Detection of Cutibacterium (Propionibacterium) acnes in orthopaedic surgery: serious problem or contamination?

PURPOSE: Bone and joint infections are an important and increasing problem. Whether intraoperatively detected bacteria should be considered relevant or not is often difficult to assess. This retrospective cohort study analyzes the relevance of C. acnes cultured from deep intraoperative specimens. METHODS: All deep tissue samples collected intraoperatively between 2015 and 2020 from a quartiary care provider were evaluated for detection of C. acnes and its therapeutical consequences. Infection rates were determined according to a standardized definition and protocol and analyzed in dependence of patient's demographic data (age and gender), operative parameters (type of surgery, body region/location of surgery, and impression of the surgeon), and initiated therapy. RESULTS: In 270 cases of more than 8500 samples, C. acnes was detected. In 30%, the detection was considered an infection. The number of samples taken and tested positive for C. acnes correlated significantly with its classification as a cause of infection. If more than one sample of the patient was positive, the detection was significantly more likely to be treated as infection (p < 0.001). In 76% of cases, a consultation to the infectious diseases (ID) department took place regarding the classification of the pathogen detection and the therapy to be carried out. Almost all of the tested isolates demonstrated the wild-type susceptibility for penicillin and clindamycin. CONCLUSION: Intraoperative detection of skin-colonizing bacteria such as C. acnes is not always synonymous with infection. In particular, if other examination results contradict an infection (pathological sample without evidence of an infectious event, detection of malignant cells, etc.), the situation must be considered in a very differentiated manner. Interdisciplinary boards, for example, are suitable for this purpose. Care should be taken to obtain a sufficiently large number of tissue samples for microbiological examination to be able to better classify the result.

Harmonized procedure coding system for surgical procedures and analysis of surgical site infections (SSI) of five European countries.

BACKGROUND: The use of routine data will be essential in future healthcare research. Therefore, harmonizing procedure codes is a first step to facilitate this approach as international research endeavour. An example for the use of routine data on a large scope is the investigation of surgical site infections (SSI). Ongoing surveillance programs evaluate the incidence of SSI on a national or regional basis in a limited number of procedures. For example, analyses by the European Centre for Disease Prevention (ECDC) nine procedures and provides a mapping table for two coding systems (ICD9, National Healthcare Safety Network [NHSN]). However, indicator procedures do not reliably depict overall SSI epidemiology. Thus, a broader analysis of all surgical procedures is desirable. The need for manual translation of country specific procedures codes, however, impedes the use of routine data for such an analysis on an international level. This project aimed to create an international surgical procedure coding systems allowing for automatic translation and categorization of procedures documented in country-specific codes. METHODS: We included the existing surgical procedure coding systems of five European countries (France, Germany, Italy, Spain, and the United Kingdom [UK]). In an iterative process, country specific codes were grouped in ever more categories until each group represented a coherent unit based on method of surgery, interventions performed, extent and site of the surgical procedure. Next two ID specialist (arbitrated by a third in case of disagreement) independently assigned country-specific codes to the resulting categories. Finally, specialist from each surgical discipline reviewed these assignments for their respective field. RESULTS: A total number of 153 SALT (Staphylococcus aureus Surgical Site Infection Multinational Epidemiology in Europe) codes from 10 specialties were assigned to 15,432 surgical procedures. Almost 4000 (26%) procedure codes from the SALT coding system were classified as orthopaedic and trauma surgeries, thus this medical field represents the most diverse group within the SALT coding system, followed by abdominal surgical procedures with 2390 (15%) procedure codes. CONCLUSION: Mapping country-specific codes procedure codes onto to a limited number of coherent, internally and externally validated codes proofed feasible. The resultant SALT procedure code gives the opportunity to harmonize big data sets containing surgical procedures from international centres, and may simplify comparability of future international trial findings. TRIAL REGISTRATION: The study was registered at clinicaltrials.gov under NCT03353532 on November 27th, 2017.

Establishment of an interdisciplinary board for bone and joint infections.

PURPOSE: The incidence of bone and joint infections is increasing while their treatment remains a challenge. Although guidelines and recommendations exist, evidence is often lacking and treatment complicated by complex clinical presentations and therapeutic options. Interdisciplinary boards shown to improve management of other diseases, seem potentially helpful. We describe the establishment of an osteomyelitis board to show the existing demand for such a platform. METHODS: All patients discussed in the board for bone and joint infections between October 2014 and September 2020 were included in this retrospective study. Data were extracted from patient records and analyzed descriptively. RESULTS: A total of 851 requests related to 563 patients were discussed in the board during the study period. After a run-in period of 3 years, a stable number of cases (> 170/year) were discussed, submitted by nearly all hospital departments (22 of 25). Recommendations were mainly related to antibiotic treatment (43%) and to diagnostics (24%). Periprosthetic joint infections were the most frequent entity (33%), followed by native vertebral osteomyelitis and other osteomyelitis. In 3% of requests, suspected infection could be excluded, in 7% further diagnostics were recommended to confirm or rule out infection. CONCLUSIONS: A multidisciplinary board for bone and joint infections was successfully established, potentially serving as a template for further boards. Recommendations were mainly related to antibiotic treatment and further diagnostics, highlighting the need for interdisciplinary discussion to individualize and optimize treatment plans based on guidelines. Further research in needed to evaluate impact on morbidity, mortality and costs.

Quality of life and mortality after surgical treatment for vertebral osteomyelitis (VO): a prospective study.

PURPOSE: Vertebral osteomyelitis (VO) has a high mortality and leads to chronic pain and functional disability. Surgical treatment is often necessary. To date, little is known about the consequences of surgery on patient outcome. The aim of this study was to determine the quality of life (QoL) and mortality rates of surgically treated VO patients for a period of 2 years. METHODS: Patients with VO undergoing surgical treatment in a tertiary referral hospital from 2008 to 2015 were included prospectively. Data were collected before (T0) as well as 1 year (T1) and 2 years (T2) post-surgery. Within the European Spine Tango registry, prospective patient and QoL data were collected using validated outcome scores: Oswestry Disability Index, Short Form 36/EuroQol, Visual Analog Scale, and Core Outcome Measures Index. RESULTS: From 195 patients surgically treated for VO, QoL data were available from 136 patients at T0, 100 patients at T1, and 82 patients at T2, respectively. The 1- and 2-year mortality rates were 20% and 23%. Mainly all QoL outcome scores showed significant improvement at T1 and did not change significantly from T1 to T2. CONCLUSION: Surgical treatment of VO patients leads to significantly improved QoL. Nevertheless, QoL levels were below those of the general population. Our results underscore that spine disability questionnaires measuring QoL are mandatory to demonstrate comprehensively the severity of this entity. Our study confirms a high mortality and points out the role of VO as a potentially life-threatening condition.

Can triclosan-coated sutures reduce the postoperative rate of wound infection? Data from a systematic review and meta-analysis.

BACKGROUND: Wound infections are typical postoperative complications with considerable therapeutic consequences and high personnel and financial costs. Previous meta-analyses have shown that triclosan-coated sutures can reduce the risk of postoperative wound infection. This work aimed to update previous meta-analyses with a special focus on different subgroups. METHODS: A systematic review with meta-analysis was performed (registration: PROSPERO 2022 CRD42022344194). The search was independently performed in the Web of Science, PubMed, and Cochrane databases by 2 reviewers. A critical methods review of all included full texts took place. The trustworthiness of the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation method. An analysis of the cost-effectiveness of the suture material was carried out. RESULTS: In this meta-analysis of 29 randomized controlled trials, the use of triclosan-coated suture material resulted in a significant reduction of postoperative wound infection rate (24%) (random-effects model; risk ratio: 0.76; 95% confidence interval: [0.67-0.87]). The effect was evident in the subgroups according to wound contamination class, underlying oncologic disease, and pure preoperative antibiotic prophylaxis. In the subgroup analysis by the operating department, the significant effect was visible only in the abdominal surgery group. CONCLUSION: Based on the randomized controlled clinical trials reviewed, triclosan-coated sutures reduced postoperative wound infection rates in the main study and most subgroups. Additional costs of up to 12 euros for the coated suture material appear to be justified to generate an economic benefit for the hospital by reducing postoperative wound infections. The additional socioeconomic benefit of reducing wound infection rates was not investigated here.

Is the rod necessary? Biomechanical comparison of static knee spacers during axial loading.

BACKGROUND: Knee Spacers are required in two-stage revision surgery of periprosthetic joint infection of the knee. Extended bone and ligamentous defects are often temporarily arthrodised via a static spacer. Regarding their weight-bearing potential and construction, there is no current consent. Our aim was to evaluate three individual static spacer variants with regard to their axial loading capacity. METHODS: The static spacer variants were tested in a cadaver model. One after the other, a spacer with metal-reinforced rods, a spacer without metal reinforcement and a rod-less spacer were implanted and tested up to an axial loading of 1000 Newton. Target parameters were plastic deformation, stiffness and spacer movement at both the femoral and tibial surface. Loading was applied up to 1000 Newton. Radiological controls of the bone substance were performed. FINDINGS: The spacer variants did not differ regarding deformation, stiffness or spacer movement. However, deformation increased significantly with the axial load in all spacer variants. Radiographs showed no fracture or spacer-dislocation resulting from testing. INTERPRETATION: While the spacer reinforcement or the sheer presence of a rod did not influence the axial loading capacity in this in vitro study, weightbearing should be discouraged to limit further bone erosion.

What Do We Know about Spondylodiscitis in Children? A Retrospective Study.

Pediatric spondylodiscitis (PSD) is a rare disease with a major impact on mobility and functional status. Data concerning demographic and microbiological characteristics, clinical course, treatment, and outcome are scarce. Therefore, the aim of this study was to present clinical experiences of a third-level hospital (2009-2019) in PSD and compare these with adult spondylodiscitis (ASD). Of a total of 10 PSD patients, most of the infants presented with unspecific pain such as hip pain or a limping, misleading an adequate diagnosis of spine origin. Eight patients could be treated conservatively whereas surgery was performed in two cases with one case of tuberculous PSD (tPSD). The causative agent was detected in three of the patients. The diagnosis of PSD is often difficult since clinical symptoms are unspecific and causative pathogens often remain undetected. Nevertheless, empirical anti-infective therapy also seems to be effective. Based on recent studies, clinicians should be encouraged to keep the duration of anti-infective therapy in children short. Since comorbidities are not presented in PSD it is unclear which children suffer from PSD; thus, studies are necessary to identify predisposing factors for PSD. In our study, PSD differs from ASD in diagnostic and especially in therapeutic aspects. Therefore, specific guidelines for PSD would be desirable.

Periprosthetic infections: How do we diagnose and treat? Results of an online survey and comparison with international recommendations.

OBJECTIVE: Endoprosthetic replacement surgery of hip and knee joints is widely performed, but always carries the risk of developing periprosthetic infection (PPI). Treatment of PPI is lengthy and demanding for the patient, often involving multiple surgeries as well as lengthy drug therapies. Remediation is not always successful despite extensive therapy. METHODS: An online survey was used to investigate whether the therapeutic measures implemented in German hospitals are based on international treatment recommendations. For this purpose, German physicians who regularly treat periprosthetic infections in their clinics were asked to complete an online questionnaire. The questionnaire asked about internal hospital procedures. These were then compared with international recommendations. RESULTS: With a response rate of 10.9%, the questionnaire shows agreement with the international recommendations in large parts of the operative and medicinal procedures. In preoperative imaging for example, two-plane radiographs are the standard. Similarly, the participants' approach to preoperative specimen collection, incubation time, and operative management (regarding one- or two-stage approach to septic joint) reflects the recommendations. Deviations were particularly evident in the area of laboratory diagnostics, where the erythrocyte sedimentation rate (ESR) is determined in only 17.1%, contrary to the recommendations. Whereas procalcitonin (PCT) and blood culture sampling takes place regularly. Clear differences emerges in the use of drains, which, contrary to the recommendations, are used very regularly (almost 70%). In this survey, the time intervals between the onset of infection symptoms and the start of therapy (prosthesis-preserving therapy) is shown to be longer than recommended internationally. CONCLUSION: In summary, however, the recommended approaches of the international groups in most respects are followed, a high willingness of respondents to collaborate with local infectious disease specialists demonstrates the complexity of the disease.

Vertebral Osteomyelitis After Spine Surgery: A Disease With Distinct Characteristics.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: We aimed to determine the 2-year survival and to identify clinical and microbiological characteristics of patients with native vertebral osteomyelitis (VO) as compared to postoperative VO to find further strategies for improvement of the management of VO. SUMMARY OF BACKGROUND DATA: A relevant subgroup (20%-30%) of patients with VO has a history of spine surgery. Infection in these patients might be clinically different from native VO. However, clinical, microbiological, and outcome characteristics of this disease entity have not been well studied as most trials either excluded these patients or are limited by a small cohort and short observation period. METHODS: Between 2008 and 2013, patients who presented at a tertiary care center with symptoms and imaging findings suggestive of VO were reviewed by specialists in infectious diseases, clinical microbiology, and orthopedics to confirm the diagnosis and followed prospectively for a period of 2 years. Statistical analysis for group comparisons, survival analysis, and uni- and multivariable Cox regression models were performed. RESULTS: Thirty percent of the patients with VO (56/189) reported a history of spine surgery in the same segment. Patients with postoperative infection had a lower ASA score (American Society of Anesthesiologists) (P = 0.01) and were less likely to suffer from comorbidities compared to native cases (P = 0.003). Infections caused by coagulase-negative staphylococci (33.3 vs. 6.5%, P < 0.001) and other bacteria of the skin flora (15.2 vs. 0%, P = 0.002) were more prevalent in postoperative patients. Suffering from native VO increased the 2-year mortality risk 3-fold, also when adjusted for the remaining risk factors ASA score and number of comorbidities (hazard ratio 2.916 [95% confidence interval 1.215 -6.999], P = 0.017). CONCLUSION: Beside clear microbiological differences, the significant better 2-year survival supports the concept of postoperative VO presenting a distinct disease entity. The subtle disease presentation of patients with postoperative VO should not attenuate clinical suspicion of physicians. LEVEL OF EVIDENCE: 3.

Periprosthetic Infection in Joint Replacement.

BACKGROUND: The volume of joint replacement surgery has risen steadily in recent years, because the population is aging and increasingly wishes to reserve a high functional status onward into old age. Infection is among the more common complications of joint replacement surgery, arising in 0.2% to 2% of patients, or as many as 9% in special situations such as the implantation of megaprostheses. The associated morbidity and mortality are high. It is thus very important to minimize risk factors for infection and to optimize the relevant diagnostic and therapeutic strategies. METHODS: This review is based on pertinent publications retrieved by a selective search in PubMed, including current guidelines and expert recommendations. RESULTS: The crucial diagnostic step is joint biopsy for the identification of the pathogenic organism, which succeeds with over 90% sensitivity and specificity. If the prosthesis is firmly anchored in bone, the pathogen is of a type that responds well to treatment, and symptomatic infection has been present only for a short time, then rapidly initiated treatment can save the prosthesis in 35-90% of cases. The pillars of treatment are thorough surgical care (radical débridement) and targeted antibiotic therapy. On the other hand, if the prosthesis is loose or the pathogen is of a poorly treatable type, the infection can generally only be cured by a change of the prosthesis. This can be performed in either one or two procedures, always in conjunction with systemic antibiotic therapy tailored to the specific sensitivity and resistance pattern of the pathogen. CONCLUSION: The risk of infection of an artificial joint is low, but the overall prevalence of such infections is significant, as the number of implanted joints is steadily rising. Artificial joint infections should be treated by a standardized algorithm oriented toward the recommendations of current guidelines. Many of these recommendations, however, are based only on expert opinion, as informative studies providing high-grade evidence are lacking. Thus, for any particular clinical situation, there may now be multiple therapeutic approaches with apparently comparable efficacy. Randomized trials are urgently needed.