Perioperative prevention and treatment strategies for spinal surgical site infections Postoperative spinal surgical site infections are a problem that spine surgeons cannot avoid. Postoperative spinal site infections, especially deep infections, can result in prolonged hospitalization, increased treatment costs, and great physical and psychological impact on patients and their families. The management of peri-implant infections is even more challenging. We emphasize that standardized perioperative management is an important measure to prevent postoperative surgical site infections. Once postoperative surgical site infection occurs, early diagnosis and correct and timely management are important to improve the infection control rate, shorten the recovery process, and reduce treatment costs. In this article, we describe the perioperative measures for the prevention and treatment of spinal surgical site infections based on our experience and the latest advances at home and abroad to further reduce the rate of postoperative surgical site infections, early diagnosis and effective treatment of surgical site infections. Surgical site infection (SSI) is defined by the Centers for Disease Control and Prevention (CDC) as a surgical site infection within 30 days after surgery without an endograft or within 1 year after surgery with an endograft. The literature reports surgical site infection rates of 0.7% to 14% in adults with spinal surgery. The rate of infection varies depending on the complexity of the procedure. The average infection rate for simple disc nucleus pulposus resection is 1%; infection rates of 14% have been reported after long segment internal fixation. In the last decade, many authors have performed various case-control and retrospective studies with SSI rates ranging from 1.9% to 4.4% after all spine surgeries. The risk factors for spinal SSI are numerous and have been divided into two categories: patient-related factors and surgery-related factors. Patient-related risk factors include advanced age, obesity, diabetes mellitus, reoperation of the spine, malnutrition, smoking, and long-term hormone use. In 2011, Dr. Koutsoumbelis of the Department of Spine Surgery at the New York Hospital for Special Surgery published an article in the JBJS reporting on 3218 patients who had posterior lumbar or lumbosacral instrumentation fixation and fusion from January 2000 to December 2006 at the hospital. Of the 3218 patients with fusion, 84 were determined to have SSI, for an infection rate of 2.61%. For each infected patient, 2 additional patients without surgical site infection from the same procedure were selected as controls and followed for at least 3 years to analyze risk factors associated with surgical site infection. Two cases of SSI after internal spinal fixation occurred in our hospital this year. SSI is divided into superficial and deep infections. Superficial infection is defined as infection limited to the superficial layer of deep fascia; deep infection is defined as infection involving the deeper part of deep fascia. The definition of early infection after spinal endoprosthesis is still controversial; Wimmer et al. referred to infections occurring within 20 weeks after surgery as early infections and those occurring after 20 weeks after surgery as late infections. In China, Equuschus et al. defined infections after 3 months postoperatively as late onset infections. Tian Wei et al. referred to infections within 30 days after surgery as early infections. Patients with early postoperative spinal incision infection mostly show symptoms of systemic toxicity, such as fever, chills, headache, and so on. Some patients first show symptoms of hyperthermia, with a marked increase in body temperature and severe back pain 2 to 3 days after surgery, while wound erythema and oozing manifest only after 6 to 7 days. In such patients, once the temperature rises, the cause should be actively sought. Early postoperative infection can be easily detected, while late infection may be more difficult to diagnose. Because of the lack of specificity of the symptoms, they are often overlooked by clinicians. Because of deep paravertebral soft tissue infections, the diagnosis is only made easily when the delayed infection has progressed to a local mass, sinus tract formation, and pus flow. There are two major clues to the diagnosis of delayed infection: increased pain in the affected area after a normal recovery period following spinal surgery; and elevated blood sedimentation or CRP in most patients. In microbiological diagnosis, the length of culture time has an important impact on the outcome, with Clark et al. reporting a positive rate of only 10% at 72 hours and 91% at 7 days or more. According to the definition of surgical site infection, superficial incisional tissue infection is an infection involving only the skin or subcutaneous tissue of the incision that occurs within 30 days of surgery and meets one of the following conditions: 1. Superficial incisional tissue has purulent fluid. 2. Pathogens are cultured from the fluid or tissue of the superficial incisional tissue. 3. Signs or symptoms of infection are present, including local redness, swelling, fever, pain and tenderness or superficial tissue of the incision opened by the surgeon. Deep incisional tissue infection is an infection involving deep soft tissues (e.g., fascia and musculature) that occurs within 30 days after surgery without implants and within 1 year after surgery with implants and meets one of the following criteria: 1. Pus is draining or puncturing from the deep incision, but the pus is not coming from an organ/cavity portion. 2. The deep incisional tissue is splitting on its own or the incision is opened by the surgeon. At the same time, the patient has signs or symptoms of infection, including localized fever, swelling and pain. 3. Abscesses or other evidence of infection in the deep tissue of the incision are found by direct examination, reoperative exploration, pathology or imaging. Positive culture of pathogenic microorganisms is not required for the diagnosis of surgical site infection. C-reactive protein (CRP) is an acute temporal protein synthesized by the liver and is only present in trace amounts in the blood of healthy people. published an article reporting 348 consecutive spine surgery patients, of which 221 were single-segment decompressions, 44 were multisegment decompressions, and 83 were combined with internal fixation. CRP was measured in 332 cases (95.4%) without early infection, which showed a normal clinical course. Sixteen cases (4.6%) had an abnormal CRP response, 12 of which were re-elevated and 4 of which were persistently elevated. The sensitivity, specificity, positive predictive value and negative predictive value of abnormal CRP elevation predicting early SSI after spine surgery were 100%, 96.8%, 31.3% and 100%, respectively. the sensitivity of CRP was very high, but its positive predictive value was low, meaning that a low percentage of postoperative patients with persistently elevated CRP were truly infected patients. Despite this, infection is highly likely if CRP values are higher at 7 days postoperatively than at 3 days postoperatively, or if CRP values are normalized and then elevated again postoperatively. To compensate for the lack of CRP to predict postoperative infection, other serum inflammatory markers have been used clinically. Such as serum calcitoninogen (PCT) and serum amyloid A (SAA). These markers are superior to CRP for early diagnosis of SSI. To prevent surgical site infection, clinicians must pay attention to all aspects of preoperative, intraoperative and postoperative procedures. Find and cure alternate foci of infection preoperatively in patients undergoing elective surgery; take a bath (soap or chlorhexidine) at least the night before surgery; and complete preoperative preparation in the shortest possible hospital stay. One study showed that nasal staphylococci can increase surgical site infection, with postoperative surgical site infection rates of 12.5% and 5% for those with and without bacteria, respectively. And preoperative nasal bone application of mupirocin is recommended, although the CDC does not recommend routine preoperative application of antimicrobial agents in the nasal cavity. Do not shave preoperatively unless hair is at the incision site, and if necessary, remove hair on the day of surgery with an electric hair clipper and depilatory cream. For high-risk orthopedic patients, perioperative prophylactic antibiotics are effective in reducing the rate of surgical site infection. For patients at low risk of methicillin-resistant Staphylococcus aureus (MRSA) colonization, a generation of cephalosporin antibiotics is available. If the patient is allergic to beta-lactams, clindamycin (600 mg intravenous administration) or vancomycin (1.0 g intravenous administration) may be used instead of cephalosporins. Prophylactic vancomycin (1.0 g intravenous) should be considered for patients who are at higher risk of colonization if they live in an environment with a high number of methicillin-resistant Staphylococcus aureus (e.g., residents of homes for the elderly, long-term residents, etc.), and patients who have had previous infections with methicillin-resistant Staphylococcus aureus are at significantly increased risk of methicillin-resistant Staphylococcus aureus infections. Many aspects of the operating room must be given adequate attention. Application of best practices for preparation of operator’s hands and patient’s skin, reduction of movement of personnel and objects in the operating room, reduction of the use of rapid pressure steam sterilization, use of powder-free gloves, and application of sutures with an antimicrobial surface layer are effective measures to reduce SSI. The use of sutures with an antimicrobial surface layer is gaining attention, and Edmiston et al. reported that such coated sutures were effective in inhibiting bacterial colonization and contamination in an in vitro trial. In another randomized controlled trial, Rozzelle et al. reported a significant reduction in surgical site infection rates after cerebrospinal fluid shunts with sutures with an antimicrobial surface layer compared to cases without such sutures. These sutures were 7% to 10% more expensive compared to similar sutures without the coating. To our knowledge, no relevant efficacy analysis has been published, but it is reasonable to apply such sutures in high-risk patients. Transportation in the operating room is another aspect that must be taken into account. Maintaining adherence to professional practices in the operating room reduces the risk of surgical site infections, and unnecessary traversal in the operating room can increase the rate of infection. In a study of spine surgery, Olsen et al. reported that having 2 or more people join in during the procedure was an independent risk factor for surgical site infection, with a 2.245 advantage ratio. Babkin et al. found that the incidence of surgical site infection was 6.7 times higher for left knee replacements than for right knee replacements when performed in the same operating room during the same time period, and that when the left side of the operating room Once the door to the left side of the operating room was locked to avoid access, the rate of surgical site infection for left knee replacements quickly decreased to a level comparable to that of right knee replacements, a finding that also confirms the importance of limiting operating room traffic. Intraoperative care should be taken to protect tissue, carefully stop bleeding, reduce foreign bodies, eliminate dead spaces, and delay closure of grade 3 or 4 wounds. The decision to place drains near the end of orthopedic surgery requires the surgeon’s decision based on their training, perspective, and personal experience, in addition to the results of relevant studies. A recent review addressing this issue, which included 36 studies (5,464 patients), showed that the application of closed drains reduced intra-incisional stasis and also reduced the need to add packaged excipients. However, the application of closed drainage has a corresponding increase in the need for blood transfusion. There was no significant difference in the rate of infection at the surgical site with or without placement of incisional drainage. The authors conclude that the effectiveness of closed negative pressure drainage remains uncertain. Blood transfusion induces immune modulation, which in turn leads to an increased risk of postoperative infection. talbot et al. reported that the rate of infection after sternotomy was 3.2 times higher in patients who had been transfused than in those who had not been transfused. In a study on cardiac surgery, Bower et al. reported that the infection rate was almost twice as high in patients who had blood transfusions as in those who had not. Early postoperative removal of catheters and management of drains; standardized incisional care, including dressing changes in a clean dressing change room, airtight incisions, hand washing before and after dressing changes, and wearing a mask and cap during dressing changes; and early detection of incisional infections. Attention to hand hygiene is an important way to prevent nosocomial infections, yet adherence to hand hygiene related protocols is suboptimal. The authors of the 2002 CDC Guidelines for Hand Hygiene in Healthcare Settings reported an average adherence rate of approximately 40%. Multiple studies have shown that over time, multifaceted interventions that include strong logistical support tend to be more successful than traditional single intervention models such as education or feedback on hand hygiene adherence data. Another strategy that can help increase hand hygiene adherence is the application of alcohol-containing hand sanitizers, which is the CDC’s preferred recommendation for routine hand hygiene. This is because alcohol-containing sanitizers tend to be more compliant versus hand sinks and are also more time efficient than traditional hand washing. In addition, alcohol-based hand sanitizers are less irritating to the skin than soap and water hand washing. Early and definitive diagnosis and identification of the etiologic organism is valuable for effective treatment of SSI. The principles of treatment for superficial surgical site infections include incision and drainage within the incision involvement, bacterial culture, oral administration of a generation of cephalosporin antibiotics, and if cephalosporin antibiotics are allergic, clindamycin may be applied. Antibiotics are adjusted according to the culture results after they are obtained. The treatment of deep infections is still controversial. The most commonly recommended treatment strategy for deep infections with internal fixation is aggressive surgical treatment combined with systemic antibiotics. Some authors believe that the internal fixation should be removed and re-fixed when the infection is controlled. Other authors recommend retaining the stable endosseous and replacing the loose endosseous. The incision can be closed after debridement and closed irrigation depending on the situation; others suggest opening the incision after debridement to close the incision in two stages. The most common pathogenic microorganism for surgical site infection is Staphylococcus aureus. In 2010, Johns Hopkins Hospital in Baltimore, USA, reported 132 cases of postoperative spinal infections in Spine. 72.6% of 84 deep infections and 85.7% of 48 superficial infections were caused by S. aureus, 17% of which were MRSA. and the Taipei Veterans Hospital in 2008 Therefore, it is wise to prefer vancomycin or teicoplanin plus a broad-spectrum antibiotic after the infection is confirmed and before the bacterial culture and sensitivity results are available. The antibiotics can be adjusted according to the results of bacterial culture and drug sensitivity after the results are obtained. Aggressive surgical treatment combined with effective antibiotics is the gold standard for the treatment of deep postoperative spinal infections. However, surgical treatment has certain shortcomings compared with conservative treatment. For example, it increases the risk of surgery, increases the cost of treatment, and is not easily accepted by patients and families. Do all deep postoperative spinal infections require surgical treatment? The answer is currently unclear. If not, which patients are suitable for conservative treatment alone? Hsu-Shan Hong et al. 2008 in Spine reported 10 consecutive patients with deep early postoperative spinal infections, three after posterior internal fixation of thoracolumbar fractures, two after posterior long-segment fixation for persistent back pain after vertebral compression fracture vertebroplasty, four after posterior decompression and internal fixation fusion for lumbar spinal stenosis, and one after nucleus pulposus removal for lumbar disc herniation. 1 case. Infection symptoms occurred at an average of 15.4 days postoperatively. Bacterial culture: methicillin-resistant Staphylococcus aureus (MRSA) in 3 cases, methicillin-resistant coagulase-negative Staphylococcus aureus (MRCNS) in 4 cases, methicillin-sensitive coagulase-negative Staphylococcus aureus (CNS) in 1 case, no bacterial growth in 1 case, and no culture in 1 case. 8 patients were treated with intravenous vancomycin or teicoplanin for an average of 29.4 days (20-42 days), followed by Two patients received oral ciprofloxacin with or without rifampicin for an average of 61 days (56-91 days). 2 patients received oral ciprofloxacin for 2 to 3 months in an outpatient setting. In one case, Steven-Johnson syndrome developed at week 4 of ticoranine and the antibiotics were discontinued for 7 weeks, followed by oral ciprofloxacin and rifampicin, and the CRP was normalized and the patient was discharged. 1 year later, the patient returned to the hospital with low back pain and again developed sinus tracts and elevated CRP, but the lumbar spine was fused on imaging. The internal fixation was removed and bacterial culture was MRSA. (No bacteria were cultured in this case 1 year ago). The incision and sinus tract healed smoothly with 2 weeks of intravenous vancomycin, and the CRP returned to normal, with no recurrence of infection at 1 year follow-up. The rest of the patients were followed for an average of 27.3 months without recurrence of infection. This group of cases suggests that early deep infection at the site of spinal surgery does not always require surgical debridement, even if internal fixation is applied. The appropriate treatment for the patient should be chosen according to the patient’s specific situation. This literature has inspired us in the treatment of postoperative SSI of the spine.