Albert F. Pull ter Gunne

Incidence, prevalence, and analysis of risk factors for surgical site infection following adult spinal surgery

Study Design. A retrospective cohort study to identify rates and analyze the risk factors for postoperative spinal wound infection. Objective. To determine significant risk factors for postoperative spinal wound infection by comparing those patients who developed a postoperative wound infection with the rest of the cohort. Summary of Background Data. A surgical site infection (SSI) is a common complication after spinal surgery. SSI leads to higher morbidity, mortality, and healthcare costs. To develop strategies to reduce the risk for SSI, independent risk factors for SSI should be identified. Methods. The electronic patient record of all 3174 patients who underwent orthopedic spinal surgery at out institution were abstracted. Individual patient and perioperative characteristics were stored in an electronic database. Results. In total, 132 (4.2%) patients were found to have an SSI with 84 having deep based infection. Estimated blood loss over 1 liter (P = 0.017), previous SSI (P = 0.012) and diabetes (P = 0.050) were found to be independent statistically significant risk factors for SSI. Obesity (P = 0.009) was found to significantly increase the risk of superficial infection, whereas anterior spinal approach decreased the risk (P = 0.010). Diabetes (P = 0.033), obesity (P = 0.047), previous SSI (P = 0.009), and longer surgeries (2–5 hours [P = 0.023] and 5 or more hours [P = 0.009]) were found to be independent significant risk factors for deep SSI. Conclusion. SSI is commonly seen after spinal surgery. In our study, we identified independent risk factors for both deep and superficial SSI. Identification of these risk factors should allow us to design protocols to decrease the risk of SSE in future patients.

A methodological systematic review on surgical site infections following spinal surgery: part 1: risk factors.

Study Design. A methodological systematic review. Objective. To critically appraise the validity of risk factors for surgical site infection (SSI) after spinal surgery. Summary of Background Data. SSIs lead to higher morbidity, mortality, and increased health care costs. Understanding which factors lead to an increased risk of SSI is important for the development of prophylactic protocols to counter this risk. To date, however, no review appraising the methodological quality of studies evaluating risk factors for spinal SSIs has been published. Methods. Contemporary studies identifying risk factors for SSI after spinal surgery were searched through the Medline and EMBASE databases (January 2001 to December 2010). References were retrieved and bias-prone study features were abstracted individually and independently by 2 authors. Results. Twenty-four eligible studies were identified, including 9 (nested) case-control studies and 15 case series. Included studies covered wide variations of indications and surgical procedures. A total of 73 different types of factors were evaluated for the risk of an SSI of which 34 (47%) were reported to be significantly related to at least 1 study. Only the following risk factors—diabetes mellitus, obesity, and previous SSI—were confirmed more often (n = 11, 8, and 3, respectively) as a significant risk factor for an SSI than they were disproved (n = 7, 6, and 1, respectively). Various sources of heterogeneity were observed, including patient selection, selection and analysis of putative risk factors, and definitions of SSI outcomes. Conclusion. There is an abundance of conflicting data on risk factors for SSI after spinal surgery. Given various sources of heterogeneity observed in observational literature, there is a paucity of solid evidence for the proof of robust risk factors. The authors recommend the introduction, validation, and use of a standardized set of strongly justified eligibility criteria and well-defined candidate risk factors and spinal SSI outcomes.

The Presentation, Incidence, Etiology, and Treatment of Surgical Site Infections After Spinal Surgery

Study Design. Descriptive, retrospective cohort analysis. Objective. To evaluate the presentation, etiology, and treatment of surgical site infections (SSI) after spinal surgery. Summary of Background Data. SSI after spine surgery is frequently seen. Small case control studies have been published reporting the results of treatment options of SSI. We performed this study to indentify the most common clinical and laboratory presentation of a SSI, the most frequently seen infective organism, and evaluate the effectiveness of current treatment. Methods. All patients who underwent spinal surgery at our institution for diagnosis other than infection between June 1996 and December 2005 (N = 3174) were reviewed. All cases of SSI were identified. Patient and operative characteristics were reviewed. Infection type (deep or superficial), treatment course, laboratory and culture results were abstracted. Results. A total of 132 cases of SSI (84 deep and 48 superficial) were identified. About 72.7% of the SSI were detected as outpatients an average 28.7 days (deep, 29.9; superficial, 25.2) after the index procedure. Wound drainage was the most common complaint (68.2%). C-reactive protein level was elevated in 98.0%, erythrocyte sedimentation rate was elevated in 94.4%, but only 48.6% had elevated white blood cell count. Staphylococcus aureus was isolated in 72.6% of deep and 85.7% of superficial positive cultures. Seventy-six percent of deep SSI could be treated with a single debridement to clear the SSI. Instrumentation was retained or primarily exchanged if loose in all cases. Around 72.9% of superficial SSI were treated without formal debridement in the operating room. Antibiotic treatment was longer in deep SSI (40.8 vs. 19.6 days). Conclusion. Deep SSI following spinal surgery was effectively treated with single stage debridement and intravenous antibiotics. Superficial SSI could be treated effectively with local wound care and oral antibiotic therapy.

Low profile pelvic fixation with the sacral alar iliac technique in the pediatric population improves results at two-year minimum follow-up.

Study Design. Retrospective review. Objective. Anchor stability and prominence are problems with pelvic fixation in pediatric spinal deformity surgery. We compared the new sacral alar iliac (SAI) fixation technique (with a starting point in the sacral ala and in-line anchors deep under the midline muscle flap) with other methods of screw fixation. Summary of Background Data. Iliac anchors have been shown to provide the best form of pelvic fixation. A trajectory from the posterior sacral surface to the iliac wings has recently been described. To our knowledge, no clinical series has compared this method of pelvic fixation in children to others. Methods. Of 32 consecutive pediatric patients who underwent SAI fixation, 2 died and 26 returned for follow-up (>2 years). Mean age at surgery was 14 years. Average screw size was 67 mm long and 7 to 9 mm in diameter. Clinical examinations, radiographs, and computed tomography scans were analyzed. Outcomes included pain over the implants, screw placement, implant prominence, radiographic lucency, need for revision, and infection. SAI patients were compared with 27 previous patients who had pelvic fixation via other screw techniques. Results. For SAI fixation, correction of pelvic obliquity and Cobb angles were 20° ± 11° (70%) and 42° ± 25° (67%), respectively. For other pelvic fixation methods, those values were 10° ± 9° (50%), and 46° ± 16° (60%), respectively. Compared with other screws, SAI screws provided significantly better pelvic obliquity correction (P = 0.002) but no difference in Cobb correction. There were 2 lucencies adjacent to screws in both groups. Computed tomography scans of 18 SAI patients showed no intrapelvic protrusion, but 1 screw extended laterally (<5 mm). One early SAI patient required revision with larger screws, which relieved pain; there was 1 revision in the comparison group. SAI patients had no deep infections, implant prominence, late skin breakdown, or anchor migration; traditional patients had 3 deep infections (P = 0.09) and 3 instances of implant prominence, skin breakdown, or anchor migration. Conclusion. SAI pelvic fixation produces better correction of pelvic obliquity than do previous techniques. Radiographic and clinical anchor stability is satisfactory at 2-year follow-up.

Influence of perioperative resuscitation status on postoperative spine surgery complications.

BACKGROUND CONTEXT Restrictive transfusion criteria have led to decreased morbidity and mortality in critically ill patients. Their use has been extended to other patient groups. In adult spine surgery, ongoing postoperative blood losses and soft-tissue trauma may make these patients not appropriate for restrictive transfusion practices. PURPOSE The purpose of this study was to assess the influence of postoperative hemoglobin (HGB) level and use of packed red blood cells (pRBC) or fresh frozen plasma on postoperative patient morbidity, mortality, and hospital length of stay (LOS). STUDY DESIGN/SETTING This was a retrospective study in a high-volume tertiary hospital. PATIENT SAMPLE The sample comprised 300 consecutive patients who underwent spinal surgeries with blood losses of more than 2 L. OUTCOME MEASURES The outcome measures were postoperative patient morbidity, mortality, and LOS. METHODS The records of patients who underwent adult spinal surgeries with blood loss of 2 or more L (N=300) were abstracted for patient characteristics, operative characteristics, transfusion, and HGB level over time. Intensive care unit and hospital LOS, discharge location, death, pulmonary embolism, stroke, seizures, surgical site infections (SSI), and myocardial infarctions were noted. Logistic regression analyses (SAS software version 9.2) were used. RESULTS Twelve (3%) patients had a postoperative HGB level of less than 8 g/dL, 126 (41.3%) had 8 g/dL or more but less than 10 g/dL, and 167 (54.8%) had 10 g/dL or more. There was no significant difference in morbidity or mortality between the two groups with higher HGB levels. Multiple regression analysis revealed that patients with initial postoperative HGB level of less than 8 g/dL were six times more likely to develop SSI (odds ratio 6.37, 95% confidence interval 1.15-35.28). Deep SSI rates were increased with greater postoperative pRBC use (p=.002). Fresh frozen plasma use in the operation room was lower in cases that developed SSI (1.50 vs. 2.69, p=.042). Intensive care unit and ward LOS were longer with increased postoperative blood product use. CONCLUSION Patients with high blood loss (more than 2 L) during spine surgery who are under-resuscitated (HGB level less than 8 g/dL) have a significant increased risk of SSI.

Surgical site infection after osteotomy of the adult spine: does type of osteotomy matter?

BACKGROUND CONTEXT Surgical site infection after spinal surgery is frequently seen. It occurs between 0.7% and 12% of patients, leading to higher morbidity, mortality, and health-care costs. Osteotomy procedures are known to have increased blood losses and surgical times when compared with other spinal surgeries. Both of these factors have previously been identified as significant risk factors for SSI. We performed a cohort study of this high-risk population to identify risk factors and rates of SSI after spinal osteotomy surgery and identify difference in risk between different types of osteotomies. PURPOSE The objective of the study was to assess the incidence and identify significant risk factors for surgical site infection (SSI) after spinal osteotomy. STUDY DESIGN Retrospective review of all adult patients who underwent spinal osteotomy surgery for deformity by an orthopedic surgeon in our university. METHODS All electronic records of adult orthopedic patients whom underwent a spinal osteotomy procedure at our department between January 1998 and December 2005 (n=363) were abstracted. During surgery, a pedicle subtraction osteotomy (transpedicular wedge resection), anterior spine osteotomy (resection of anterior and middle columns), posterior Smith-Petersen osteotomy (resection of a portion of the superior and inferior lamina, ligamentum flavum, and the inferior and superior articular processed), or a combined anterior and posterior osteotomy (vertebral column resection [VCR]) (circumferential resection of the vertebrae via either a combined anterior/posterior or posterior-only approach) was performed. Primary outcome measurement was SSI. Subanalysis to deep and superficial SSI was performed. RESULTS Twenty patients (5.5%) were found to have an SSI, with nine (2.5%) having deep SSI. Analysis showed that patients undergoing VCR (p=.042) had a significant increased risk for deep SSI (11.1%). Obese patients had a significant increased risk (p=.045) for superficial SSI. CONCLUSIONS Vertebral column resection has a significant increased risk for SSI (11.1%) compared with other types of osteotomies (4.1%). When possible, osteotomy techniques that involve less extensive exposures and soft-tissue dissection should be chosen to minimize deep SSI risk. Obese patients should be counseled on weight loss to try minimizing superficial SSI risk.

Letter to the Editor: Surgical infections

Preface With this Review, Surgery in Africa begins a series of discussions on fundamental surgical questions. We are starting with the topic of Surgical Infections. Surgical Infections can be classified as those requiring surgical treatment or those, like wound infections, which arise as a result of surgical intervention. In this Review we deal with Surgical Infections requiring surgical intevention and in particular, soft tissue infections. Subsequent reviews in this series will deal with septic arthritis, acute and chronic osteomyelitis and the surgery of specific abscesses and infected spaces, including hands. Post-surgical infections will be considered in subsequent Reviews as well.

Fracture characteristics predict patient mortality after blunt force cervical trauma.

Fractures of the cervical spine after blunt cervical trauma are associated with high rates of patient mortality. The purpose of this study was to investigate patient and fracture characteristics that predict mortality. This is a retrospective, case cohort study of all adult patients admitted to our institution between January 1998 and June 2008 with cervical fracture after blunt cervical trauma (N = 218). All patient records were reviewed. The patient and fracture characteristics and outcome data were stored. Age (P = 0.002), involvement of the fourth cervical vertebra (P = 0.002), lamina fracture (P = 0.001), and a facet fracture (P = 0.006) were identified as independent significant risk factors for mortality. In conclusion, mortality is highly affected by patient age, but fracture location and fracture pattern are also predictive of poor patient outcome. Fracture patterns may increase the risk of spinal cord injury at a level that can affect but not eliminate neural control of the diaphragm, which have the worst prognosis for patient mortality.