Chronic Osteomyelitis

Physical Rehabilitation Subsequent to Fixation of Ilizarov Ring Fixator for the Management of Distal Femur Fracture: A Case Report

Distal femur fractures are severe all over the world. The goal of the study was to assess the effect of physiotherapy on ROM, strength, and improving quality of life. Due to the anatomy of distal femur fracture, the Ilizarov ring fixator is useful as it helps maintain mobility and stability. Distal femur fractures are most treated surgically compared to non-surgical treatment. The use of external fixators differs according to the patient's condition and the stability of the patient. This study's objective was to evaluate the effectiveness of an evidence-based procedure prepared for the management of distal femur fracture and chronic osteomyelitis femur. In some cases, due to discharging sinus, the patient requires long-term treatment followed by a home physiotherapy rehabilitation program. The objective was to assess the effects of Ilizarov circular external fixators (ICEF) on distal femur fracture.

Efficacy of Silver Nanoparticles-Loaded Bone Cement against an MRSA Induced-Osteomyelitis in a Rat Model

Background and Objectives: The purpose of this study was to assess the cytotoxicity and antibacterial effects of AgNP-impregnated Tetracalcium phosphate-dicalcium phosphate dihydrate (TTCP-DCPD). Materials and Methods: Using in vitro experiments, the cytotoxicity of AgNP-impregnated TTCP-DCPD against fibroblasts and osteocytes was assessed in terms of cell viability by water-soluble tetrazolium salt assay. To assess antibacterial effects, a disc diffusion test was used; osteomyelitis was induced first in vivo, by injection of methicillin-resistant Staphylococcus aureus into the tibia of rats. AgNP-impregnated TTCP-DCPD bone cement was then applied at various silver concentrations for 3 or 12 weeks. Antibacterial effects were assessed by culturing and reverse transcription-polymerase chain reaction (RT-PCR). For histological observation, the bone tissues were stained using hematoxylin and eosin. Results: Cell viability was decreased by the impregnated bone cement but did not differ according to AgNP concentration. The diameter of the growth-inhibited zone of MRSA was between 4.1 and 13.3 mm on the disks treated with AgNP, indicating antimicrobial effects. In vivo, the numbers of bacterial colonies were reduced in the 12-week treatment groups compared to the 3-week treatment groups. The groups treated with a higher (10×) dose of AgNP (G2-G5) showed a tendency of lower bacterial colony counts compared to the group without AgNP (G1). The PCR analysis results showed a tendency of decreased bacterial gene expression in the AgNP-impregnated TTCP-DCPD groups (G2-G5) compared to the group without AgNP (G1) at 3 and 12 weeks. In the H&E staining, the degree of inflammation and necrosis of the AgNP-impregnated TTCP-DCPD groups (G2-G5) showed a tendency to be lower at 3 and 12 weeks compared to the control group. Our results suggest that AgNP-impregnated TTCP-DCPD cement has antimicrobial effects. Conclusions: This study indicates that AgNP-impregnated TTCP-DCPD bone cement could be considered to treat osteomyelitis.

Surgical management of chronic osteomyelitis: Organisms, recurrence and treatment outcome

PURPOSE

The study aimed to identify the risk factors of recurrence in chronic osteomyelitis (COM) and to document the microbiological patterns pre- and intra-operatively and at recurrence, if any.

METHODS

We performed retrospective review on COM patients treated with surgical debridement and a six-week course of antibiotics. The patients with symptoms of osteomyelitis for at least six weeks, present or past episodes of discharging sinus, documentation of bone sequestration in operative notes or preoperative images were included in the study. Patients with symptoms of osteomyelitis < 6 weeks, lack of history of discharging sinus or lack of evidence of sequestration in preoperative images or intraoperative notes were excluded. Logistic regression models were used to assess the impact of risk factors of recurrence. Cohen-Kappa scores were derived to see the concordance between pre-operative and intra-operative isolates and at recurrence.

RESULTS

Totally, 147 COM patients (115 males and 32 females, mean age (33 ± 19) years) were included in this study. Recurrence was noted in 28 patients (19.0%). Polymicrobial growth and extended spectrum beta-lactamase producing Enterobacteriaceae increased the chance of recurrence. Cierny-Mader stage-1, hematogenous aetiology and negative intraoperative culture reduced the chance of recurrence. Concordance between pre-operative and intra-operative cultures was 59.85% (Kappa score 0.526, p < 0.001) and between index surgery and at recurrence was 23.81% (Kappa score 0.155, p < 0.001). Lack of knowledge of causative organism preoperatively did not affect outcome. At mean follow-up (42 ± 15) months, all patients were apparently infection free for at least one year.

CONCLUSION

Polymicrobial growth and multi-drug resistant organisms increase the risk of recurrence in COM. Patients' age, gender, diabetes mellitus, previous failed treatment, duration of symptoms, haemoglobin, white cell count, C-reactive protein and erythrocyte sedimentation rate at presentation did not have any impact on the recurrence of infection. Preoperative isolation of organism is of questionable value. Recurrences of infections do occur and are more of re-infections than relapses. Diligent isolation of organism must be attempted even in re-debridements. Even patients with recurrences do well with appropriate debridement and antibiotic therapy.

Osteosynthesis-associated infection of the lower limbs by multidrug-resistant and extensively drug-resistant Gram-negative bacteria: a multicentre cohort study

Purpose: The purpose of this study was the clinical and therapeutic assessment of lower-limb osteosynthesis-associated infection (OAI) by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria (GNB), which have been poorly studied to date. Methods: A prospective multicentre observational study was conducted on behalf of ESGIAI (the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group on Implant-Associated Infections). Factors associated with remission of the infection were evaluated by multivariate and Cox regression analysis for a 24-month follow-up period. Results: Patients ( n = 57 ) had a history of trauma (87.7 %), tumour resection (7 %) and other bone lesions (5.3 %). Pathogens included Escherichia coli ( n = 16 ), Pseudomonas aeruginosa ( n = 14 ; XDR 50 %), Klebsiella spp. ( n = 7 ), Enterobacter spp. ( n = 9 ), Acinetobacter spp. ( n = 5 ), Proteus mirabilis ( n = 3 ), Serratia marcescens ( n = 2 ) and Stenotrophomonas maltophilia ( n = 1 ). The prevalence of ESBL (extended-spectrum β -lactamase), fluoroquinolone and carbapenem resistance were 71.9 %, 59.6 % and 17.5 % respectively. Most patients ( n = 37 ; 64.9 %) were treated with a combination including carbapenems ( n = 32 ) and colistin ( n = 11 ) for a mean of 63.3 d. Implant retention with debridement occurred in early OAI (66.7 %), whereas the infected device was removed in late OAI (70.4 %) ( p = 0.008 ). OAI remission was achieved in 29 cases (50.9 %). The type of surgery, antimicrobial resistance and duration of treatment did not significantly influence the outcome. Independent predictors of the failure to eradicate OAI were age > 60  years (hazard ratio, HR, of 3.875; 95 % confidence interval, CI95 %, of 1.540-9.752; p = 0.004 ) and multiple surgeries for OAI (HR of 2.822; CI95 % of 1.144-6.963; p = 0.024 ). Conclusions: Only half of the MDR/XDR GNB OAI cases treated by antimicrobials and surgery had a successful outcome. Advanced age and multiple surgeries hampered the eradication of OAI. Optimal therapeutic options remain a challenge.

Epidemiology and outcomes of bone and joint infections in solid organ transplant recipients

Bone and joint infection (BJI) epidemiology and outcomes in solid organ transplant recipients (SOTr) remain largely unknown. We aim to describe BJI in a multi-center cohort of SOTr (Swiss Transplant Cohort Study). All consecutive SOTr with BJI (01.05.2008-31.12.2019) were included. A nested case-control study to identify risk factors for BJI was performed. Among 4482 patients, 61 SOTr with 82 BJI were included, at an incidence of 1.4% (95% CI 1.1-1.7), higher in heart and kidney-pancreas SOTr (Gray's test p < .01). Although BJI were predominately late events (median of 18.5 months post-SOT), most infections occurred during the first year post-transplant in thoracic SOTr. Diabetic foot osteomyelitis was the most frequent infection (38/82, 46.3%), followed by non-vertebral osteomyelitis (26/82, 31.7%). Pathogens included Gram-positive cocci (70/131, 53.4%), Gram-negative bacilli (34/131, 26.0%), and fungi (9/131, 6.9%). BJI predictors included male gender (OR 2.94, 95% CI 1.26-6.89) and diabetes (OR 2.97, 95% CI 1.34-6.56). Treatment failure was observed in 25.9% (21/81) patients and 1-year mortality post-BJI diagnosis was 14.8% (9/61). BJI remain a rare event in SOTr, associated with subtle clinical presentations, high morbidity and relapses, requiring additional studies in the future.

Honey dressing: a missed way for orthopaedic wound care

Purpose

Orthopaedic-related wounds are critical situations calling for care to avoid deep infections and its consequences. The purpose of this study was to evaluate the efficacy of using honey for care of orthopaedic-related wounds with limited resources.

Patients and methods

This prospective study included 50 cases with an average age of 38.18 (range 17–63) years with 38 males and 12 females. The most frequent wound location was the leg (41 patients; 82%), then the foot (six patients; 12%), and the ankle in three patients (6%). The aetiologies were open fractures (34 cases; 68%), infected tibial non-unions (nine cases; 18%), and post-operative infections (seven cases; 14%). Exposed tendon was present in three cases. Bone exposure was present in two cases. Deep infection was present in 29 cases (58%). Besides treating the primary cause, a ribbon of gauze soaked with honey was applied to the wounds after thorough saline washing.

Results

Wound sizes were variable. All cases showed improvement in all parameters with complete wound healing and full coverage of bone and tendons. Recurrence of deep infection occurred in three cases and treated by debridement. One case needed sequestrectomy of a small exposed tibial cortical fragment. Exposed tendon cases showed superficial necrosis which was treated by simple debridement. Initial mild itching occurred in five patients with spontaneous resolution.

Conclusion

With treating the underlying aetiology and optimising the patient’s general condition, honey was an effective, simple, and affordable method of wound care in different orthopaedic conditions even with exposed bone or tendons.

[Severe chronic osteomyelitis of the os ileum in an alpaca - Diagnostic and pathological findings]

A 5.5-year-old alpaca mare was referred to the University Clinic for Ruminants due to a lameness in the right hind limb. Six months prior to presentation, the mare had been treated with systemic antibiotics resulting in resolution of the initial lameness. At the time there had been no indication of an inciting trauma. Clinical examination revealed an approx. 2 × 2 cm large, fluctuating, neither excessively warm nor painful mass caudal to the right tuber coxae fixed to the underlying tissue. In addition, a moderate, mixed lameness with a predominant proportion of the swinging leg component was present in the right hind limb. Subsequently, sonographic examination of the right gluteal region was performed, revealing severe alterations of bone contour in the area of the right hip joint. Radiographic assessment of the pelvis was carried out for further clarification. Based on the clinical finding of a fistula in the right gluteal region as well as the results of the radiologic examination, a long-standing infected fracture of the right iliac bone accompanied by high-degree, irregularly calcified callus formation and low to moderate osteomyelitis in the fracture area was diagnosed. The patient was euthanized in consequence of the grave prognosis. Computed tomographic examination of the pelvis and the lumbar spine in the L3-L6 area was undertaken in order to further document the extent of the pathological changes. For final clarification, patho-histological examination as well as a microbiologic analysis of the abscess exudate were performed.The presented case shows the importance of clinical as well as orthopedic examinations, as the individual animal frequently only exhibits minimal clinical signs despite the presence of severe changes.

Imaging Review of Normal and Abnormal Skeletal Maturation

The growing skeleton undergoes well-described and predictable normal developmental changes, which may be misinterpreted a as pathologic condition at imaging. Primary and secondary ossification centers (SOCs), which form the diaphysis and the epiphysis of long bones, respectively, are formed by endochondral and intramembranous ossification processes. During skeletal maturation, the SOCs may appear irregular and fragmented, which should not be confused with fractures, osteochondritis dissecans, and osteochondrosis. These normal irregularities are generally symmetric with a smooth, round, and sclerotic appearance, which are aspects that help in the differentiation. The metaphysis, epiphysis, and growth plates or physes are common sites of injuries and normal variants in the pediatric skeleton. The metaphysis contains the newly formed bone from endochondral ossification and is highly vascularized. It is predisposed to easy spread of infections and bone tumors. The physis is the weakest structure of the immature skeleton. Injuries to this location may disrupt endochondral ossification and lead to growth disturbances. Pathologic conditions of the epiphyses may extend into the articular surface and lead to articular damage. At MRI, small and localized foci of bone marrow changes within the epiphysis and metaphysis are also a common finding. These can be related to residual red marrow (especially in the metaphysis of long bones and hindfoot), focal periphyseal edema (associated with the process of physeal closure), and ultimately to a normal ossification process. The authors review the imaging appearance of normal skeletal maturation and discuss common maturation disorders on the basis of developmental stage and location. ^©RSNA, 2022.

Osteoarticular infections: a specific program for older patients?

BACKGROUND

With the increasing number of elderly patients, arthroplasties, fractures and diabetic foot infections, the worldwide number of osteoarticular infections (OAI) among the elderly is concomitantly expected to rise.

AIMS

We explore existing scientific knowledge about OAI in the frail elderly population.

METHODS

We performed a literature search linking OAIs to geriatric patients and comparing elderly patients (> 65 years) with average adults (range 18-65 years).

RESULTS

In this literature, financial aspects, comparison of diverse therapies on quality of life, reimbursement policies, or specific guidelines or nursing recommendations are missing. Age itself was not an independent factor related to particular pathogens, prevention of OAI, nursing care, and outcomes of OAI. However, geriatric patients were significantly more exposed to adverse events of therapy. They had more co-morbidities and more conservative surgery for OAI.

CONCLUSION

Available literature regarding OAI management among elderly patients is sparse. In recent evaluations, age itself does not seem an independent factor related to particular epidemiology, pathogens, prevention, nursing care, rehabilitation and therapeutic outcomes of OAI. Future clinical research will concern more conservative surgical indications, but certainly reduce inappropriate antibiotic use.

Four versus six weeks of antibiotic therapy for osteoarticular infections after implant removal: a randomized trial

BACKGROUND

The optimal duration of antibiotic therapy for treating orthopaedic implant infections after surgical drainage and complete implant removal is unknown.

METHODS

This was a single-centre, unblinded, prospective trial randomizing (1:1) eligible patients to either 4 or 6 weeks of systemic, pathogen-targeted antibiotic therapy. Clinical trial registration number: ClinicalTrials.gov (NCT0362209).

RESULTS

We analysed 123 eligible patients (62 in the 4 week antibiotic arm and 61 in the 6 week arm) in the ITT analysis. The patients' median age was 64 years, 75 (61%) were men and 38 (31%) were immunocompromised. The most common types of infection treated included: two-stage exchange procedure for prosthetic joint infection (n = 38); orthopaedic plate infection (44) and infected nail implants (11). The median duration of post-explant intravenous antibiotic therapy was 4 days. Overall, 120 episodes (98%) were cured microbiologically and 116 (94%) clinically after a median follow-up period of 2.2 years. During follow-up, four patients had a clinical recurrence with a pathogen other than the initial causative agent. We noted recurrence of clinical infection in four patients in the 4 week arm and three patients in the 6 week arm (4/62 versus 3/61; χ2 test; P = 0.74); in all cases, this occurred at around 2 months following the end of antibiotic treatment.

CONCLUSIONS

We found no statistically significant difference in the rates of clinical or microbiological remission between patients randomized to only 4 compared with 6 weeks of systemic antibiotic therapy after removal of an infected osteoarticular implant.

Principles and practice of antibiotic stewardship in the management of diabetic foot infections

PURPOSE OF REVIEW

Systemic antibiotic therapy in persons with a diabetic foot infection (DFI) is frequent, increasing the risk of promoting resistance to common pathogens. Applying principles of antibiotic stewardship may help avoid this problem.

RECENT FINDINGS

We performed a systematic review of the literature, especially seeking recently published studies, for data on the role and value of antibiotic stewardship (especially reducing the spectrum and duration of antibiotic therapy) in community and hospital populations of persons with a DFI.

SUMMARY

We found very few publications specifically concerning antibiotic stewardship in persons with a DFI. The case-mix of these patients is substantial and infection plays only one part among several chronic problems. As with other types of infections, attempting to prevent infections and avoiding or reducing the spectrum and duration of antibiotic therapy are perhaps the best ways to reduce antibiotic prescribing in the DFI population. The field is complex and necessitates knowledge over the current scientific literature and clinical experience. On a larger scale, clinical pathways, guidelines, and recommendations are additionally supportive.

Short postsurgical antibiotic therapy for spinal infections: protocol of prospective, randomized, unblinded, noninferiority trials (SASI trials)

BACKGROUND

There are several open scientific questions regarding the optimal antibiotic treatment of spinal infections (SIs) with or without an implant. The duration of postsurgical antibiotic therapy is debated.

METHODS

We will perform two unblinded randomized controlled trials (RCTs). We hypothesize that shorter durations of systemic antibiotic therapy after surgery for SI are noninferior (10% margin, 80% power, α = 5%) to existing (long) treatment durations. The RCTs allocate the participants to two arms of 2 × 59 episodes each: 3 vs. 6 weeks of targeted postsurgical systemic antibiotic therapy for implant-free SIs or 6 vs. 12 weeks for implant-related SIs. This equals a total of 236 adult SI episodes (randomization scheme 1:1) with a minimal follow-up of 12 months. All participants receive concomitant multidisciplinary surgical, re-educational, internist, and infectious disease care. We will perform three interim analyses that are evaluated, in a blinded analysis, by an independent study data monitoring committee. Besides the primary outcome of remission, we will also assess adverse events of antibiotic therapy, changes of the patient's nutritional status, the influence of immune suppression, total costs, functional scores, and the timely evolution of the (surgical) wounds. We define infection as the presence of local signs of inflammation (pus, wound discharge, calor, and rubor) together with microbiological evidence of the same pathogen(s) in at least two intraoperative samples, and we define remission as the absence of clinical, laboratory, and/or radiological evidence of (former or new) infection.

DISCUSSION

Provided that there is adequate surgical debridement, both RCTs will potentially enable prescription of less antibiotics during the therapy of SI, with potentially less adverse events and reduced overall costs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04048304. Registered on 5 August 2019.

PROTOCOL VERSION

2, 5 July 2019.

Oral Flucloxacillin for Treating Osteomyelitis: A Narrative Review of Clinical Practice

Flucloxacillin (FLU) administered by the oral route is widely used for treating various infections, but there are no published retrospective or prospective trials of its efficacy, or its advantages or disadvantages compared to parenteral treatment or other antibiotics for treating osteomyelitis. Based on published in vitro data and expert opinions, other non-β-lactam oral antibiotics that have better bone penetration are generally preferred over oral FLU. We reviewed the literature for studies of oral FLU as therapy of osteomyelitis (OM), stratified by acute versus chronic and pediatric versus adult cases. In striking contrast to the prevailing opinions and the few descriptive data available, we found that treatment of OM with oral FLU does not appear to be associated with more clinical failures compared to other oral antibiotic agents. Because of its narrow antibiotic spectrum, infrequent severe adverse effects, and low cost, oral FLU is widely used in clinical practice. We therefore call for investigators to conduct prospective trials investigating the effectiveness and potential advantages of oral FLU for treating OM.

Health Care Costs of Post-traumatic Osteomyelitis in China: Current Situation and Influencing Factors

BACKGROUND

Currently, very limited information is available regarding the economic burdens of patients with extremity post-traumatic osteomyelitis (OM). This study aimed to investigate direct health care costs and utilization for inpatients with extremity post-traumatic OM and analyze its constituent ratios and influencing factors in Southern China.

METHODS

We searched in the electronic medical record system for inpatients who had received surgical interventions at our department between 2013 and 2016 for extremity post-traumatic OM. Data of direct health care costs incurred during their hospitalizations were collected in six main categories (service, diagnosis, treatment, materials, pharmaceuticals, and miscellaneous expenses). In addition, data of total medical costs for contemporaneous inpatients with non-post-traumatic OM were also collected as controls.

RESULTS

A total of 278 post-traumatic OM and 10,420 controls were included. The median cost for the post-traumatic OM inpatients was $10,504 US dollars, 4.8-fold higher than that for those with non-post-traumatic OM ($2189, P < 0.001). The direct cost in the category of materials accounted for the largest proportion (61%), followed by that in pharmaceuticals (12%) and treatment (11%). The median number of hospital admissions for post-traumatic OM patients was 1 time, with a median length-of-stay of 22 d. The most influencing factors for the health care costs of the post-traumatic OM inpatients were use of an external fixator ($16,016 for those who used versus $4956 for those who did not, P < 0.001), external fixator type ($19,563 for ring fixator versus $14,966 for rail fixator, P < 0.001), infection site ($13,755 for tibia, $14,216 for femur and $5673 for calcaneus, P < 0.001), and infection-associated injury type ($12,890 for infection after open fracture versus $8087 for infection after closed fracture, P = 0.001).

CONCLUSIONS

An unexpectedly large proportion of the direct health care costs for inpatients with extremity post-traumatic OM went to cover an external fixator, with expenses for pharmaceuticals and treatment accounting for only a little more than the tenth of the total health care costs. Use of external fixator, external fixator type, infection site, and infection-associated injury type directly influenced the health care costs.

Oral amoxicillin-clavulanate for treating diabetic foot infections

AIM

To assess amoxicillin-clavulanate (AMC) for the oral therapy of diabetic foot infections (DFIs), especially for diabetic foot osteomyelitis (DFO).

METHODS

We performed a retrospective cohort analysis among 794 DFI episodes, including 339 DFO cases.

RESULTS

The median duration of antibiotic therapy after surgical debridement (including partial amputation) was 30 days (DFO, 30 days). Oral AMC was prescribed for a median of 20 days (interquartile range, 12-30 days). The median ratio of oral AMC among the entire antibiotic treatment was 0.9 (interquartile range, 0.7-1.0). After a median follow-up of 3.3 years, 178 DFIs (22%) overall recurred (DFO, 75; 22%). Overall, oral AMC led to 74% remission compared with 79% with other regimens (χ² -test; P = 0.15). In multivariate analyses and stratified subgroup analyses, oral AMC resulted in similar clinical outcomes to other antimicrobial regimens, when used orally from the start, after an initial parenteral therapy, or when prescribed for DFO.

CONCLUSIONS

Oral AMC is a reasonable option when treating patients with DFIs and DFOs.

A two-stage cold isostatic pressing and gelling approach for fabricating a therapeutically loaded amorphous calcium polyphosphate local delivery system

Local delivery systems have taken on a greater clinical focus for osteomyelitis therapy owing to their ability to overcome many disadvantages of systemic delivery. This study reports for the first time the capacity to fabricate strontium- and vancomycin-doped calcium polyphosphate beads using a two-stage cold isostatic pressing and gelling approach. The fabricated beads were of uniform shape and diameter, and upon gelling exhibited reduced porosity. Of greatest significance in the subsequent in vitro study was the improvement of bead long-term structural stability upon vancomycin incorporation; a characteristic that further encourages the extended release of therapeutically relevant levels of antibiotic. Overall, this study provides support for the inclusion of a cold isostatic pressing step in the fabrication of a therapeutically loaded calcium polyphosphate bead-based local delivery system intended for osteomyelitis treatment.

Factors Associated With Treatment Failure of Infected Pressure Sores

OBJECTIVE

In this study, we assess interdisciplinary surgical and medical parameters associated to recurrences of infected pressure ulcers.

BACKGROUND

There is a little in the published literature regarding factors associated with the outcome of treatment of infected pressure ulcers.

METHODS

We undertook a single-center review of spinal injured adults hospitalized for an infected pressure ulcer or implant-free osteomyelitis and reviewed the literature on this topic from 1990-2015.

RESULTS

We found 70 lesions in 31 patients (52 with osteomyelitis) who had a median follow-up of 2.7 years (range, 4 months to 19 years). The median duration of antibiotic therapy was 6 weeks, of which 1 week was parenteral. Clinical recurrence after treatment was noted in 44 infected ulcers (63%), after a median interval of 1 year. In 86% of these recurrences, cultures yielded a different organism than the preceding episode. By multivariate analyses, the following factors were not significantly related to recurrence: number of surgical interventions (hazard ratio 0.9, 95% confidence interval 0.5-1.5); osteomyelitis (hazard ratio 1.5; 0.7-3.1); immune suppression; prior sacral infections, and duration of total (or just parenteral) antibiotic sue. Patients with antibiotic treatment for <6 weeks had the same failure rate as those with as >12 weeks (χ test; P = 0.90).

CONCLUSIONS

In patients with infected pressure ulcers, clinical recurrence occurs in almost two-thirds of lesions, but in only 14% with the same pathogen(s). The number of surgical debridements, flap use, or duration of antibiotic therapy was not associated with recurrence, suggesting recurrences are caused by reinfections caused by other extrahospital factors.

Aggregatibacter actinomycetemcomitans osteomyelitis in a 12 year old boy: case report emphasizing the importance of tissue culture, and review of literature

Background

Aggregatibacter actinomycetemcomitans most commonly causes periodontitis but has been reported to infect heart valves, soft tissue, brain and lungs, and distal bones. Osteomyelitis distal to the jaw is rarely described.

Case presentation

We report an unusual and rare case of chronic osteomyelitis caused by A. actinomycetemcomitans in the toe of a paediatric patient, and review the available literature. The infection was managed with intravenous antibiotics followed by oral antibiotics.

Conclusion

This is an unusual presentation of A. actinomycetemcomitans causing chronic osteomyelitis presumed due to nidation in a minimally damaged bone, associated with bacteraemia of an oral commensal. It occurred in the toe, without obvious dental predisposition; associated with minimal clinical disturbance and with muted immune response.

Variables associated with remission in spinal surgical site infections

BACKGROUND

There is few medical literature regarding factors associated with remission after surgical and medical treatment of postoperative spine infections.

METHODS

Single-centre case-control study 2007-2014. Cluster-controlled Cox regression model with emphasis on surgical and antibiotic-related parameters.

RESULTS

Overall, we found 66 episodes in 48 patients (49 episodes with metalwork) who had a median follow-up of 2.6 years (range, 0.5 to 6.8 years). The patients had a median of two surgical debridements. The median duration of antibiotic therapy was 8 weeks, of which 2 weeks parenteral. Clinical recurrence after treatment was noted in 13 episodes (20%), after a median interval of 2 months. In 53 cases (80%), the episodes were considered as in remission. By multivariate analyses, no variable was associated with remission. Especially, the following factors were not significantly related to remission: number of surgical interventions [hazard ratio (HR) 0.9; 95% confidence interval (CI), 0.8-1.1]; infection due to Staphylococcus aureus (HR 0.9; 0.8-1.1), local antibiotic therapy (HR 1.2; 0.6-2.4), and, duration of total (HR 1.0; 0.99-1.01) (or just parenteral) (HR 1.0; 0.99-1.01) antibiotic use.

CONCLUSIONS

In patients with post-operative spine infections, remission is achieved in 80%. The number of surgical debridement or duration of antibiotic therapy shows no association with recurrence, suggesting that individual risk factors might be more important than the duration of antibiotic administration.

Phages targeting infected tissues: novel approach to phage therapy

While the true efficacy of phage therapy still requires formal confirmation in clinical trials, it continues to offer realistic potential treatment in patients in whom antibiotics have failed. Novel developments and approaches are therefore needed to ascertain that future clinical trials would evaluate the therapy in its optimal form thus allowing for reliable conclusions regarding the true value of phage therapy. In this article, we present our vision to develop and establish a bank of phages specific to most threatening pathogens and armed with homing peptides enabling their localization in infected tissues in densities assuring efficient and stable eradication of infection.

Association Between Chronic Osteomyelitis and Risk of End-Stage Renal Disease: A Nationwide Population-Based Cohort Study

Inflammation, which initiates endothelial dysfunction, vascular atherosclerosis, and oxidative stress, may negatively influence renal function and accelerate the development of end-stage renal disease (ESRD). The role of chronic osteomyelitis (COM), a chronic inflammatory disease, in the development of ESRD has not been investigated. This study explored whether patients with COM have a higher risk of ESRD than that of patients without COM.Taiwan National Health Insurance claims from 1997 to 2010 were used to identify 24,267 newly diagnosed patients with COM and 97,068 age- and sex-matched non-COM controls for comparison. The risks of ESRD among COM patients, with adjustment for comorbidities, namely, hypertension, diabetes, coronary artery disease, congestive heart failure, and hyperlipidemia, were assessed until the end of 2010.ESRD risk was 2.01-fold higher (95% confidence interval [CI]: 1.81-2.25) in the COM cohort than in the non-COM cohort. Regarding the joint effect of COM with comorbidity, the ESRD risk was 1.57-fold higher (95% CI: 1.23-2.00) for the COM cohort without comorbidities and increased to 2.25 (95% CI: 1.97-2.57) for the COM cohort with at least 1 comorbidity. Age-specific analysis revealed that the adjusted ESRD risk for the COM cohort increased as age decreased, with the highest hazard ratio being 17.8 (95% CI: 5.18-61.4) for patients aged 20-34 years.This was the first study to report that COM is associated with an increased risk of ESRD, particularly among patients with comorbidities and younger patients.

Challenges in diagnosing infection in the diabetic foot

Diagnosing the presence of infection in the foot of a patient with diabetes can sometimes be a difficult task. Because open wounds are always colonized with microorganisms, most agree that infection should be diagnosed by the presence of systemic or local signs of inflammation. Determining whether or not infection is present in bone can be especially difficult. Diagnosis begins with a history and physical examination in which both classic and 'secondary' findings suggesting invasion of microorganisms or a host response are sought. Serological tests may be helpful, especially measurement of the erythrocyte sedimentation rate in osteomyelitis, but all (including bone biomarkers and procalcitonin) are relatively non-specific. Cultures of properly obtained soft tissue and bone specimens can diagnose and define the causative pathogens in diabetic foot infections. Newer molecular microbial techniques, which may not only identify more organisms but also virulence factors and antibiotic resistance, look very promising. Imaging tests generally begin with plain X-rays; when these are inconclusive or when more detail of bone or soft tissue abnormalities is required, more advanced studies are needed. Among these, magnetic resonance imaging is generally superior to standard radionuclide studies, but newer hybrid imaging techniques (single-photon emission computed tomography/computed tomography, positron emission tomography/computed tomography and positron emission tomography/magnetic resonance imaging) look to be useful techniques, and new radiopharmaceuticals are on the horizon. In some cases, ultrasonography, photographic and thermographic methods may also be diagnostically useful. Improved methods developed and tested over the past decade have clearly increased our accuracy in diagnosing diabetic foot infections.

Coating with a novel gentamicinpalmitate formulation prevents implant-associated osteomyelitis induced by methicillin-susceptible Staphylococcus aureus in a rat model

PURPOSE

Implant-associated osteomyelitis still represents a demanding challenge due to unfavourable biological conditions, bacterial properties and incremental resistance to antibiotic treatment. Therefore different bactericide or bacteriostatic implant coatings have been developed recently to control local intramedullary infections. Controlled local release of gentamicin base from a highly lipophilic gentamicin palmitate compound achieves extended intramedullary retention times and thus may improve its bactericide effect.

METHODS

Forty male Sprague-Dawley rats were divided into two groups receiving an intramedullary femoral injection of 10(2) colony-forming units (CFU) of a common methicillin susceptible Staphylococcus aureus strain (MSSA Rosenbach) and either an uncoated femur nail (Group I) or a nail coated with gentamicin palmitate (Group II). Animals were observed for 28 and 42 days. Serum haptoglobin and relative weight gain were assessed as well as rollover cultures of explanted femur nails and histological scores of periprosthetic infection in dissected femurs.

RESULTS

Implants coated with gentamicin palmitate significantly reduced periprosthetic bacterial growth as well as signs of systemic inflammation compared with uncoated implants.

CONCLUSIONS

Gentamicin palmitate appears to be a viable coating for the prevention of implant-associated infections. These findings will have to be confirmed in larger animal models as well as in clinical trials.

Do Diabetic Foot Infections With Methicillin-Resistant Staphylococcus aureus Differ From Those With Other Pathogens?

There is controversy as to whether or not diabetic foot infections (DFIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) are associated with worse outcomes than DFIs caused by other pathogens. To address this issue we performed a nonsystematic literature search of published articles in English language journals seeking studies reporting on the outcomes of DFIs related to their microbiology. We retrieved 48 articles published from 1999 to 2013 that described a total of 7771 cases of DFI. The overall proportion of DFIs with an isolate of S aureus was about 30%; just over one third of these (11% of all cases) were MRSA strains. Among the DFI cases caused by MRSA 1543 were episodes of soft tissue infections and 113 of osteomyelitis, while non-MRSA organisms caused 5761 soft tissue infections and 354 cases of osteomyelitis. Only 5 of the included articles attempted a comparison between DFI caused by MRSA and those caused by other pathogens, with no clear differences noted. The median total duration of antibiotic therapy for DFI caused by MRSA was 26 days, of which a median of 10 days was given intravenously. Only a few articles reported the proportion of patients with a recurrence, but they often did not differentiate between MRSA and non-MRSA cases. Four publications reported a worse functional or microbiological outcome in MRSA, compared to non-MRSA, cases, but the findings were variable and differences did not seem to be significant. Many trials failed to adjust for case-mix or to definitively demonstrate a relationship between microbiology and outcomes. Few of the articles specifically commented on whether the MRSA isolates were health care- or community-acquired strains. Notwithstanding the substantial limitations of the available literature, there does not appear to be a need for any special treatment for DFI caused by MRSA. The current guidelines for treating according to established international recommendations seem appropriate.

Diabetic foot infections: state-of-the-art

Foot infections are frequent and potentially devastating complications of diabetes. Unchecked, infection can progress contiguously to involve the deeper soft tissues and ultimately the bone. Foot ulcers in people with diabetes are most often the consequence of one or more of the following: peripheral sensory neuropathy, motor neuropathy and gait disorders, peripheral arterial insufficiency or immunological impairments. Infection develops in over half of foot ulcers and is the factor that most often leads to lower extremity amputation. These amputations are associated with substantial morbidity, reduced quality of life and major financial costs. Most infections can be successfully treated with optimal wound care, antibiotic therapy and surgical procedures. Employing evidence-based guidelines, multidisciplinary teams and institution-specific clinical pathways provides the best approach to guide clinicians through this multifaceted problem. All clinicians regularly seeing people with diabetes should have an understanding of how to prevent, diagnose and treat foot infections, which requires familiarity with the pathophysiology of the problem and the literature supporting currently recommended care.

Analysis of the factors affecting the formation of the microbiome associated with chronic osteomyelitis of the jaw

Chronic osteomyelitis of the jaw (COMJ) is one of the most intractable diseases among head and neck infections. Antimicrobial agents are routinely administered for COMJ without sufficient bacterial information, resulting in frequent treatment failures. To improve our knowledge of the bacterial aetiology of COMJ and to assist in the development of effective treatments, we performed a comprehensive analysis of the microbiome. Sixteen patients with four clinical types of COMJ (four with suppurative osteomyelitis, three with osteoradionecrosis of the jaw, four with primary chronic osteomyelitis, and five with bisphosphonate-related osteonecrosis of the jaw) were enrolled in this study. Bone samples were subjected to bacterial community comparisons by 16S rRNA gene pyrosequencing. As a result, we clarified that COMJ was caused by a far greater range of bacterial species (12 phyla and 163 genera) than previously reported. Moreover, the bacterial structures in COMJ changed dramatically with disease stage and the condition of the affected bone. Multiple correlation analyses revealed that sequestration and bone exposure could affect the community structure. On the basis of these factors, we reclassified COMJ into three clinical stages: I, inflamed or sclerotic bone without exposure; II, sequestrum without exposure; and III, exposed sequestrum. In stage II, the bacterial diversity was significantly lower, and the anaerobe genera Fusobacterium, Tannerella (formerly Bacteroides) and Porphyromonas were more abundant, than observed during other stages. Because these bacteria habitually reside in any clinical stage, they were considered to constitute the core microbiome of COMJ. Targeting these bacteria should lead to the development of effective preventive measures and cures.

Remission rate of implant-related infections following revision surgery after fractures

PURPOSE

In contrast to a large amount of epidemiological data regarding the incidence of implant infections after fracture management, surprisingly few have been published concerning the success of their treatment.

METHODS

This was a single-centre cohort study at Geneva University Hospitals from 2000 to 2012 investigating the remission rates of orthopaedic implant infections after fracture repair and associated variables.

RESULTS

A total of 139 episodes were included: There were 51 women (37%) and 28 immunosuppressed (20%) patients with a median age and American Society of Anaesthesiologists (ASA) score of 51 years and 2 points, respectively. The infected implants were plates (n = 75, 54 %), nails (24, 17%), wires (20), screws (10), cerclage cables or wires (3), hip screws (4) or material for spondylodesis (3). A pathogen was identified in 135 (97%) cases, including Staphylococcus aureus (73, 52%), coagulase-negative staphylococci (20), streptococci (7) and 19 Gram-negative rods. All patients underwent antibiotic treatment, and 128 (92%) remained in remission at a median follow-up time of 2.6 years (range one to 13 years). In multivariate logistic regression analysis, the plate infections were significantly associated with lower remission rates [65/75, 87%, odds ratio (OR) 0.1, 95% confidence interval (CI) 0.01-0.90]. No associations were found for gender, age, immune status, ASA score, additional surgical interventions (OR 0.4, 95% CI 0.1-4.1) or duration of antibiotic treatment (OR 1.0, 95% CI 0.98-1.01).

CONCLUSIONS

Among all infected and removed orthopaedic implants, plates were associated with slightly lower remission rates, while the overall treatment success exceeded 90%. The duration of antibiotic therapy did not alter the outcome.