Assistive diagnostic indicators for infections related to lumbar posterior interbody fusion internal fixation: platelet count and mean platelet volume

BACKGROUND

The most severe complication after posterior single-segment lumbar interbody fusion and internal fixation (PIFIF) surgery for degenerative lumbar diseases is deep surgical site infection (DSSI). Preoperatively diagnosing such complications proves to be challenging. Platelets, as acute-phase reactants, undergo changes in response to infections and inflammation. This study aims to assess whether platelet indices can further aid in the diagnosis of DSSI.

METHODS

A single-center retrospective study was conducted from January 2016 to February 2021 at Xi'an Jiaotong University-Affiliated Honghui Hospital, involving 83 patients who underwent revision surgery after PIFIF due to lumbar degenerative diseases. Among them, 24 patients were diagnosed with DSSI based on combined bacterial culture and imaging data. Preoperative complete serological indicators including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and platelet count and mean platelet volume ratio (P/M ratio) were analyzed using receiver operating characteristic (ROC) curve analysis to determine cutoff values, sensitivity, and specificity. This was done to further assess the ability of these serological indicators to identify the occurrence of DSSI after PIFIF.

RESULTS

There were no significant differences in baseline demographic characteristics between the two patient groups (P > 0.05). The P/M ratio was 13.54 ± 5.05 in the aseptic revision group, while it was 19.21 ± 6.30 in the DSSI revision patients, showing a significant difference (P < 0.001). ROC curve analysis revealed that the optimal cutoff value for the P/M ratio was 17.50, with a sensitivity of 58.3% and a specificity of 78.6%. The areas under the curve (AUC) for ESR, CRP, and P/M ratio were 0.797, 0.845, and 0.756, respectively. The negative predictive value (NPV) was 87.04%, 89.47%, and 82.45%, respectively; the positive predictive value (PPV) was 58.62%, 69.23%, and 53.84%, respectively, for ESR, CRP, and P/M ratio, respectively. When P/M ratio is used in combination with ESR and CRP, the AUC is 0.887, with a sensitivity of 95.4%, specificity of 67.8%, NPV of 97.56%, PPV of 54.76%. The diagnostic performance of the model for evaluating DSSI is significantly improved compared to using ESR and CRP alone (P < 0.05).

CONCLUSION

Platelets and their related serum biomarkers are closely associated with DSSI. The P/M ratio can serve as a reliable test for screening DSSI and is worth considering for inclusion in the assessment of patients at risk of developing DSSI after potential PIFIF surgery.

Cost-effectiveness and clinical utility of universal pre-admission MRSA screening in total joint arthroplasty patients

BACKGROUND

For patients undergoing total joint arthroplasty (TJA), pre-admission meticillin-resistant Staphylococcus aureus (MRSA) nasal screening has been widely adopted to prevent postoperative joint infection. However, screening cost-effectiveness and clinical utility have not been adequately evaluated.

AIM

To assess the MRSA infection rate, associated costs, and costs of screening at our institution, before and after screening implementation.

METHODS

This was a retrospective cohort study examining patients who underwent TJA at a health system in New York State, between 2005 and 2016. Patients were divided into the 'no-screening' group if the operation occurred prior to adoption of the MRSA screening protocol in 2011 and the 'screening' group if afterwards. The number of MRSA joint infections, cost of each infection, and costs associated with preoperative screening were recorded. Fisher's exact test and cost comparison analysis were performed.

FINDINGS

The no-screening group had four MRSA infections in 6088 patients over a seven-year period, whereas the screening group had two in 5177 patients over five years. Fisher's exact test showed no significant association between screening and MRSA infection rate (P = 0.694). The cost of postoperative MRSA joint infection treatment was US$40,919.13 per patient, whereas annual nasal screening was US$103,999.97.

CONCLUSION

At our institution, MRSA screening had little impact on infection rates and led to increased costs, with 2.5 MRSA infections required annually to meet the costs of screening. Therefore, the screening protocol may be best suited for high-risk populations, rather than the average TJA patient. The authors recommend a similar clinical utility and cost-effectiveness analysis at other institutions implementing MRSA screening programmes.

A meta-analysis of risk factors for non-superficial surgical site infection following spinal surgery

BACKGROUND

Surgical site infection (SSI) is the most common complications in spinal surgery. In SSI, non-superficial surgical site infections are more likely to result in poor clinical outcomes. It has been reported that there are multiple factors contributing to postoperative non-superficial SSI, but still remains controversial. Therefore, the aim of this meta-analysis is to investigate the potential risk factors for non-superficial SSI following spinal surgery.

METHODS

A systematic database search of PubMed, Embase, Web of Science, Cochrane Library and Clinical Trials was performed for relevant articles published until September 2022. According to the inclusion and exclusion criteria, two evaluators independently conducted literature screening, data extraction and quality evaluation of the obtained literature. The Newcastle-Ottawa Scale (NOS) score was used for quality evaluation, and meta-analysis was performed by STATA 14.0 software.

RESULTS

A total of 3660 relevant articles were initially identified and 11 articles were finally included in this study for data extraction and meta-analysis. The results of meta-analysis showed that the diabetes mellitus, obesity, using steroids, drainage time and operative time were related to the non-superficial SSI. The OR values (95%CI) of these five factors were 1.527 (1.196, 1.949); 1.314 (1.128, 1.532); 1.687(1.317, 2.162); 1.531(1.313, 1.786) and 4.255(2.612, 6.932) respectively.

CONCLUSIONS

Diabetes mellitus, obesity, using steroids, drainage time and operative time are the current risk factors for non-superficial SSI following spinal surgery. In this study, operative time is the most important risk factor resulting in postoperative SSI.

Economic outcomes associated with deep surgical site infection from lower limb fractures following major trauma

AIMS

This study aims to estimate economic outcomes associated with 30-day deep surgical site infection (SSI) from closed surgical wounds in patients with lower limb fractures following major trauma.

METHODS

Data from the Wound Healing in Surgery for Trauma (WHiST) trial, which collected outcomes from 1,547 adult participants using self-completed questionnaires over a six-month period following major trauma, was used as the basis of this empirical investigation. Associations between deep SSI and NHS and personal social services (PSS) costs (£, 2017 to 2018 prices), and between deep SSI and quality-adjusted life years (QALYs), were estimated using descriptive and multivariable analyses. Sensitivity analyses assessed the impact of uncertainty surrounding components of the economic analyses.

RESULTS

Compared to participants without deep SSI, those with deep SSI had higher mean adjusted total NHS and PSS costs (adjusted mean difference £1,577 (95% confidence interval (CI) -951 to 4,105); p = 0.222), and lower mean adjusted QALYs (adjusted mean difference -0.015 (95% CI -0.032 to 0.002); p = 0.092) over six months post-injury, but this difference was not statistically significant. The results were robust to the sensitivity analyses performed.

CONCLUSION

This study found worse economic outcomes during the first six months post-injury in participants who experience deep SSI following orthopaedic surgery for major trauma to the lower limb. However, the increase in cost associated with deep SSI was less than previously reported in the orthopaedic trauma literature. Cite this article: Bone Jt Open 2022;3(5):398-403.

Surgeon volume and the risk of deep surgical site infection following open reduction and internal fixation of closed tibial plateau fracture

BACKGROUND

Emerging evidences supported that the surgeon case volume significantly affected post-operative complications or outcomes following a range of elective or non-elective orthopaedic surgery; no data has been available for surgically treated tibial plateau fractures. We aimed to investigate the relationship between surgeon volume and the risk of deep surgical site infection (DSSI) following open reduction and internal fixation (ORIF) of closed tibial plateau fracture.

METHODS

This was a further analysis of the prospectively collected data. Adult patients undergoing ORIF procedure for closed tibial plateau fracture between January 2016 and December 2019 were included. Surgeon volume was defined as the number of surgically treated tibial fractures in the preceding 12 months and dichotomized on the basis of the optimal cut-off value determined by the receiver operating characteristic (ROC) curve. The outcome was DSSI within one year post-operatively. Multiple multivariate logistic models were constructed for "drilling down" adjustment of confounders. Sensitivity and subgroup analyses were performed to assess the robustness of outcome and identify the "optimal" subgroups.

RESULTS

Among 742 patients, 20 (2.7%) had a DSSI and 17 experienced re-operations. The optimal cut-off value for case volume was nine, and the low-volume surgeon was independently associated with 2.9-fold (OR, 2.9; 95%CI, 1.1 to 7.5) increased risk of DSSI in the totally adjusted multivariate model. The sensitivity analyses restricted to patients with original BMI data or those operated within 14 days after injury did not alter the outcomes (OR, 2.937, and 95%CI, 1.133 to 7.615; OR, 2.658, and 95%CI, 1.018 to 7.959, respectively). The subgroup analyses showed a trend to higher risk of DSSI for type I-IV fractures (OR, 4.6; 95%CI, 0.9 to 27.8) classified as Schatzker classification and substantially higher risk in patients with concurrent fractures (OR, 6.1; 95%CI, 1.0 to 36.5).

CONCLUSION

The surgeon volume is independently associated with the rate of DSSI, and a number of ≥ nine cases/year are necessarily kept for reducing DSSIs; patients with concurrent fractures should be preferentially operated on by high-volume surgeons.

A Novel Technique for Treating Early Deep Surgical Site Infection After Posterior Lumbar Fusion with Instrumentation

OBJECTIVE

To introduce a novel technique of using incisional vacuum-assisted closure (VAC) after 1-stage incision suture combined with closed suction irrigation system (CSIS) for treating early deep surgical site infection (SSI) after posterior lumbar fusion with instrumentation and to compare it with traditional CSIS.

METHODS

This was a retrospective study. Patients with early deep SSI after posterior lumbar fusion with instrumentation from January 2013 to May 2020 who were treated by meticulous debridement followed by either CSIS or incisional VAC after 1-stage incision suture combined with CSIS were identified. The demographic characteristics, treatment features, and outcomes were analyzed and compared between the 2 treatment methods.

RESULTS

A total of 48 patients (48/5016, 0.96%) developed early deep SSI, 46 of whom were enrolled in this study. This included 24 patients in the CSIS group (group 1) and 22 patients in the incisional VAC after 1-stage incision suture combined with CSIS group (group 2). All patients received follow-up, with an average of 19.7 months (range, 13-30 months). There were no significant differences in demographic characteristics in both groups (P > 0.05). The number of VAC foam dressing or ordinary dressing changes (P < 0.001), number of debridements (P = 0.028), intravenous antibiotic duration (P = 0.042), oral antibiotic duration (P = 0.019), and hospital stay (P = 0.029) in group 1 were significantly higher than those in group 2. The irrigation duration in group 1 was significantly shorter than that in group 2 (P = 0.007). All patients were eventually cured with satisfactory outcomes.

CONCLUSIONS

Compared with CSIS, incisional VAC after 1-stage incision suture combined with CSIS may be recommended considering that it has fewer dressing changes, fewer debridements, longer irrigation duration, shorter duration of antibiotic use, shorter hospital stay, and more convenient nursing care.

Implant-Associated Infection of Long-Segment Spinal Instrumentation: A Retrospective Analysis of 46 Consecutive Patients

Study Design

This single-center retrospective study analyzed patients with an implant-associated infection of spinal instrumentation (four or more segments) treated between 2010 and 2018.

Purpose

This study aimed to investigate the treatment of implant-associated infections of long-segment spinal instrumentation and to define risk factors for implant removal.

Overview of Literature

Implant-associated infection occurs in 0.7%–20% of spinal instrumentation. Significant blood loss, delayed reoperation, and use of effective antibiotics are reported risk factors for implant removal.

Methods

Patients with superficial infections not involving the implant were excluded. All patients received surgical and antibiotic treatments according to our interdisciplinary osteomyelitis board protocol. An infection was considered healed if a patient showed no signs of infection 1 year after termination of treatment. The patients were divided into an implant retention group and implant removal group, and their clinical and microbiological data were compared.

Results

Forty-six patients (27 women, 19 men) with an implant-associated infection of long-segment spinal instrumentation and mean age of 65.3±14.3 years (range, 22–89 years) were included. The mean length of the infected instrumentation was 6.5±2.4 segments (range, 4–13 segments). Implant retention was possible in 21 patients (45.7%); in the other 25 patients (54.3%), a part of or the entire implant required removal. Late infections were associated with implant removal, which correlated with longer hospitalization. Both groups showed high postoperative complication rates (50%) and high mortality rates (8.7%). In 39 patients (84.8%), infection was eradicated at a mean follow-up of 18.9±11.1 months (range, 12–60 months). Three patients (6.5%) were lost to follow-up.

Conclusions

Implant-associated infections of long-segment spinal instrumentations are associated with high complication and mortality rates. Late infections are associated with implant removal. Treatment should be interdisciplinary including orthopedic surgeons and clinical infectiologists.

Prognosis of deep infection in spinal surgery using implants, treated by retention, removal of bone graft and lengthy antibiotherapy

OBJECTIVE

Surgical site infections (SSIs) are complications that predispose to a high risk of unfavourable surgical outcomes. The aim of this study was to assess the SSI rate in this type of patients and their prognosis with similar treatment.

MATERIALS AND METHODS

A retrospective case series of 799 patients above 18 years old with spinal instrumentation surgery, between January 2010 and December 2014 in the traumatology and orthopaedic surgery department of our institution. All patients with SSIs were treated by debridement, graft replacement, retention of the instrumentation and lengthy courses of antimicrobial therapy. The patients were followed up for a period of 12 months.

RESULTS

Of all the patients with arthrodesis, 32 (4%) had spinal SSIs. Three patients were lost to follow-up. The final sample analyzed comprised 29 cases, with a median age of 54.9 years (IQR, 45.7-67 years) and a Charlson comorbidity index of 2.0 (IQR; 0-3). A microbiological diagnosis was obtained in 75.8% of the cases. Of these, the ISSs were monomicrobial in 68.2% and polymicrobial in 31.8%. Once treatment had been completed, 96% were cured without sequelae, and the rate of recurrence and reoperation was 4%.

CONCLUSIONS

Treatment based on debridement, retention of the instrumentation, graft replacement and lengthy courses of antimicrobial therapy seems a very effective strategy in the treatment of patients with deep surgical site infection in spine surgery.

Recurrence of Deep Surgical Site Infection in Cerebral Palsy After Spinal Fusion Is Rare

STUDY DESIGN

Retrospective review of prospective registry.

OBJECTIVES

To assess the following in children with cerebral palsy (CP) who develop deep surgical site infection (DSSI) after spinal fusion: (1) rate of infection recurrence after treatment; (2) treatments used; (3) radiographic outcomes; and (4) differences in Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) scores versus those of children with no infection (NI).

SUMMARY OF BACKGROUND DATA

Studies show high rates of surgical site infection in patients with CP but do not address late recurrence or quality-of-life effects.

METHODS

One hundred fifty-one children with CP underwent spinal fusion surgery from 2008 through 2011 and had ≥2-year follow-up. Patients who developed DSSI were compared with patients with NI. Student t tests were used to analyze deformity; analysis of variance was used to analyze CPCHILD scores in both groups preoperatively and at final follow-up.

RESULTS

Eleven patients developed DSSI. Causative organisms were polymicrobial infection (5 cases), Escherichia coli (2 cases), and Proteus mirabilis, Staphylococcus aureus, Enterococcus faecalis, and Peptostreptococcus (1 case each). All patients underwent irrigation and debridement and received at least 6 weeks of antibiotics. Six had negative-pressure-dressing-assisted wound closure; 5 had primary closure. At mean 4-year follow-up (range, 3-5 years) no patient had recurrent infection. From immediate postoperative to final follow-up, no patient had significant loss of coronal curve (p = .77) or pelvic obliquity (p = .71) correction. However, at final follow-up, comfort and emotions, overall quality-of-life, and total CPCHILD scores in the DSSI group were significantly lower compared with the NI group (p = .005, .022, and .026, respectively).

CONCLUSIONS

In children with CP who developed DSSI after spinal fusion, there was no recurrence of infection or deformity after infection treatment. CPCHILD scores in patients with DSSI were lower compared with the NI group.