion was done in 59 patients. Eight infections in the first group (3%) and six in the second group (10.1%) were identified. Mean followup was 18 months (range, 12-38 months). All infections were early, presenting at a mean of 18 days (range, 11-28 months). All but one infection were in the posterior wound and deep. A high number of risk factors were present in these patients. Initial treatment included wound debridement and broad spectrum antibiotics, until culture results indicated the final antibiotic regimen. Infection recurred as osteomyelitis in one patient with multiple previous surgeries and anterior/posterior fusion. This was treated with removal of the posterior instrumentation and the interbody graft and extensive anterior/posterior reconstruction. Clinical outcomes were good in 10 patients, fair in two and poor in one using the Stauffer-Coventry scale. One pseudarthrosis was identified in a patient with anterior interbody fusion at final followup. Salvage of the interbody graft and retaining the instrumentation was safe in most cases in the presented series and did not adversely affect outcome.

LEVEL OF EVIDENCE

Therapeutic study, level IV (case series). Please see the Guidelines for Authors for a complete description of levels of evidence.

Reduction of postoperative spinal infections based on an etiologic protocol

Acute postoperative spinal infections are serious complications. We saw a sudden increase in the infection rate in our unit during a 6-month period. This led us to construct an assessment protocol combining risk factors into a mnemonic we named the "Nine Ps Protocol" (patient-related factors, personnel, place, preoperative length of stay, procedure, prosthetics, prophylaxis, packed red blood cells, and pus cultures). We reviewed 102 consecutive patients having spine surgery in three sequential 6 month periods: Group A included 34 patients before the outbreak of infection and Group B included 26 patients during the outbreak of infection. We prospectively applied the protocol in 26 patients (Group C) after the outbreak. After the implementation of the protocol the infection rate dropped from 16.7% (Group B) to 3.6% (Group C). Increased risk factors for postoperative infection included advanced age, posterior instrumented fusion, high allogenic blood transfusion rates, and suboptimal sheet and dressing changing conditions. We propose the Nine Ps Protocol as a useful clinical tool for the etiologic assessment and prevention of spinal infections.

LEVEL OF EVIDENCE

Prognostic study, Level II (Lesser quality prospective study [eg, patients enrolled at different points in their disease or < 80% followup]). Please see Guidelines for Authors for a complete description of levels of evidence.

Outcome after less-invasive decompression of lumbar spinal stenosis: a randomized comparison of unilateral laminotomy, bilateral laminotomy, and laminectomy

OBJECT

Recently, limited decompression procedures have been proposed in the treatment of lumbar stenosis. The authors undertook a prospective study to compare the safety and outcome of unilateral and bilateral laminotomy with laminectomy.

METHODS

One hundred twenty consecutive patients with 207 levels of lumbar stenosis without herniated discs or instability were randomized to three treatment groups (bilateral laminotomy [Group 1], unilateral laminotomy [Group 2], and laminectomy [Group 3]). Perioperative parameters and complications were documented. Symptoms and scores, such as visual analog scale (VAS), Roland-Morris Scale, Short Form-36 (SF-36), and patient satisfaction were assessed preoperatively and at 3, 6, and 12 months after surgery. Adequate decompression was achieved in all patients. The overall complication rate was lowest in patients who had undergone bilateral laminotomy (Group 1). The minimum follow up of 12 months was obtained in 94% of patients. Residual pain was lowest in Group 1 (VAS score 2.3 +/- 2.4 and 4 +/- 1 in Group 3; p < 0.05 and 3.6 +/- 2.7 in Group 2; p < 0.05). The Roland-Morris Scale score improved from 17 +/- 4.3 before surgery to 8.1 +/- 7, 8.5 +/- 7.3, and 10.9 +/- 7.5 (Groups 1-3, respectively; p < 0.001 compared with preoperative) corresponding to a dramatic increase in walking distance. Examination of SF-36 scores demonstrated marked improvement, most pronounced in Group 1. The number of repeated operations did not differ among groups. Patient satisfaction was significantly superior in Group 1, with 3, 27, and 26% of patients unsatisfied (in Groups 1, 2, and 3, respectively; p < 0.01).

CONCLUSIONS

Bilateral and unilateral laminotomy allowed adequate and safe decompression of lumbar stenosis, resulted in a highly significant reduction of symptoms and disability, and improved health-related quality of life. Outcome after unilateral laminotomy was comparable with that after laminectomy. In most outcome parameters, bilateral laminotomy was associated with a significant benefit and thus constitutes a promising treatment alternative.

Adjacent level discitis after anterior cervical discectomy and fusion (ACDF): a case report

This report describes a case of spondylodiscitis occurring adjacent to levels at which anterior cervical discectomy and fusion was performed. The objective is to describe a rare cause of spondylodiscitis and discuss its successful management. Post-operative discitis involving the same level is a known occurrence. We report an interesting case of spondylodiscitis occurring at the adjacent level of fusion, and to our knowledge this is the first such case reported in literature. A two-level decompression and fusion was performed at C5–6 and C6–7 levels with PEEK cages and anterior cervical plating in a middle-aged gentleman for persistent axial neck pain and left-sided radiculopathy involving C6 and C7 distribution. After 6 weeks, the patient presented to us with complaints of mild paresthesia in the abdomen and extremities. Radiological investigations including plain radiographs and MRI revealed a surprising finding of discitis at C4–5 level with an associated epidural abscess. In view of the patient’s myelopathic symptoms, surgical debridement and decompression of the spinal cord was performed. The plate and screws were removed, the cages were left intact, and the C4–5 disc level was reconstructed with tricortical iliac crest autograft. No further instrumentation was performed. The biopsy specimen from the disc at C4–5 level grew Serratia marcescens. It was contemplated that C4–5 discitis was initiated by inoculation of bacteria at the superior endplate of C5 by contaminated vertebral pins/drill-bit or screws. Adjacent level discitis is a rare but potentially serious complication of anterior cervical fusion. A high index of suspicion of infection is necessary if the patient complains of new symptoms after anterior cervical fusion. Thorough assessment and aggressive treatment is necessary for successful management.

Adolescent idiopathic scoliosis screening for school, community, and clinical health promotion practice utilizing the PRECEDE-PROCEED model

BACKGROUND

Screening for adolescent idiopathic scoliosis (AIS) is a commonly performed procedure for school children during the high risk years. The PRECEDE-PROCEDE (PP) model is a health promotion planning model that has not been utilized for the clinical diagnosis of AIS. The purpose of this research is to study AIS in the school age population using the PP model and its relevance for community, school, and clinical health promotion.

METHODS

MEDLINE was utilized to locate AIS data. Studies were screened for relevance and applicability under the auspices of the PP model. Where data was unavailable, expert opinion was utilized based on consensus.

RESULTS

The social assessment of quality of life is limited with few studies approaching the long-term effects of AIS. Epidemiologically, AIS is the most common form of scoliosis and leading orthopedic problem in children. Behavioral/environmental studies focus on discovering etiologic relationships yet this data is confounded because AIS is not a behavioral. Illness and parenting health behaviors can be appreciated. The educational diagnosis is confounded because AIS is an orthopedic disorder and not behavioral. The administration/policy diagnosis is hindered in that scoliosis screening programs are not considered cost-effective. Policies are determined in some schools because 26 states mandate school scoliosis screening. There exists potential error with the Adam's test. The most widely used measure in the PP model, the Health Belief Model, has not been utilized in any AIS research.

CONCLUSION

The PP model is a useful tool for a comprehensive study of a particular health concern. This research showed where gaps in AIS research exist suggesting that there may be problems to the implementation of school screening. Until research disparities are filled, implementation of AIS screening by school, community, and clinical health promotion will be compromised. Lack of data and perceived importance by school/community health planners may influence clinical health promotion practices.

Efficacy of dilute betadine solution irrigation in the prevention of postoperative infection of spinal surgery

STUDY DESIGN

Prospective, single-blinded, randomized study.

OBJECTIVES

To evaluate the efficacy of dilute betadine irrigation of spinal surgical wounds in prevention of postoperative wound infection.

SUMMARY AND BACKGROUND

Deep wound infection is a serious complication of spinal surgery that can jeopardize patient outcomes and increase costs. Povidoneiodine is a widely used antiseptic with bactericidal activity against a wide spectrum of pathogens, including methicillin-resistant Staphylococcus aureus. The aim of this study was to evaluate the efficacy of dilute betadine solution in the prevention of wound infection after spinal surgery.

METHODS

Four hundred and fourteen patients undergoing spinal surgery were randomly assigned to two groups. In group 1 (208 patients), surgical wounds were irrigated with dilute betadine solution (3.5% betadine) before wound closure. Betadine irrigation was not used in group 2 (206 patients). Otherwise, perioperative management was the same for both groups.

RESULTS

Mean length of follow-up was 15.5 months in both groups (range, 6-24 months). No wound infection occurred in group 1. One superficial infection (0.5%) and six deep infections (2.9%) occurred in group 2. The differences between the deep infection rate (P = 0.0146) and total infection rate (P = 0.0072) were significant between the two groups.

CONCLUSIONS

Our report is the first prospective, single-blinded, randomized study to evaluate the clinical effectiveness of dilute betadine solution irrigation for prevention of wound infection following spinal surgery. We recommended this simple and inexpensive measure following spinal surgery, particularly in patients with accidental wound contamination, risk factors for wound infection, or undergoing surgery in the absence of routine ultraviolet light, laminar flow, and isolation suits.

Postoperative deep wound infections in adults after spinal fusion: management with vacuum-assisted wound closure

OBJECTIVE

Vacuum-assisted wound closure (VAC) exposes the wound bed to negative pressure, resulting in removal of edema fluid, improvement of blood supply, and stimulation of cellular proliferation of reparative granulation tissue. It has been used to treat open wounds in the extremities, open sternal wounds, pressure ulcers, and abdominal wall wounds. This study retrospectively reviewed instrumented spine fusions complicated by surgical wound infection and managed by a protocol including the use of VAC in order to evaluate the efficacy of applying vacuum therapy on patients with deep spine infections and exposed instrumentation.

METHODS

Twenty consecutive patients with deep wound infections after undergoing spinal fusion procedures were studied. There were 12 men and 8 women with an average age of 55 years (31-81 years). Eight patients had undergone concomitant anterior and posterior arthrodesis, nine patients had a posterior spinal fusion, and three patients had a transforaminal lumbar interbody fusion. Seven patients had a decompression with exposed dura. Sixteen patients presented with a draining wound within the first 6 weeks postoperatively (average 24 days). There were four patients who presented with back pain and temperature after 1 year postoperatively (average 3 years). All patients were taken to the operating room for irrigation and debridement followed by placement of the VAC with subsequent delayed closure of the wound.

RESULTS

There was an average of 1.8 (1-8) irrigation and debridement procedures prior to placement of the VAC. Once the VAC was initiated, there was an average of 2.2 (2-3) procedures until and including closure of the wound. The wound was closed an average of 7 days (5-14 days) after the placement of the initial VAC in the wound. All patients tolerated the VAC without adverse effects. All patients were kept on a 6-week course of intravenous antibiotic therapy. The average follow-up was 10 months (6-24 months). There were no cases of uncontrolled sepsis once the VAC was initiated. All patients achieved a clean closed wound without removal of instrumentation at a minimum follow-up of 6 months.

CONCLUSION

VAC therapy is an effective adjunct in closing complex deep spinal wounds with exposed instrumentation.

Is spinal instrumentation a risk factor for late-onset infection in cases of distant infection or surgery? Case report

As a cause of revision spinal surgery, spinal epidural abscess after instrumentation-assisted fusion is rare in neurosurgical practice. Postoperative infections are frequently seen in the time period soon after surgery. The authors report on the case of a 45-year-old woman who had undergone posterior instrumentation-augmented fusion for L4-5 degenerative spondylolisthesis. Ten months after the operation she presented to the neurosurgery clinic with complaints of severe low-back pain and radicular right lower-extremity pain. She had undergone laparoscopic surgery for acute cholecystitis 1 month prior to readmission. Radiological study revealed a spinal epidural abscess in communication with a right psoas abscess at L4-5. The abscess was drained percutaneously with the aid of C-arm fluoroscopic guidance, and a 6-week course of parenteral antibiotic therapy was administered. Retrograde lymphatic bacterial translocation, hematopoietic spread, and the suitable characteristics in the host may facilitate the development of infection around the implant. Thus, distant surgery and infection may be a risk factor in cases in which spinal instrumentation is placed. In such cases a prolonged antibiotic therapy for distant infection after surgery is recommended.

Staged posterior surgery for severe adult spinal deformity

STUDY DESIGN

Retrospective analysis with prospective outcomes.

OBJECTIVE

To analyze the strategy of dividing one prolonged, complex, posterior surgery into two smaller posterior procedures staged during one hospitalization.

SUMMARY OF BACKGROUND DATA

When operating on complex revision adult deformity, the posterior surgery alone can be unduly prolonged, placing patients at risk for hemodynamic complications associated with protracted same-day surgery.

MATERIALS AND METHODS

Forty-two consecutive adults with severe deformity and 2 years or more of follow-up were included. Thirty-three presented for revision surgery. Twenty-two had more than one previous fusion. During first-stage posterior surgery, existing implants were removed, decompressions performed, and new fixation points established. Five to 7 days later, patients underwent second-stage posterior surgery, consisting of osteotomies (34 patients), completion of instrumentation, and fusion. Anterior surgery was performed during either stage as necessary. Age at surgery was 47 (range 18-68); 4.8 (range 1-9) levels were fused anteriorly and 11.3 (range 4-17) levels posteriorly.

RESULTS

No major perioperative medical complications occurred (e.g., myocardial infarction, pulmonary embolus, death). All completed staged surgery as planned. Only five required any postoperative intubation. There was only one perioperative deep infection, one superficial infection, and one sterile seroma. No medical or surgical complication could be related to the staging of posterior surgery. SRS-24 and radiographic outcomes were excellent at >or=2-year follow-up.

CONCLUSION

Staged posterior surgery can be performed safely with few surgical complications and no major medical complications, as well as excellent outcomes in a population known to be at high risk. Such staging can be useful in performing complex posterior revision and osteotomy surgery while limiting hemodynamic stresses.

Postoperative wound infections of the spine

Postoperative spinal wound infections occur in 1 to 12% of patients. The rate of infection is related to the type and duration of the procedure, comorbidities, nutritional status, and various other risk factors. Antibiotic prophylactic therapy has been clearly shown to decrease the rate of infection dramatically after lumbar surgery. These infections typically manifest with signs and symptoms of wound swelling, erythema, and drainage. Laboratory-detected values such as the erythrocyte sedimentation rate and C-reactive protein can be elevated beyond what is normal for the uncomplicated postoperative course following lumbar surgery, and combined with the clinical symptoms should alert the physician to the possibility of infection. When detected, these infections should be managed aggressively with operative debridment and irrigation, including the deep subfascial layer in all cases except those with clearly demarcated superficial infection. The choice of one versus multiple debridments can be made based on the appearance of the wound, patient factors, and nutritional status. Hardware and incorporated bone graft can be left in place in the majority of cases, adding to stability. Outcomes following aggressive treatment of this complication can be excellent, with no long-term loss of function and complete eradication of the infection.

Delayed infection after instrumented spine surgery: case reports and review of the literature

BACKGROUND CONTEXT

A delayed infection after instrumented spine surgery can be difficult to diagnose because of its low incidence and variety of clinical symptoms.

PURPOSE

To describe four cases of delayed infection after instrumented spine surgery and to review the literature of such cases with regard to the clinical symptoms and risk factors, possible causes of infection and treatment.

STUDY DESIGN/SETTING

Personal review of cases and literature review.

PATIENT SAMPLE

Four cases in this report and 93 other cases reported in the literature.

OUTCOME MEASURES

Not measured.

METHODS

Summary of the clinical symptoms, risk factors, causes of infection and treatment regimens.

RESULTS

Three possible causes of a delayed infection have been cited: intraoperative seeding, metal fretting causing a sterile inflammatory response or stimulating low-virulent organisms to fester and hematogenous seeding. A variety of clinical symptoms were found, but spontaneous drainage appears to be most common. Many patients had either a fluctuant mass, localized drainage or an abscess. Abscesses or drainage material is typically contiguous with the instrumentation and the fusion mass. Fever was present in only six patients. Effective treatment usually includes removal of the implants, irrigation and debridement, followed by the administration of antibiotics.

CONCLUSIONS

A high level of suspicion is needed to diagnose a delayed infection after instrumented spine surgery.

Risk factors for surgical site infection in spinal surgery

OBJECT

The objective of this study was to identify specific independent risk factors for surgical site infections (SSIs) occurring after laminectomy or spinal fusion.

METHODS

The authors performed a retrospective case-control study of data obtained in patients between 1996 and 1999 who had undergone laminectomy and/or spinal fusion. Forty-one patients with SSI or meningitis were identified, and data were compared with those acquired in 178 uninfected control patients. Risk factors for SSI were determined using univariate analyses and multivariate logistic regression. The spinal surgery-related SSI rate (incisional and organ space) during the 4-year study period was 2.8%. Independent risk factors for SSI identified by multivariate analysis were postoperative incontinence (odds ratio [OR] 8.2, 95% confidence interval [CI] 2.9-22.8), posterior approach (OR 8.2, 95% CI 2-33.5), procedure for tumor resection (OR 6.2, 95% CI 1.7-22.3), and morbid obesity (OR 5.2, 95% CI 1.9-14.2). In patients with SSI the postoperative hospital length of stay was significantly longer than that in uninfected patients (median 6 and 3 days, respectively; p < 0.001) and were readmitted to the hospital for a median additional 6 days for treatment of their infection. Repeated surgery due to the infection was required in the majority (73%) of infected patients.

CONCLUSIONS

Postoperative incontinence, posterior approach, surgery for tumor resection, and morbid obesity were independent risk factors predictive of SSI following spinal surgery. Interventions to reduce the risk for these potentially devastating infections need to be developed.

Risk factors for spinal surgical-site infections in a community hospital: a case-control study

OBJECTIVE

To characterize risk factors for surgical-site infection after spinal surgery.

DESIGN

A case-control study.

SETTING

A 113-bed community hospital.

METHOD

From January 1998 through June 2000, the incidence of surgical-site infection in patients undergoing laminectomy, spinal fusion surgery, or both increased at community hospital A. We compared 13 patients who acquired surgical-site infections after laminectomy, spinal fusion surgery, or both with 47 patients who were operated on during the same time period but did not acquire a surgical-site infection. Information collected included demographics, risk factors, personnel involved in the operations, length of hospital stay, and hospital costs.

RESULTS

Of 13 case-patients, 9 (69%) were obese, 9 (69%) had spinal compression, 5 (38.5%) had a history of tobacco use, and 4 (31%) had diabetes. Oxacillin-sensitive Staphylococcus aureus (6 of 13; 46%) was the most common organism isolated. Significant risk factors for postoperative spinal surgical-site infection were dural tear during the surgical procedure and the use of glue to cement the dural patch (3 of 13 [23%] vs 1 of 47 [2.1%]; P = .02) and American Society of Anesthesiologists risk class of 3 or more (6 of 13 [46.2%] vs 7 of 47 [15%]; P = .02). Case-patients were more likely to have prolonged length of stay (median, 16 vs 4 days; P< .001). The average excess length of stay was 11 days and the excess cost per case was $12,477.

CONCLUSION

Dural tear and the use of glue should be evaluated as potential risk factors for spinal surgical-site infection. Systematic observation for potential lapses in sterile technique and surgical processes that may increase the risk of infection may help prevent spinal surgical-site infection.