Analysis of surgical site infection after musculoskeletal tumor surgery: risk assessment using a new scoring system

Dental Applications of Ion-Substituted Hydroxyapatite: A Review of the Literature

Hydroxyapatite (HA) forms an essential constituent of human teeth and bone. Its distinctive characteristic features, such as bioactivity and osteoconductivity, make it an ideal candidate to be used as an implant coating in restorative dentistry and maxillofacial surgery for bone regeneration. However, low fracture toughness and brittleness are a few of the inherent features of HA, which limit its application in load-bearing areas. The potential of HA to engage its lattice structure with either partial or complete substitution with external ions has become an increasing area of research as this phenomenon has the potential to enhance the biological and functional properties of the material. Consequently, this review aimed to highlight the role of various substituted ions in dental applications. Data indicate that the newly formed HA-substituted biomaterials demonstrate enhanced remineralization and antimicrobial activity along with improved hardness. Ion-substituted HA offers a promising strategy for future clinical research as these materials may be incorporated into various dental products for therapeutic treatments.

Development and validation of a nomogram to predict surgical site infection after soft-tissue sarcoma resection

Aims

Surgical site infection (SSI) after soft-tissue sarcoma (STS) resection is a serious complication. The purpose of this retrospective study was to investigate the risk factors for SSI after STS resection, and to develop a nomogram that allows patient-specific risk assessment.

Methods

A total of 547 patients with STS who underwent tumour resection between 2005 and 2021 were divided into a development cohort and a validation cohort. In the development cohort of 402 patients, the least absolute shrinkage and selection operator (LASSO) regression model was used to screen possible risk factors of SSI. To select risk factors and construct the prediction nomogram, multivariate logistic regression was used. The predictive power of the nomogram was evaluated by receiver operating curve (ROC) analysis in the validation cohort of 145 patients.

Results

LASSO regression analysis selected possible risk factors for SSI, including age, diabetes, operating time, skin graft or flap, resected tumour size, smoking, and radiation therapy. Multivariate analysis revealed that age, diabetes, smoking during the previous year, operating time, and radiation therapy were independent risk factors for SSI. A nomogram was developed based on the results of multivariate logistic regression analysis. In the development cohort, the incidence of SSI was 4.5% in the low-risk group (risk score < 6.89) and 26.6% in the high-risk group (risk score ≥ 6.89; p < 0.001). In the validation cohort, the incidence of SSI was 2.0% in the low-risk group and 15.9% in the high-risk group (p = 0.004).

Conclusion

Our nomogram will enable surgeons to assess the risk of SSI in patients with STS. In patients with high risk of SSI, frequent monitoring and aggressive interventions should be considered to prevent this.

Surgical Site Infections During the Pandemic: The Impact of the "COVID Bundle"

BACKGROUND

A reduction in surgical site infections (SSIs) has been reported in several discrete patient populations during the COVID-19 pandemic. Herein, this study evaluates the impact of the COVID-19 pandemic on SSI in a large patient cohort incorporating multiple surgical disciplines. We hypothesize that enhanced infection control and heightened awareness of such measures is analogous to an SSI care bundle, the hypothetical "COVID bundle", and may impact SSI rates.

METHOD

Data collected for the American College of Surgeons National Surgical Quality Improvement Program between January 1, 2015, and April 1, 2021, were retrospectively analyzed. SSI rates were compared among time-dependent patient cohorts: Cohort A (pre-pandemic, N = 24,060, 87%) and Cohort B (pandemic, N = 3698, 13%). Time series and multivariable analyses predicted pre-pandemic and pandemic SSI trends and tested for association with timing of surgery.

RESULTS

The overall SSI incidence was reduced in Cohort B versus Cohort A (2.8% vs. 4.5%, p < 0.001). Multivariable analysis indicated a downward SSI trend before pandemic onset (IRR 0.997, 95% CI 0.994, 1). At pandemic onset, the trend reduced by a relative factor of 39% (IRR 0.601, 95% CI 0.338, 1.069). SSI then trended upward during the pandemic (IRR 1.035, 95% CI 0.965, 1.111). SSI rates significantly trended downward in general surgical patients at pandemic onset (IRR 0.572, 95% CI 0.353, 0.928).

CONCLUSION

Although overall SSI incidence was reduced during the pandemic, a statistically significant decrease in the predicted SSI rate only occurred in general surgical patients at pandemic onset. This trend may suggest a positive impact of the "COVID bundle" on SSI rates in these patients.

Patient and Surgical Risk Factors for Surgical Site Infection in Lower-Extremity Oncological Endoprosthetic Reconstruction: A Secondary Analysis of the PARITY Trial Data

BACKGROUND

The specific risk factors for surgical site infection (SSI) in orthopaedic oncology patients undergoing endoprosthetic reconstruction have not previously been evaluated in a large prospective cohort. In the current study, we aimed to define patient- and procedure-specific risk factors for SSI in patients who underwent surgical excision and endoprosthetic reconstruction for lower-extremity bone or soft-tissue tumors using the prospectively collected data of the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial.

METHODS

PARITY was a multicenter, blinded, randomized controlled trial with a parallel 2-arm design that aimed to determine the effect of a long duration (5 days) versus short duration (24 hours) of postoperative prophylactic antibiotics on the rate of SSI in patients undergoing surgical excision and endoprosthetic reconstruction of the femur or tibia. In this secondary analysis of the PARITY data, a multivariate Cox proportional hazards regression model was constructed to explore predictors of SSI within 1 year postoperatively.

RESULTS

A total of 96 (15.9%) of the 604 patients experienced an SSI. Of the 23 variables analyzed in the univariate analysis, 4 variables achieved significance: preoperative diagnosis, operative time, volume of muscle excised, and hospital length of stay (LOS). However, only hospital LOS was found to be independently predictive of SSI in the multivariate regression analysis (hazard ratio per day = 1.03; 95% confidence interval = 1.01 to 1.05; p < 0.001). An omnibus test of model coefficients demonstrated that the model showed significant improvement over the null model (χ2 = 78.04; p < 0.001). No multicollinearity was found.

CONCLUSIONS

This secondary analysis of the PARITY study data found that the only independent risk factor for SSI on multivariate analysis was hospital LOS. It may therefore be reasonable for clinicians to consider streamlined discharge plans for orthopaedic oncology patients to potentially reduce the risk of SSI.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Unexpected Benefits of Coronavirus Disease 2019: Impact of Coronavirus Disease 2019 Pandemic on Surgical Site Infection: A Systematic Review and Meta-Analysis

Background: We aimed to summarize and synthesize the current evidence regarding the indirect impact of the coronavirus disease 2019 (COVID-19) pandemic and its associated measures on the surgical site infection (SSI) rate compared with the pre-pandemic period. Methods: A computerized search was conducted on MEDLINE via PubMed, Web of Science, and Scopus using the relevant keywords. Two-stage screening and data extraction were done. The National Institutes of Health (NIH) tools were used for the quality assessment. The Review Manager 5.4.1 program was used for the analysis. Results: Sixteen articles (n = 157,426 patients) were included. The COVID-19 pandemic and lockdown were associated with reduced risk of SSIs after surgery (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.56-0.75; p < 0.00001) and (OR, 0.49; 95% CI, 0.29-0.84; p = 0.009), respectively. There was no significant reduction in the SSIs rate after applying the extended use of masks (OR, 0.73; 95% CI, 0.30-1.73; p = 0.47). A reduction in the superficial SSI rate during the COVID-19 pandemic compared with the pre-COVID-19 pandemic period was observed (OR, 0.58; 95% CI, 0.45-0.75; p < 0.0001). Conclusions: The current evidence suggests that the COVID-19 pandemic may have some unexpected benefits, including improved infection control protocols, which resulted in reduced SSI rates, especially superficial SSIs. In contrast to extended mask use, the lockdown was associated with reduced rates of SSIs.

Presurgical Perspective and Posttreatment Evaluation of Soft Tissue Tumors of the Ankle and Foot in Adults

This article discusses soft tissue tumors of the ankle and foot region in adults, including tumors of the joints, and also briefly addresses tumor-simulating lesions. We offer general recommendations and describe specific aspects of common entities in that region, such as typical imaging appearance, therapeutic strategies, and posttherapeutic considerations. Focal masses and diffuse swelling are common in the foot and ankle region; most of them are non-neoplastic. Some of the tumors, such as plantar fibromatosis, tenosynovial giant cell tumor, synovial chondromatosis, or schwannoma, have a very typical appearance on magnetic resonance imaging. Sarcomas are rare among true soft tissue tumors; however, they can be small and well demarcated, may grow slowly, and are often misinterpreted as benign. This is especially true for synovial sarcoma, one of the most common sarcomas in this region. Densely packed tissues in the foot and ankle may hamper determining the tissue of origin. Adherence to diagnostic guidelines and cooperation with tumor centers is crucial including for posttherapeutic surveillance. We also describe typical posttherapeutic changes and complications after surgery, radiation therapy, and chemotherapy, as well as parameters for the detection and exclusion of recurrence of soft tissue tumors of the ankle and foot.

Customized three dimensional printed prosthesis as a novel intercalary reconstruction for resection of extremity bone tumours: a retrospective cohort study

AIMS

The 3D-printed prosthesis (3DP) is a novel treatment for massive bone defect reconstruction after tumor resection. This study was aiming to explore the clinical efficacy of customized 3DP for intercalary reconstruction by comparing the clinical outcomes after implanting customized 3DP or conventional allograft in limb salvage surgery.

METHODS

A total of 28 patients with extremity bone tumors who underwent customized 3DP or conventional allograft reconstruction between 2011 and 2018 at our institution were analyzed retrospectively. Among them, 14 cases received customized 3DP reconstruction (3DP group), and 14 cases received conventional allograft reconstruction (control group). Demographics, surgical outcomes, radiographical assessments, limb functions, and post-operative complications between these two groups were collected to evaluate clinical outcomes.

RESULTS

No significant difference was observed in the demographics, mean intra-operative blood loss, MOSI scores, and MSTS scores between the two groups. Patients in 3DP group had a shorter operative time (157.9 vs 199.6 min, p = 0.03) and lesser number of fluoroscopy (4.1 vs 8.1, p < 0.001) compared to control group. The mean time to osseointegration at bone-implant interfaces in 3DP group was significantly earlier than that in control group (6.1 vs 12.2 months, p < 0.001). Moreover, the 3DP group had a significantly lower post-operative complication rate than the control group (7% vs 50%, p = 0.03).

CONCLUSIONS

The customized 3DP might provide a promising strategy for intercalary reconstruction in limb salvage surgery with more precise reconstruction, higher surgical efficiency, and comparable satisfactory clinical outcomes.

Development of Injectable and Biodegradable Needle-Type Starch Implant for Effective Intratumoral Drug Delivery and Distribution

Introduction

Compared to intravenous administration, intratumoral drug administration enables the direct delivery of drugs to tumors and mitigates the systemic absorption of drugs and associated drug-induced side effects. However, intratumoral drug administration presents several challenges. The high interstitial fluid pressure (IFP) of the tumor prevents the retention of drugs within the tumor; thus, significant amounts of the drugs are absorbed systemically through the bloodstream or delivered to non-target sites. To solve this problem, in this study, a drug-enclosed needle-type starch implant was developed that can overcome IFP and remain in the tumor.

Methods

Injectable needle-type starch implants (NS implants) were prepared by starch gelatinization and drying. The structure, cytotoxicity, and anticancer effects of the NS implants were evaluated. Biodistribution of NS implants was evaluated in pork (in vitro), dissected liver (ex vivo), and 4T1 tumors in mice (in vivo) using a fluorescence imaging device.

Results

The prepared NS implants exhibited a hydrogel structure after water absorption. NS implants showed effective cytotoxicity and anticancer effects by photothermal therapy (PTT). The NS implant itself has sufficient strength and can be easily injected into a desired area. In vivo, the NS implant continuously delivered drugs to the tumor more effectively and uniformly than conventional hydrogels and solutions.

Conclusion

This study demonstrated the advantages of needle-type implants. An injectable NS implant can be a new formulation that can effectively deliver drugs and exhibit anticancer effects.

Neoadjuvant Chemotherapy and Endoprosthetic Reconstruction for Lower Extremity Sarcomas: Does Timing Impact Complication Rates?

INTRODUCTION

Sarcoma patients undergoing surgical resection and endoprosthetic reconstruction often receive neoadjuvant chemotherapy (NACT). The objective of the current study was to determine if the timing of NACT impacts the rates of surgical site infections (SSI) and reoperations.

METHODS

This study was a secondary analysis of the recently published Prophylactic Antibiotic Regimens in Tumor Surgery trial. Patients who underwent NACT, tumor resection, and endoprosthetic reconstruction for a bone or soft tissue sarcoma were included. Multivariate Cox proportional hazards regression models were created to evaluate if NACT timing was predictive of SSI or reoperations.

RESULTS

Overall, 216 patients from 39 clinical sites were included in the analysis. The most common diagnosis was osteosarcoma (75%), followed by Ewing's sarcoma (16%). The median time from completion of NACT to surgery was 24 days (interquartile range 15-42 days). Eighty-five (39%) patients underwent surgery within 3 weeks of completing NACT, 78 (36%) underwent surgery 3-6 weeks after completing NACT, and 53 (22%) patients underwent surgery > 6 weeks after completion of NACT. The timing of NACT did not impact SSI rates or reoperation rates. Longer operative time was an independent predictor of both SSI [hazard ratio (HR) per hour of 1.21, 95% confidence interval (CI) 1.07-1.40; p = 0.002] and reoperation rates (HR of 1.15 per hour, 95% CI 1.03-1.28; p = 0.014).

CONCLUSION

The timing of surgery following NACT varied considerably. Chemotherapy timing did not impact SSI or reoperations in patients undergoing surgical resection and endoprosthetic reconstruction in sarcoma patients.

The Management of an Open Biopsy Tract Site Infection and Ulceration in the Setting of Osteosarcoma

Biopsy site infection in the setting of osteosarcoma is a potentially devastating complication. We present the case of a 16-year-old adolescent girl with a distal femur osteosarcoma who developed an open biopsy site ulceration and infection after initiation of neoadjuvant chemotherapy. This was treated with careful local excision of the ulcerated biopsy site and systemic antibiotic therapy throughout the duration of her chemotherapy course. She subsequently underwent wide resection of the tumor en bloc with a generous ellipse around the biopsy scar and reconstruction with cemented knee megaprosthesis. No recurrence of either infection or malignancy was observed. This case represents the successful treatment of a biopsy site ulceration and infection in a patient with osteosarcoma and may merit adoption in future instances of this complication.

Megaprosthesis anti-bacterial coatings: A comprehensive translational review

Periprosthetic joint infections (PJI) are catastrophic complications for patients with implanted megaprostheses and pose significant challenges in the management of orthopaedic oncology patients. Despite various preventative strategies, with the increasing rate of implanted orthopaedic prostheses, the number of PJIs may be increasing. PJIs are associated with a high rate of amputation. Therefore, novel strategies to combat bacterial colonization and biofilm formation are required. A promising strategy is the utilization of anti-bacterial coatings on megaprosthetic implants. In this translational review, a brief overview of the mechanism of bacterial colonization of implants and biofilm formation will be provided, followed by a discussion and classification of major anti-bacterial coatings currently in use and development. In addition, current in vitro outcomes, clinical significance, economic importance, evolutionary perspectives, and future directions of anti-bacterial coatings will also be discussed. Megaprosthetic anti-bacterial coating strategies will help reduce infection rates following the implantation of megaprostheses and would positively impact sarcoma care. STATEMENT OF SIGNIFICANCE: This review highlights the clinical challenges and a multitude of potential solutions to combating peri-prosthetic join infections in megaprotheses using anti-bacterial coatings. Reducing infection rates following the implantation of megaprostheses would have a major impact on sarcoma care and major trauma surgeries that require reconstruction of large skeletal defects.

Cutaneous diphtheria complicated oncologic reconstruction surgery in osteosarcoma

Diphtheria is an uncommon bacterial infection of the upper respiratory tract. We described a surgical site infection in a young adolescent female on maintenance chemotherapy. Corynebacterium diphtheriae was recovered from the wound, and she was treated with antibiotics and antitoxin. Cutaneous diphtheria should be considered in immunocompromised patients receiving chemotherapy.

Surgical Site Infections in patients undergoing major oncological surgery during the COVID-19 paNdemic (SCION): A propensity-matched analysis

Background and Objectives

There are reports of outcomes of elective major cancer surgery during the COVID‐19 pandemic. We evaluated if reinforcement of hand hygiene, universal masking, and distancing as a part of pandemic precautions led to a decrease in the incidence of surgical site infections (SSIs) in major oncologic resections.

Methods

Propensity score matching using the nearest neighbor algorithm was performed on 3123 patients over seven covariates (age, comorbidities, surgery duration, prior treatment, disease stage, reconstruction, and surgical wound type) yielding 2614 matched (pre‐COVID 1612 and COVID 1002) patients. Conditional logistic regression was used to identify if SSI incidence was lower amongst patients operated during the pandemic.

Results

There was a 4.2% (p = 0.006) decrease in SSI in patients operated during the pandemic. On multivariate regression, surgery during the COVID‐19 period (odds ratio [OR] = 0.77; 95% confidence interval [CI] = 0.61–0.98; p = 0.03), prior chemoradiation (OR = 2.46; CI = 1.45–4.17; p < 0.001), duration of surgery >4 h (OR = 2.17; 95%CI = 1.55–3.05; p < 0.001) and clean contaminated wounds (OR = 2.50; 95% CI = 1.09–2.18; p = 0.012) were significantly associated with SSI.

Conclusion

Increased compliance with hand hygiene, near‐universal mask usage, and social distancing during the COVID‐19 pandemic possibly led to a 23% decreased odds of SSI in major oncologic resections. Extending these low‐cost interventions in the post‐pandemic era can decrease morbidity associated with SSI in cancer surgery.

A Short-Course Antibiotic Prophylaxis Is Associated with Limited Antibiotic Resistance Emergence in Post-Operative Infection of Pelvic Primary Bone Tumor Resection

Resections of primary pelvic bone tumors are frequently complicated by surgical site infections (SSIs), thereby impairing the functional prognosis of patients, especially in case of implant removal. Although prophylactic antibiotics play an essential role in preventing SSIs, there are presently no recommendations that support their appropriate use. This study aimed to assess the impact of a 24 h prophylactic protocol on the bacterial ecology, the resistance pattern, and the SSI healing rate. We hypothesized that this protocol not only limits the emergence of resistance but also results in a good cure rate with implant retention in case of SSI. A retrospective study was performed that included all patients with an SSI following a pelvic bone tumoral resection between 2005 and 2017 who received a 24 h antibiotic prophylaxis protocol. Twenty-nine patients with an SSI were included. We observed a 75.9% rate of polymicrobial infection, with a high prevalence of digestive flora microorganisms and a majority of wild-type phenotypes. We confirmed that there was no significant emergence of resistant flora. After first-line debridement, antibiotics (DA) if any implant was used, or debridement, antibiotics, and implant retention (DAIR) whenever possible, we obtained a 79.3% cure rate, with implant removal in 20% of cases. The absence of an implant was significantly associated with SSI healing. Early infection management and low resistance profiles may also have a positive effect, but this needs to be confirmed in a larger cohort. In light of this, the use of a 24 h prophylactic protocol in primary pelvic bone tumor resections is associated with a favorable infection cure rate and implant retention in case of SSI, and minimal selection of resistant microorganisms.

Topical vancomycin: Does it reduce surgical site infection in bone tumors?

INTRODUCTION

We retrospectively analyzed a consecutive group of patients operated for bone tumors of extremity and pelvis who received only perioperative antibiotics (Group A) against a similar group that had additional 1 g topical vancomycin sprinkled in the wound before closure (Group B). The aim was to determine if the addition of topical vancomycin decreases the incidence of deep surgical site infection (SSI).

MATERIALS AND METHODS

A total of 221 patients operated between January 2011 and December 2011 were analyzed in Group A and 254 patients operated between April 2012 and March 2013 were analyzed in Group B. Any patient who required operative intervention for wound discharge was considered to be infected. All patients had a 1 year follow-up to determine the incidence of SSI.

RESULTS

The overall rate of SSI was 7% (31 of 475 patients). Seventeen (8%) of Group A patients had SSI as against 14 (6 %) of Group B patients (P = 0.337). A subgroup analysis of endoprosthetic reconstructions, internal fixation implants (plates/intramedullary nails), extracorporeal radiation treated bones and strut allografts showed no difference between the two groups of patients.

CONCLUSION

Our data suggest that the addition of topical vancomycin before wound closure in patients operated for bone tumors does not decrease the incidence of SSI. Further investigation of this technique using a case-controlled methodology with an increase in the dose of vancomycin may be warranted.

Soft Tissue Sarcoma Follow-up Imaging: Strategies to Distinguish Post-treatment Changes from Recurrence

Soft tissue sarcomas encompass multiple entities with differing recurrence rates and follow-up intervals. The detection of recurrences and their differentiation from post-therapeutic changes is therefore complex, with a central role for the clinical radiologist. This article describes approved recommendations. Prerequisite is a precise knowledge of the current clinical management and surgical techniques. We review recurrence rates and treatment modalities. An adequate imaging technique is paramount, and comparison with previous imaging is highly recommended. We describe time-dependent therapy-related complications on magnetic resonance imaging compared with the spectrum of regular post-therapeutic changes. Early complications such as seromas, hematomas, and infections, late complications such as edema and fibrosis, and inflammatory pseudotumors are elucidated. The appearance of recurrences and radiation-associated sarcomas is contrasted with these changes. This systematic approach in follow-up imaging of soft tissue sarcoma patients will facilitate the differentiation of post-therapeutic changes from recurrences.

Risk Factors for Surgical Site Infection in Orthopaedic Oncology

INTRODUCTION

Surgical site infections (SSIs) are common complications after surgeries involving musculoskeletal tumors, but we know little about SSI risk factors unique to orthopaedic oncology. A greater understanding of these factors will help risk-stratify patients and guide surgical decision-making.

METHODS

A retrospective review at a single-institution identified 757 procedures done on 624 over 6 years. The patients had a preoperative diagnosis of a malignant or potentially malignant neoplasm of the bone or soft tissues. Patient-specific and procedure-specific variables and diagnosis of SSI were recorded for each case. Data were analyzed through univariate analysis and multiple logistic regression.

RESULTS

On univariate analysis, significant patient-specific risk factors for SSI included malignancy (P < 0.001), smoking history (P = 0.041), and American Society of Anesthesiologists Score (P = 0.002). Significant procedure-specific risk factors for SSI on univariate analysis included surgery time (P < 0.001), estimated blood loss (P < 0.001), blood transfusion volume (P < 0.001), neoadjuvant chemotherapy (P < 0.001), neoadjuvant radiation therapy (P < 0.001), inpatient surgery (P < 0.001), and number of previous surgeries within the study period (P < 0.001). The two factors that independently predicted risk of SSI when controlling for all other variables in a multiple logistic regression were whether the surgery was done on an inpatient basis (P = 0.005) and the number of previous surgeries done on the same site (P = 0.001).

CONCLUSIONS

We found a number of risk factors that correlate markedly with SSI after orthopaedic oncology surgery. The surgeon can use these risk factors to aid in surgical decision-making.

Antimicrobial Prophylaxis for the Prevention of Surgical Site Infections in Orthopaedic Oncology - A Narrative Review of Current Concepts

The incidence of surgical site infections (SSIs) after elective tumour orthopaedic surgery in adults is higher than non-oncologic orthopaedic surgery. Their causative microorganisms and antibiotic susceptibilities are also different from the non-oncologic cases; with no apparent predictable microbiological patterns. Clinicians continue to struggle to tailor the optimal prophylactic regimen for the very heterogeneous group of tumour patients. Many clinicians thus prolong the first-and second-generation cephalosporin agents, while a minority chooses to broaden the antimicrobial spectrum by combination prophylaxis. The variability in current practices and surgical techniques is enormous, even within the same setting. The scientific literature lacks adequate retrospective case-studies and there is currently only one prospective randomized trial. In this narrative review, we discuss various perioperative antibiotic concepts in oncologic orthopaedic surgery, including a summary of the state-to-the-art, opinions and difficulties related to the different prophylactic strategies.

Risk Factors for Surgical Site Infection after Soft-Tissue Sarcoma Resection, Including the Preoperative Geriatric Nutritional Risk Index

Malignant soft-tissue sarcoma resection is associated with a relatively high incidence of surgical site infection (SSI). The known risk factors for SSI following soft-tissue sarcoma resection include tumor size and location, prolonged surgery, and massive blood loss. The geriatric nutritional risk index (GNRI) was used as a tool to help predict the occurrence of SSI after major surgery. We investigated the utility of the GNRI as a predictor of SSI following soft-tissue sarcoma resection. We retrospectively reviewed 152 patients who underwent surgical resection of soft-tissue sarcoma in our institute, and found that the incidence of SSI was 18.4% (28/152). The SSI and non-SSI groups significantly differed regarding surgical time, diameter of the skin incision, maximum tumor diameter, instrumentation, presence of an open wound, preoperative chemotherapy, preoperative C-reactive protein concentration, and GNRI. Binomial logistic regression analysis showed that the risk factors for SSI following soft-tissue sarcoma surgery were male sex, larger skin incision diameter, larger maximum tumor diameter, presence of an open wound, and lower GNRI. Our findings indicate that malnutrition is a risk factor for SSI after soft-tissue sarcoma resection, and suggest that appropriate assessment and intervention for malnutrition may reduce the incidence of SSI.

Preoperative evaluation of intraoperative blood loss during malignant soft tissue tumor resection by ultrasonography

BACKGROUND

Preoperative evaluation of the risk of surgery-related blood loss in malignant soft tissue tumor resection is difficult because of wide variations in histological subtype, malignancy, location, and size. Ultrasonography is useful for the evaluation of blood flow around a soft tissue tumor and has the potential to preoperatively estimate intraoperative blood loss in tumor resection. To date, there has been no report regarding blood loss evaluation using ultrasonography in this field.

PATIENTS AND METHODS

The usefulness of information obtained by ultrasonography, including tumor size, vessel density in the tumor, and blood flow volume in the vessels, was analyzed for the prediction of intraoperative blood loss in malignant soft tissue tumor resection.

RESULTS

Vessel density in the tumor and blood flow in the vessels were identified as independent risk factors for blood loss. Using these factors, a new index for the prediction of blood loss was established. Receiver operating characteristic analyses revealed a high area under the curve value (0.80), confirming the accuracy of the index for the prediction of blood loss.

CONCLUSION

Ultrasonography is a useful modality for predicting intraoperative blood loss in malignant soft tissue tumor surgery.

Prolonged Operative Duration Increases Risk of Surgical Site Infections: A Systematic Review

Background: The incidence of surgical site infection (SSI) across surgical procedures, specialties, and conditions is reported to vary from 0.1% to 50%. Operative duration is often cited as an independent and potentially modifiable risk factor for SSI. The objective of this systematic review was to provide an in-depth understanding of the relation between operating time and SSI.

Patients and Methods: This review included 81 prospective and retrospective studies. Along with study design, likelihood of SSI, mean operative times, time thresholds, effect measures, confidence intervals, and p values were extracted. Three meta-analyses were conducted, whereby odds ratios were pooled by hourly operative time thresholds, increments of increasing operative time, and surgical specialty.

Results: Pooled analyses demonstrated that the association between extended operative time and SSI typically remained statistically significant, with close to twice the likelihood of SSI observed across various time thresholds. The likelihood of SSI increased with increasing time increments; for example, a 13%, 17%, and 37% increased likelihood for every 15 min, 30 min, and 60 min of surgery, respectively. On average, across various procedures, the mean operative time was approximately 30 min longer in patients with SSIs compared with those patients without.

Conclusions: Prolonged operative time can increase the risk of SSI. Given the importance of SSIs on patient outcomes and health care economics, hospitals should focus efforts to reduce operative time.

High Frequency of Polymicrobial Infections After Surgical Resection of Malignant Bone and Soft Tissue Tumors: A Retrospective Cohort Study

Introduction

Surgical resection of a malignant bone tumor (BT) or soft tissue tumor (STT), with or without prosthetic replacement, carries a high risk of developing postoperative infections. There is limited knowledge on the bacteriological spectrum of these postsurgical infections that necessitate empirical antibiotic therapy. The aim of this study was to analyze the incidence and microbiological features of site infections following BT or STT resection.

Methods

In this retrospective mono-center study, we analyzed the surgical and bacteriological data of all consecutive patients who developed an infection after surgical resection of a BT or STT between January 2010 and April 2014.

Results

Seventy-two consecutive patients who developed an infection on the site of surgical treatment for a BT (n = 42) or SST (n = 30) were included. Polymicrobism was frequently observed, more often associated with STTs (93%) than BTs (71%; P = 0.03). Gram-negative bacteria were more frequently isolated in STTs (55%) than in BTs (26%; P = 0.01) and non-prosthesis-associated infections (54%) than prosthesis-associated infections (29%; P = 0.04), whereas staphylococci were more frequently found in BTs (76%) than in STTs (52%; P = 0.03). Overall, we found gram negatives in 82% of early acute infections, 11% of chronic infections and 7% of late acute infections (P < 0.01).

Conclusion

Postoperative infections in patients after surgical resection of BTs or STTs were often polymicrobial, especially following STTs. Causative bacteria were often gram negatives in STTs and non-prosthesis-associated infections, whereas staphylococci were predominant in BTs. Based on these findings, we recommend antibiotic coverage of both gram-positive and -negative bacteria with a combination of broad-spectrum antibiotics in STTs and antistaphylococcal antibiotics as first-line therapy in infections following BT surgery.

Enrichment of bacteria samples by centrifugation improves the diagnosis of orthopaedics-related infections via real-time PCR amplification of the bacterial methicillin-resistance gene

Background

To effectively treat orthopaedic infections by methicillin-resistant strains, an early diagnosis is necessary. Bacterial cultures and real-time polymerase chain reaction (PCR) have been used to define methicillin-resistant staphylococci. However, even when patients display clinical signs of infections, bacterial culture and real-time PCR often cannot confirm infection. The aim of this study was to prospectively compare the utility of real-time PCR for the mecA gene detection following centrifugation of human samples with suspected orthopaedic infections.

Results

In addition to the conventional real-time PCR method, we performed real-time PCR following centrifugation of the sample at 4,830×g for 10 min in a modified real-time PCR (M-PCR) method. We suspended cultured methicillin-resistant Staphylococcus aureus and generated standard dilution series for in vitro experiments. The in vitro detection sensitivity of the M-PCR method was approximately 5.06 times higher than that of the conventional real-time PCR method. We performed bacterial culture, pathological examination, real-time PCR, and M-PCR to examine the infectious fluids and tissues obtained from 36 surgical patients at our hospital. Of these, 20 patients who had undergone primary total hip arthroplasty were enrolled as negative controls. In addition, 15 patients were examined who were clinically confirmed to have an infection, including periprosthetic joint infection (eight patients), pyogenic spondylitis (two patients), infectious pseudoarthrosis (two patients), and after spine surgery (three patients). In one sample from a patient who developed infectious pseudoarthrosis and two samples from surgical site infections after spine surgery, the mecA gene was detected only by the M-PCR method. In one patient with infectious pseudoarthrosis, one patient with infection after arthroplasty, and two patients with purulent spondylitis, the detection sensitivity of the M-PCR method was increased compared with PCR (clinical sample average: 411.6 times).

Conclusions

These findings suggest that the M-PCR method is useful to detect methicillin-resistant strains infections. In addition, the centrifugation process only takes 10 min longer than conventional real-time PCR methods. We believe that the M-PCR method could be clinically useful to detect orthopaedic infections caused by methicillin-resistant strains.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1180-2) contains supplementary material, which is available to authorized users.

Substituted hydroxyapatites with antibacterial properties

Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions) and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency.