Predisposing factors for recurrence of chronic posttraumatic osteomyelitis: a retrospective observational cohort study from a tertiary referral center in Brazil

Comorbid status in patients with osteomyelitis is associated with long-term incidence of extremity amputation

INTRODUCTION

Osteomyelitis is associated with significant morbidity, including amputation. There are limited data on long-term amputation rates following an osteomyelitis diagnosis. We sought to determine the incidence of amputation in patients with osteomyelitis over 2 years.

RESEARCH DESIGN AND METHODS

Observational cohort study of 1186 inpatients with osteomyelitis between 2004 and 2015 and stratified by osteomyelitis location status to evaluate the impact on amputation, mortality rates, readmission data, and inpatient days.

RESULTS

Persons with diabetes had 3.65 times greater probability of lower extremity amputation (p<0.001), readmission (p<0.001), and longer inpatient stay (p<0.001) and had higher 2-year mortality (relative risk (RR) 1.23, p=0.0027), adjusting for risk factors. Male gender (RR 1.57, p<0.001), black race (RR 1.41, p<0.05), former smoking status (RR 1.38, p<0.01), myocardial infarction (RR 1.72, p<0.001), congestive heart failure (RR 1.56, p<0.001), peripheral vascular disease (RR 2.25, p<0.001) and renal disease (RR 1.756, p<0.001) were independently associated with amputation. Male gender (RR 1.39, p<0.01), black race (RR 1.27, p<0.05), diabetes (RR 2.77, p<0.001) and peripheral vascular disease (RR 1.59, p<0.001) had increased risk of lower, not upper, extremity amputation.

CONCLUSIONS

Patients with osteomyelitis have higher rates of amputation and hospitalization. Clinicians must incorporate demographic and comorbid risk factors to protect against amputation.

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.

Progress in diagnosis and treatment of post-traumatic osteomyelitis

Post-traumatic osteomyelitis is one of the most common disorders of bone infection, which is secondary to open fracture caused by machinery injury, traffic accident, and it is also the main manifestation in the postoperative infection of open fracture. After trauma, bacteria invade bone tissue and reproduce rapidly in large quantities, which easily leads to osteomyelitis. Patients are often complaint of pain at the affected limb, loss of function, or even amputation due to deteriorated infection, resulting in loss of labor capability and poor quality of life. Because the diagnosis and treatment are not timely and standard, the treatment for post-traumatic osteomyelitis is often delayed, resulting in the difficulty of clinical cure. It also makes patients and their families bear a serious financial burden. However, the diagnosis and treatment for this disease is difficult for orthopedic physicians. In recent years, imaging methods (such as CT and MRI) combined with immune techniques have significantly improved the diagnostic accuracy and early diagnosis ability. The application of new diagnostic technologies (such as gene chip and second-generation sequencing) also makes the diagnosis more convenient and sensitive. The novel reconstruction and repair surgery (such as Ilizarov technology and Orthofix LRS technology) provides new treatment direction for orthopedic surgeons and patients.

Treatment of postoperative tibial chronic osteomyelitis using bone transport techniques; an observational study

PURPOSE

Postoperative Tibial chronic osteomyelitis is one of the most challenging orthopaedic conditions especially when extensive, the anatomy of subcutaneous anteromedial part of the tibia with less soft tissue coverage complicates the situation. The extent of infected tibial part varies in size and duration from one patient to another. We report our experience using Bifocal and Monofocal bone transport techniques with regard to clinical outcome, recurrence of infection and re-fracture rate.

METHODS

This is a retrospective observational review of 49 patients with postoperative Tibial chronic osteomyelitis which were treated using either Bifocal distraction compression BFDCO technique group I (31 patients) or Monofocal compression osteosynthesis MFCO technique Group II (18 patients). The average age of the patients was (41.6 ± 13.1 years), (range: 17-67 years). Leg length discrepancy was measured in 33 (58.9%) patients with an average of (1.4 ± 1.7 cm). Contracture of the ankle joint and equinus deformity were detected in 36 (64.3%) patients. Pre and Post-operative radiography together with Modified Irzhansky A.A et al. leg functional assessment system were used to assess the functional outcome.

RESULTS

The time spent in the Ilizarov fixator (External Fixation Index) in the first group was (142 ± 72 days) and in the second group was (75 ± 54 days). The infection recurred in 2 patients (6%) in group I and in 5 patients (28%) in group II. Lack of consolidation or re-fracture within 6 months after the dismantling of the apparatus was detected in 6 patients (19.5%) in group I and in 5 patients (27.8%) in group II. Lack of consolidation or re-fracture within 6 months after dismantling of the apparatus in group I was detected in 6 patients (19.5%) in group I and in 5 patients (27.8%) in Group II. The average functional state score (AFSS) in the first group was (12.45 ± 2.41) on admission and increased to (16.16 ± 2.99) on the final follow-up which corresponded to a "good" result. In the second group II the AFSS was (12.11 ± 2.22) on admission and increased to (15.06 ± 2.88) at the final follow-up which corresponded to a "satisfactory" result.

CONCLUSION

Treatment of Tibial chronic osteomyelitis using either Bifocal or Monofocal bone transport is an effective method. However our results have demonstrated better functional outcome and less infection recurrence and re-fracture rates when using the Bifocal distraction compression technique (BFDCO).

Epidemiology and microbiology of fracture-related infection: a multicenter study in Northeast China

Objective

This study aimed to explore the epidemiological and microbiological characteristics of fracture-related infection (FRI), analyze the drug resistance characteristics of major pathogens, and provide timely and relatively complete clinical and microbiological data for antimicrobial treatment of FRI.

Methods

The clinical and microbiological data of patients with FRI from January 1, 2011, to December 31, 2020, were collected from three tertiary hospitals in Northeast China. The automatic microbial analysis system was used for strain identification and drug susceptibility testing, and the drug susceptibility results were determined in accordance with the latest Clinical and Laboratory Standards Institute (CLSI) criteria (as applicable each year).

Results

A total of 744 patients with FRI were enrolled. The incidence of FRI was about 1.5%, and 81.7% were male patients, with an average age of 48.98 ± 16.01 years. Open fractures accounted for 64.8%. Motor crush (32.8%) and falling (29.8%) were the main causes of injuries. The common sites of infection were the tibia and fibula (47.6%), femur (11.8%), foot (11.8%), and hand (11.6%). A total of 566 pathogenic bacteria were cultured in 378 patients with positive bacterial cultures, of which 53.0% were Gram-positive bacteria and 47.0% were Gram-negative bacteria. The most common pathogen at all sites of infection is Staphylococcus aureus. Staphylococcus aureus had a high resistance rate to penicillin (PEN), erythromycin (ERY), and clindamycin (CLI), exceeding 50%. Methicillin-resistant Staphylococcus aureus (MRSA) was more than 80% resistant to CLI and ERY.

Conclusions

The incidence of FRI in Northeast China was at a low level among major medical centers nationwide. Staphylococcus aureus was still the main pathogen causing bone infections, and the proportion of MRSA was lower than reported abroad, but we have observed an increase in the proportion of infections. Enterobacteriaceae have a higher resistance rate to third-generation cephalosporins and quinolones. For Enterobacteriaceae, other sensitive treatment drugs should be selected clinically.

Systematic review of risk prediction studies in bone and joint infection: are modifiable prognostic factors useful in predicting recurrence?

Background: Classification systems for orthopaedic infection include patient health status, but there is no consensus about which comorbidities affect prognosis. Modifiable factors including substance use, glycaemic control, malnutrition and obesity may predict post-operative recovery from infection. Aim: This systematic review aimed (1) to critically appraise clinical prediction models for individual prognosis following surgical treatment for orthopaedic infection where an implant is not retained; (2) to understand the usefulness of modifiable prognostic factors for predicting treatment success. Methods: EMBASE and MEDLINE databases were searched for clinical prediction and prognostic studies in adults with orthopaedic infections. Infection recurrence or re-infection after at least 6 months was the primary outcome. The estimated odds ratios for the primary outcome in participants with modifiable prognostic factors were extracted and the direction of the effect reported. Results: Thirty-five retrospective prognostic cohort studies of 92 693 patients were included, of which two reported clinical prediction models. No studies were at low risk of bias, and no externally validated prediction models were identified. Most focused on prosthetic joint infection. A positive association was reported between body mass index and infection recurrence in 19 of 22 studies, similarly in 8 of 14 studies reporting smoking history and 3 of 4 studies reporting alcohol intake. Glycaemic control and malnutrition were rarely considered. Conclusion: Modifiable aspects of patient health appear to predict outcomes after surgery for orthopaedic infection. There is a need to understand which factors may have a causal effect. Development and validation of clinical prediction models that include participant health status will facilitate treatment decisions for orthopaedic infections.

Risk factors associated with infection recurrence of posttraumatic osteomyelitis treated with Ilizarov bone transport technique-a retrospective study of 149 cases

BACKGROUND

Post-traumatic tibial osteomyelitis is considered as complex clinical problem due to its unique characteristics such as prolonged course, multi-staged treatment and high recurrence rate. The purpose of this study is to identify and analyze the causes and risk factors associated with infection recurrence of tibial osteomyelitis treated with Ilizarov technique.

METHODS

From January 2011 to January 2019, a total of 149 patients with post-traumatic tibial osteomyelitis treated with Ilizarov bone transport technique were included in this study. Demographic and clinical data were collected and analyzed. Univariate analysis and logistic regression analysis were used to analyze the factors that may affect the recurrence or reinfection of post-traumatic tibial osteomyelitis after treated with Ilizarov bone transport technique.

RESULTS

All included patients were successfully followed up with an average of 37.5 month (18-78 month), among them, 17 patients (11.4%) occurred with recurrence or reinfection of tibial osteomyelitis in which 2 cases were in distraction area and 15 cases in docking site. Among them, 5 patients were treated successfully with appropriate intravenous antibiotic, the remaining 12 patients were intervened by surgical debridement or bone grafting after debridement. Univariate analysis showed that Pseudomonas aeruginosa infection, bone exposure, number of previous operations (> 3 times), blood transfusion during bone transport surgery, course of osteomyelitis > 3 months, diabetes was associated with recurrence or reinfection of postoperative tibial osteomyelitis. According to the results of logistic regression analysis, Pseudomonas aeruginosa infection, bone exposure, and the number of previous operations (> 3 times) are risk factors for recurrence or reinfection of posttraumatic tibial osteomyelitis treated with Ilizarov bone transport technique, with odds ratios (OR) of 6.055, 7.413, and 1.753, respectively.

CONCLUSION

The number of previous operations (> 3 times), bone exposure, and Pseudomonas aeruginosa infection are risk factors for infection recurrence of posttraumatic tibial osteomyelitis treated with Ilizarov bone transport technique.

No increased risk of acute osteomyelitis associated with closed or open long bone shaft fracture

OBJECTIVES

Osteomyelitis of the long bones can result from hematogenous spread, direct inoculation or from a contiguous focus of infection. The association of osteomyelitis after long bone fractures has widely been believed to be true by practicing surgeons since the 1950s, even though the evidence has been poor. We hypothesized that long bone shaft fracture and major bone surgery are independent risk factors for osteomyelitis in adult trauma patients.

METHODS

The National Trauma Data Bank (NTDB) was queried between 2007 and 2015 for patients ≥18 years of age presenting after trauma. Patients with long bone shaft fractures (femur, tibia/fibula, humerus) were identified and rate of acute osteomyelitis was calculated. Univariable logistic regression was performed. A multivariable logistic regression was performed to identify risk factors for development of acute osteomyelitis.

RESULTS

From 5,494,609 patients, 358,406 were identified to have long bone shaft fractures (6.5%) with the majority being tibia/fibula (44.3%). The osteomyelitis rate in long bone shaft fractures was 0.05%. Independent risk factors for osteomyelitis included major humerus surgery and major tibia/fibula surgery. The strongest risk factor was non-pseudomonas bacteremia. Long bone shaft fractures were not found to be an independent risk factor for osteomyelitis (p > 0.05).

CONCLUSIONS

Long bone shaft fractures are not independently associated with increased risk for osteomyelitis. Major extremity surgery on the humerus and tibia/fibula, but not femur, are independent risk factors for osteomyelitis. However, the strongest risk factor is non-pseudomonas bacteremia.

Post-traumatic osteomyelitis in Middle East war-wounded civilians: resistance to first-line antibiotics in selected bacteria over the decade 2006-2016

BACKGROUND

War-wounded civilians in Middle East countries are at risk of post-traumatic osteomyelitis (PTO). We aimed to describe and compare the bacterial etiology and proportion of first-line antibiotics resistant bacteria (FLAR) among PTO cases in civilians from Syria, Iraq and Yemen admitted to the reconstructive surgical program of Médecins Sans Frontières (MSF) in Amman, Jordan, and to identify risk factors for developing PTO with FLAR bacteria.

METHODS

We retrospectively analyzed the laboratory database of the MSF program. Inclusion criteria were: patients from Iraq, Yemen or Syria, admitted to the Amman MSF program between October 2006 and December 2016, with at least one bone biopsy sample culture result. Only bone samples taken during first orthopedic surgery were included in the analysis. To assess factors associated with FLAR infection, logistic regression was used to estimate odds ratio (ORs) and 95% confidence intervals (CI).

RESULTS

558 (76.7%) among 727 patients included had ≥1 positive culture results. 318 were from Iraq, 140 from Syria and 100 from Yemen. Median time since injury was 19 months [IQR 8-40]. Among the 732 different bacterial isolates, we identified 228 Enterobacteriaceae (31.5%), 193 Staphylococcus aureus (26.3%), 99 Pseudomonas aeruginosa (13.5%), and 21 Acinetobacter baumanii (2.8%). Three hundred and sixty four isolates were FLAR: 86.2% of Enterobacteriaceae, 53.4% of Pseudomonas aeruginosa, 60.5% of S. aureus and 45% of Acinetobacter baumannii. There was no difference in bacterial etiology or proportion of FLAR according to the country of origin. In multivariate analysis, a FLAR infection was associated with an infection of the lower extremity, with a time since the injury ≤12 months compared with time > 30 months and with more than 3 previous surgeries.

CONCLUSIONS

Enterobacteriaceae were frequently involved in PTO in war wounded civilians from Iraq, Yemen and Syria between 2006 and 2016. Proportion of FLAR was high, particularly among Enterobacteriaceae, regardless of country of origin.