Postoperative Spinal Implant Infections (PSII)-A Systematic Review: What Do We Know So Far and What is Critical About It?

STUDY DESIGN

Systematic review.

OBJECTIVES

Postoperative spinal implant infections (PSII) are an increasing challenge in the daily clinical routine. This review summarizes existing knowledge in the field of PSII, including definitions, epidemiology, classifications, risk factors, pathogenesis, symptoms, diagnosis, and treatment.

METHODS

A systematic review was performed using a structured PubMed analysis, based on the PRISMA criteria. The search terminology was set as: "spinal implant associated infection OR spinal implant infection OR spinal instrumentation infection OR peri spinal implant infection." PubMed search was limited to the categories randomized controlled trials (RCT), clinical trials, meta-analysis and (systematic) reviews, whereas case reports were excluded. Studies from January 2000 to December 2020 were considered eligible. A total of 572 studies were identified, 82 references included for qualitative synthesis, and 19 for detailed sub analysis (12 meta-analysis, 7 prospective RCT).

RESULTS

Structural problems in the field of PSII were revealed, including (1) limited level of evidence in clinical studies (missing prospective RCT, metanalyzes), (2) small patient numbers, (3) missing standardized definitions, (4) heterogeneity in patient groups, and (5) redundancy in cited literature.

CONCLUSION

Evidence-based knowledge about spinal implant-associated infections is lacking. All involved medical fields should come together to define the term PSII and to combine their approaches toward research, training, and patient care.

Value of procalcitonin as a marker of surgical site infection following spinal surgery

AIM

To compare the value of Procalcitonin (PCT) as a marker of surgical site infection to other inflammatory markers, including C-Reactive Protein (CRP), White Cell Count (WCC) and Erythrocyte Sedimentation Rate (ESR) in patients undergoing a number of spinal procedures. This study also aims to describe the biokinetic profile of the above-named markers in patients developing surgical site infection and those remaining infection-free post-operatively.

METHODS

200 patients undergoing four routine elective spinal procedures were included for analysis. All patients had blood specimens taken at baseline, day 1, 2, 3, 4 and 5 post-operatively for analysis of PCT, CRP, ESR and WCC levels. All patients were monitored for early surgical site infection. Patients with other sources of infection in the early postoperative period were excluded.

RESULTS

Procalcitonin was the most sensitive and specific marker for the detection of surgical site infection in the immediate post-operative period with sensitivity and specificity of 100% and 95.2% respectively. Although Procalcitonin is an inflammatory marker, extent of surgical physiological insult did not alter its biokinetics as opposed to the other inflammatory markers making it a valuable marker of infection.

CONCLUSION

Procalcitonin was found to be superior to the other inflammatory markers investigated in this study as a marker for early surgical site infection in patients undergoing spinal surgery.

A Systematic Review and Meta-Analysis of Procalcitonin as a Marker of Postoperative Orthopedic Infections

Procalcitonin is a serologic marker that increases in response to inflammatory stimuli, especially those of bacterial origin. Postoperative orthopedic periprosthetic infections are often difficult to diagnose. This study systematically reviewed the literature to evaluate the statistical measures of performance of procalcitonin as a marker of postoperative orthopedic infection. This study showed that procalcitonin has a weighted pooled sensitivity of 67.3%, specificity of 69.4%, positive likelihood ratio of 1.778, negative likelihood ratio of 0.423, and diagnostic odds ratio of 5.770. These results illustrate that procalcitonin is an effective serologic marker for postoperative bacterial infections. [Orthopedics. 2018; 41(3):e303-e309.].

Postoperative Changes in Presepsin Level and Values Predictive of Surgical Site Infection After Spinal Surgery: A Single-Center, Prospective Observational Study

STUDY DESIGN

Single-institutional, prospective observational study.

OBJECTIVE

To elucidate the perioperative kinetics of presepsin (PSEP) in patients undergoing spinal surgery, and to evaluate the possibility of PSEP in the early diagnosis of surgical site infection (SSI).

SUMMARY OF BACKGROUND DATA

Early diagnosis of SSI after spinal surgery is important. Although several biomarkers have been used as early indicators of SSI, the specificity of these markers in SSI diagnosis was not high. PSEP was found as a novel diagnostic marker for bacterial sepsis in 2004. However, its kinetics after spinal surgery and its usefulness in early diagnosis of SSI have never been evaluated.

METHODS

A total of 118 patients who underwent elective spinal surgery were enrolled. PSEP was measured before, immediately after, 1 day after, and 1 week after surgery. In patients without postoperative infection, perioperative kinetics of PSEP were analyzed. PSEP levels in patients with postoperative infection were also recorded separately, and their utility in SSI diagnosis was evaluated.

RESULTS

In the 115 patients without postoperative infection, the median PSEP value was 126, 171, 194, and 147 pg/mL before, immediately after, 1 day after, and 1 week after surgery, respectively. Compared with the preoperative value, PSEP was significantly higher immediately after surgery and the next day, and return to the preoperative level 1 week after surgery. The estimated reference value for 95 percentile in patients without postoperative infection was 297 pg/mL 1 week after surgery. In three patients with postoperative infection, higher levels (>300 pg/mL) were observed 1 week after surgery.

CONCLUSION

In patients after spinal surgery without infectious complications, blood levels of PSEP may immediately increase and return to preoperative levels 1 week after surgery. The PSEP value of 300 pg/mL 1 week after surgery might be used as a novel indicator for suspected SSI.

LEVEL OF EVIDENCE

4.

Diagnosis and management of spinal infections

The number of spinal infections has been increasing due to aging populations and larger numbers of immunocompromised hosts and intravenous drug users. Magnetic resonance imaging is a useful tool for the early diagnosis of spinal infections, and can yield positive findings just 3-5 days after disease onset. Before antibiotic administration, cultures must be initiated from blood and from specimens collected from the locus of infection. Based on the pathogens identified by culture, appropriate antibiotics should be selected with careful consideration of antimicrobial susceptibility and spinal tissue penetration. Antibiotic treatment of spinal infections should be continued for longer than for most other types of infections, although the optimal duration remains unknown. The indications for surgical treatment include progressive neurologic deficits, progressive deformity, spinal instability, persistent or recurrent infection, and unbearable pain. In most patients with spinal infection, the gold standard surgical treatment is anterior radical debridement followed by autologous strut bone grafting. The addition of posterior instrumentation has recently become popular. This procedure may be performed alone as an alternative surgical option in patients in poor condition, and if it dramatically reduces pain, subsequent observation may be reasonable. If progressive deformity is observed or pain relief is inadequate after posterior instrumentation, additional anterior debridement and bone grafting should be scheduled.

Surgical Site Infections After Pediatric Spine Surgery

Surgical site infection (SSI) after spinal deformity surgery is a complication in the pediatric population resulting in high morbidity and cost. Despite modern surgical techniques and preventative strategies, the incidence remains substantial, especially in the neuromuscular population. This review focuses on recent advancements in identification of risk factors, prevention, diagnosis, and treatment strategies for acute and delayed pediatric spine infections. It reviews recent literature, including the best practice guidelines for infection prevention in high-risk patients. Targets of additional research are highlighted to assess efficacy of current practices to further reduce risk of SSI in pediatric patients with spinal deformity.

Update on procalcitonin measurements

Procalcitonin (PCT) is used as a biomarker for the diagnosis of sepsis, severe sepsis and septic shock. At the same time, PCT has also been used to guide antibiotic therapy. This review outlines the main indications for PCT measurement and points out possible pitfalls. The classic indications for PCT measurement are: (i) confirmation or exclusion of diagnosis of sepsis, severe sepsis, or septic shock, (ii) severity assessment and follow up of systemic inflammation mainly induced by microbial infection, and (iii) individual, patient adapted guide of antibiotic therapy and focus treatment. Using serially monitored PCT levels, the duration and need of antibiotic therapy can be better adapted to the individual requirements of the patient. This individualized approach has been evaluated in various studies, and it is recommended to be a part of an antibiotic stewardship program.